# Corsair vs. BF 109G,K or FW 190's



## 16KJV11 (Nov 2, 2007)

​How would one of the US Navy's top fighters in the Pacific (the Corsair) match up to top aircraft in the Euopean Theatre such as the later BF 109's and FW 190's?


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## lesofprimus (Nov 2, 2007)

Pretty much eat them for lunch...


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## CPWN (Nov 3, 2007)

British test pilot Eric Brown seems ever to say Corsair II is inferior to Fw190A.


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## comiso90 (Nov 3, 2007)

Interview: Captain Eric Brown

http://www.ww2aircraft.net/forum/aviation/interview-captain-eric-brown-7136-2.html

.


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## DerAdlerIstGelandet (Nov 3, 2007)

I think overall the Fw 190 and the Corsair would be a pretty good match. Ofcourse at certain alltitudes each one had its advantages. Corsair had the speed and range advantage. 

I think it would come down to pilot skill.

I dont like Browns rating system so I take what he has to say with a grain of salt.


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## comiso90 (Nov 3, 2007)

I think aircraft designed from the start as carrier vs. land based are automatically handicapped. If a carrier based aircraft is comparable, it is a engineering victory.

.


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## Kurfürst (Nov 3, 2007)

Which Corsair? Which 190? Which 109...?


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## Neto (Nov 3, 2007)

there is no way to compare these 3 fighters ..  but i think that the fighters that combat in europe may be better that pacific fighters (europe was a very hostile theater more that the pacific) so i think the bf ou fw may be better that corsair.


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## lesofprimus (Nov 3, 2007)

In a "typical" combat, the Fw 190A-8 with normal combat load, and the F4U-1D in similar drag, it really wouldnt be much of a contest.... The Corsair was a much better performer....

If we compare the Fw 190D-9/13 against the -1D, it becomes alittle different to compare, but then, if u take the next generation of Focke Wulf, u have to take the next gen of Corsair, and the F4U-4 is in a class of its own....

However, the pilots who are flying in this "mythical" combat would be the deciding factor...


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## Micdrow (Nov 3, 2007)

lesofprimus said:


> However, the pilots who are flying in this "mythical" combat would be the deciding factor...



Very true Les


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## drgondog (Nov 3, 2007)

lesofprimus said:


> In a "typical" combat, the Fw 190A-8 with normal combat load, and the F4U-1D in similar drag, it really wouldnt be much of a contest.... The Corsair was a much better performer....
> 
> If we compare the Fw 190D-9/13 against the -1D, it becomes alittle different to compare, but then, if u take the next generation of Focke Wulf, u have to take the next gen of Corsair, and the F4U-4 is in a class of its own....
> 
> However, the pilots who are flying in this "mythical" combat would be the deciding factor...



Dead on. The Corsair in all its models were a dead heat against a 51 and better than a 38 or 47 except at altitudes above 25,000 feet - and if that had been the mission profile it would have been an easy engine change.

I believe that the Fw190D-13 may have been a better dogfighter at than all of the 47D, 51D, 38L and F4U-4 above 34,000ft but who the hell was going to fight up there when the mission was at 20-26,000 ft - and the 51H fits in next Gen with 47N and F4U-4 - bring it down there and you are in the strike zone of all of our best fighters


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## drgondog (Nov 3, 2007)

comiso90 said:


> I think aircraft designed from the start as carrier vs. land based are automatically handicapped. If a carrier based aircraft is comparable, it is a engineering victory.
> 
> .



The F4U was virtually a dead heat in a fight with a 51 and given equal pilot skill was better below 15-20K feet - so by definition it was a match in most combat against the 109G and Fw190A6. In the same arena it would do well against the Fw190D-9 (in my opinion) an it would have been well matched by the Me109K above 20,000 feet 

Brown had a lot of pilot experience in all these aircraft and deserves respect for his opinions..but in a long running debate (gentlemanly) in which I questioned his rankings of both the P-51 and F4U below the F6F and Fw190 he declared victory on the 190 based on Critical Mach number being higher! 

He won our argument because I could never find the Mcr on either the F4U or Fw190... and candidly the debate blurred between objective performance metrics, and the more subject contibution to the war and multi roles.

His argument for placing the F6F above the P-51 was based on the crucial impact against JNAF airpower in Pacific while the 51 was joined by P-47, P-48, Spitfire and Tempest agianst the Luftwaffe..

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## Jank (Nov 3, 2007)

As was already pointed out, it depends which Corsair. The 1-D would have afforded little benefit over the late Thundebolt D with paddle blade. The Dash 4 is another animal. Like comparing the Thunderbolt D to the M.

If you read yhe encounter reports of Pony and Bolt drivers, you will see that a lot of combat in the European Theatre is at higher altitudes. Not so in the Pacific.

http://mywebpages.comcast.net/markw4/MSWF4UDATA.pdf


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## JimM (Nov 3, 2007)

Umm...any of you guys ever read "I Fought You from The Skies" by Willi Heilmann? He flew 190's in the war.

In the context of experienced pilots...

He said the only thing they were afraid of were the Jugs diving on them from high above. They didn't fear the Mustangs...the Corsairs were more or less the equal of the Mustang...

What does that tell you about a good German pilot facing a Corsair?
Food for thought.

Bud Anderson also said that the 190 was the equal of the Mustang.


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## drgondog (Nov 3, 2007)

Jank said:


> As was already pointed out, it depends which Corsair. The 1-D would have afforded little benefit over the late Thundebolt D with paddle blade. The Dash 4 is another animal. Like comparing the Thunderbolt D to the M.
> 
> *Jank - while the paddle blade did improve the Jug's accleration and hence low to medium altitude performance - even the D-25 through 28 would have struggled against the 190 and 109 and F4U-1 all the way from SL through perhaps 20,000 feet. IIRC the first paddle blade was introduced to the 56th Fg starting in January 1944 and didn't reach such outfits as the 355th or 352nd by the time they were replaced with P-51B's...so wide spread use didn't really happen until April/May timeframe
> 
> ...



I would add a point. The F4u-1D was introduced about the time the Paddle Blade was added to the P-47D-10(?) and the R2800-8 boosted the max HP about 12% giving the lighter Corsair and even better comparison against the 51 and the 47.

Having said all this I Do NOT have inflight, performance comparisons to throw at you so consider my comments in that light?


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## Kurfürst (Nov 3, 2007)

Tell me if I got it right : basically, 1943 P-47D do not have a paddle blade, and are having a top speed of ca 660 km/h / 410 mph at altitude.

Beginning January 1944, they start to receive paddle blades, and the conversion becomes widespread in use by April/May 1944. This boosts speed to about 690 km/h / 429mph at critical altitude.

Correct ? Or did I get something wrong ? I have to admit, P-47/F4U developments are a bit of a Terra Incognita to me, as far as boost increases/improvements concerned and the date of their implementation.


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## Jank (Nov 3, 2007)

dragondog,

I did say "late Thunderbolt" for a reason. It wasn't until about mid 1944. The paddle blade increased the performance and climb at all altitudes and not just low and medium. Finally, yes, Bolts struggled with 109's and Fw-190's. 

_There are a lot of encounter reports of out manuevering Fw190 and Me 109 at high altitude where the performance of the D really kicked in - but not so many on the deck - primarily because that's where a lot of 47s were shot down._

Actually, I did not say anything about out manuevering the Krauts at higher atitudes. I just said that was where a lot of the combat was taking place which was not the case in the Pacific. Most all shoot downs do not involve out manuevering your opponent. Just getting into place at a moment when he is not aware of you and hitting him with a volley of rounds that cause enough damage or injury to partially disable. (Shock and awe) Then you pour on the lead. Remember that the Bolt was spitting out almost 100 rounds a second. 

Keep in mind that the Bolt had a 4.6:1 air to air record and lots of Bolts were shot down in high altitude furballs "primarily because" that is where lots of combat was taking place.

On an aside, once the 150 grade fuel was in use (44-1), the late war "D" model with paddle blade and water injection was performing at a much higher level than people give it credit.

P 47D Performance Test

70Hg - 444mph at 23,200ft
65Hg - 439mph at 25,200ft

65Hg - 3,260 fpm at 10,000ft (yes, that's 65Hg and 10,000ft and not 70Hg and S/L)

(the above are all at full combat load)

Here's an interesting chart showing relative performance of F4U-1 and P-47 both with water injection:
http://www.wwiiaircraftperformance.org/p-47/fighter-comp-chart.jpg


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## drgondog (Nov 3, 2007)

JimM said:


> Umm...any of you guys ever read "I Fought You from The Skies" by Willi Heilmann? He flew 190's in the war.
> 
> In the context of experienced pilots...
> 
> ...



Bud also said he was talking about medium and low altitudes. My father who only had 7 in the air was more concerned about the 109G so I suspect what all this really means is that the 51s and 47s and F4Us had advantages of speed and range, equal in most manuever envelopes, deficient in roll (less deficient for 47) to Fw190 at all altitudes and less in turn at low/medium altitudes and speed. 

Nobody that fought enough 109s at medium altitudes was under any illusions that a 51 would 'easily' out turn it nor could the 51 stay with it in a hard turning climb to the right..back again to the pilot skill factor

The Fw190D-9 created total parity with the latest combat ops P-51s and P-47s and the Fw190D-13 would have been better than all but the P-51H at altitude.. ditto Ta152H and the 51H would have been slightly at a disadvantage at normal combat envelopes.

With all these fighters at medium altitude pilot skill and tactical advantage would prevail.

Since the F4U never made the ETO it is all speculation but fun to think about. Personally I love the Mustang and believe it was most important contributor to daylight Strategic Bombing - but I believe the introduction of the F4U-1 in late 1942 would have made the P-51, P-47 and P-38 un necessary for long range escort in ETO.


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## drgondog (Nov 3, 2007)

Kurfürst said:


> Tell me if I got it right : basically, 1943 P-47D do not have a paddle blade, and are having a top speed of ca 660 km/h / 410 mph at altitude.
> 
> Beginning January 1944, they start to receive paddle blades, and the conversion becomes widespread in use by April/May 1944. This boosts speed to about 690 km/h / 429mph at critical altitude.
> 
> Correct ? Or did I get something wrong ? I have to admit, P-47/F4U developments are a bit of a Terra Incognita to me, as far as boost increases/improvements concerned and the date of their implementation.


Kurfurst - Jank's performance figures are correct for the really late P-47s that came into ETO (late as in post D-Day)..I haven't looked but I suspect the model he is referencing is the P-47D-28RA. The 47s that were in the inventory in January 1944 were largely P-47D-5RA and RE's plus some -10s dribbling in.

As he noted the Paddle Blade was a major performance enhancement for both climb and initial acceleration at all altitudes... and the 150 octane fuel did add to top speeds but was not an instant success when introduced in September timeframe - several Mustangs and Thunderbolts had engine failures early on.

*Jank *- the reason I only noted low to medium altitude performance change for Paddle blade is that was the envelope that a Jug better have an altitude advantage so he could trade energy for speed then get the energy back with a zoom climb.. but do not stick around and turn with the 190 or 109. A 51 was more forgiving because it accelerated and turned better than the Jug at those altitudes - as did the F4U.

I haven't cross checked my data yet but you might be interested to know that so far for 8th AF, the 56th FG with all P-47 ops was around 12:1 air to air ratio while all the other groupsMustang groups were in the 5:1 to 15:1 ratios. The lower ratios were for groups like the 356th and 78th (and 20th/55th/364th) that flew something other than 51s for most of their ops... the higher ratios were for dominant Mustang ops (except for 56th) like the 479th, 357th and 361st..

Where groups flew different a/c I will try to break out ratios later for the different a/c. Only the 56th, 357th and 339th flew only one type in 8th AF.

This is strictly air to air, does not take into account losses to flak, weather, mechanical or accidents. What I did do is assign an "air loss" where a loss to unknown causes on the MACR was in an area where enemy fighters existed to make sure the air to air ratios were unfairly skewed... where no fighter activity was known the loss remained "unknown-other"

I will publish the data on Mike Williams site in near term and here in draft form on another new thread.

9th AF Jugs were far lower because of the nature of tac air combat on the deck.


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## Soren (Nov 3, 2007)

*Drgondog,*

No US fighter in the ETO could turn with the Bf-109 at low to medium altitude, the P-51 wasn't even close, and I'm sure you agree with that but I'm just stating it clearly. 

Ofcourse the green Bf-109 pilots unwilling to exploit the full potential of their a/c were not very difficult targets, and unfortunately there were many of these within the LW by 1944. Bf-109 armed with gun-pods were also vulnerable and these were equipped on the majority of 109's fighting the bomber streams in 1944-45.

As to the FW-190 Dora-9, well it was clearly superior in every aspect of flight compared to the P-51 Mustang at low to medium altitudes, but this superiority diminished as altitude increased, and at typical bomber altitude the P-51 was definitly fit for fight. Go further up passed 32,000 ft and the P-47 Thunderbolt was pretty much unrivalled, even being able to out-turn 109's at this alt. The Ta-152H is the only piston engined fighter of WW2 which would been able to give the P-47 a licking at very high altitudes.

Anyway getting on topic:

The FW-190 Dora-9 would've proven a match for the F4U-4 at most altititudes, maneuverability I believe would've been roughly the same, the Dora-9 holding a slight advantage in turn rate at high speeds and a more noticable advantage in roll rate at all speeds.

The Bf-109 K-4 is superior to the F4U-4 Corsair in everything but roll rate, the K-4 being much more agile in horizontal vertical maneuvers, easily out-turning out-climbing the Corsair. The Corsair did have the advantage of better control at high speeds though, something which is VERY valuable as demonstrated by the FW-190 fighting the Spitfire over the channel. 

And then ofcourse there's the fact that the F4U Corsair was a multiple purpose a/c in the same way as the FW-190 but with better range, making the F4U a MUCH MUCH more versatile single engined fighter than any other fighter of WW2 really. The best Allied fighter of WW2 IMO.


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## Jank (Nov 3, 2007)

"several Mustangs and Thunderbolts had engine failures early on."

I am not aware of R-2800 engine failures. 

I know the new fuel proved very problematic for the P-51's and to a lesser extent, P-38's and Thunderbolts. There were parallel tests of the new fuel with all three aircraft and the Thunderbolt (now rated at 2,600hp) suffered the fewest issues. (overheating at 70Hg in sustained climbs was one).The Mustangs had their plugs constantly fouling and their maintenance schedules had to be significantly shortened.


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## Negative Creep (Nov 3, 2007)

Fleet Air Arm Corsairs did meet them on a couple of occasions and came out on top. Of course you can't use the results of a few sorties as definitive proof of which was better, but either way there doesn't seem to be much in it


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## Jank (Nov 3, 2007)

Problems associated with the use of 150 grade fuel:
150 Grade Fuel

*P-38*
Spark plug leading was increased. The extent of this leading was such that plug change was required after approximately 15 hours flying. This conditions was aggravated considerably by low cruising powers used to and from target areas, while trying to get the maximum range possible. It was found, however, that regular periods of high power running for a minute of two in most cases smoothed out any rough running engines unless the cause was other than leading.

*P-51*
The same type of lead fouling as described in a and b above happened in the case of the P-51 except that is was probably more serious than in either of the other two types. Using 130 grade fuel with 4½ cc. of lead, the average operational P-51 could last 5 missions (roughly 25 hours) before the fouling required plug change. With 150 grade fuel containing 6 cc. of lead, 10 to 12 hours, or normally 2 missions, was the average length of time between spark plug changes or cleaning. At various times in the six months of operation of P-51 aircraft on 150 grade fuel many other maintenance difficulties were attributed to the fuel, but final analysis proved that the only real effect of the fuel was the lead fouling. Some units maintained that they had some deteriorations of seals, but this was not borne our throughout the command, nor was there any concrete evidence that it existed in the units.

The excessive fouling of spark plugs usually exhibited itself in roughing up of engines after a couple of hours of low power cruising. Periodic bursts of high power in most cases smoothed the engine out. However, if the engine was allowed to go too long a period without being cleaned out, the accumulation of lead bromide globules successfully withstood any attempts to blow them out. In some instances, long periods of idling while waiting for take-off and a failure to use high power on take off resulted in loss of power during take-off run and in some cases caused complete cutting out with subsequent belly landing. The cases of cutting-out on take-off definitely attributed to excessive fouling were comparatively few, although numerous enough to list it as an effect of the extra lead.

As a result of several months operational use with the fuel, an SOP – designed to reduce power failures on take-off, leading troubles in flight, and other things which were causing early returns and abortive aircraft – was published. This is inclosure no. 1. Almost immediately after this section published this SOP practically all of the troubles then existing ceased, although it was necessary to change plugs after each two missions or thereabouts. 

*P-47*
Spark plug fouling was the only maintenance difficulty encountered during the period in which 150 grade fuel was used. Spark plug life was reduced by about 50%, the same low power cruising as described above being the principle cause for the extra fouling. No deleterious effects on diaphragms, fuel hose or any other rubber of synthetic rubber materials were noted.


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## drgondog (Nov 3, 2007)

Soren said:


> *Drgondog,*
> 
> No US fighter in the ETO could turn with the Bf-109 at low to medium altitude, the P-51 wasn't even close, and I'm sure you agree with that but I'm just stating it clearly.
> 
> ...



I tend to agree the last statement even though we are both being subjective in the evaluation.. the Fw190D series, the Tempest series and the P-47 series are certainly contenders


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## Soren (Nov 3, 2007)

This is getting beyond ridiculous Bill !

Take a look at the wing loadings, power-loading, span-loading, AR, T/D, CLmax Cd0 figures for crying out loud ! The P-51 doesn't stand a chance in a turn fight against the Bf-109, and thats reality ! Use what'ever knowledge you have about aerodynamics and you should realize this as-well. You can hear it from veteran as-well as modern 109 -51 pilots as-well if you want, I can direct you.

Here's a preview: 
_View: https://www.youtube.com/watch?v=TFl8X4y9-94_

There! Now you've got it from two guys who fly both a/c.


And quit the after action reports at Mike's site, anything can happen in a dogfight and each pilot doesn't know what the other is doing in his own cockpit. Also Mike could've very well handpicked each every single one of those reports - hence why its a dead end with these after-action reports.

In the last debate we had Bill I presented to you my sources and they're still the same, Hermann's books on the FW-190 Ta-152 series, Willi Reschkes book "Wilde Sau" as-well as LW test pilot Hans Werner Lerches book "LuftWaffe Test Pilot". In these books are the official comparative conclusions drawn by the German fighter arm - read them please !

You want other facts ? Ok how about this; The british test pilot evaluating the Bf-109 had ZERO experience with auto LE slats and VERY little hours if any in the plane he was testing, and like we know it took time to learn to fly the 109 to the limit (Explained by countless LW aces as-well) so why should we even consider the final conclusion as even remotely valid ? Also IIRC the 109G captured by the RAF featured gun-pods. And what about using the right fuel ?? Using the wrong fuel leads to less performance, further putting into doubt the validity of the test. And the same goes for the RAF's comparative flights with their captured FW-190 Jabo, it featured an ETC-501 rack and was running on low power throughout the test, even still it managed to turn with the P-51B ! 

Note that in German tests the FW-190 proved no match what so ever for the Bf-109 in turning fights [kurvenkampf].


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## drgondog (Nov 3, 2007)

Soren said:


> This is getting beyond ridiculous Bill !



ah, yes you are quite right


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## drgondog (Nov 3, 2007)

Soren said:


> This is getting beyond ridiculous Bill !
> 
> Take a look at the wing loadings, power-loading, span-loading, AR, T/D, CLmax Cd0 figures for crying out loud ! The P-51 doesn't stand a chance in a turn fight against the Bf-109, and thats reality ! Use what'ever knowledge you have about aerodynamics and you should realize this as-well. You can hear it from veteran as-well as modern 109 -51 pilots as-well if you want, I can direct you.
> 
> ...




The rack was never on during the March 8, 1944 RAF Tests, the 190 had the BMW801D engine and was inferior to the P-51B in speed, dive, turn and climb(51 slightly better), but inferior in roll. The report states the DB603 would probably bring climb and speed closer to parity. 

Quote from Gunther Rall when He was Kommandeur of the Luftwaffe Fighter Leader School while recovering from his May 12 wound.

" During this time I had the opportunity to fly the P-51 in two or three mock dogfights with Me109 and Fw190 fighters. This was not extensive experience and certainly I cannot claim any profound knowledge of the P-51 but what impressed me was the comfort in the cockpit, the ease of the electrical starting system, the long endurance of the aircraft and its manueverabilty in a dogfight. However the Me 109 was superior in all steep climbing turns,in which the P-51 had a tendency, when low on speed, to sanp on the outside wing." Page 120 Mustang A Documentary History - Jeffrey Ethell.

I Have Personally had this same conversation with Rall, Krupinski and Galland in 1984 (?) Fighter Aces Reunion at Tuscon that included Olds, Whisner and Goodson.

All agreed the following points - 

1.) 109 a formidable opponent to the 51 in the hands of a real expert..
2.) 109 always playing catch up to try to offset performance deficiencies of the 109 versus the 51
3.) 109 'evade' manuever is a steep climbing turn
4.) 109 will out turn a 51 low and at low speeds, that 51 jocks must be very cognizant of maintaining energy against 109 at low to medium altitudes.

Soren, so far two of your references are 'subjective' opinions of notable LW pilots - one of which didn't even make the comparison you stated.

I have presented
1. Two RAF test programs with documented comparisons and opinions expressed as a result of the fighter versus fighter fly offs
2. An Opinion by a noted LW top ace (Rall) - documented and referencable- that makes no claim of 109 superiority (by a MASTER 109 Experten) except for steep climbing turns.
3. Many, many Encounter reports of diving and turning combat in which the P-51 handily out maunuevered the 109 in dive and turn.


and, 

4. I can produce verifyable operations statistics of P-51s versus Me 109s in which the 51 operated at nearly 9:1 against the 109 for the 355th FG during all of its ops in WWII.

What are you going to produce in the way of facts?


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## drgondog (Nov 3, 2007)

Soren said:


> Here's a preview:
> _View: https://www.youtube.com/watch?v=TFl8X4y9-94_
> 
> There! Now you've got it from two guys who fly both a/c.




Ah, I get it. Two guys who never fired a shot in combat making judgements about the 109G based on flying 65 year old warbirds. Both claiming that the 109G and F out turn a Spit and grossly out turning a Mustang - 

I now get why Galland requested a squadron of Spits from Goering - so he could become more equal with RAF? - he just didn't want the horrid experience of flying an airplane (the 109) with so much advantage over the Spit and do the honorable thing of fighting with equal dueling instruments?

BTW one of these 'expert witnesses' (the owner - not skip) made the claim that it was all about the leading edge slat but that he only had one hour in the 109. Guess that puts a hole in your theory about taking long hours of training to master the slats? He was obviously a guy well acquainted with the aiplane.

I guess you win Soren. How could anybody doubt the credibility of your sources?


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## the su-47 is gangsta (Nov 4, 2007)

The bgfv-109 would win cos of its nahdling and vfersatility.


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## Soren (Nov 4, 2007)

LoL ! I knew you'd do everything in your power to try and deny the comments from pilots who actually fly both a/c !  

As to comparisons between the 190 109, Heinrich Beauvais [Chief LW test-pilot] made it very clear that the 190 was no match what so ever for the 109 in a turn fight. There's a rechlin comparison out there which I don't have access to at the moment [not at home] which describes in detail the differences between both a/c. 

Heinrich Beauvais also knew that the Spitfire was no better a turnfighter than the 109, he tested both, and he tried to contact Brown after war, Brown refused.

As to Hans Werner Lerches book, well read the comparative test between the La-5FN, 109 and 190 for crying out loud ! Again the 109 turns allot better than both. 

As to Galland's famous comment that he wanted Spits, it was nothing but a simple joke - read his book !

And take a look at BoB stats Bill, the 109's shot down more Spit's Hurricanes than vice versa. So why have Spits ? Thats right, there'd be no logic in that.

And about RAF testing with their captured 190G, I think you shoul talk to Crumpp about - I'll contact him.


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## AL Schlageter (Nov 4, 2007)

So Allied testing of German planes is useless because the pilots didn't have enough flight time in the 109, yet German testing of Allied types is gospel?  It is even questionable that it was a La-5FN.

The comparison of a Fw190A-2 vs the 109F or G. Sure Soren. Slow speed dogfights went the way of the dodo. At high speeds, the 109 was at a disadvantage with the high control forces required by the pilot.

How many RAF bombers did the 109 shoot down? The prime objective of RAF FC was the LW bombers. The prime objective of LW fighters was to protect the LW bombers. Makes sense that the 109 would shoot down more RAF fighters but the RAF fighters shot down more LW planes.


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## Soren (Nov 4, 2007)

AL Schlageter said:


> So Allied testing of German planes is useless because the pilots didn't have enough flight time in the 109, yet German testing of Allied types is gospel?  It is even questionable that it was a La-5FN.



LoL ! No it is not questionable, it was a La-5FN. Read the book!



> The comparison of a Fw190A-2 vs the 109F or G. Sure Soren. Slow speed dogfights went the way of the dodo.



Nope thats not it, what you're talking about one can get a hold of here:
Beim-Zeugmeister: Startseite



> At high speeds, the 109 was at a disadvantage with the high control forces required by the pilot.



In the roll yeah, but not in pitch. Its about what the pilot is used to, again something which has been explained countless times by LW aces. You can't just go fly a completely new aircraft and then take it to its full capabilities, you need hours in the type to be able to do that.



> How many RAF bombers did the 109 shoot down? The prime objective of RAF FC was the LW bombers. The prime objective of LW fighters was to protect the LW bombers. Makes sense that the 109 would shoot down more RAF fighters but the RAF fighters shot down more LW planes.



You really think so ?! Could that perhaps be why so many LW fighters got shot down by the escorting Mustangs as-well then? Yes!


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## drgondog (Nov 4, 2007)

Soren said:


> LoL ! I knew you'd do everything in your power to try and deny the comments from pilots who actually fly both a/c !
> 
> *My father flew both also and he flew the 'fresh' twin seat Me109 for several flights including mock fights - maybe the same amount of time init as Rall had in 51. His comments were the same as Rall except he amplified two area - steep climbing turn the 51 could not match skill being equal. turn at low altitudes (5,000 ft in this case) and the 109G would out turn the 51.. that was ALL of the performance advantage he could find.
> 
> ...



I respect Crump's opinion but I would ask of him the same references I ask of you as I would expect him to do if I make some claim of my own. I would also ask what his opinion is of the best example of Me109 turn performance (suspecting 109F) and ask how the turn performance degraded as the 109G and K series came into play with weight increases. 

As it stands today - only two series of flight tests that document performance comparisons between the 51 and the 109 are on the table - both done by RAF during and shortly after WWII. Both accomplished by professional pilots, albeit with whatever political agenda...

You have yet to produce another such test or series of tests by GAF as any form of counter, or tests performed by any other organization. I suspect the USSR did a thorough and professional job but I personally have not seen the results.


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## Kurfürst (Nov 4, 2007)

drgondog said:


> I respect Crump's opinion but I would ask of him the same references I ask of you as I would expect him to do if I make some claim of my own. I would also ask what his opinion is of the best example of Me109 turn performance (suspecting 109F) and ask how the turn performance degraded as the 109G and K series came into play with weight increases.



How the turn performance degraded as the P-51D replaced the B series (the 109G tests were vs. a Mustang III, ie. B version) came into play with weight increases, and practically no increase in power? What was the weight increase between the two aircraft?

Even between the 109F4 and K-4, we talk about 16% increase in weight, but some 50% increase in power to compensate it.



> As it stands today - only two series of flight tests that document performance comparisons between the 51 and the 109 are on the table - both done by RAF during and shortly after WWII. Both accomplished by professional pilots, albeit with whatever political agenda...



Hmm, none of these tests actually tell what power rating the German aircraft is using, what speed or altitude they refer to when they make their statements. At what altitude was the turnining comparison performed, with what power? How many hours the pilot had in the 109? Without these data, the results are just as useless to us as they were to combat pilots in WW2.

As for the 109Gs the 'light one' you refer to was captured in the Desert in late 1942, it`s propeller had a splinter mark on it, the thermostat constantly malfunctioned - to cut it short, it was in poor state. The Germans left it behind because it wasn`t airworthty after combat with a P-40. (It`s Black Six btw). How many hours do you think it had in the engine by the comparison trials.. ? How many before it was captured? 

The other example being a gondie G-6 from a Nachtjagd unit. So unless you want to tell me a battle-damaged tropical Gustav flown by pilots with little experience with it, and a gondola armed nightfighter is representative to the LW opposition they had over the Reich... 



> You have yet to produce another such test or series of tests by GAF as any form of counter, or tests performed by any other organization. I suspect the USSR did a thorough and professional job but I personally have not seen the results.



The Russians have performed turn tests with captured 109G-2 (in excellent condition, appearantly), measuring the turn time as 20 secs for 360 degree. They also tested Allison P-51s, which had 23 secs for the same. 
Figures for 1000 meter altitude.

Basically, nothing in the physics world would support why the Mustang would be able to outturn the 109 - You have a lightweight fighter with as much or even more power available to it, with on of the most benign stall characteristics of the war vs. a heavier one with no aces up the sleeve to speak of - unless we speak of an earlier model 109G against the new P-51s. The P-51s contemporary was however, the G-6/AS and later models. I am sure a 109K would look extremely mean if compared to an Allison Mustang, too. That doesn`t rule out they didn`t met and had one-sided fights.


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## Soren (Nov 4, 2007)

Exactly Kurfürst.


*Bill,*

I am only going to respond to the below in your post, the rest of your post is just you going in circles.



> You made the bold claim that Lerches book had definitive statements about P-51 vs Me 109 flight performance characteristics



Wrong ! I made no such claim what so ever ! I mentioned some of the sources I used as reference for my comparison between the P-47, P-51, FW-190, F4U-4 Bf-109.


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## Glider (Nov 4, 2007)

I suspect the major factor in the general debate over which was the better fighter in a one to one duel, P51 or 109 had more to do with the speed, not the height. Most things that I have read say the 109 was better at slower speeds. 

Please note I said better in a one to one, not which would outurn the other. 

So how does the aeroplane _(109)_ compare with other contemporary fighters ? First, let me say that all my comments are based on operation below 10,000 feet and at power settings not exceeding +12 (54") and 2700 rpm. I like it as an aeroplane, and with familiarity I think it will give most of the allied fighters I have flown a hard time, particularly in a close, hard turning, slow speed dog-fight. It will definitely out-maneuver a P-51 in this type of flight, the roll rate and slow speed characteristics being much better. The Spitfire on the other hand is more of a problem for the '109 and I feel it is a superior close in fighter. Having said that the aircraft are sufficiently closely matched that pilot abilty would probably be the deciding factor. At higher speeds the P-51 is definitely superior, and provided the Mustang kept his energy up and refused to dogfight he would be relatively safe against the '109.
I like the aeroplane very much, and I think I can understand why many of the Luftwaffe aces had such a high regard and preference for it."
- Mark Hanna of the Old Flying Machine Company flying the OFMC Messerschmitt Bf 109 G (Spanish version).


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## drgondog (Nov 4, 2007)

Kurfürst said:


> How the turn performance degraded as the P-51D replaced the B series (the 109G tests were vs. a Mustang III, ie. B version) came into play with weight increases, and practically no increase in power? What was the weight increase between the two aircraft?
> 
> *Thoughtful questions - here is what I know and what I believe to be true
> 
> ...



Well if my figures are right for the 109G-6 it had a wing area of 16.02 M>2=172.44 feet>2 (?), an empty weight of 5908 pounds and gross of 7054 which would yield Wing loadings of 34.26 (empty) and 45.85 (max) versus the P-51D of 32.38 empty and 49.2 (max). The weight of a 51 over Berlin would be closer to 9600 for a max WL of 40.7 and less on the way back

The WL, while important, aren't by themselves the only factor, and the WL of a -14 and the K-4 were less than the G-6 empty and higher loaded... so some physics may lead you to look at the 51 having drained a lot of fuel and a 109 the same condition - then look at control forces between the two at high and medium speeds and altitudes to see a probable favorable condition for the 51 in that arena? (>15,000-20,000) but less than 32,000 in case of G-14?

At the end of the day one can judge based on personal anecdotes, published tests, ratios in combat, etc. but the questions of tests still lends more weight if they are fair.

I submit that the Brits weren't trying to put a snow job on their bosses if they found serious deficiencies in the Mustang vs Fw190 0r me 109?


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## drgondog (Nov 4, 2007)

Soren said:


> Exactly Kurfürst.
> 
> 
> *Bill,*
> ...



Soren - you said THIS.

_In the last debate we had Bill I presented to you my sources and they're still the same, Hermann's books on the FW-190 Ta-152 series, Willi Reschkes book "Wilde Sau" as-well as LW test pilot Hans Werner Lerches book "LuftWaffe Test Pilot". *In these books are the official comparative conclusions drawn by the German fighter arm *- read them please !
_

What may I ask are we to infer from this specific comment you wrote yesterday at 3:20pm forum time? There is NO "official comparative conclusions" drawn about the P-51 and the Fw 190 or Me 109 in any of them - nor can I see anything other than anecdotal comments by Lerches. Perhaps you can?


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## Soren (Nov 5, 2007)

Again wrong Bill - read Hermann's book on the FW-190 longnose. There's a comparison there.


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## drgondog (Nov 5, 2007)

Soren said:


> Again wrong Bill - read Hermann's book on the FW-190 longnose. There's a comparison there.



Soren - can you stay focused on the debate of turn performance (high, medium and low) between a Me109 and P-51? 

Getting you to answer definitively a request for documentation on THIS subject - to refute two other RAF sources - has been impossible. Cornering you on a subject you are emotional about is like corralling cats. 

Let me spell it out S L O W L Y.

F I N D a Luftwaffe Report (or Soviet) report that displays the metrics you claim regarding *'clear superiority of a Me 109 in turn over a P-51 Mustang'*

You keep claiming it, you find all the excuses in the world why the RAF tests aren't valid. You claim the references you posted were the definitve Luftwaffe comparisons - but none of them support your thesis, your claim, your position.

P R E S E N T the document so all of may learn another point of view on this subject other than the RAF reports and the many, many, Encounter Reports of the winners.

It is OK to express your OPINION on the subject, but quit claiming them as FACTS absent facts and sources.


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## Kurfürst (Nov 5, 2007)

Hi Bill ! 8) 



drgondog said:


> Thoughtful questions - here is what I know and what I believe to be true
> 
> The Mustang III in the Test was the 8 March 1944 Test and a.) did not have the aileron seals that were first incorporated in the P51B-10, and b.) did have the 1650-3 Engine that not only had slightly less horsepower than the -7 at War Emergency settings ([email protected]" vs [email protected]" but also less power at war emergency high blower at 23,000 ([email protected]" vs [email protected],300ft). Having said this the -3 had MORE hp at 25,800 feet [
> 
> ...



That`s some pretty cool info in the wing profile.  

Any specific figures from US etc. testing on the Merlin powered Mustang`s turn time, radius or something like that? I was looking for such data and while ago about USAAF fighters - it turned up nothing specific, unfortunately.  



drgondog said:


> The third wild card in this discussion is the combination low drag in the overall airframe combined with incremental thrust obtained by the unique radiator design expelling hot air via the duct.



I don`t think we have much of a difference between the two fighters, actually. If we can believe the drag data, both fighters had very similiar, equiv. of ca. 4 sq. feet plate`s drag - the power/speed requirements underline this.. Same for the radiator design, it`s very similiar basically, even though the Mustang`s is a more aerodynamic execution. In the end, both planes reached about the same speed with the same power, so there`s not much in it.



drgondog said:


> Well if my figures are right for the 109G-6 it had a wing area of 16.02 M>2=172.44 feet>2 (?), an empty weight of 5908 pounds and gross of 7054 which would yield Wing loadings of 34.26 (empty) and 45.85 (max) versus the P-51D of 32.38 empty and 49.2 (max). The weight of a 51 over Berlin would be closer to 9600 for a max WL of 40.7 and less on the way back



The wing area is 16.05 m2 indeed, the weight of the G-6 is somewhat controversial. One GLC datasheet published in a secondary source tells it`s 3196 kg, but I presume it some special variant and a case of 'lost in translation'. It`s rather illogical given the G-2`s weight of 3037kg, from which the G-6 did not differ much (the 13mm MGs+ammo overall added 40 kg) - unless by 1944 considerable extra equipment in the order of 100kg was added, or we speak of a /U4 variant and again a case of LiT. In any case, datasheets give the weigth of the G-6 as 3100kg, a logical figure while another for the G-6/trop (containing some 50 kg of tropical equipment!) as 3148 kg.



drgondog said:


> The WL, while important, aren't by themselves the only factor, and the WL of a -14 and the K-4 were less than the G-6 empty and higher loaded... so some physics may lead you to look at the 51 having drained a lot of fuel and a 109 the same condition - then look at control forces between the two at high and medium speeds and altitudes to see a probable favorable condition for the 51 in that arena? (>15,000-20,000) but less than 32,000 in case of G-14?



I think it all boils down to variant. The G-14 (not the /AS model) is essentially a low-medium altitude variant, the K-4 is high altitude fighter with a lot more power at altitude. though, especially at high altitude, I don`t think control forces would mean anything - correct me if I am wrong, but high altitude flying technically slow-speed flight at low IAS numbers, with the added problem of most engines loosing power above rated altitude? And low-speed dogfight and controllability is something the 109 definietely excelled in.



drgondog said:


> At the end of the day one can judge based on personal anecdotes, published tests, ratios in combat, etc. but the questions of tests still lends more weight if they are fair.



Absolutely agree, in fact, I absolutely favour controlled tests over any anecdote..



> I definitely agree.... but the alternative to the conclusions is yet another un-produced set of compariative date to refute the conclusions?
> ...
> I submit that the Brits weren't trying to put a snow job on their bosses if they found serious deficiencies in the Mustang vs Fw190 0r me 109?



I don`t think it`s intentional, I think they tested what enemy equipment they had in more or less working order. OTOH, if you read the other AFDU 109G test, for example vs the Tempest, it says the pilots of the 109G are 'emberassed by the opening of the slats' in turns - ie. they weren`t pushing the unfamiliar aircraft to it`s true limits in turns. This is reinforced by the fact that if you look at the 190/109/51 result in turns, it says :

the 51 turns better then the 109
the 51 turns about as well as the 190
which means that logically the 190 should outturn the 109... and as per the 3 German tactical evaluations we know, the Soviet etc. testing, and even by simply common sense, this was not the case. All of it points towards the results are caused by British pilots not pressing the aircraft hard enough in turns, this is somewhat of a returning topos with British test, their test pilots backing off from turn ASA the slats are opening, leaving the party when it just gets started.



> I suspect without proof that many parts, including engines may have been obtained from different sources - no proof by the way but there were quite a few 109s down in USSR, Africa, Italy, UK and being flown by Swiss. I Speculate that spares could be obtained and doubt there was any fuel issue or spark plugs etc deficiency to perform tests with a relaiable engine?



Maybe - do you have the complete original papers (not just the test themselves, but attached plane operation diaries, requests etc.) of these tactical trials? I am just working transcribing the papers regarding the 109F-2 tested in the UK, those papers shed light on lot of the background maintaince work and mechanical state of the aircraft, and also valuable pilot comments before they`re squeezed into (and perhaps, made a bit more PC..) the summary report.

As for the 109G-2/trop tested, I have some of the papers from the 1990s issued by modern authorities to declare the aircraft airworthy; these include the operational/mechanical history of Black Six, and it notes several of the original damages the aircraft sustained in air combat in late 1942 before it was captured, still present (splinter marks on airscrew, for example). So, I have reason to believe the aircraft was just patched to be airworthy. Similiarly, there`s a fraction of a German tact. trial on a P-51B somewhere, and it notes some supercharger troubles, 2nd stage simply not working IIRC. 




> What was the G-10 flown to UK in June/July timeframe?



G-10 ..? In June-July? Sorry I don`t get it.  



> And, R6 with Gondola are kits aren't they? Should be easy enough to take off.



Yup, they`re kits like droptanks, however every single description and photo (inc. the test itself describing as3x20mm cannon, also shown on attached photos) of that particular plane I have seen shows them on (it landed with a droptank too, but I am sure that they took off for trials). The Brits may have not realized the gondolas being kits, given the G-6, they could have though this is some sort of new heavy 109G 'Mark'. Russians seem to have believed the same initially.



> K- you will note that I have NEVER disputed better one on one performance in favor of 109 over P-51 at SL up to approximately 15,000 feet. Having said that, the P-51A should turn better, most aerodynamics being better than D and 800 pounds lighter



Perhaps it would be worthy to narrow it down to some typical variants..? Like, G-14 (normal altitude), G-14/AS (high altitude), P-51D all appearing around June-July 1944, perhaps throw in the basic G-6 still being very much around, playing the role of the small fish in this case, but the big wish when it met with say Spitfire Mk Vs, still being very much around..? 

This adds an interesting layer to the discussion, and shows how much complex real life engagment have been, ie. the first (and intially, few) Mustang groups that arrived on the scene usually met with the older, standard G-6s of the '1943 generation'. Against these, the P-51B obviously enjoyed some significant advantages, most notably greater speed at all but especially high altitudes, given it`s high altitude engine, that would also give it advantage _in all other flight conditions_, ie. turning, at those high altitude regimes. Simply it had more power to work with, but the same wasn`t true when the new P-51s met the new 109Gs, with methanol boost and improved superchargers, and which had comparable power output at all altitudes.


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## lesofprimus (Nov 5, 2007)

Excellent post...


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## drgondog (Nov 5, 2007)

Kurfürst said:


> Hi Bill ! 8)
> 
> 
> 
> ...



Crump may have developed some interesting energy charts for comparing the P-51 to Me 109 but even well developed theory taking into account energy available at initiation of ACM has soo many factors to apply to develop rate of energy loss in the ACM... it still should have definitive test data to validate conclusions.

These a/c (Me 109G-14 and K-4) were evenly matched to P-51D as standard equipment - the specialized 109K-4s gave a slight advantage in acceleration and maybe even climb at altitudes above 30,000 feet - but I can't find definitive data for climb rate or acceleration.. and while WL isn't the only indicator the 51 was like to have same or lower WL after burning fuel to get central Germany and still be lighter on the controls above 15,000 feet.


Regards,

Bill

Reactions: Informative Informative:
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## renrich (Nov 5, 2007)

Since this thread is supposed to be about a comparison between the Corsair and the FW190 and the BF109 I would like to bring up a few advantages a Corsair would have over both German AC. The various models of the Corsair would always have a range advantage over the two German fighters. Likewise the Corsair would always have an ammunition load greater than the German fighters. The Corsair would always have a ruggedness and reliability advantage over the BF109 because of the radial versus liquid cooled engine. It would always have the same engine advantage over the FW190D9. The Corsair would always have an advantage over the German AC as far as air frame strength is concerned. I believe those advantages are not arguable.


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## drgondog (Nov 5, 2007)

renrich said:


> Since this thread is supposed to be about a comparison between the Corsair and the FW190 and the BF109 I would like to bring up a few advantages a Corsair would have over both German AC. The various models of the Corsair would always have a range advantage over the two German fighters. Likewise the Corsair would always have an ammunition load greater than the German fighters. The Corsair would always have a ruggedness and reliability advantage over the BF109 because of the radial versus liquid cooled engine. It would always have the same engine advantage over the FW190D9. The Corsair would always have an advantage over the German AC as far as air frame strength is concerned. I believe those advantages are not arguable.



And last but not least the Corsair basically was slightly better in turn and climb until high altitude over the 51..which is where we got off topic on the 109 and 190.


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## Soren (Nov 6, 2007)

> I don`t think it`s intentional, I think they tested what enemy equipment they had in more or less working order. OTOH, if you read the other AFDU 109G test, for example vs the Tempest, it says the pilots of the 109G are 'emberassed by the opening of the slats' in turns - ie. they weren`t pushing the unfamiliar aircraft to it`s true limits in turns. This is reinforced by the fact that if you look at the 190/109/51 result in turns, it says :
> 
> the 51 turns better then the 109
> the 51 turns about as well as the 190
> which means that logically the 190 should outturn the 109... and as per the 3 German tactical evaluations we know, the Soviet etc. testing, and even by simply common sense, this was not the case. All of it points towards the results are caused by British pilots not pressing the aircraft hard enough in turns, this is somewhat of a returning topos with British test, their test pilots backing off from turn ASA the slats are opening, leaving the party when it just gets started.



Exactly Kurfürst, and it was the same for new LW pilots. The British test-pilots weren't used to automatic LE slats, infact they had flown no aircraft featuring it, hence their concerned reaction to the deployment of the slats which would sometimes give a slight notch and a loud bang. I remember reading Handley Page mention he wasn't even contacted during the war by the RAF, despite being the only one in Britain knowledgable about this device. The reason why a few seasoned 109 pilots, including Rall, were reluctant to push past slat deployment was past bad experience with doing so in the 109E which suffered from it slats jamming in turns, one deployed while the other stayed in, pulling the aircraft into a dangerous spin, one which nearly cut Rall's carreer short. 

And this is not just reinforced by the German comparative tests as Kurfürst mentions but also comfirmed multiple times by LW Aces explaining the reason why green pilots were afraid of going past slats deployment:


*Erwin Leykauf, German fighter pilot, 33 victories*
_"The Bf 109s also had leading edge slats. When the 109 was flown, advertently or inadvertently, too slow, the slats shot forward out of the wing, sometimes with a loud bang which could be heard above the noise of the engine. Many times the slats coming out frightenened young pilots when they flew the Bf 109 for the first time in combat. One often flew near the stalling speed in combat, not only when flying straight and level but especially when turning and climbing. *Sometimes the slats would suddenly fly out with a bang as if one had been hit, especially when one had throttled back to bank steeply. Indeed many fresh young pilots thought they were pulling very tight turns even when the slats were still closed against the wing. For us, the more experienced pilots, real manoeuvring only started when the slats were out. For this reason it is possible to find pilots from that period (1940) who will tell you that the Spitfire turned better than the Bf 109*. That is not true. I myself had many dogfights with Spitfires and I could always out-turn them. 
One had to enter the turn correctly, then open up the engine. It was a matter of feel. When one noticed the speed becoming critical - the aircraft vibrated - one had to ease up a bit, then pull back again, so that in plan the best turn would have looked like an egg or a horizontal ellipse rather than a circle. In this way one could out-turn the Spitfire - and I shot down six of them doing it." _

*Walter Wolfrum, German fighter ace. 137 victories. *
_"Unexperienced pilots hesitated to turn tight, bacause the plane shook violently when the slats deployed. I realised, though, that because of the slats the plane's stalling characteristics were much better than in comparable Allied planes that I got to fly. Even though you may doubt it, I knew the Bf-109 could manouver better in turnfight than LaGG, Yak or even Spitfire."_


And then ofcourse comes the fact that aerodynamics supports the above as-well, and I'll get to that in my next post.


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## AL Schlageter (Nov 6, 2007)

I don't know why people get so hung up on turning circle times. Even a P-47 could out turn a 109 doing a flat turn. Not sure what the maneuver (yo-yo turn?) was called but the P-47 would trade altitude gain for speed loss while turning.

Only about 1/3 of the G-14s produced were of the /AS type. The first appearing in Aug 1944 with some 398 being produced. In July and Aug 1944 some 1527 regular G-14s were produced. Total _neabau_ G-14 was 2689 compared to 1377 G-14/ASs.

American naval fighters (F6F (?) in FAA service off Norway and USN (F6F) off southern France) and came away victorious. Some say the F6F was not as good as the F4U.


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## lesofprimus (Nov 6, 2007)

U would combat the Hellcat differently than u would the Corsair, using each planes attibutes in ur favor.... Different planes, different tactics...


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## drgondog (Nov 6, 2007)

AL Schlageter said:


> I don't know why people get so hung up on turning circle times. Even a P-47 could out turn a 109 doing a flat turn. Not sure what the maneuver (yo-yo turn?) was called but the P-47 would trade altitude gain for speed loss while turning.
> 
> Only about 1/3 of the G-14s produced were of the /AS type. The first appearing in Aug 1944 with some 398 being produced. In July and Aug 1944 some 1527 regular G-14s were produced. Total _neabau_ G-14 was 2689 compared to 1377 G-14/ASs.
> 
> American naval fighters (F6F (?) in FAA service off Norway and USN (F6F) off southern France) and came away victorious. Some say the F6F was not as good as the F4U.



Al - I don't know about being hung up on the question - more like if a claim is made regarding one performance profile compared between two ships - how do you debate it.

Dan is right, you use what you have, take advantage of any favorable situation, and try to escape the bad one. 

At the end of the day the ultimate determinant is which fighter generally prevailed in the fights - but with all of the a/c we have been debating the general performance is close enough that the victor had positive tactical situation and pilot skill.

Regards,

Bill


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## delcyros (Nov 6, 2007)

Does we know how the F4U´s airframe was composed off? What material at which thickness was used as skin for:

-underbelly(fuselage)
-underbelly (engine)
-wingroots lower side
-wings upperside
-wingtips
-tail leading edge
-tail
-fuselage 

I know that the F4U had lot´s of armour installed. Does soemone know where exactly?
Even if this tends to appear secondary, I think it has some relevance here with the 20mm mine rounds in mind, the germans used. The F4U commonly is understood to be one of the ruggest single engined A/C to see widespread service and with the datas above I could make some approximations free from personal opinions as how sensible the airframe would be to different scenarios of battle damage.

Thanks in advance,
delc


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## renrich (Nov 6, 2007)

The armor on the F4U consisted of: a .109 inch hardened aluminum alloy plate above the gas tank in front of the pilot, a large piece of armor plate weighing 53 pounds directly behind the pilot, bullet resistant plexiglass in front of the pilot, a removeable quarter inch steel plate could be placed beneath the pilot's seat. The gas tank and gas lines were self sealing. The wing internal tanks in the F4U1 were not protected but those tanks were deleted later in the war. Also early Corsairs had an additional piece of armor in front of the oil tank in the engine compartment. I have a complete description of the structural details but can't type that much except to say that the wing center section comprised mainly one huge casting that contributed much to the Corsair's robustness.


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## Juha (Nov 6, 2007)

"The British test-pilots weren't used to automatic LE slats, infact they had flown no aircraft featuring it, "

Soren, are you sure on that, for example very early Westland Whirlwinds had LE slats.


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## FLYBOYJ (Nov 6, 2007)

Juha said:


> "The British test-pilots weren't used to automatic LE slats, infact they had flown no aircraft featuring it, "
> 
> Soren, are you sure on that, for example very early Westland Whirlwinds had LE slats.



Yep - that's like saying a pilot had difficulty flying an aircraft because the landing gear handle was on the left side of the cockpit instead of the right....


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## AL Schlageter (Nov 6, 2007)

Juha said:


> "The British test-pilots weren't used to automatic LE slats, infact they had flown no aircraft featuring it, "
> 
> Soren, are you sure on that, for example very early Westland Whirlwinds had LE slats.


All Whirlwinds had le slats but had them locked closed after an accident.

The Swordfish had le slats on its upper wing.


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## Glider (Nov 6, 2007)

I have heard this claim about the 109 slats only being used by the experienced pilots because new pilots were scared or nervous of the slats deployment.

My question is this. The Germans were many things in the war but they were not stupid. It would be very easy to train the new pilots to 'fly' through the deployment of the slats. They even had the Me108 to use as the perfect trainer, even with the Me109, a couple of follow my leader flights would suffice.
So why didn't they unless the benefits are less than thought?

Another thought
Its also worth remembering that the 109 was at its best in a slow turning fight and the slat deployment is the result of a slow speed combat, something no experienced P51 pilot would follow. Therefore the main difference could well be the old favourite, an experienced pilot in a 109 will always have an advantage over an inexperienced pilot in a P51


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## drgondog (Nov 6, 2007)

delcyros said:


> Does we know how the F4U´s airframe was composed off? What material at which thickness was used as skin for:
> 
> -underbelly(fuselage)
> -underbelly (engine)
> ...



Delc - unless someone has detailed drawings for each assy or installation on the F4U you would be hard pressed to get what you need.

In general the thickness of the aluminum skin would depend on the following criteria:

1.) Am I trying to take bending loads and transfer them to shear in the panels to redistribute the loads
2.) Do I want flush or button rivets for the application - this would have considerable influence on edge distance and thickness of rivets between the two.
3.) What are the buckling considerations.

I have read that certain aircraft like a Me 109 which had to be more innovative in wing design to accomodate a main spar at 40+ percent chord versus 25+ % for most a/c had to create more of a 'torque box effect'.. 

one way of creating a stronger torque box is to increase the thickness of the skin (top and bottom) to not only enhance rigitidy of the box but also effectively increase the top and bottom 'cap area' for the spars..

I suspect w/o proof that most of the F4U was .032 to .040 2024 for surface skin and that the spars were designed to take bending loads in the wing more or less independent of additional torque box effects - and suspect you could use those thicknesses to calculate blast effects


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## renrich (Nov 6, 2007)

My reference says that the wing leading edge torque boxes had metal skins of .091 inches thickness. The fuselage made use of large metal skin sheets and employed spot welding to a great extent. The largest skin sheet was pre formed and measured 43 by 102 inches. Fuselage skins were up to .072 inches thick. Interestingly the left and right horizontal stabilizers were identical and were interchangeble.


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## drgondog (Nov 6, 2007)

renrich said:


> My reference says that the wing leading edge torque boxes had metal skins of .091 inches thickness. The fuselage made use of large metal skin sheets and employed spot welding to a great extent. The largest skin sheet was pre formed and measured 43 by 102 inches. Fuselage skins were up to .072 inches thick. Interestingly the left and right horizontal stabilizers were identical and were interchangeble.



I don't doubt your info, but would comment that keeping skin below .050 as much as possible is as much about weight of rivets as anything else. Thicker skins are generally for heavy bending applications

Leading edge torque box would probably be limited to .091 just for sheer ability to form an airfoil nose section w/o cracking.

Does your source state the type of 'skin' being welded (ie. steel or 6064 aluminum?


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## Soren (Nov 6, 2007)

LoL, guys just because the whirlwind had slats doesn't mean the test pilots were used to or trusted them, esp. considering the fact that one crashed because of slat malfunction (Like 109E) and all production a/c after that had the slats shut against the wing in flight - just one more reason for British test pilots to be vary about the LE slats on the 109. And then ofcourse its not even sure that the test pilot flying the 109 ever flew a Whirlwind.

_"While Handley-Page slats were fitted to the outer wings, the production aircraft flew with them locked shut, since at least one crash of the test aircraft was attributable to slat failure."_

There's also a reason why experienced LW aces and test-pilots mention the same concern about slat deployment amongst fresh LW pilots. 

Later in the war new LW pilots were taught not to be afraid of the slats deploying and that the fun was only beginning when they deployed, which is why you wont find any pilots from this point on saying they had any trouble against the Spitfire in maneuvering flight. Infact you've even got a British Spitfire pilot [Pierre Closterman] admitting that the Spitfire was inferior in turn performance compared to the Bf-109 at slow speed.



> Yep - that's like saying a pilot had difficulty flying an aircraft because the landing gear handle was on the left side of the cockpit instead of the right....



You've got to be kidding me FLYBOYJ.. Automatic LE slats were not a std. addition on WW2 a/c, esp. not British a/c, comparing this device to placing a handle on the right instead of the left is just plain ridiculous. 

Claiming that British test pilots had no reason for concern and weren't is also just plain ridiculous, esp. considering the comments actually made by British pilots and also esp. when considering that Westland had the slats shut in flight because they were afraid of the slats jamming, expressing the exact same concern as any test pilot would, infact it was most surely a test pilots who had adviced Westland to have them shut in flight in the first place.



_"The 109 being embarrased by the opening of its slots"_ This doesn't exactly indicate that the pilot was pushing past slat deployment, infact the only thing it clearly points to is that he wasn't even attempting to do so and abandoned the maneuver entirely.


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## renrich (Nov 6, 2007)

Bill, the skin of the fuselage was aluminum that was spot welded. The skin on the torque boxes refers to the wing center section and they seem to be aluminum, but not specified and the wing outer panels seem to have had the same skin on the leading edge. The wing tips were plastic and the British ones were different from the American.


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## renrich (Nov 6, 2007)

Whoops, just found a note under the title "F4U1D Structural Description" note reads-(metal noted is aluminum alloy unless otherwise stated)


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## FLYBOYJ (Nov 6, 2007)

Soren said:


> You've got to be kidding me FLYBOYJ.. Automatic LE slats were not a std. addition on WW2 a/c, esp. not British a/c, comparing this device to placing a handle on the right instead of the left is just plain ridiculous.


No more than a test pilot being "afraid" to stall an airplane that has them.


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## Glider (Nov 7, 2007)

No one seems to be awnsering my question which is _If the Slats were such a good idea in combat, why didn't the Germans train their pilots to use them?_.
As I said before, its an easy process to do.


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## Juha (Nov 7, 2007)

Soren
“And then ofcourse its not even sure that the test pilot flying the 109 ever flew a Whirlwind.”

That’s true, but your first claim was 
"The British test-pilots weren't used to automatic LE slats, infact they had flown no aircraft featuring it, "

At least Eric Brown had flown Whirlwind and from his description probably very early version which suffered badly from tail buffeting in tight turns. Now LE slats tests were flown by 32nd production Whirlwind, not very early my memory made a trick, in April-May 41, ie when a/c was already in sqn service. So it’s not so farfetched that British test pilots had flown a/c with LE slats unlocked and after all there was Swordfish and Brown had flown that type many times. In fact it a bit strange if a testpilot ordered to fly Bf 109 would not try a a/c with LE slats before starting testing a rare captured a/c. 

More probably is that British test pilots didn’t try to use a bit flaps, circa 8 deg, to momentarily tighten their turns in Bf 109, because at least Spit and Hurri had only up or fully down option for flaps. And that might have led to underestimate the turning ability of well flown bf 109 in slow speed turning match. And of course it true that one can flew safely Bf 109 to its limits in turning match because it benign stall characteristics.

Juha


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## Soren (Nov 7, 2007)

Glider said:


> No one seems to be awnsering my question which is _If the Slats were such a good idea in combat, why didn't the Germans train their pilots to use them?_.
> As I said before, its an easy process to do.



I did, read my post again Glider.


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## Soren (Nov 7, 2007)

FLYBOYJ said:


> No more than a test pilot being "afraid" to stall an airplane that has them.



What are you talking about ?

Stalling an aircraft at 1G is differen't than stalling it at multiple G's in turns. But British pilots weren't afraid of stalling the a/c at 1G, it was in turns they obviously mistrusted the slats and feared they would jam causing the airplane to enter an unrecoverable spin.


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## Glider (Nov 7, 2007)

Soren said:


> I did, read my post again Glider.



Thanks for pointing it out, my mistake. Can I ask where you can substantiate this comment, as I am afraid that the words don't logically hold any water. 
Your saying that in the later stages of the war when German training hours were under severe strain and training pilots to have the basic skills was a priority. When pilots were spending less and less time in the air, we are expected to believe they started to train the pilots in this way. 
Whereas up until 1942 when the Germans had a very detailed training scheme as good as the best in the world, your saying they didn't.

You can see the problem in your argument, as this issue would have been obvious from the days of the Spanish Civil War.


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## Kurfürst (Nov 7, 2007)

FLYBOYJ said:


> No more than a test pilot being "afraid" to stall an airplane that has them.



Yet...



> COMBAT TRIALS AGAINST Me.109G
> 
> Turning Circle
> 47. The Tempest is slightly better, *the Me.109G being embarrassed by its slots opening near the stall.*


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## FLYBOYJ (Nov 7, 2007)

Soren said:


> What are you talking about ?
> 
> Stalling an aircraft at 1G is differen't than stalling it at multiple G's in turns. But British pilots weren't afraid of stalling the a/c at 1G, it was in turns they obviously mistrusted the slats and feared they would jam causing the airplane to enter an unrecoverable spin.


A stall is a stall!!! If you're a test pilot 1 or 4 Gs in a turn or an accelerated straight stall shouldn't make a differance - If they (the test pilots) feared the slats would "jam" they shouldn't be flying the aircraft. It's their job to figure out the way things work including getting the aircraft into an uncontrollable spin.

Soren, you produced little evidence to back of this claim....


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## AL Schlageter (Nov 7, 2007)

Kurfürst said:


> Yet...
> Turning Circle
> 47. The Tempest is slightly better, the Me.109G being embarrassed by its slots opening near the stall.


It doesn't say the pilot was embarrassed, only the plane was.


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## Soren (Nov 7, 2007)

LoL, you guys are incredible!

FLYBOYJ, there's a big difference between an uncontrollable spin and an irrecoverable spin! - in the irrecoverable one your aircraft doesn't walk away unscaved. Are you seriously suggesting that the RAF test pilots were willing to itentionally crash a captured a/c just to possibly find out once where the limit might be, loosing all notes in the process and being unable to repeat the procedure again to rule out possible mistakes and conditions responsible for the end result, leaving you without the chance of ever getting it right ???! 

Seriously now, put yourself in their shoes! All they'd heard about the slats was bad news about them failing in turns and sending the aircraft into an unrecoverable spin. 

Test-pilots take risks, but not unnecessary ones.


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## Soren (Nov 7, 2007)

Glider,

After the introduction of the F series with its improved and fail free LE slats new pilots would've been instructed as I mentioned. And as we know the F series entered service in 1941 - try finding pilots who started flying the F series who complain that the Spitfire was a handful in a dogfight, you won't find any..


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## FLYBOYJ (Nov 7, 2007)

Soren said:


> LoL, you guys are incredible!
> 
> FLYBOYJ, there's a big difference between an uncontrollable spin and an irrecoverable spin! - in the irrecoverable one your aircraft doesn't walk away unscaved. Are you seriously suggesting that the RAF test pilots were willing to itentionally crash a captured a/c just to possibly find out once where the limit might be, loosing all notes in the process and being unable to repeat the procedure again to rule out possible mistakes and conditions responsible for the end result, leaving you without the chance of ever getting it right ???!


That's the job of a test pilot - to test the limits of an aircraft's performance and sometimes that is done with risk and it doesn't matter if you're testing a captured enemy aircraft or the newest fighter. A determination is made to find the "edge of the envelope" and again that's the job of a properly trained test pilot...


Soren said:


> Seriously now, put yourself in their shoes! All they'd heard about the slats was bad news about them failing in turns and sending the aircraft into an unrecoverable spin.
> 
> Test-pilots take risks, but not unnecessary ones.


You said "they heard." I'd put my self in their shoes and consult with an engineer and maintenance personnel assigned to the program to assure that the slats were working properly and I'm sure the Air Ministry at that time had procedures to develop a test flight profile based on information they wished to attained. Again not exploiting the aircraft to its fullest is just nonsense.


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## FLYBOYJ (Nov 7, 2007)

AL Schlageter said:


> It doesn't say the pilot was embarrassed, only the plane was.


Yes - there is no evidence in any of those reports that the pilots "backed off" any maneuvers based on the slats deploying. BTW the first aircraft to have automatic operating leading edge slats? Well it wasn't German and it was well before the war stated...







*"It was equipped with automatic wing slats and slotted flaps, which were novel features for the era. The combination of these wing enhancements gave the Lysander a stalling speed of 65 mph"*

So with that Soren, I doubt the British lacked knowledge of automatic leading edge slats and their function....


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## Kurfürst (Nov 7, 2007)

FLYBOYJ said:


> Again not exploiting the aircraft to its fullest is just nonsense.



Nope, it`s a fact readily acknowledged by the report, supported by evidence from several German, Russian flying test centres and Luftwaffe pilots quoted in this thread, and last but not least, physics.



FLYBOYJ said:


> BTW the first aircraft to have automatic operating leading edge slats? Well it wasn't German and it was well before the war stated....



Half-true. It was German, and it was well before the war started. FYI, leading edge slats are the invention of a WW1 German fighter pilot, who then joined later Handley-Page, and it was the latter who`s company acquired the patent for it (in Britiain).


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## FLYBOYJ (Nov 7, 2007)

Kurfürst said:


> Nope, it`s a fact readily acknowledged by the report, supported by evidence from several German, Russian flying test centres and Luftwaffe pilots quoted in this thread, and last but not least, physics.


What are you talking about, that German, Russian flying test centres and Luftwaffe pilots quoted in this thread just flew the aircraft intil the slats deployed and called it a day?




Kurfürst said:


> Half-true. It was German, and it was well before the war started. FYI, leading edge slats are the invention of a WW1 German fighter pilot, who then joined later Handley-Page, and it was the latter who`s company acquired the patent for it (in Britiain).


Yes and it was the Lysander that was the first production aircraft to feature fully automatic leading edge slats....


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## Glider (Nov 7, 2007)

Soren said:


> Glider,
> 
> After the introduction of the F series with its improved and fail free LE slats new pilots would've been instructed as I mentioned. And as we know the F series entered service in 1941 - try finding pilots who started flying the F series who complain that the Spitfire was a handful in a dogfight, you won't find any..



Certainly 
Joahanns Steinhoff 1943 over Malta
_The Malta Spitfires are back again, their fitted with high altitude superchargers and at anything over 25000ft they just play cat and mouse with us.
At 28000ft the Spitfire could turn in an astonishingly narrow radius. We on the other hand in the thin air had to carry out every manoeuver with caution and at full power so as not to lose control_

The interesting point is that this took place at altitude which I understood to be the 109's strongest suite.

Note also that Joahanns was the commander of JG77 a very experienced pilot

PS its also worth noting that in late 1942 the Spitfire V's on Malta held their own against the G2's of JG27


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## delcyros (Nov 7, 2007)

Thank You, Renrich and Drgondog for providing the informations on the F4-U´s structure. I will use 0.09" for wing leading edge, wing top surface: 0.049 tapered to .038" at the wingtips (use 0.049 at wingroots and 0.04" at mid wing), engine cowling: 0.072" (about the thickest I could find).
I will compile a probability-related Monte-Carlo alike step system for drawing conclusions. This takes some time as the following projectiles are simmed:
0.50 cal M2 API
13mm AP
20mm/151 API and mine + 20mm Hisp. MK V HE/HEI
30mm/108 mine

I will sim hit´s on from 1000 and 500 yards for each projectile on the following sections:
engine cowling (from near vertical, deflection shoot)
gull wingroot (from near vertical, deflection shoot and from near behind)
rear fuselage without tails.
mid wing leading edge (from head on and near vertical)

I estimate about two weeks for making the necessary maths and another week for crosschecking.


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## Soren (Nov 7, 2007)

LoL, I never claimed that LE slats were a WW2 invention - once again someone tries to put words into my mouth.

But keep running circles around the facts if you want FLYBOYJ, doesn't matter to me. I'm just especially surprised that you don't even for a second stop to think about why RL LW pilots (Aces even) tell the exact same story as we've tried getting across to you, abit strange if it wasn't true don't you think ? 

Its also abit strange how the 109 is mentioned as being embarrased by the opening of its slats if not because the pilot thought that this was the very limit of the a/c. Its a pretty clear message to me!


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## Soren (Nov 7, 2007)

Glider,

You're comparing the Spitfire IX which has better high alt performance to the heavy 109G-6. Besides the 109G-6's favorite place to be was at low to medium alt.

Anyway can you find others ? I can't.


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## FLYBOYJ (Nov 7, 2007)

Soren said:


> LoL, I never claimed that LE slats were a WW2 invention - once again someone tries to put words into my mouth.


No but you did say this...

*"The British test-pilots weren't used to automatic LE slats, infact they had flown no aircraft featuring it" *



Soren said:


> But keep running circles around the facts if you want FLYBOYJ, doesn't matter to me. I'm just especially surprised that you don't even for a second stop to think about why RL LW pilots (Aces even) tell the exact same story as we've tried getting across to you, abit strange if it wasn't true don't you think ?


No - the fact here is that RAF test pilots knew exactly what the stats did, how they performed and when they deployed...


Soren said:


> Its also abit strange how the 109 is mentioned as being embarrased by the opening of its slats if not because the pilot thought that this was the very limit of the a/c. Its a pretty clear message to me!


That's just an assumption.....


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## drgondog (Nov 7, 2007)

Soren said:


> LoL, I never claimed that LE slats were a WW2 invention - once again someone tries to put words into my mouth.
> 
> But keep running circles around the facts if you want FLYBOYJ, doesn't matter to me. I'm just especially surprised that you don't even for a second stop to think about why RL LW pilots (Aces even) tell the exact same story as we've tried getting across to you, abit strange if it wasn't true don't you think ?
> 
> Its also abit strange how the 109 is mentioned as being embarrased by the opening of its slats if not because the pilot thought that this was the very limit of the a/c. Its a pretty clear message to me!



Soren - Rall did NOT 'tell the same story' in public and in print as I pointed out to you earlier, including the source and the context as head of the German Fighter School. Are you suggesting that he won 275 fights w/o pushing his 109s to limit? or was never in an awkward combat situation that did not require skilled and aggressive turning against his enemy?

The Allied pilots that tested the 109 versus the Spit V, Spit IX, P-51B-5, the P-47D-10 in March 1944 presumably had an objective in mind, namely compare strengths and weaknesses for two reasons (minimum).
1. Advisories to Allied pilots concerning flight profiles in which they (Allied) pilots had advantages and weaknesses against the German types, and 
2. Provide intelligence regarding design enhancements/modifications to improve capabilities.

Presumably they reviewed intelligence briefings from captured pilots, shared intelligence with Russians, used skilled pilots from the RAF who did their best to wring the ships out.

I could see that nobody would be enthusiastic about 1.) taking a 51 low and slow and attempted to work turns to stall point.. but there are several manuevers with a loud "Do Not Do" printed in 51 Manuals.. and that is one of them - snap rolls at high speed is another, running up throttle while low and slow with flaps deployed is another..

Unless you are suggesting that it was impossible to steal or have available Me 109G Flight Manuals by early 1944 and that German manuals had a clear prohibition against continuing turns in low speed or with slats deployed - then test pilots would do just that. It is plain silly to think that the RAF pilots were afraid to fly a flight profile not prohibited by official German manuals, or not suggested as a problem by captured pilots.

Now, I am assuming the above criteria as far as intelligence is concerned - but you are assuming as fact an even sillier proposition - namely that a leading edge slat deploying (as it is clearly designed to do) freaks out test pilots to point they suspend tests on more aggressive turns.

Reactions: Agree Agree:
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## Soren (Nov 7, 2007)

FLYBOYJ, the pilot who tested the 109 had most likely never flown any a/c with slats before, which is esp. apparent with his comment that the 109 was 'embarrased' by the opening o its slats - a guy who knows how slats function wouldn't fling out BS like that. 

But its not the first time BS has been said by a British test-pilot, I remember a certain individual by the name of Kit Carson. 



> No - the fact here is that RAF test pilots knew exactly what the stats did, how they performed and when they deployed...



Thats just an assumption... and a wrong one...

Also if the British understood the slats so well then how come they couldn't manage to get them to work on the Westland and had to have them shut ???

Yes, it all supports what I and Kurfürst have been saying all along.


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## AL Schlageter (Nov 7, 2007)

Soren said:


> But its not the first time BS has been said by a British test-pilot, I remember a certain individual by the name of Kit Carson.


When did Carson become a British citizen?

I understood he was a fighter pilot in the USAAF.


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## Jank (Nov 7, 2007)

Test of captured Fw190A-4 and F4U-1:

http://www.wwiiaircraftperformance.org/fw190/ptr-1107.pdf


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## FLYBOYJ (Nov 7, 2007)

Soren said:


> FLYBOYJ, the pilot who tested the 109 had most likely never flown any a/c with slats before, which is esp. apparent with his comment that the 109 was 'embarrased' by the opening o its slats - a guy who knows how slats function wouldn't fling out BS like that.
> 
> But its not the first time BS has been said by a British test-pilot, I remember a certain individual by the name of Kit Carson.


I doubt that - what do you think qualified this guys as a test pilot? My guess is he flew dozens of aircraft prior to even being considered for test pilot training...

Kit Carson wasn't a WW2 test pilot...


Soren said:


> Also if the British understood the slats so well then how come they couldn't manage to get them to work on the Westland and had to have them shut ???


Because it was a maintenance issue and it was better just to wire them shut than have to deal with them in the field.


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## Glider (Nov 7, 2007)

Soren said:


> Glider,
> 
> You're comparing the Spitfire IX which has better high alt performance to the heavy 109G-6. Besides the 109G-6's favorite place to be was at low to medium alt.
> 
> Anyway can you find others ? I can't.



How comes only I have to substatiate the comments.

1) You make a comment about the training of the German pilots which I question giving my reasons for questioning your comments. I ask you to support your comment.
You cannot support your comment.
2) You make a definate statement that I will not find any example of a German pilot finding the the Spitfire a handfull. 
I do, but suddenly that isn't good enough. 
3) I point out that the Spit V over Malta held their own against the 109G2's. Clearly the only way that could happen is if the Spit could turn faster than the 109 as its slower, dives less well, has a slower climb and doesn't roll as well either. If the 109 F or G2 could turn tighter as well they would have slaughtered the Spit V
No comments from you
4) You have been asked a number of times to support your comment that the British test pilots were afraid or nervous of the slat deployment.
You cannot or have not supported that comment 

The emphasis old son, is on you.


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## Graeme (Nov 7, 2007)

Soren said:


> Also if the British understood the slats so well then how come they couldn't manage to get them to work on the Westland and had to have them shut ???



They broke.





Page 47 of 'Whirlwind' by Victor Bingham-1987


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## Soren (Nov 7, 2007)

> Kit Carson wasn't a WW2 test pilot...



He certainly seems to think so though


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## drgondog (Nov 7, 2007)

Soren said:


> FLYBOYJ, the pilot who tested the 109 had most likely never flown any a/c with slats before, which is esp. apparent with his comment that the 109 was 'embarrased' by the opening o its slats - a guy who knows how slats function wouldn't fling out BS like that.
> 
> But its not the first time BS has been said by a British test-pilot, I remember a certain individual by the name of Kit Carson.
> 
> ...



Soren - it is highly possible that he 109G2 captured in Afrika was the test ship. What is probable is that the pilots that flew it in tests with the 109 against the Allied fighters in March 1944 would not have matched the skill with the 109 that a top German pilot with hundreds of hours in the airplane.

What is improbable is that the RAF pilot would be afraid of the slats. What is improbable is that Gunther Rall intentionally limited his observations of relative merits of Me 109 versus Mustang to steep climbing turn as the 'out' manuever if a 'tight horizontal turn" was equally effective?

What is just as improbable is that a Luftwaffe pilot would fly the Mustang in the Rechlin trials any better than the RAF pilot would fly the 109 in England.

What is equally improbable is that Lerches does NOT make any reference to Mustang inferiority to 109 while he was flying both - even by anecdotal reference to OTHER pilot recollections in comparative flights, if the me 109 showed clear superiority??

Lets sum it up.

Two 'tainted' or accurate flight comparisons by RAF test pilots in which the first, March 1944, tests the P-51B against the Fw190 and Me 109 in comparative trials - and comments that the Mustang out turns the 109 and 190 but is out turned by the Spitfire(s). No data attached. RAF makes no recommendation for performance adjustment/design for Mustang as a result of theses tests.

A 'tainted' trial (?) by USN test pilots flying F4U-1 versus same version P-51B slightly out turns and outclimbs P-51B. No data attached. If true we can conclude that the Navy pilots were less experienced in Mustangs and may not have achieved a fair test - but if so, the F4U-1 out turns Mustang which out turns the Fw 190 and Me 109 by virtue of only published test results and inference.

A Report by Soviets in which they demonstrated superior 360 degree turn time of an me 109 over an P-51A by 20 secs to 23 secs. No data regarding energy lost or airspeed after completion of first turn - or airsppeeds entering the turn. No dat other than 100m altitude.

No report, 'tainted' or otherwise of LW test pilots making judgements of ANY Me 109 in trials against Mustang at Rechlin. Only anecdotal comments produced so far are the above mentioned ones by Gunther Rall but none by experienced Test Pilot lerches. No data presented.

A Post war RAF Test series in which the P-51D, the Spit XIV and Spit (?) , plus Tempest V, plus Meteor V, plus Me 109 (unspecifed model) Fw 190A and P-47D and P-38L are flown in various comparitive tests. The P-51D out turns the Fw190, the Me 109 and one of the Spits. The Tempest and other Spit out turns the Mustang. No data presented to support anecdotal comments or graphs.

Many (How many??) encounter reports are on file in which a.) the Mustang out turns the Me 109G and later models, b.) the Mustang catches and shoots down the Me 109 in dives or watches them disintegrate. The Mustang shoots down more Me 109s than any other single fighter, the fw 190 is second.

And your case for the Me109 being superior in turn at altitudes above 15,000 feet and 300 kts is?


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## Soren (Nov 7, 2007)

Glider said:


> How comes only I have to substatiate the comments.
> 
> 1) You make a comment about the training of the German pilots which I question giving my reasons for questioning your comments. I ask you to support your comment.



Already have, can't help you wont read.



> You cannot support your comment.



I already did.



> 2) You make a definate statement that I will not find any example of a German pilot finding the the Spitfire a handfull.
> I do, but suddenly that isn't good enough.



No you're right it isn't good enough, the reason being he's doing a comparison at 28,000 ft - not the 109G-6's favorite operating alt, it is however a very nice operational altitude for the Spitfire.

PS: I do know that the Spit V turns better than the G-6, but the G-2 would've been a handful for the Spit.



> 3) I point out that the Spit V over Malta held their own against the 109G2's. Clearly the only way that could happen is if the Spit could turn faster than the 109 as its slower, dives less well, has a slower climb and doesn't roll as well either.



Wouldn't make any difference at all. Zekes were shot down in swarms despite their VASTLY superior turn performance - the reason for this: Inferior climb, speed roll rate. The same happened to the Spitfire over channel against the FW-190, the FW-190's slaughtered the Spitfire's in dogfights using yo yo tactics. 



> If the 109 F or G2 could turn tighter as well they would have slaughtered the Spit V



No cause had it been all about superior performance handling then the G-2 would've done so already with its superior speed, climb roll rate, slow speed turn performance isn't that important. The Spitfire pilots were however excellent and did well to protect each other in aerial engagements (Something the IJN IJA didn't do well at all), hence why the managed to hold their own. Steinhoff himself called British pilots some of the bravest and very best pilots he ever faced, much better than USAAF USSR pilots according to him.



> 4) You have been asked a number of times to support your comment that the British test pilots were afraid or nervous of the slat deployment.
> You cannot or have not supported that comment



What ?! Now thats just plain lying Glider cause I've been doing nothing else, seriously !


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## Soren (Nov 7, 2007)

Bill, the captured FW-190 [Jabo] actually managed to match the P-51B in turn performance, the P-51B didn't turn any better. Says quite abit! 

In German tests the FW-190A [Fighter] proved no match for the Bf-109 in turn fights, yet another clear indication that something wasn't done quite right in those RAF tests.

Do I really need to sum up the rest ??


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## drgondog (Nov 7, 2007)

Soren said:


> Bill, the captured FW-190 [Jabo] actually managed to match the P-51B in turn performance, the P-51B didn't turn any better. Says quite abit!
> 
> In German tests the FW-190A [Fighter] proved no match for the Bf-109 in turn fights, yet another clear indication that something wasn't done quite right in those RAF tests.
> 
> Do I really need to sum up the rest ??



No don't sum anything up - produce facts and sources - which you seem incapable of doing?

No facts on turn radius data at high and medium speeds/altitudes between Me 109 and Mustang (or F4U-1 which the Japanese thoughtfully shipped to Germany). You tried to claim Luftwaffe Test Pilot as an unequivocal source on this subject when lerches did not even address it.

You explain away Rall's observations on lack of structural integrity of 109 in dive versus Thunderbolt or Mustang as fear on his part? Would you say that to his face?

No facts or sources on limit or ultimate loads to support your thesis that the Me 109 was much stronger (or even close to being as strong) as the Mustang in a dive.

No facts or data on a Ta 152 (any version) actually flown above 475mph when you claim 500+

No facts or data from you to support a. Numerical superiority of Mustangs over Luftwaffe single engine fighters on Target Escort for period December 1, 1944 through May 30, 1944, or b.) small numerical superiority, or c.) the *:1 or 12:1 that you lovingly like to pull from a dark place and proclaim 'Fact'..not one single fact and you still have not refuted the Order of Battle I have presented to you multiple times - either for 8th/9th AF target Escort or LuftFlotte Reich.

No data to support velocity advantage of 8mm vs 30-06 with 22" or 24" barrel with 180 or 190 gr bullets - you tried to skate your argument with me by failing to dislose your ballistics as from a 29" barrel!

No, summaries jes won't do.. that only presents a platform for the Great Claimer (that would be you)..

People are not banding together to 'pick on Soren' - you seem to be a smart guy and actually I respect you - but I lose interest when I or someone else puts documents or facts/sources that you don't rebut with facts/sources -only your claim - then declare victory. 

You basically treat anyone who disagrees with you as stupid - most of us are not amused by that posture.

Regards (and I mean it),

Bill


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## drgondog (Nov 7, 2007)

Soren said:


> PS: I do know that the Spit V turns better than the G-6, but the G-2 would've been a handful for the Spit.
> 
> *Isn't the G2 the alleged test bed for the March 2, 1944 RAF comparison tests?*
> 
> ...



see my comments in thread below. You are better person and debater than reflected by that comment to Glider.


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## Juha (Nov 8, 2007)

Soren

“Besides the 109G-6's favorite place to be was at low to medium alt.”

And how you definite low and medium altitude? Finns thought that Bf 109G-6 wasn’t at its best at low level and from 2000m to 3000m was the worst height to fought against Soviet fighters in Bf 109G-6. They thought that the best altitude for G-6 was from 5 to 7 km.

“I do know that the Spit V turns better than the G-6, but the G-2 would've been a handful for the Spit.”

How is it so, G-6 had two MG 131s instead of two MG17 cowling mgs and FuG 16 instead of FuG VII, but those were main differences. G-2 was a bit faster, lacking the cowling bulges and a bit better climber but some 90kg more weight should not have big influence on turning ability.


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## DerAdlerIstGelandet (Nov 8, 2007)

Not taking sides here but I would just like to make an observation. I think some people seem to think that there word is like the word of god and proof eneogh.

How about some actual sources here...


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## Soren (Nov 8, 2007)

I have presented plenty of sources and facts Bill, you just either ignore them or claim I use one singularly for the entire subject. Claiming I present no sources is very wrong and immature of you Bill, esp. considering you in the very next moment try to critize and make up which sources I use as reference for particular arguments. You're trying very hard to put words into my mouth. I used LW Test Pilot by Lerche for information on the P-47 esp., which Lerche provides plenty of info on, I never claimed I used Lerche's book as reference for comparative info on the Mustang LW a/c, I never said that Bill, and its about time you get that !

The 109G captured tested by the RAF was a G-6 IIRC, I have photos at home. It featured gun-pods and a center rack for 300 L droptank.

The Ta-152H topped 500 mph according to reports from the pilots who flew it.

As to the 7.92x57mm vs 30.06 debate, well I can't really remember exactly what was said but one but thing is for sure, the std. 8x57 IS is a 198gr FMJ-BT bullet at 790 m/s, where'as the std. 30.06 round during WW2 was a 150 gr FMJ Spitzer bullet at 855 m/s. With a 154gr FMJ Spitzer bullet muzzle velocity was 890 m/s for the 8x57mm. (This is all from 600mm barrels) The main difference however is that the 8x57mm is more effective with heavier bullets than the 30.06. 

Anyway why do you insist upon getting off topic Bill ???

As to Steinhoff, well here's what he says:
_"Well, first of all, when we fought the RAF, it was almost evenly matched in fighters against fighters, so true dogfights, even in the Schwarm [German fighter formation], were possible. That was the truest test of men and their machines, and only the best survived. You learned quickly, or you did not come back. When the Americans arrived, they came over in such force that by the time I arrived back from Russia to fight them, there was no opportunity to engage in that kind of sportive contest. Attacking hundreds of [Boeing] B-17 and [Consolidated] B-24 bombers with fighter escorts was not what I considered sportive, although I must admit it had many moments of excitement and sheer terror. "_

This is from an interview with him.


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## Soren (Nov 8, 2007)

Juha said:


> Soren
> 
> “Besides the 109G-6's favorite place to be was at low to medium alt.”
> 
> And how you definite low and medium altitude? Finns thought that Bf 109G-6 wasn’t at its best at low level and from 2000m to 3000m was the worst height to fought against Soviet fighters in Bf 109G-6. They thought that the best altitude for G-6 was from 5 to 7 km.



Against VVS fighters, esp. the later ones, low to medium alt wasn't the favorite operational alt as the VVS fighters performed at their best there, where'as the 109 performed allot better at alt by comparison. The Germans had no problems fighting at low alt against the VVS though as their crates featured MW-50 boost.

By comparison the Spitfire didn't perform at its best at low alt.



> How is it so, G-6 had two MG 131s instead of two MG17 cowling mgs and FuG 16 instead of FuG VII, but those were main differences. G-2 was a bit faster, lacking the cowling bulges and a bit better climber but some 90kg more weight should not have big influence on turning ability.



The G-2 weighs 148 kg's less than the G-6, and climb rate is very much better, which improves turn performance.


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## Juha (Nov 8, 2007)

Soren
"The Germans had no problems fighting at low alt against the VVS though as their crates featured MW-50 boost."

I think they had problems with VVS otherwise the LW losses would have been lighter but yes, MW-50 made situation better for LW although I don't thing that all LW's G-6s had the system.

"The G-2 weighs 148 kg's less than the G-6"
where you got that number. If you look for ex. Kurfürst's site, it gives 90 kg difference between G-2 and G-6 kannonvogels. That goes with the recollections of Finnish 109 pilots who said that there wasn't much difference between them.


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## Glider (Nov 8, 2007)

Soren said:


> Already have, can't help you wont read.



Sorry, but no you didn't comment on this

_Your saying that in the later stages of the war when German training hours were under severe strain and training pilots to have the basic skills was a priority. When pilots were spending less and less time in the air, we are expected to believe they started to train the pilots in this way. 
Whereas up until 1942 when the Germans had a very detailed training scheme as good as the best in the world, your saying they didn't.

You can see the problem in your argument, as this issue would have been obvious from the days of the Spanish Civil War._



> No you're right it isn't good enough, the reason being he's doing a comparison at 28,000 ft - not the 109G-6's favorite operating alt, it is however a very nice operational altitude for the Spitfire.


Interesting. I will need to find out what type of Spit they were. If it was a low level version presumably your saying that the Spit would beat the G6 at any altitude



> PS: I do know that the Spit V turns better than the G-6, but the G-2 would've been a handful for the Spit.


PPS The Spit V was against the G2 not the G6



> Wouldn't make any difference at all. Zekes were shot down in swarms despite their VASTLY superior turn performance - the reason for this: Inferior climb, speed roll rate. The same happened to the Spitfire over channel against the FW-190, the FW-190's slaughtered the Spitfire's in dogfights using yo yo tactics.


No one would disagree that the FW190 was a much better fighter than the Spit V, but we are talking about the 109.


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## Kurfürst (Nov 8, 2007)

Glider said:


> Certainly
> Joahanns Steinhoff 1943 over Malta
> _The Malta Spitfires are back again, their fitted with high altitude superchargers and at anything over 25000ft they just play cat and mouse with us.
> At 28000ft the Spitfire could turn in an astonishingly narrow radius. We on the other hand in the thin air had to carry out every manoeuver with caution and at full power so as not to lose control_



Selective quoting... some parts missing from that qoute. 



> The interesting point is that this took place at altitude which I understood to be the 109's strongest suite.



I understand they specifiy they had problems with this special kind of Spit (the reference to it is clear in the context, but this is missing from the quote) over 7600+m. That`s actually well above the rated altitude (5800m) of the contemporary _standard_ Bf 109G, which is why they remark about the probkem being specifically _over_ 25000ft..which is quite understandable as well if you take into account the parts left out from your quote. Of course it would be another matter if JG 77 at the time would have been equipped with the special high altitude 109G subtypes as well.



> Note also that Joahanns was the commander of JG77 a very experienced pilot



Yes, but at this time which he gives account in his book, he was basically describes the latest gossip of other JG 77 pilots about new enemy a/c.


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## Kurfürst (Nov 8, 2007)

drgondog said:


> And your case for the Me109 being superior in turn at altitudes above 15,000 feet and 300 kts is?



Hmm, to me it seems the first part of the question can be decided by the relative falling of power at rated altitude and the respective outputs of the engine at altitude (unless there`s significant difference, I believe the relative turn will be the same as at low altitude), while the turning ability above 300 kts is basically a question of excess thrust vs. drag in turns.

In fact, turning radius is largely definied by stall speed =~ wingloading, and here you can`t expect much of a difference between the two aircraft - nothing meaningful at least. Sustained turn rate is largely about available power vs. thrust, at high speed a good indication is power required /max speed reached, at low speeds, we can draw some conclusions based on climb rates.


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## renrich (Nov 8, 2007)

The Zeke did not have an inferior rate of climb. From 1941 to 1943 it was at least equal to the Allied types it faced in climb rate. Since this thread is supposed to be about Corsair versus BF and FW, how about some discussion of the USN comparison of a FW190A4 and F6F3 and F4U1.


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## Jank (Nov 8, 2007)

See Post #85


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## otftch (Nov 8, 2007)

The Brits sent Spitfires to the far east and the Zeros chewed them up.This was probably due more to tactics than airframe limitations.However the Corsair chewed up even the late model Japanese aircraft.On paper the F4F should have been totally outclassed by the Zero,but held its own pretty well.Tactics again. A Phillipene pilot knocked down a bunch of Zeros using a P-26.It all comes down to pilot skill.
Ed


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## FLYBOYJ (Nov 8, 2007)

The Philippine pilot you are referring to had 2 Zero kills....

_"Philippine P-26s led by Capt. Jesus Villamor shot one bomber and two Zeros with the loss of three P-26s."_

Operational History of Boeing P-26


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## Crumpp (Nov 8, 2007)

Hi guys,

I hope all is well with all of you.

I really hate to see these kinds of discussions. The more you learn about the science and engineering of aircraft, the more silly these discussions become from the standpoint of "my plane is better than yours". It really does just become an opinion.

First, aircraft maintenance is the largest factor in aircraft performance. The same design can exhibit a wide margin of performance much of it based on how well it is assembled and how well it is maintained.

Any aircraft owners know this fact very well. If an aircraft is not maintained to exacting standards, it is highly unlikely it will perform as intended. Simple things make a significant difference. Each design is different in this aspect. While generalities exist the details are very important. What maybe great oil for one aircraft might degrade power production in another? A good friend of mine learned this the hard way. He used an aviation approved additive that was "all the rage" for many owners with essentially the same motor or at least one would think so. It ruined his engine and now he is buying a new one to the tune of 57,000USD.

One of the first things any potential aircraft buyer will do is have the compressions checked. Compression directly relates to power production and all engines will vary the amount of power they produce amoung the same design. 

Conditions also have a very large influence. It is useless to compare performance that was not gathered under the same conditions. Temperature alone can vary such things as climb rate by several thousand fieet per minute. An airplane that barely achieves a 1700fpm climb rate at a different temperature can exhibit a climb rate of 4500fpm(+).

If we consider all factors being equal, airplane performance is still a percentage range over a mean average simply because of natural variations in the manufacturing process.

Next we have the science of flight. Statements such as "Plane A outturns Plane B" really have no bearing whatsoever in the air. Facts are all aircraft at the same angle of bank and velocity will make exactly the same turn.

The portion of the envelope where a design contemporary aircraft will exhibit any amount of "superiority" is extremely tiny. Any aircraft can neutralize a level turn advantage by rolling it's vector of lift below the horizon thus adding a component of weight to thrust. This is why fighter designers concentrate on rolling ability and it is considered the "agility" of a fighter and not level turn ability.



> Notice in the development of the radius of turn equation that the weight (W) canceled out of the equation. This is a very important observation since it means that the size of the aircraft has no effect on the radius of turn. Thus, two aircraft flying at the same angle of bank and velocity will make the same radius of turn even if one is 1000 times larger than the other.



Radius of Turn

The aircraft traveling the slowest will outturn the faster aircraft.



> We can see that if the aircraft is flying twice as fast the radius of turn will be four times as great.



Radius of Turn

The only difference is any aircraft's turning ability is the location of the stall line. However this does not mean that the best turn is at that stall line:



> The catch 22 however, is that the stall speed of the airplane will increase as we increase the angle of bank. Thus, we will have to fly at a higher speed if we use a large angle of bank. So, the question is would it be better to do the turn at a slower speed, and a lower angle of bank, or at a higher speed and a higher angle of bank?



Minimum Radius of Turn


I have a mathematical analysis of the FW-190A8 and P51D Mustang. I will post them later and we can discuss them.

All the best,

Crumpp


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## JoeB (Nov 8, 2007)

FLYBOYJ said:


> _"Philippine P-26s led by Capt. Jesus Villamor shot one bomber and two Zeros with the loss of three P-26s."_


The Japanese fighters in that action (Dec 12, '41) weren't actually credited to Villamor, just the bomber. The Zero credits were shared among other pilots of the Filipino 6th Pursuit Sd. But only a bomber was lost, a Type 96 Land Attack Bomber ('Nell') of the 1st Air Group, whose crew, uncharacteristically, was captured alive. The fighter opponents were 3rd Air Group Zeroes; who claimed 8 "P-35's or P-26's" without loss. See 'Bloody Shambles' by Shores Vol 1 p. 184-185.

It's not to constantly contradict, but if we say 'even P-26's could down Zeroes' it matters if it actually happened, which apparently it didn't.

Villamor was an brave pilot though. Later he flew a recon mission in a PT-13 biplane trainer to photograph Japanese siege artillery positions for which he won the DSC.

On Spitfire V's (poor, 1: several) 1943 results v Zeroes; compared to F4F's 1:1 ratio against Zeroes even in 1942, each according to both side's loss accounts, it's one of the best examples of how little you can predict or conclude about combat effectivness from paper statistics of WWII fighter performance. 'Pilots' or 'tactics' is the all purpose catchall explanation and must have some truth, but I think there might be more to it than that. That is, stuff about fighter combat effectiveness that isn't captured by speed, climb etc. statistics most people focus on in saying one plane is better than another on paper. Plus, the issue of how accurate official paper statistics were for actual production examples of various planes in particular environments.

Joe


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## renrich (Nov 8, 2007)

Jank, I had already seen your post #85, reread the report, as I have it saved but everyone else on this thread seems to ignore that report and I have heard no discussion of it. I suppose that comparison is somewhat tainted because it was conducted apparently by USN pilots but it seems pretty objective and certainly goes against what I have read by Eric Brown. At any rate it would seem an open and shut case that a pilot who properly handles a Corsair should have the upper hand over either an FW or BF and that probably goes for the Hellcat also.


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## Jank (Nov 8, 2007)

As our resident Corsair expert, I know YOU have seen the report (probably committed it to memory).  It was my intention that others might read it in response to your point.

Also, although the post appears limted to air-superiority, it bears noting that the Corsair is also far superior to the 109 and 190 in the fighter bomber role which constitutes a great advantage in pinpoint ground attack and close air support. This versatility has tremendous value.


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## renrich (Nov 8, 2007)

Jank, you have found me out. I became enamored of the Corsair during WW2 when I was given a picture book of airplanes. The book is long gone but I remember the picture of the Corsair was of the XF4U all silver and yellow. While in college,(1955) I worked part time at Temco Aircraft which was right next to Vought in the mid-cities between Dallas and Fort Worth. My first job was in flight test engineering and I was able to walk out on the flight line and gaze at airplanes. Although Vought was then mainly involved with F7Us(they were designing the F8U at that time) there were still some Corsairs around and I avidly inspected them. Some of the people who worked at Temco had been WW2 pilots and their stories were absorbed with great interest. One you would enjoy was told me by an ex-Jug driver. He said they were detailed to escort a bunch of B-26s late in the war on a raid. They rendevouxed with the bombers at an altitude several thousand above and settled into their normal weave since the Jug's cruise was faster than the B26s. Apparently they did not look closely at the bombers at first but soon, in order to keep up with them. they had to increase throttle and come out of the weave and soon they were straining to keep up( This was at a low altitude) It was then they realised that these were not Marauders they were escorting but rather A26 Invaders that were far faster. I wish I remember further details but that is all I can recall. Anyway I have had friends and relatives who flew the Corsair in WW2 and Korea and an uncle who enjoyed mock dogfights with them while serving as an IP in P39s and P47s. Once again I regret not paying closer attention to these individual's stories.


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## drgondog (Nov 8, 2007)

Crumpp said:


> Hi guys,
> 
> I hope all is well with all of you.
> 
> ...



With Respect

Bill


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## FLYBOYJ (Nov 8, 2007)

JoeB said:


> The Japanese fighters in that action (Dec 12, '41) weren't actually credited to Villamor, just the bomber. The Zero credits were shared among other pilots of the Filipino 6th Pursuit Sd. But only a bomber was lost, a Type 96 Land Attack Bomber ('Nell') of the 1st Air Group, whose crew, uncharacteristically, was captured alive. The fighter opponents were 3rd Air Group Zeroes; who claimed 8 "P-35's or P-26's" without loss. See 'Bloody Shambles' by Shores Vol 1 p. 184-185.
> 
> It's not to constantly contradict, but if we say 'even P-26's could down Zeroes' it matters if it actually happened, which apparently it didn't.
> 
> ...




great info Joe - I remember that chapter in Bloody Shambles." Point made that A Philippine pilot NEVER knocked down a "bunch" of Zeros using a P-26.


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## davparlr (Nov 8, 2007)

Kurfürst said:


> In the end, both planes reached about the same speed with the same power, so there`s not much in it.



The P-51D had significanly more propulsion efficieny than the Bf-109G. With similar HP available, the P-51D would obtain an airspeed of 375 mph at sea level while the Bf-109G could only get 335 mph. The P-51B, cleaner still, could achieve 386 mph at sea level. The P-51D had significant airspeed advantages at all altitudes. However, the Bf-109G had much better climb at altitudes up to 20k, where the Bf-109G was then starting to run out of air and the P-51D was getting its second wind.

A few comments on these discussions.

The F4U-1 was faster at all altitudes than the F-190A-8 and had similar climb performance. The Bf-109G was much slower, but could climb much better.

The F4U-4 was similar in airspeed to the Bf-109K up to about 25K where the F4U-4 began to pull away. The F4U-4 would outclimb the Bf-109K at all altitudes. The FW-190D-9 was similar in airspeed to the F4U-4 up to 15K and was quickly left behind after that. The FW-190D-9 was also no match to the F4U-4 in rate of climb.

Side note: The P-51B was significantly faster and had a significantly better climb rate at all altitudes than the F4U-1. In fact, the P-51B was very close to the FW-190D-9 in airspeed and climb performance at all altitudes (actually better at hight altitudes).

The comments on slat operations was very strange. I find it unbelieveable that test pilots would be afraid of this feature. From the test pilots I know, this is a reasonable scenario.

Brit test pilot: What's this?

Ops officer: They are called slats. They are suppose to improve low speed and high AOA flight.

Test pilot: Awwright he says with a smile on his face (except with a Brit accent) Let's go see what it will do! 

Ops officer: Be careful, if they don't work right, you might get into a nasty situation.

Test pilot: I'm a test pilot. I can take care of anything.

Lesson: Brit pilots have never had the reputation of being "afraid" of anything.

These pilots knew the lives of there fellow pilots depended on what they could wring out of the enemy aircraft.

Remember, Chuck Yeager, on testing the first captured Mig 15, pointed the nose straight down, with full power, to see how fast it would go. That's not the sign of a timid soul but rather a sign of a test pilot.

It is also hard to believe that a Bf-109 fighter pilot with P-51 on his tail would not try to pull the wings off his aircraft to avoid a buzz saw of 50 cal. bullets.


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## Soren (Nov 9, 2007)

Exactly how big a climb rate are you under the illusion that the F4U-4 possesses Davparlr ???


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## DerAdlerIstGelandet (Nov 9, 2007)

Crumpp said:


> First, aircraft maintenance is the largest factor in aircraft performance. The same design can exhibit a wide margin of performance much of it based on how well it is assembled and how well it is maintained.
> 
> Any aircraft owners know this fact very well. If an aircraft is not maintained to exacting standards, it is highly unlikely it will perform as intended. Simple things make a significant difference. Each design is different in this aspect. While generalities exist the details are very important. What maybe great oil for one aircraft might degrade power production in another? A good friend of mine learned this the hard way. He used an aviation approved additive that was "all the rage" for many owners with essentially the same motor or at least one would think so. It ruined his engine and now he is buying a new one to the tune of 57,000USD.



As a maintainer I agree 100 percent.


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## Glider (Nov 9, 2007)

davparlr said:


> Lesson: Brit pilots have never had the reputation of being "afraid" of anything.
> 
> These pilots knew the lives of there fellow pilots depended on what they could wring out of the enemy aircraft.
> 
> .



I think its worth remembering that in 1943 the British set up the Empire Test Pilot Training school so that all test pilots were trained to the highest degree and used common standards.
It was the first school of its kind and is still recognised as a leading establishment of its kind. 
Its also worth noting that one of the reasons it was set up, was because of the loss ratio of pilots untertaking test pilot duties. From this its safe to work on the premise, that the test pilots were not afraid of pushing the boundry to the limit, quite the opposite.


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## Kurfürst (Nov 9, 2007)

Glider said:


> From this its safe to work on the premise, that the test pilots were not afraid of pushing the boundry to the limit, quite the opposite.



Yet still...



> COMBAT TRIALS AGAINST Me.109G
> 
> Turning Circle
> 47. The Tempest is slightly better, *the Me.109G being embarrassed by its slots opening near the stall.*






> Indeed many fresh pilots thought they were pulling very tight turns even when the slots were still closed against the wing. *For us, the more experienced pilots, real manouvering only started when the slots were out.*
> 
> - Erwin Leykauf



IMHO it`s rather futile to speculate how good 'British testpilots' were, when the facts are quite clearly there.

And what experience they had with the aircraft BTW? 

The AFDU also tested a 109F in 1941 for example. The pilot had the opportunity to gain _precisely 25 minutes worth of flying 'experience' _in the 109 before he attemped to fly comperative trials against a Spitfire pilot with what - hundreds of flying hours in a Spitfire? Even an 1944/45 Luftwaffe rookie in the 109had at least a dozen or two flying hours in a 109 before entering combat.. you`re telling me that after just 25 minutes of familiarisation, the pilot was capable to push the aircraft to it`s final limits..?! 

Attempted because the aircraft was in such a poor shape they had to cancel the trials to make some makeshift repairs, despite which oil pressure was still abnormal in the 109.

The battle damaged 109G-2/trop they tested vs the P-51B was hardly in any better shape. It`s condition is detailed in the Middle East report that can be found on my site.

I mean, you can keep ignoring and denying these circumstances, but to what end, I cannot imagine. Any reasonable man would see that ill-maintained aircraft in which the pilot has nil experience ain`t gonna shine in any comparison when flown against well maintained aircraft flown by a pilot who has extensive knowledge of flying the type.


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## Kurfürst (Nov 9, 2007)

davparlr said:


> The P-51D had significanly more propulsion efficieny than the Bf-109G. With similar HP available, the P-51D would obtain an airspeed of 375 mph at sea level while the Bf-109G could only get 335 mph.
> The P-51B, cleaner still, could achieve 386 mph at sea level.



I have 364 mph for the 51B/1650-7/67", and 354 mph for the 51D/1650-7/67". 
This translates to about 1630 HP at SL. 

The 109G/K performance figures depend on the type you speak of. 
All of these are for 1800 PS at SL, or a bit below 1800 HP.

Bf 109G-14 : 352 mph
Bf 109G-14/AS : 348 mph
Bf 109G-10 : 349 mph
Bf 109K-4 : 370 mph

I don`t see breathtaking differences here. The Mustang D is slightly better than the 109G, and apprx. the same aerodynamic effiency as the 109K.


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## AL Schlageter (Nov 9, 2007)

Kurfürst said:


> The AFDU also tested a 109F in 1941 for example. The pilot had the opportunity to gain _precisely 25 minutes worth of flying 'experience' _in the 109 before he attemped to fly comperative trials against a Spitfire pilot with what - hundreds of flying hours in a Spitfire? Even an 1944/45 Luftwaffe rookie in the 109had at least a dozen or two flying hours in a 109 before entering combat.. you`re telling me that after just 25 minutes of familiarisation, the pilot was capable to push the aircraft to it`s final limits..?!


He sure could push the 109 further with those _hundreds of flying hours_ than what the Luftwaffe rookie could with his minimum number of flight hours.



> COMBAT TRIALS AGAINST Me.109G
> 
> Turning Circle
> 47. The Tempest is slightly better, the Me.109G being embarrassed by its slots opening near the stall.


It doesn't say the pilot was embarrassed but the 109 was embarrassed. Badly operating slats possibly but that would not be restricted to just captured 109s.



> The battle damaged 109G-2/trop they tested vs the P-51B was hardly in any better shape.


"The aircraft had been restored to standard good condition
except that the oil radiator flap was locked open as received,
as the functioning of the thermostatic control was apparantly
bad; no oil therometer was available; there was a splinter
hole and score mark in one airscrew blade........"

I could not find the 109F test on your site to compare to the in bad shape 109G-2.


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## AL Schlageter (Nov 9, 2007)

Kurfürst said:


> I have 364 mph for the 51B/1650-7/67", and 354 mph for the 51D/1650-7/67".
> This translates to about 1630 HP at SL.


The speeds when 25lb boost and 150pn fuel is ________?

_Notes : 
The given performance figures are going to be reached with well-built serial production machines for certain._

Yet it was questioned when 1.98ata was being tested, 'why go for 1.98 when the airframes are is such bad condition?'


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## Kurfürst (Nov 9, 2007)

Milo,

Perhaps search for another board for your feuds and flamebaitings.


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## Glider (Nov 9, 2007)

Kurfürst said:


> IMHO it`s rather futile to speculate how good 'British testpilots' were, when the facts are quite clearly there.
> 
> And what experience they had with the aircraft BTW?
> 
> ...



What I find amusing is your continual knocking of the tests, because the planes were battle damaged it makes the tests far less that perfect. Of course they were damaged, how else would the allies get hold of them!!!. The tests were the best that could be done in the situation available. No doubt as were the German tests with aircraft they captured in similar situations.

For sake of argument lets say the tests (both allied and German) were done using 90% of the performance available because of damage, uncertainty re maintanence, not wanting to lose almost unique aircraft, whatever. The question is does it matter?

I would suggest the awnser is no. What matters is the ability to give advice to the average pilot on how best they can deal with the opposition. The average pilot of any airforce will not get the absolute best out an aircraft. If your average opponent is getting 90% out their aircraft then the test and more importantly the advice remains valid.
We all recognise that aces and highly experienced pilots will get more out of aircraft they are familiar with, than the average squadron pilot. 

On a slightly different topic the experience of the Test pilots in the German aircraft. In the UK testing of captured aircraft was a two stage process.
The first stage was testing the handling of the aircraft and pushing it as far as they could in the circumstances.
The second stage handled by a different unit covered the tactical trials. 
As one person didn't carry the whole process through it may have some impact on the time in the cockpit.

One thing that I have noticed is that most of the reports of tactical trials are from the Allied point of view. Germany would have carried out similar tests but I have been unable to find many reports, do you have any idea where I can find them?


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## Kurfürst (Nov 9, 2007)

There`s a fraction of a German report available comparing G-6/AS, G-6, A-8 v. P-47D and P-51 (presumably B, a 'newest model Mustang', report the dated 19-6-44).

Unfortunately, most of the report appearantly went missing due to damaged microfilms, and the part about the Mustang is limited to general description and some words on generic flying/handling, but no comparison; it is mentioned that flight of the Mustang had to be abandoned above 7000m due to faulty supercharger..


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## FLYBOYJ (Nov 9, 2007)

Glider said:


> I think its worth remembering that in 1943 the British set up the Empire Test Pilot Training school so that all test pilots were trained to the highest degree and used common standards.
> It was the first school of its kind and is still recognised as a leading establishment of its kind.
> Its also worth noting that one of the reasons it was set up, was because of the loss ratio of pilots untertaking test pilot duties. From this its safe to work on the premise, that the test pilots were not afraid of pushing the boundry to the limit, quite the opposite.


BINGO!!!! And I would think that loudly deploying L/E slats (In any aircraft) weren't going to be a deterrent from any of these folks from performing their mission...


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## davparlr (Nov 9, 2007)

Soren said:


> Exactly how big a climb rate are you under the illusion that the F4U-4 possesses Davparlr ???



My illusion on climb rates for the F4U-4 was determined by this site:
http://www.wwiiaircraftperformance.org/f4u/f4u-4.pdf

Climb rates of the F4U-4 vs. Fw-190D-9 and Bf-109K

SL
*F4U-4* 4800 *Fw-190D-9* 4330 *Bf-109K-4* 4400

10k
*F4U-4* 4800 *Fw-190D-9* 4320 *Bf-109K-4* 4020

20k
*F4U-4* 3800 *Fw-190D-9* 3054 *Bf-109K-4* 3520

30k
*F4U-4* 2000 *Fw-190D-*9 1476 *Bf-109K-4* 1900



Kurfurst said:


> I have 364 mph for the 51B/1650-7/67", and 354 mph for the 51D/1650-7/67".
> This translates to about 1630 HP at SL.
> 
> The 109G/K performance figures depend on the type you speak of.
> ...



I have no problems with your numbers. 

Airspeed vs. HP at SL where “q” is max is probably the best method of judging the propulsive efficiency of an aircraft. At this condition, where every mph comes at the biggest HP cost, the 23 – 27 mph advantage of the P-51D is not a “slight” difference but a significant difference and an operational advantage at any altitude. Imagine cruising down the freeway/interstate/autobahn at 70 mph (112 km/hr) and a car goes by you at 93 mph (150 km/hr). That’s how fast a P-51D will go by a Bf-109G-14 at SL. Oh, by the way, if that Mustang is a P-51B, that passing car would be doing 104 mph (167 km/hr) (remember your doing 70)!

The Bf-109K-4 is a much later version and is more comparable to the P-51H. But in any event, it is interesting to note that the P-51D is still slightly faster at SL (insignificant) and the P-51B is noticeably faster.


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## Kurfürst (Nov 9, 2007)

davparlr said:


> I have no problems with your numbers.
> 
> Airspeed vs. HP at SL where “q” is max is probably the best method of judging the propulsive efficiency of an aircraft. At this condition, where every mph comes at the biggest HP cost, the 23 – 27 mph advantage of the P-51D is not a “slight” difference but a significant difference and an operational advantage at any altitude.



The point being the P-51D does not seem having_ '23 – 27 mph advantage' _over any of these aircraft. 

At least, the 354mph achieved by the P-51D/67" vs. the 352mph achieved by the G-14 is not ~25 mph difference in my book, more like 2 mph (though the 109 achieves it with slightly more power available, so on even footing, the Mustang is probably a bit better, say 360-365).




> The Bf-109K-4 is a much later version and is more comparable to the P-51H.



How come, the P-51D was introduced what, June-July 1944, the 109K in October the same year. _'Much later'_ - like what, four months...?

The P-51H, with it`s performance apprx. on the level of the 109K, appeared in when, something like August 1945 on operation, some 10 months after the 109K (I am not sure about the 51H ever seeing combat in WW2)..?



> But in any event, it is interesting to note that the P-51D is still slightly faster at SL (insignificant) and the P-51B is noticeably faster.



Still, the 355 mph or so achieved by the P-51D in normal condition at 67" does not seem to me higher than 370 mph achieved by the 109K at 1.8ata (alternate comparison can be made at similiar power at 81"/1.98ata, at comparable power ie. 379/377mph. Again not much of a difference).

PS : You might want to add the 1.98ata climb rates into your climb rate comparison to keep the playing field even, also I can`t understand why the F4U4 climb figures you are showing are so much higher than every other Navy document shows. 

Ie. 

SL
Your F4U-4 4800 vs 4400 reported for F-4U4 at 12450 lbs, at 70", inOctober 1944 specs.

10k
Your F4U-4 4800 vs ~4300 reported for F-4U4 at 12450 lbs, at 70", in October 1944 specs. (revised and superseed to 4000 fpm in April 1945)

20k
Your F4U-4 3800 vs 2980 reported for F-4U4 at 12450 lbs, at 70", in October 1944 specs.
(revised and superseed to 3270 fpm in April 1945)

30k
Your F4U-4 2000 vs ~1400 reported for F-4U4 at 12450 lbs, at 70", in October 1944 specs

Your data is very significantly higher than the official US performance data reported in October 1944. Why?


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## AL Schlageter (Nov 9, 2007)

24 April 1944

Flight Tests on the North American
P-51B-5-NA Airplane, AAF No. 43-6883

Maximum speed at sea level (67" Hg. manifold pressure 3000 RPM) - 371.0 MPH

15 June 1945

Flight Tests on the North American
P-51D Airplane, AAF No. 44-15342

Maximum speed at sea level	

War Emergency power (3000 RPM and 67")	375 MPH
Military power (3000 RPM and 61") 364 MPH
Normal Rated power (2700 RPM and 46") 323 MPH


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## Soren (Nov 9, 2007)

What a surprise, Mike William's site again - thought you guy knew better by now not to use his site as reference for German a/c performance.

The FW-190 Dora-9 has a climb rate of 4,400 ft/min, the Bf-109K-4 over 5,000 ft/min ! Even with the thin experimental DünblattSchraube the Bf-109 K-4 boasted a 4,800 ft/min climb rate!

PS: Have you got time to climb figures for the F4U-4 as-well ?? I'd like to see wether the F4U-4 is able even to beat the Dora-9 to 10km. 

And about your assumption on the RAF test-pilots, well thats all it is, an assumption. 

Kurfürst and I have both provided more than enough evidence as proof that the British test-pilot flying the 109 didn't push it beyond the deployment of the slats. 

Let me sum it up here:

1.) The British test-pilot makes the comment:_ "The 109 being embarrased by the opening of its slots"_, this alone being a clear enough sign that he wasn't pushing past slat deployment.

2.) During the British comparative testing the test-pilot didn't even accomplish to turn the 109 as tightly as the FW-190 or P-51, eventhough the Bf-109 clearly always out-turned the FW-190 P-51 in German Soviet comparative testing.

3.) Several German experten make it clear that green 109 pilots didn't push past slat deployment, the slight notch and loud bang sometimes heard convincing the green pilots that they were right at the limit. 

4.) The 109E had frequent problems with slat failure, being enough reason for even a German experten to choose not to push the 109 to the limit in turns because of their past experience with the Emil. The British test-pilots (if not having experienced troubles with the slats on the Emil and therefore being concerned when testing later versions) had themselves heard nothing but bad news about the slats, seeing that a few Westlands crashed because of slat failure and that this had led o hem being locked shut in flight, given more than enough reason for British pilots to be vary about the slats.


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## Kurfürst (Nov 9, 2007)

Curious, it seems the manufacturer North American`s performance figures are always much higher than all the figures obtained elsewhere. I wonder why.


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## FLYBOYJ (Nov 9, 2007)

Kurfürst said:


> Curious, it seems the manufacturer North American`s performance figures are always much higher than all the figures obtained elsewhere. I wonder why.



Because the aircraft used at the factory are pristine, probably polished bare metal and tested with minimum fuel on board.

The normal rule of thumb for any flight is to have at least 30 minutes of reserve fuel on board (that's actually a regulation for civilian aircraft). I once read that when many WW2 and post WW2 era aircraft went on speed runs they did so with minimum fuel, sometimes dead-sticking the aircraft because of fuel exhaustion.

6 pounds per gallon could add up to some excess weight......

I think this was depicted in the Howard Hughes movie when he was setting a speed record with his R-1.


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## AL Schlageter (Nov 9, 2007)

Kurfürst said:


> Curious, it seems the manufacturer North American`s performance figures are always much higher than all the figures obtained elsewhere. I wonder why.


I did not know that

Army Air Forces Material Command
Flight Test Engineering Branch
Wright Field, Dayton, Ohio 

was a manufacturer.


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## Glider (Nov 9, 2007)

Soren said:


> 1.) The British test-pilot makes the comment:_ "The 109 being embarrased by the opening of its slots"_, this alone being a clear enough sign that he wasn't pushing past slat deployment.



I have a different understanding of the phrase 'the 109 being embarrased by the opening of its slots.

If you are flying in a tight turn on the edge of the stall then one wing is going more slowly than the other. As a result the slats will not open evenly, one will open before the other causing the aircraft to 'stagger' or 'lurch' to one side for a second.
In a tight turning dogfight this could easily give the opponent the advantage. Not in every case but in some depending on the tactical situation. This is a more logical definition of the phrase embarrased.

I have been part of a stack of gliders in a thermal, when one of them has overcooked it and I have had to take evasive action. Its suprising how quickly things happen even in a glider, the other machine almost seems to stop.

I am not saying that when both slats extend that the turn doesn't significantly improve, but there is that short but dangerous period when the aircraft is at significant risk.

Just a thought


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## drgondog (Nov 9, 2007)

Kurfurst - the first production H's were delivered Feb 3, 1945.

The Experimental lightweight P-51F, 'father of the 51H', first flew on February 14, 1944. It was completely new design basically and weighed 5635 pounds empty. With the same engine as the P-51B at that time (1650-3) it had a top speed of 466mph at a Gross weight of 7265 pounds at 29,000 feet.. cruise speed of 380mph at 25,000 feet.. less than 5 minutes to 20,000 feet for climb.

This was with guns but only half load of fuel and no external rack. Max TO was 7630 pounds

In the flight tests the roll rates for 90 degrees were 1.6 ses, 2.0 sec and 2.6 sec at 300, 360 and 400 mph at 10,000 feet.. 

In order to boost the new airframe even more the forerunner of the 1650-11, the 14 S.M. engine, was installed as the X-p51G which had the most Hp -2000 at 80" at 20,000 feet and max speed at 495mph at 22,800 feet - service ceiling at 46,000 due to lack of pressurization (according to Gruenhagen' Mustang- Story of the P-51). He states that this ship attained 20,000 feet in 3.4 minutes but I am still looking for the actual data.

Points have been made that the P-51H never was in combat and should not be used in comparisons to Ta152 or Fw 190D-9, etc. I would pose the question.

Does anyone think that if the 51H was deemed critical to the war effort that it would not have been available in Oct-Dec 1944? The aircraft production contract for 2400 a/c was let in April 1944 (about the same time as Ta 152) but the XP-51F actually flew a couple of months before the Ta 152. 

One of the sources I read stated that the Ta 152 was only tested 51 hours before first production version was delivered to the field in late October - is that true?

At any rate the P-51H was available in squadron strength in March and could have been deployed either to ETO or PTO if deemed necessary - but never was deployed over seas remaining USAAF and USAF front line interceptor until the P-80s replaced all the active duty squadrons.

When my father was CO of 35FBW in Occupied Japan - all the Mustangs were late model P-51D's mostly -25 and -30's.

I'll find the website (linked to Tony Woods) which has all the JG TO data i was referring to.

Regards,

Bill

Reactions: Informative Informative:
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## Kurfürst (Nov 9, 2007)

This seems relevant. An extreme coincident, too, the_ restored_ Black Six being the SAME airframe that was tested vs. Tempest, Mustang:



> Flying Black 6 by Dave Southwood
> 
> The idle power stall characteristics of the aircraft are very benign and affected little by undercarriage and flap position. Stalling warning is a slight wing rock with the stick floating right by about 2 inches. This occurs 10klph before the stall. The stall itself is a left wing drop through about 15 degrees with a slight nose drop, accompanied by a light buffet. All controls are effective up to the stall, and recovery is instant on moving the stick forward. Stall speeds are 155kph clean and 140kph with gear and flap down. In a turn at 280kphwith display power set, stall warning is given by light buffet at 3g, and the stall occurs at 3.5g with the inside wing dropping. Again, recovery is instant on easing the stick forward. One interesting feature is the leading edge slats. *When these deploy at low speeds or in a turn, a 'clunk' can be heard and felt, but there is no disturbance to the aircraft about any axis.* I understand that the Bf109E rolled violently as the slats deployed, and I am curious to know the difference to the Gustav that caused this.


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## drgondog (Nov 9, 2007)

Kurfurst - this is the Order Of Battle reference

Flugzeugbestand und Bewegungsmeldungen, Jagdverbände

Regards,

Bill


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## drgondog (Nov 9, 2007)

Kurfurst - this is the Order Of Battle reference

Flugzeugbestand und Bewegungsmeldungen, Jagdverbände

Here is the NA test data on the rate of climb and climb rate. So, it appears Gruenhagen's reference to 3.4 minutes to 20,000 feet was not in error. 

I did not realize the initial climb rate at SL was 6400 ft min and still doing 5700 fpm at 17500 and 470mph at 35,000 feet

http://www.wwiiaircraftperformance.org/mustang/xp-51g-chart.jpg

Regards,

Bill

Soren - you can complain about Mike's collection of test reports not conforming to your notions of the Fw 190D-9 or other LW a/c... but you should emulate Kurfurst and at least produce similar bona fide test data form LW to refute what you believe to be 'predjudice'??


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## Crumpp (Nov 9, 2007)

> If you are flying in a tight turn on the edge of the stall then one wing is going more slowly than the other. As a result the slats will not open evenly, one will open before the other causing the aircraft to 'stagger' or 'lurch' to one side for a second.



There is nothing bad aerodynamically about properly designed LE devices. They are mainstay of modern wing design.

Handley Page automatic slats deploy at a specific coefficient of lift. The wing deploys them "as needed". Handley Page automatic slats represent both a camber change and energize the boundry layer. 

The pilots reaction to this is much more important to flight performance than the slat itself. My aircraft has them and yes, they took some getting used too. Once I conditioned my reactions though, the low speed performance with them deployed is fantastic. The effect is very noticable. 

Yes the plane will lurch if the pilot does not react properly with appropriate inputs. That is not to say the slats are at fault. The pilot is at fault for not having the experience to use them. The slats definately will improve low speed performance. That is why most modern fighters have LE devices.

All the best,

Crumpp


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## Glider (Nov 9, 2007)

Crumpp said:


> There is nothing bad aerodynamically about properly designed LE devices. They are mainstay of modern wing design.
> 
> Handley Page automatic slats deploy at a specific coefficient of lift. The wing deploys them "as needed". Handley Page automatic slats represent both a camber change and energize the boundry layer.
> 
> ...



I am not saying that there are any problems with the design of the slats, they are doing exactly what they are designed to do. 
What I would like to ask when the plane deploys one slat due to being in a tight high banked turn does it lose speed in that period before the second slat deploys?
I think you can see where I am coming from, if you are in a tight turning battle with an enemy close behind then any loss of momentum, no matter how slight could explain the comments in the reports.


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## Crumpp (Nov 10, 2007)

> I think you can see where I am coming from, if you are in a tight turning battle with an enemy close behind then any loss of momentum, no matter how slight could explain the comments in the reports.



I agree with you. If a pilot was not used to the rapid stick movements and loud bang of the slats deploying he would certainly loose some monentum.



> What I would like to ask when the plane deploys one slat due to being in a tight high banked turn does it lose speed in that period before the second slat deploys?



Yes, it does lose some speed. Velocity as you know is the key component of turn performance. 

More importantly, the usable angle of attack is increased further tightening the turn.

This is why experienced 109 pilots felt that the real maneuvering did not begin until the slats deployed.

All the best,

Crumpp


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## Glider (Nov 10, 2007)

Thanks for this


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## davparlr (Nov 10, 2007)

Kurfürst said:


> The point being the P-51D does not seem having '23 – 27 mph advantage' over any of these aircraft.
> 
> At least, the 354mph achieved by the P-51D/67" vs. the 352mph achieved by the G-14 is not ~25 mph difference in my book, more like 2 mph (though the 109 achieves it with slightly more power available, so on even footing, the Mustang is probably a bit better, say 360-365).



I got the info from this site which looks authentic including the identification of the aircraft number. In addition, two other sources I have and trust agree to the data shown in this flight test. The P-51D shows 375 mph at SL using about 1630 hp. I think my comments are good.

http://www.wwiiaircraftperformance.org/mustang/p51d-15342-level.jpg




> How come, the P-51D was introduced what, June-July 1944, the 109K in October the same year. 'Much later' - like what, four months...?



The P-51D was introduced into the 8th AF in March ’44. The Bf-109K was introduced in November, ’44. Six months in WWII during this time was a generation of aircraft development. In the summer and fall of 1944, a whole family of aircraft with much greater performance over the mainstay of WWII aircraft, was introduced on both sides. These include Fw-190D-9, Bf-109K, F4U-4, P-47M/N, P-51F (later H), Ta-152H, and others.



> The P-51H, with it`s performance apprx. on the level of the 109K, appeared in when, something like August 1945 on operation, some 10 months after the 109K (I am not sure about the 51H ever seeing combat in WW2)..?



The XP-51F, the predecessor of the H, flew in Feb. 44. Unlike Germany, who was desperate to stop the hordes of P-51s, P-47s, B-17s, B-24s, and Brit planes, with advanced aircraft, the US, whose aircraft performance was adequate and the quantity was overwhelming, did not expedite new models. Had the need arose, there is no doubt that a P-51H or the similar P-51F could have been available in the fall of ’44. 



> Still, the 355 mph or so achieved by the P-51D in normal condition at 67" does not seem to me higher than 370 mph achieved by the 109K at 1.8ata (alternate comparison can be made at similiar power at 81"/1.98ata, at comparable power ie. 379/377mph. Again not much of a difference).



My multiple sources show that the P-51D was capable of 375 mph at SL at about 1640 hp. The Bf-109K had 1800 horses available and could not achieve that (and my source for that is not Mike Williams site). 



> PS : You might want to add the 1.98ata climb rates into your climb rate comparison to keep the playing field even, also I can`t understand why the F4U4 climb figures you are showing are so much higher than every other Navy document shows.
> 
> Ie.
> 
> ...



I don’t know. While the data I referenced looks authentic and professional and states that it is flight test data (no tail numbers however), I have researched a lot and have not come up with support data for those values. Since I do not like depending on sole source data, especially when other data is available, I must withdraw my comments referencing F4U-4 climb rates.


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## davparlr (Nov 10, 2007)

AL Schlageter said:


> 24 April 1944
> 
> Flight Tests on the North American
> P-51B-5-NA Airplane, AAF No. 43-6883
> ...



Flight test of the P-51B in May ’44 with 150 gas shows a airspeed at SL of 374 mph. The number I gave before of 386 mph was on manufacturer estimates and is not as reliable as flight test.

http://www.wwiiaircraftperformance.org/mustang/eglin-p51b-level.jpg


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## davparlr (Nov 10, 2007)

Soren said:


> What a surprise, Mike William's site again - thought you guy knew better by now not to use his site as reference for German a/c performance.
> 
> The FW-190 Dora-9 has a climb rate of 4,400 ft/min, the Bf-109K-4 over 5,000 ft/min ! Even with the thin experimental DünblattSchraube the Bf-109 K-4 boasted a 4,800 ft/min climb rate!



As you know, I always insist on having the best data in my data base. All the numbers I showed on the Fw-190D-9 and airspeed for the Bf-109K were based on data you provided. Unfortunately, I do not have any data from you on climb for the Bf-109K, so the only data I could use was from Mike Williams site and this particular data (but not most at Mike’s site) may be a bit suspect. I would be glad to update my data base to better data if you could give it to me.



> PS: Have you got time to climb figures for the F4U-4 as-well ?? I'd like to see wether the F4U-4 is able even to beat the Dora-9 to 10km.



Unfortunately, I do not have this data. I will try to find some.



> And about your assumption on the RAF test-pilots, well thats all it is, an assumption.
> 
> Kurfürst and I have both provided more than enough evidence as proof that the British test-pilot flying the 109 didn't push it beyond the deployment of the slats.
> 
> ...



You haven't changed my mind. It is just inconsistent with the nature of flight test pilots. And my impression of British pilots is that they are a daring lot.


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## Crumpp (Nov 10, 2007)

> http://www.wwiiaircraftperformance.org/mustang/eglin-p51b-level.jpg



According to this graph, the data is recorded at an isobaric altitude in May 44. It is the pressure altitude and is not corrected for density. At higher altitudes our TAS increases as we factor in the SMOE. 

May is a high density alitude month generally speaking and the chart clearly states it is not corrected to STO.

_This means our airplanes level speed performance in this graph will be faster than it will be under STO._

All the best,

Crumpp


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## Crumpp (Nov 10, 2007)

These graphs represent performance of an aircraft using the manufacturer's data on the type in a standard atmosphere. All data was compiled and calculated under the NACA Standard Atmosphere of 1922 using KEAS so altitude conversion is not necessary. Altitude effects will shift the curve, changing the specific velocity in KTAS performance occurs but will not effect the shape or general conclusions.

Compressibility effects were applied adopting a standard of 200KTS and 10,000feet. Position error corrections were taken from the manufacturers supplied data along with IAS data.

Here is the maximum sustainable load factor for an FW-190A8 in clean configuration, overloaded fighter variant:






Here is the P51D in clean configuration, overloaded fighter variant:






At TO Weight, the FW-190A8 holds a slight advantage in Nzmax sustainable in the medium and low velocity realms. At higher velocity where the P51D becomes the faster aircraft, the P51D holds a slight advantage in Nzmax sustainable. Neither aircraft has an advantage that would be noticeable in the air. Pilot skill would make the difference.

What is clear is that these aircraft in like configuration are very much equals in sustained turning performance.

I have other configurations and aircraft types calculated too.

All the Best,

Crumpp


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## davparlr (Nov 11, 2007)

Crumpp said:


> According to this graph, the data is recorded at an isobaric altitude in May 44. It is the pressure altitude and is not corrected for density. At higher altitudes our TAS increases as we factor in the SMOE.
> 
> May is a high density alitude month generally speaking and the chart clearly states it is not corrected to STO.
> 
> ...



Several believable flight test show the P-51B was capable of SL speeds of over 370 mph to up 388 mph. Actually, I have to withdraw my previous comment about the 386 mph being a manufacturers speed when these show actual test results.

http://www.wwiiaircraftperformance.org/mustang/p-51b-24771-level-blue.jpg


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## FLYBOYJ (Nov 11, 2007)

Soren said:


> The British test-pilots (if not having experienced troubles with the slats on the Emil and therefore being concerned when testing later versions) had themselves heard nothing but bad news about the slats, seeing that a few Westlands crashed because of slat failure and that this had led o hem being locked shut in flight, given more than enough reason for British pilots to be vary about the slats.


Again Soren, you're assuming or imagining things - I challenge you to show any evidence that any Brit who flew Lysanders to be "vary" of the LE slats. They were locked down because of maintenance constraints and the aircraft performed well with or without them.

Off topic but for you Lysander fans...



_View: https://www.youtube.com/watch?v=CRYCx_G25ro_

Here's one being flown today - watch the clip, on take off and landing you could see the slats deploy. If these items were such a hazard, its amazing 60 years later they are being used on the last flying examples.


_View: https://www.youtube.com/watch?v=MGVebC2SJsM_


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## Glider (Nov 11, 2007)

Which reminded me, I should have thought of it earlier.


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## Crumpp (Nov 11, 2007)

> Several believable flight test show the P-51B was capable of SL speeds of over 370 mph to up 388 mph. Actually, I have to withdraw my previous comment about the 386 mph being a manufacturers speed when these show actual test results.



Certainly the performance is believable. All aircraft performance is a percentage range over a mean average. The manufacturer only reports the average and not the optimistic or pessimistic examples.

Without more information on this particular flight test it is simply impossible to make any conclusions.

However we can certainly conclude that North American was privy to all of the data on their own design when they reported the performance averages and percentage range to the USAAF.



> They were locked down because of maintenance constraints and the aircraft performed well with or without them.



Do you have proof that the slats where locked down? I find this very unusual as it would alter the handling and performance of the aircraft considerably. It would alter the design drastically.

All the best,

Crumpp


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## Crumpp (Nov 11, 2007)

Interesting system on the Lysander. It is a modification of Handley Page automatic slats:



> The last of the preflights are then completed before you sit down in the cockpit; this entails checking the inner slat movement-that the flaps are moving with them and that both sides move equally. The outer slats are aerodynamically actuated and are totally independent of the inner slats and of each other. The inner slats are also aerodynamically actuated but are linked so that they operate together. These inner slats also operate the flaps; when the slats deploy, the flaps are automatically extended.



Clandestine warrior Flight Journal - Find Articles

I look forward to the details on these slats being locked shut.

All the best,

Crumpp


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## FLYBOYJ (Nov 11, 2007)

Crumpp said:


> Do you have proof that the slats where locked down? I find this very unusual as it would alter the handling and performance of the aircraft considerably. It would alter the design drastically.
> 
> All the best,
> 
> Crumpp



I've been trying to find the source of the information regarding the disabling of the Lysander's LE slats, and if I remember right the article stated this involved Lysander I and IIs and it was done pretty early in its career. As far as disabling the system, I doubt it would do nothing but raise the stall and landing speed by a few knots - there have been many aircraft where because of modifications or problems in the field high lift devices were removed or disabled or limitations placed on flap settings.


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## FLYBOYJ (Nov 11, 2007)

Getting close - from the Canadain War Museum..

_*"When the serious fighting got going it was found to be impractical, as it was too big, too heavy and too vulnerable and needed massive support of fuel and mechanics. Lysanders were replaced by small light planes such as the Piper L-4 Cub."*_


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## drgondog (Nov 11, 2007)

davparlr said:


> The P-51D was introduced into the 8th AF in March ’44. The Bf-109K was introduced in November, ’44. Six months in WWII during this time was a generation of aircraft development. In the summer and fall of 1944, a whole family of aircraft with much greater performance over the mainstay of WWII aircraft, was introduced on both sides. These include Fw-190D-9, Bf-109K, F4U-4, P-47M/N, P-51F (later H), Ta-152H, and others.
> 
> 
> 
> ...


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## Soren (Nov 11, 2007)

By now its been solidly proven that the British test pilot did not push past slat deployment. He simply wasn't used to them and got concerned when they deployed therefore backing off the maneuver (Hence his comment). This was normal for green 109 pilots as explained by several LW aces. Furthermore this fully explains the results of the British comparative tests and why they are questioned by modern 109 pilots as-well. 

The slats also do way more than just lower the stall speed by a few knots, 10 knots wouldn't be unusual.


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## Crumpp (Nov 11, 2007)

> I doubt it would do nothing but raise the stall and landing speed by a few knots - there have been many aircraft where because of modifications or problems in the field high lift devices were removed or disabled or limitations placed on flap settings.



It will completely change the stall characteristics and most likely will make the aircraft's stall very dangerous.

Let me know when you find that source. Reason I ask is this will be the very first case I have found of such devices being disabled and the design continuing to operate. 



> there have been many aircraft where because of modifications or problems in the field high lift devices were removed or disabled or limitations placed on flap settings.



Any docmented examples? These are very much a part of the design. An engineer sets the design parameters to achieve specific design goals. Removing LE devices and TE devices will make certain performance goals unattainable. Things like safe controlled landings or stall characteristics that will not kill the pilot, for example.

As you know, coefficients of lift, drag, and angle of attack are connected in a fixed and finite relationship.

All the best,

Crumpp


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## FLYBOYJ (Nov 11, 2007)

Soren said:


> By now its been solidly proven that the British test pilot did not push past slat deployment. He simply wasn't used to them and got concerned when they deployed therefore backing off the maneuver (Hence his comment). This was normal for green 109 pilots as explained by several LW aces. Furthermore this fully explains the results of the British comparative tests and why they are questioned by modern 109 pilots as-well.


No Soren, I think what was shown here is the British had a firm understanding of leading edge slats and how they worked. If this British test pilot backed off a maneuver as alleged in this report, it wasn't out of fear of the system or the aircraft. 


Soren said:


> The slats also do way more than just lower the stall speed by a few knots, 10 knots wouldn't be unusual.


So you're landing at 76 rather than 65 mph....


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## DerAdlerIstGelandet (Nov 11, 2007)

Soren said:


> By now its been solidly proven that the British test pilot did not push past slat deployment.



Soren I am not going to take sides in the arguement. You do however state that this is has been proven solid. Please post solid facts and sources to these facts please.


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## FLYBOYJ (Nov 11, 2007)

Crumpp said:


> Any docmented examples? These are very much a part of the design. An engineer sets the design parameters to achieve specific design goals. Removing LE devices and TE devices will make certain performance goals unattainable. Things like safe controlled landings for example.
> 
> As you know, coefficients of lift, drag, and angle of attack are connected in a fixed and finite relationship.
> 
> ...



Off the top of my head in some Cessna 172s, 182s, the max flap extension was raised from 40 degrees to 30 degrees because of the possibility of "washing out the elevators in a slip." I also know that on the C-17 you could place the aircraft in an "Abnormal Configuration" with regards to LE slat and flap settings.

I've also seen 707s and DC-8s with limited or disabled slat/ slot/ flap systems flown during maintenance ferry flights.....


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## FLYBOYJ (Nov 11, 2007)

Found it - way off topic but this References the -1 TO where a C-17 can be flown outside the normal Flap/ slat configurations...

Abnormal Configuration


(Ref: TO 1C-17A-1 and TO 1C-17A-1-1) 



A. C-17A-1-1 Restrictions: (TO 1C-17A-1-1, Paragraph 9-131)

*Actual slat positions are determined used for performance planning

1. CAUTION: With slats retracted, do not use flap settings greater than 20º. Higher flap settings may result in a nose-down approach attitude which could result in nose gear failure at touchdown

a. The flap settings in the C-17 provide the most efficient flap setting for gross weight, CG and ambient conditions which reduce the approach speed in order to give added short field landing capabilities

b. Certain combinations are limited to 5.5º nose-high for forward visibility (unconfirmed source)

2. Some of the approach speeds for abnormal flap/slat configurations appear much higher in order to keep the pitch angle below the 5.5º nose-high limit (unconfirmed source)

3. 20º of flap extension is the maximum if the slats are retracted in order to keep the nose high enough so as not to hit the nose wheel first. Additional flap extension would permit lower approach speeds but would also lower the nose excessively at touchdown (unconfirmed source) 



B. CAUTION: With abnormal configuration procedures, use of the AFCS (F/D, AP and ATS) is not recommended because alpha speeds will be incorrect and may not provide adequate margin from stall under abnormal flap/slat conditions. (TO 1C-17A-1, 3-184) 



C. Each Spoiler Control/Electric Flap Control (SC/EFC) has an Analog Backup Unit (ABU) that will provide for flap retraction but not extension if the SC/EFC digital function should fail. If a flap asymmetry is evident, the SC/EFC will lock the flaps when a variance of 4.8º develops (3-185) 


1. If dual SC/EFC failure has occurred and the flaps are being retracted through the use of the flap ABU, the allowable variance will be 7º before the flaps lock

2. Once the ABU engages in flight because it senses a variance of > 7º, it remains engaged

3. Attempt an EFCS reset (will reset if SC/EFC failure is cause of problem)

If this doesn’t clear problem, flaps are locked in place by mechanical jam or hyd problem 
If flaps are extended, slats will not retract 
Perform ASYMMETRIC FLAPS OR NO FLAP LANDING WITH SLATS checklist 



D. Additional Considerations: 



If aircraft control is not an immediate concern, the aircraft commander should perform the checklist to calculate the data, review the procedure, and make pertinent decisions on landing gross weight and divert options


If touchdown speed exceeds 182 knots GS, consider further weight reductions


Time, fuel and weather permitting, practice the approach while planning a go-around no lower than 500' AGL so as to observe handling qualities


Fly the approach with a slightly wider downwind and longer final approach than a normal pattern requires


Complete normal landing checklists


Fly using frontside approach characteristics (Pitch = GS, Throttles = Speed)


Normal (3° or less) glide path


Do not flare


Use brakes as required


Use immediate and maximum available reverse thrust


Wx mins 300’/ ¾ SM due to faulty Flight Director


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## Crumpp (Nov 11, 2007)

> *Abnormal Configuration*





> If this doesn’t clear problem,





> *If aircraft control is not an immediate concern*





> If touchdown speed exceeds 182 knots GS, _consider further weight reductions_





> *Fly using frontside approach characteristics (Pitch = GS, Throttles = Speed)*





> Use immediate and maximum available reverse thrust



Certainly the USAF includes emergency procedures in the event of a mechanical failure.

That is not the same thing as a design purposely having the slats fixed and then continuing to be operated.

All the best,

Crumpp


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## Crumpp (Nov 11, 2007)

> Off the top of my head in some Cessna 172s, 182s, the max flap extension was raised from 40 degrees to 30 degrees because of the possibility of "washing out the elevators in a slip."



TE flaps are being reduced. Not the same thing as LE slats being disabled for normal operation. Lets clear up the confusion here. I did not catch you refered to TE devices. Different characteristics and I would have specified so had I caught this.

There are many designs that do not have any flaps at all that operate safely. The point is however, that a design with LE devices cannot have the LE devices safely disabled and continue normal operations. The LE devices are there to achieve a design performance goal.



> I've also seen 707s and DC-8s with limited or disabled slat/ slot/ flap systems flown *during maintenance ferry flights.....*



Certainly, they were being flown to a location in order to be fixed. Again not the same thing as being disabled for normal operation.

All the best,

Crumpp


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## FLYBOYJ (Nov 11, 2007)

But the bottom line the aircraft shown can be flown and were flown under certain conditions and it would not be unreasonable to believe that in a combat situation and in a foward combat area an aircraft like the Lysander would operate with its LE slats closed due to maintenance limitations...

BTW I'm still searching for the article about the Lysander's LE slats being disabled....


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## Kurfürst (Nov 11, 2007)

davparlr said:


> I got the info from this site which looks authentic including the identification of the aircraft number. In addition, two other sources I have and trust agree to the data shown in this flight test. The P-51D shows 375 mph at SL using about 1630 hp. I think my comments are good.
> 
> http://www.wwiiaircraftperformance.org/mustang/p51d-15342-level.jpg



Please see below. 



davparlr said:


> The P-51D was introduced into the 8th AF in March ’44. The Bf-109K was introduced in November, ’44.



I am afraid this is incorrect, I trust Bill on this, and practically all publications I`ve seen say June 1944 for the P-51D as an introduction date.

The 109K was introduced in during October, units received it in huge numbers already that month (some 200 were around, even though some were wrecked during refit). It was certainly in combat by the start of November since the first combat loss is known from 2 November 1944.

So, if you want to keep the playing field truely even, you need to find the first date by which at least 200 P-51Ds were in service with first line units, and, they suffered losses in combat. For the 109K, it`s November 2, even though it was in production since August 1944. 

To me a couple of months seems rather indifferent, and, there were plenty of 'interim' aircraft produced since early 1944 which ensured the 109K`s absance until October 1944 was not really felt - the K itself offered mostly just cleaner lines and more importantly, a standardized airframe with rationalized internal arrangements.



davparlr said:


> Six months in WWII during this time was a generation of aircraft development. In the summer and fall of 1944, a whole family of aircraft with much greater performance over the mainstay of WWII aircraft, was introduced on both sides. These include Fw-190D-9, Bf-109K, F4U-4, P-47M/N, P-51F (later H), Ta-152H, and others.



I think the 51F wasn`t introduced at all, or the p51H for that matter in the second half of 1944. I`d suggest you check out the new models of 109G that were introduced in the first half of 1944, especially the /AS types with methanol. By all accounts, these were excellent aircraft, and very close to the 109K in performance, albeit some 20 km/h slower due to their less clean airframes. Nevertheless, they stepped in for the 109K and DB605D since March 1944 as an interim solution.



davparlr said:


> The XP-51F, the predecessor of the H, flew in Feb. 44. Unlike Germany, who was desperate to stop the hordes of P-51s, P-47s, B-17s, B-24s, and Brit planes, with advanced aircraft, the US, whose aircraft performance was adequate and the quantity was overwhelming, did not expedite new models. Had the need arose, there is no doubt that a P-51H or the similar P-51F could have been available in the fall of ’44.



There`s much speculation in this and grossly underestimates development problems. Germany, _who was desperate to stop the hordes of P-51s, P-47s, B-17s, B-24s, and Brit planes, with advanced aircraft, _ as you say, was developing the 109K since _March 1943_. How much easy it would have been for them to have it, one may say, by late 1943...? It`s certainly very easy to say - but in It took them until late 1944 until it actually arrive at the units, and it was far less radical departure from the existing G-airframes. Not to mention, that to my best knowledge, the F-series Mustang, as hot their spec are, are essentially experiemental aircraft that toyed with the idea of lowering airframe stress limits and weight in favour for higher performance. Apart from it never been realized in this form, it`s also questionable how much use such lightly stressed aircraft would be operationally, how many potential problems would be needed to be solved with the airframe and engine before it would be combat ready, how long it would take factories to re-tool etc.

I don`t like such speculations, and after all, the facts are on the table, we know how it was, anything else is a swamp of guesswork, riddled with dangerous intellectual traps every step. The 51F did not become an operational type just and the P-51H, which just missed the war, eventually did not produce the very impressive performance figures originally expected and calculated for it. 



davparlr said:


> My multiple sources show that the P-51D was capable of 375 mph at SL at about 1640 hp.



Individual aircraft performance of course, differ from plane to plane, and it especially seems to be true w the Mustang. 

I prefer this one for the P-51D Performance since it notes that _'the data presented represent good agreement with most of the flight test results'._ It`s probably a good middle-value.

It shows 368 mph at SL, and I presume the wingracks are missing (I could be wrong), which chopped some 12 mph off from top speed and were std fitting. With them it would do about* 356 mph*, and there`s also a test with the RAF`s TK 589 which I have which had 354mph at SL (w. racks).

The one you shown, with 375 mph claimed at SL at the same rating of 67", from June 1945, is very much higher than that. I can only guess why - perhaps an exceptionally good aircraft was tested, and/or it was polished and had special surface treatment. But I doubt it`s normal (and so do even North American, see above), it`s probably the best figure around.



> The Bf-109K had 1800 horses available and could not achieve that (and my source for that is not Mike Williams site).



The 109K had 1800 PS in it`s earliest engine that was not fitted to too many aircraft though, or 1850 or 2000 PS. With the two latter ratings, it was officially rated at 370mph and 377 mph respectively, and some 8 mph if polishing was applied. 

And of course, as in the case of the Mustang, there were worser and better planes. The tolerance was usually 3%, so theoretically you could have a production 109K anywhere between 360 mph (a plane w. the lowest rating, so badly built it just passed acceptance tests) and ~395 mph (a plane with the highest rating, with exceptionally good finish, polished by the loving groundcrew).



> I don’t know. While the data I referenced looks authentic and professional and states that it is flight test data (no tail numbers however), I have researched a lot and have not come up with support data for those values. Since I do not like depending on sole source data, especially when other data is available, I must withdraw my comments referencing F4U-4 climb rates.



That`s what puzzles me. I have seen half a dozen set of data for the the F4U4, and none of them agree. It seems they were continously revised, for some reason.



> Unfortunately, I do not have any data from you on climb for the Bf-109K, so the only data I could use was from Mike Williams site and this particular data (but not most at Mike’s site) may be a bit suspect. I would be glad to update my data base to better data if you could give it to me.



You may find this kind of climb rate data (copies of the original papers) on my site, for both 1,8 and 1,98ata. Mike used to have 1,98ata performance displayed, ableit barely visibly on some previous version of his controversial comparison articles, but appearantly he couldn`t bear it even being there so he removed it a while ago. It seems some of his current values for the K-4 at 1.8ata are in fact taken from the K-6 heavy fighter.

In any case you can view the whole thing on my site, here : Kurfürst - Performance of 8 - 109 K4 and K6 with DB 605 ASCM/DCM This is the only thing, I dare say, most if not all of us aircraft geeks have on 109K performance.


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## Crumpp (Nov 11, 2007)

> But the bottom line the aircraft shown can be flown and were flown under certain conditions and it would not be unreasonable to believe that in a combat situation and in a foward combat area an aircraft like the Lysander would operate with its LE slats closed due to maintenance limitations...



For a single incident on a one time maintenance flight to be repaired. Maybe...

As for continuing normal operations, no way.

Nothing you have shown has any aircraft continuing to operate normally.



> I've also seen 707s and DC-8s with limited or disabled slat/ slot/ flap systems flown during maintenance ferry flights.....



Do you know for a fact the LE slats were disabled on these?

You are pilot correct? Have you made many frontside curve approaches? 


All the best,

Crumpp


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## FLYBOYJ (Nov 11, 2007)

Crumpp said:


> For a single incident on a one time maintenance flight to be repaired. Maybe...
> 
> As for continuing normal operations, no way.
> 
> Nothing you have shown has any aircraft continuing to operate normally.



From an earlier post - ironically it was another Westland Product..







Page 47 of 'Whirlwind' by Victor Bingham-1987


Crumpp said:


> Do you know for a fact the LE slats were disabled on these?


Yes, ferry flights out of Mojave Ca on aircraft removed from storage. Not the norm however.....



Crumpp said:


> You are pilot correct? Have you made many frontside curve approaches?


If you want to include short field landings in a Super Cub!?!?


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## Soren (Nov 11, 2007)

Crumpp,

What would the sustained load factor be for the Fw-190 A-5 by comparison to the A-8 ?


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## Crumpp (Nov 11, 2007)

> If you want to include short field landings in a Super Cub!?!?



You can't be on the frontside of the curve in a Super Cub and make a short flield landing. You would be dead.

You are probably confusing terms here as I do not doubt your experience in a Cub.



> Page 47 of 'Whirlwind' by Victor Bingham-1987



That would be a first. As it is this second hand information and not a primary source, I would be interested in seeing the Boscume Down reports. It would not be the first time a secondary source is wrong in it's conclusions.

All the best,

Crumpp


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## FLYBOYJ (Nov 11, 2007)

Crumpp said:


> You can't be on the frontside of the curve in a Super Cub and make a short flield landing. You would be dead.
> 
> You are probably confusing terms here as I do not doubt your experience in a Cub.


 I take your term as being on the front side of the curve as having both power and airspeed in a landing configuration....


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## Crumpp (Nov 11, 2007)

> What would the sustained load factor be for the Fw-190 A-5 by comparison to the A-8 ?



It is worse than the FW-190A8's. 

The P51D has a slight advantage over the FW-190A5 throughout the envelope.

Nzmax is a direct reflection of Power Available to Power Required. The FW-190A8 has a better P/W ratio than the FW-190A5.

FW-190A5 Take Off Weight as per Ladeplan for an overloaded clean configuration fighter:







> I take your term as being on the front side of the curve as having both power and airspeed in a landing configuration....



We are confusing terms here. 

The front side of the power curve refers to the portion of the flight envelope where throttle controls airspeed and elevator controls altitude. We can only use the term "power curve" when referring to propeller aircraft.

This is also called the region of normal command. In this portion if we go slower, it requires less thrust and to go faster requires more thrust. Think of operating the aircraft at speeds at or faster than maximum range cruise or L/Dmax.

You can see why landing of the front side of the power curve is not normal or safe. You can also see why the C-17 manual calls for maximum braking and reverse thrust ASAP.

The backside of the power curve is the portion where throttle controls altitude and elevator controls airspeed such as landing.

This is also called the Region of reversed command. If for any reason, the aircraft is slowed down, more thrust is required to maintain altitude. Here going slower requires more thrust and going faster less thrust. Notice on landing that reducing thrust causes our sink rate to increase. Sink rate is velocity. The airplane needs this speed to remain aloft. However it takes a large amount of power to maintain level flight at approach speeds. 

Because propeller aircraft are not thrust limited at low velocity, they can lead pilots to the wrong conclusions about what is going on with aircraft.

All the best,

Crumpp


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## delcyros (Nov 11, 2007)

I think this has been a good discussion so far. And my estimation is that we all have learned a bit.

Good work Crumpp for providing us with an approach to sustained turning rates free from personal objection. I hope You stay with us.

I think Glider, Kurfürst and others have pointed us to a very important constraint: typical performance vs. best (or for that matter...worst) aircraft performance.
There are a lot of first hand sources in those webpages, and selective perception may happen on all sides.

Thanks also to Drdondog, You are a wealth of information!


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## FLYBOYJ (Nov 11, 2007)

Crumpp said:


> We are confusing terms here.
> 
> The front side of the power curve refers to the portion of the flight envelope where throttle controls airspeed and elevator controls altitude. We can only use the term "power curve" when referring to propeller aircraft.
> 
> ...




Ok - I think I Gotcha - you're on final (say in a cub, no wind) nose high and using power to control pitch - if you lack the airspeed, you drop, if you lack the power you drop BUT if you had altitude you could lower the nose to pick up that precious airspeed without increasing power - am I understanding?


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## Soren (Nov 11, 2007)

Thank you Crumpp, but is that with the A-5 running at 1.65ata ?

The A-5 weighed in at 4,100 kg and the A-8 4,300 kg, correct ?

PS: The LW deployed a light version of the A-7 with MW-50, how would that compare ?


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## Crumpp (Nov 11, 2007)

> Ok - I think I Gotcha - you're on final (say in a cub, no wind) nose high and using power to control pitch - if you lack the airspeed, you drop, if you lack the power you drop BUT if you had altitude you could lower the nose to pick up that precious airspeed without increasing power - am I understanding?



Hi FlyboyJ,

In this example you are on the backside of the power curve. You are using elevator to control airspeed and throttle to control sink rate.

That is a clear indicator you are on the backside.



> Thank you Crumpp, but is that with the A-5 running at 1.65ata ?



Hi Soren,

No it is normal fighter variant. There were not any fighter variants that used 1.65ata in any form for the FW-190A5.



> The A-5 weighed in at 4,100 kg and the A-8 4,300 kg, correct ?



FW-190A8 - 4272Kg
FW-190A5 - 4106Kg



> The LW deployed a light version of the A-7 with MW-50, how would that compare ?
> Today 04:49 PM



I am not aware of this variant and none of Focke Wulfs documentation show such a variant.

MW-50 was used in the H and S series engines. Very late in the war it possibly was used in the BMW801D2 series. Alkohol-Einsptrizung systems produced less power and required the additional weight of the tank over other systems used by BMW.

All the best,

Crumpp


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## FLYBOYJ (Nov 11, 2007)

Crumpp said:


> Hi FlyboyJ,
> 
> In this example you are on the backside of the power curve. You are using elevator to control airspeed and throttle to control sink rate.
> 
> That is a clear indicator you are on the backside.




Now I gotcha!

Sorry to go off topic guys......


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## Crumpp (Nov 11, 2007)

> I think Glider, Kurfürst and others have pointed us to a very important constraint: typical performance vs. best (or for that matter...worst) aircraft performance.



Thank you, delcyros. I enjoy these discussions with mature individuals.

I agree that typical performance is very important. 

All the best,

Crumpp


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## renrich (Nov 11, 2007)

My reference show the P51 D with a sea level vmax of 367 mph, the P51B was slightly faster at SL. The F4U 4 was fastest of all at SL(US fighters) with Vmax of 380 mph. Same reference shows the P51D is introduced into the 8th AF in March of 1944. Same reference shows F4U4 could climb to 20000 ft in 6.8 minutes. Another reference shows the FW190D9 took 7min 6sec to climb to 19685 ft. The F4U4 was a significantly better climber.


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## FLYBOYJ (Nov 11, 2007)

Crumpp said:


> Hi FlyboyJ,
> 
> In this example you are on the backside of the power curve. You are using elevator to control airspeed and throttle to control sink rate.
> 
> That is a clear indicator you are on the backside.



Hey Crumpp;

In answering your original question about this - I've flown L-29s and on landing you are controlling sink rate with elevator because of the spool-up time of the engine and because of a very long flare if you do come in with power at that point you rely on the speed brake providing you're not on a short field...

OK guys, again sorry for going off topic....


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## Glider (Nov 11, 2007)

Personally I enjoyed it and continue to learn something in most threads


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## DerAdlerIstGelandet (Nov 11, 2007)

FLYBOYJ said:


> OK guys, again sorry for going off topic....




Hey Joe you know you dont have to apologize. It is a good and informative side discussion. I think everyone can gain from it as well.


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## Soren (Nov 11, 2007)

I know you're more knowledgable about the FW-190 than me Crumpp, but I have a leistung chart for the A-5 using C3 to run at 1.58/1.65ata. I'm sure you know which one I'm talking about.

Running on C3 at 1.58/1.65ata the power of the BMW-801D2 is 2,050 PS right ? So running at 1.58/1.65ata and weighing nearly 300kg less than the A-8 the A-5 should have a higher sustained load factor ?

As to the light version of the A-7, I remember reading about it as simply being a normal A-7 being lightened by the groundcrew (Removing the outer MG-151/20's etc.) and meant for use as a fighter interceptor, ei. meant to fight the Allied escorts.


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## drgondog (Nov 11, 2007)

Kurfürst said:


> Please see below.
> 
> 
> 
> ...



True


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## Crumpp (Nov 11, 2007)

> I know you're more knowledgable about the FW-190 than me Crumpp, but I have a leistung chart for the A-5 using C3 to run at 1.58/1.65ata. I'm sure you know which one I'm talking about.



Hi Soren,

Thank you for the compliment.

Yes I have that report. The airframe is an FW-190A5 as is the WNr but that is where the similarity ends with a production FW-190A5.

That airframe is one of several airframes Focke Wulf used for factory testing. The engine is being tested with a ladedruckerhöhung and not C-3 Einspritzung. To achieve this simple manifold pressure increase, the engine required stronger pistons from the BMW801F series, a larger capacity fuel pump, lines/valve tapping into the manifold pressure regulator, Plugs, changes to the electrical system, and a new vorstellgetriebe to take advantage of the power gains.

None of these were available during the FW190A5 series production runs and there was no retrofit kit. However all serial production BMW801D2's came with the modifications as standard in June 1944. Until then only FW-190A8 production saw the modifications. So any surviving FW-190A5 airframe needing an engine after June of 1944, would have to have the new motor as a replacement or find old stock somewhere. This also means a completely new cowling, wiring harness, and other modifications. As the FW-190A5 did not have a universal harness I would think that Focke Wulf's airframe restoration program would be the only feasible way to receive a new engine with the modification. Of course this would mean it was rebuilt by the factory as an FW-190A8.

All the Best,

Crumpp


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## Crumpp (Nov 11, 2007)

> (Removing the outer MG-151/20's etc.) and meant for use as a fighter interceptor, ei. meant to fight the Allied escorts.



There is no noticeable difference in performance between a fighter with full wing armament and one with the outboard weapons removed.

This is why Focke Wulf discontinued manufacturing the fighter variant FW-190A series without the outboard weapons.

All the best,

Crumpp


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## Crumpp (Nov 11, 2007)

> In answering your original question about this - I've flown L-29s and on landing you are controlling sink rate with elevator because of the spool-up time of the engine and because of a very long flare if you do come in with power at that point you rely on the speed brake providing you're not on a short field...
> 
> OK guys, again sorry for going off topic....



Many of the early jets had to use this technique. That is why your choice of early jet operational airfields was limited.

Key part of your post is "at that point you rely on the speed brake". 

All the best,

Crumpp


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## Soren (Nov 11, 2007)

Thank you for the explanation Crumpp.

Now would it be possible for me to ask you to post the sustained load factors for the Bf-109K-4 (1.98ata) Fw-190 Dora-9 ?

Thanks in advance


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## drgondog (Nov 11, 2007)

renrich said:


> My reference show the P51 D with a sea level vmax of 367 mph, the P51B was slightly faster at SL. The F4U 4 was fastest of all at SL(US fighters) with Vmax of 380 mph. Same reference shows the P51D is introduced into the 8th AF in March of 1944. Same reference shows F4U4 could climb to 20000 ft in 6.8 minutes. Another reference shows the FW190D9 took 7min 6sec to climb to 19685 ft. The F4U4 was a significantly better climber.



Renrich - even if the phrase 'introduced' means someone in 8th AF was able to see one, perhaps the 51D delivered to RAF for testing, it would be tough to project as the first P-51D rolled off the production line in 'late March' according to Ray Wagner in "Mustang Designer". Gruenhagen talks about 'deliveries of P-51D in March' with no context.

The rule of thumb for the delivery to USAAF from factory to operational deployment at the squadron level was 6 weeks so Mid May would be an optimistic '1st mission' and early June (matching 355th and 4th experience) would sound right?

I have not yet heard back from Ted Damick but he is THE authority on 8th AF aircraft and data..

Regards,

Bill


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## Crumpp (Nov 11, 2007)

> Now would it be possible for me to ask you to post the sustained load factors for the Bf-109K-4 (1.98ata) Fw-190 Dora-9 ?



The Spreadsheet is not designed to compare different aircraft but rather the same aircraft under different configurations. I made it for an advanced aircraft performance class.

It takes time to convert it from one aircraft type to another so give it a few days. It took an hour to convert to the FW-190D series.

So far I have the Zeke 52, Spitfire, P47, P51, and FW190 series done. I will have to add the Bf-109 to it.

All the best,

Crumpp


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## davparlr (Nov 11, 2007)

Kurfürst said:


> I am afraid this is incorrect, I trust Bill on this, and practically all publications I`ve seen say June 1944 for the P-51D as an introduction date.



Two sources I have reference initial production delivery of March, 1944. “American Combat Planes” by Ray Wagner, and “America’s Hundred Thousand” by Francis Dean, which states that the P-51D was introduced to the 8th AF. This last reference does state that the P-51D was delivered to the 8th AF in quantity in June, 1944. 



> The 109K was introduced in during October, units received it in huge numbers already that month (some 200 were around, even though some were wrecked during refit). It was certainly in combat by the start of November since the first combat loss is known from 2 November 1944.



My reference states that the 109K appeared in November, 1944. The reference is excellent, but I think the difference is semantics.



> So, if you want to keep the playing field truely even, you need to find the first date by which at least 200 P-51Ds were in service with first line units, and, they suffered losses in combat. For the 109K, it`s November 2, even though it was in production since August 1944.



I disagree. The proper indication of when aircraft development cycle is complete, which is what we are discussing, is the date of the first production unit, in this case, March ’44 for the P-51D, and October ’44, for the 109K. To be really fair, since the major changes of the P-51D over the P-51B is a bubble canopy and two added guns, you really have to go back to May, 1943, when the first production P-51B appeared, to get the right design genealogy. The 109K traces directly back to the G-10 (AS?) according to my reference. I have no reference (including your site) that references the production date of the G-10, except your reference of early ’44. If you have a more precise date of production start, I would like to see it. I didn’t trace the lineage to the G-6 as explained in the following paragraph. In any event, this would be a six to nine month difference.



> To me a couple of months seems rather indifferent, and, there were plenty of 'interim' aircraft produced since early 1944 which ensured the 109K`s absance until October 1944 was not really felt - the K itself offered mostly just cleaner lines and more importantly, a standardized airframe with rationalized internal arrangements.



There appears to be a major redesign of the Bf-109 from the G-6 through the G-10 to the K. This is manifested in almost a 900 lb reduction in empty weight (6050 lbs vs. 5161 lbs). This is not a “just cleaner lines” redesign of the G-6. This is why I did not go back to the G-6.




> I think the 51F wasn`t introduced at all, or the p51H for that matter in the second half of 1944. I`d suggest you check out the new models of 109G that were introduced in the first half of 1944, especially the /AS types with methanol. By all accounts, these were excellent aircraft, and very close to the 109K in performance, albeit some 20 km/h slower due to their less clean airframes. Nevertheless, they stepped in for the 109K and DB605D since March 1944 as an interim solution.



You are correct on the 51F as it was really a XP-51F, but it and the “G” incorporated the major changes implemented in the H. Since the changes to the P-51 were in the same scope as the Bf-109G-10 (including the reduction in airframe weight including reduction in armament (two gun on the G-10?)) and the same time frame (early ’44), it is indeed reasonable that the very capable North American engineers could have fielded a viable aircraft by October ’44. After all, they were able to take the highly advanced new design P-51 from drawing board to first flight in only few months. In reality, the Bf-109K was to the Bf-109G-6 as the P-51H was to the P-51D. Airframe was lightened and ammo and fuel reduced and bigger engine installed (did the Bf-109H only have two guns like the G-10?). In addition, the changes were in same time frame; the only difference was that the pressure to replace the P-51D was small. A fair comparison is the Bf-109K to the P-51H.




> There`s much speculation in this and grossly underestimates development problems. Germany, who was desperate to stop the hordes of P-51s, P-47s, B-17s, B-24s, and Brit planes, with advanced aircraft, as you say, was developing the 109K since March 1943. How much easy it would have been for them to have it, one may say, by late 1943...? It`s certainly very easy to say - but in It took them until late 1944 until it actually arrive at the units, and it was far less radical departure from the existing G-airframes.



Not true. There was a 889 lb reduction in empty weight from the G-6 to the K. There was only a 540lb reduction between the P-51D and P-51H. Which one was more radical?




> Not to mention, that to my best knowledge, the F-series Mustang, as hot their spec are, are essentially experiemental aircraft that toyed with the idea of lowering airframe stress limits and weight in favour for higher performance. Apart from it never been realized in this form, it`s also questionable how much use such lightly stressed aircraft would be operationally, how many potential problems would be needed to be solved with the airframe and engine before it would be combat ready, how long it would take factories to re-tool etc.



The weight reduction was to reduce what the British considered over-design of the P-51D by incorporating the design loads of the Spitfire. To my knowledge, there was no complaint about the Spitfire being too lightly stressed to be an effective fighter. Remember the Bf-109G-6 lost more weight than the P-51D did.



> I don`t like such speculations, and after all, the facts are on the table, we know how it was, anything else is a swamp of guesswork, riddled with dangerous intellectual traps every step. The 51F did not become an operational type just and the P-51H, which just missed the war, eventually did not produce the very impressive performance figures originally expected and calculated for it.



I don’t think test results support this statement



> Individual aircraft performance of course, differ from plane to plane, and it especially seems to be true w the Mustang.



I don’t think this is exceptional. There certainly is more information available over a wider time frame on the P-51 performance than for German designs.



> I prefer this one for the P-51D Performance since it notes that 'the data presented represent good agreement with most of the flight test results'. It`s probably a good middle-value.
> 
> It shows 368 mph at SL, and I presume the wingracks are missing (I could be wrong), which chopped some 12 mph off from top speed and were std fitting. With them it would do about 356 mph, and there`s also a test with the RAF`s TK 589 which I have which had 354mph at SL (w. racks).



I'll accept 368 mph. 




> The one you shown, with 375 mph claimed at SL at the same rating of 67", from June 1945, is very much higher than that. I can only guess why - perhaps an exceptionally good aircraft was tested, and/or it was polished and had special surface treatment. But I doubt it`s normal (and so do even North American, see above), it`s probably the best figure around.



The associated write up on the test indicated one wing rack per wing was included in the “clean” design (remember, you were assuming the wing racks were missing). While no modifications were mentioned regarding making it more slick, I wouldn’t be surprised if gaps were filled, gun ports covered and maybe some wax. I would be surprised if the German test were not performed with similar modifications.




> The 109K had 1800 PS in it`s earliest engine that was not fitted to too many aircraft though, or 1850 or 2000 PS. With the two latter ratings, it was officially rated at 370mph and 377 mph respectively, and some 8 mph if polishing was applied.



So, you are saying that the 109K, generating roughly 200 hp to 350 hp more than the P-51D (remember the P-51D engine is generating 1630 hp at 67”), can only eke out 2 to 9 mph more (using your figure for the P-51, no racks). By the way, did the 109K have wing racks on during the test? Doesn't this basically proves my point.



> And of course, as in the case of the Mustang, there were worser and better planes. The tolerance was usually 3%, so theoretically you could have a production 109K anywhere between 360 mph (a plane w. the lowest rating, so badly built it just passed acceptance tests) and ~395 mph (a plane with the highest rating, with exceptionally good finish, polished by the loving groundcrew).



You seem to assign the P-51D data to the highest of the variance (your original argument was that it was the norm) and the Bf-109K to the norm of the data, when, it seems, you only have one point of data to work with on the 109K. I don’t think this is a statically valid assumption. It could very easily be the top of the performance range.





> In any case you can view the whole thing on my site, here : Kurfürst - Performance of 8 - 109 K4 and K6 with DB 605 ASCM/DCM This is the only thing, I dare say, most if not all of us aircraft geeks have on 109K performance.



Thanks for the site. I will get busy trying to interpret charts and convert metrics and update my data base.


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## Soren (Nov 12, 2007)

Crumpp said:


> The Spreadsheet is not designed to compare different aircraft but rather the same aircraft under different configurations. I made it for an advanced aircraft performance class.
> 
> It takes time to convert it from one aircraft type to another so give it a few days. It took an hour to convert to the FW-190D series.
> 
> ...



Can you post the work you've finished so far ? Would be really interesting


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## Glider (Nov 12, 2007)

Soren said:


> Can you post the work you've finished so far ? Would be really interesting



Can I second that request please.


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## renrich (Nov 12, 2007)

Bill, Sorry for my misleading post about P51D deployment. I should have looked further. I am glad to see that Dav has what I consider as a thorough and comprehensive reference on US WW2 fighters, "America's One Hundred Thousand" and it states the June 1944 date as to when P51Ds began to reach the 8th AF in quantity.


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## Crumpp (Nov 12, 2007)

Here is the FW-190D9 using B4 and the Oldenburg system, clean configuration overloaded fighter at Take Off Weight:






Here is the FW-190D9 using C3 and MW50, clean configuration, overloaded fighter at Take Off Weight:






Here is the P47D-22 at _Combat Weight_ = 60% fuel remaining at overloaded clean fighter configuration:






Here is the FW190A8 at Combat Weight for a clean configuration overloaded fighter:






Here is the FW-190A8 at Take Off Weight, Overloaded fighter with ETC 501 rack and 115 Liter Auxillary Tank/propeller weights:






Here is the Zeke 52 at Take Off weight:






All the best,

Crumpp


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## drgondog (Nov 12, 2007)

Dave - the first P-51D-5, 44-13260, was the 7th Mustang off the Production line and reached the 4th FG on June 2. The 44-13300 was badly damaged by flak on June 7 and salvaged after Belly Landing at Manston (Goodson)

44-13305, 279, 302 were delivered to 355FG on June 5 but did not fly ops until June 8.

The 44-13260 was the 8th P51D-5 manufactured t Inglewood and so far I have not been able to find a -5 between 260 and 279 assigned to 8th AF. The block starting with 300 all the way through 900 were largely devoted to 8th and 15th AF. The fact that I can't yet find an earlier delivery than June 2nd does NOT mean it didn't happen - just that I can't find an occurance yet.

Ted is researching when the first D's came to Britain and into 8th AF Depots for 'combat mods - radios, etc). I also don't know if they (the first) came by surface transport or flown in by Ferry Pilots. 

Regards,

Bill


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## FLYBOYJ (Nov 12, 2007)

davparlr said:


> I disagree. The proper indication of when aircraft development cycle is complete, which is what we are discussing, is the date of the first production unit, in this case, March ’44 for the P-51D, and October ’44, for the 109K. To be really fair, since the major changes of the P-51D over the P-51B is a bubble canopy and two added guns, you really have to go back to May, 1943, when the first production P-51B appeared, to get the right design genealogy. The 109K traces directly back to the G-10 (AS?) according to my reference. I have no reference (including your site) that references the production date of the G-10, except your reference of early ’44. If you have a more precise date of production start, I would like to see it. I didn’t trace the lineage to the G-6 as explained in the following paragraph. In any event, this would be a six to nine month difference.


Just a note; I remember reading somewhere that there were late model P-51Bs and Cs (Dallas Built) that had a field conversion where the bubble canopy (Not a Malcolm Hood) was installed in the field basically making them "Ds." If I remember correctly these aircraft along with the first production "Ds" did not have the dorsal fin just in front of the vertical stabilizer. T.O. 01-60J-18 installed the dorsal fin.


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## AL Schlageter (Nov 12, 2007)

FLYBOYJ said:


> Just a note; I remember reading somewhere that there were late model P-51Bs and Cs (Dallas Built) that had a field conversion where the bubble canopy (Not a Malcolm Hood) was installed in the field basically making them "Ds." If I remember correctly these aircraft along with the first production "Ds" did not have the dorsal fin just in front of the vertical stabilizer. T.O. 01-60J-18 installed the dorsal fin.


That would be some field conversion.


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## drgondog (Nov 12, 2007)

FLYBOYJ said:


> Just a note; I remember reading somewhere that there were late model P-51Bs and Cs (Dallas Built) that had a field conversion where the bubble canopy (Not a Malcolm Hood) was installed in the field basically making them "Ds." If I remember correctly these aircraft along with the first production "Ds" did not have the dorsal fin just in front of the vertical stabilizer. T.O. 01-60J-18 installed the dorsal fin.



The very first two (and only)P-51D-1s were 42-106539 and 106540 - both P-51B-10s from California. Both kept the 51B wing intact whereas the subsequent P-51D-5 had neither the 'dorsal' nor the beefed up tail but did the 'more angled leading edge' and upright guns. Both went to Eglin for testing for duration of war.

None of the -5's had the dorsal, but the dorsal modification, production uplocks and beefed up tail marked the break in dash number from -5 to -10.

Joe - I am not aware of a depot/Service Group level mod converting B/D to D's - do you have a notion where I could learn more about such?


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## FLYBOYJ (Nov 12, 2007)

drgondog said:


> The very first two (and only)P-51D-1s were 42-106539 and 106540 - both P-51B-10s from California. Both kept the 51B wing intact whereas the subsequent P-51D-5 had neither the 'dorsal' nor the beefed up tail but did the 'more angled leading edge' and upright guns. Both went to Eglin for testing for duration of war.
> 
> None of the -5's had the dorsal, but the dorsal modification, production uplocks and beefed up tail marked the break in dash number from -5 to -10.
> 
> Joe - I am not aware of a depot/Service Group level mod converting B/D to D's - do you have a notion where I could learn more about such?



I'll look for it Bill - I remember seeing the old photo of "LOU IV" in formation with caption under the photograph about 2 of the aircraft in that photo being converted from a P-51 "C" to "D"?!? Perhaps they were confusing the bubble canopy mod with the dorsal fin mod?????


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## FLYBOYJ (Nov 12, 2007)

My mistake - I found the reference... 

It was the dorsal fin mod being spoken of......







The two P-51Ds in the foreground show a variation in dorsal fin configuration seen on early production "D" models. Both aircraft are P-51D-5-NAs originally produced without the fin, which has been retrofitted on the E2*S. The photo has been taken around end-July 1944, and the aircraft belong to 375th Fighter Squadron, 361st FG


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## drgondog (Nov 12, 2007)

FLYBOYJ said:


> My mistake - I found the reference...
> 
> It was the dorsal fin mod being spoken of......
> 
> ...



You're right about the E2-S - the P-51D-10 with factory ventral started w/44-14053 so that definitely is a -5 with ventral kit.

I heard from Ted Damick. The first D's arrived vi Ferry Pilots May 6-15 at the ETO Service Depots with a few going to 4th, 352nd, 355th and 357th which the CO's sanpped up. The 15th actually got D's in the same timeframe.

Neither one of us can positively identify a D that experienced combat before June 7 for sure.


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## Soren (Nov 13, 2007)

Very nice charts Crumpp! Thank you for posting them.

Looking forward to you adding the Bf-109 Spitfire


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## Crumpp (Nov 13, 2007)

> Looking forward to you adding the Bf-109 Spitfire



I will work on adding the Bf-109. I hope the charts are useful in helping people to gain insight into the nature of aircraft turn performance.

All the best,

Crumpp


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## drgondog (Nov 13, 2007)

renrich said:


> Bill, Sorry for my misleading post about P51D deployment. I should have looked further. I am glad to see that Dav has what I consider as a thorough and comprehensive reference on US WW2 fighters, "America's One Hundred Thousand" and it states the June 1944 date as to when P51Ds began to reach the 8th AF in quantity.



Ted Damick gave me March 17, 1944 as the date 44-13254 P-51D-5 (#1) rolled off the California line. It was delivered to Eglin. 44-13257 P-51D-5 (#4) was delivered to Langley.

P-51D-5 44-13258 through 13278 were flown to 15th AF a couple to 9th, 13279 went to ETO (then 355th along with 44-13305) along with most of the 44-13300 through 500 starting May 6. The Air Service Depots started delivery to 8th AF Groups around June 4-6 (no firm date yet) and the first two recorded P-5D-5 accidents were from 363rd (9th AF) and 4th FG on June 7, 1944..

The first recorded LOST IN COMBAT P-51D was June 18 in 44-13307 VF-J Lt Lane (flak)


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## lesofprimus (Nov 13, 2007)

Bill, unreal ifo ur pumpin out to the masses brother... 

Cheers!!!

As for the graphs, Im havin trouble actually understanding what they are interpeting for me....


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## Crumpp (Nov 13, 2007)

> As for the graphs, Im havin trouble actually understanding what they are interpeting for me....



The maximum load factor or number of "G's" an aircraft is capable of sustaining in a turn. It is termed "Nz" for normal accelerations on the z axis. 

Load Factor in a Level Turn

All the best,

Crumpp


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## Hunter368 (Nov 13, 2007)

Of course it! How silly of me, I knew that.


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## drgondog (Nov 13, 2007)

Crumpp said:


> I will work on adding the Bf-109. I hope the charts are useful in helping people to gain insight into the nature of aircraft turn performance.
> 
> All the best,
> 
> Crumpp



Crumpp - I forgot to ask whether you have have curves presented several power available/altitude profiles of say the Fw 190A8 vs the P-51D? At first observation it seems like these are normalized to Sea Level??


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## Crumpp (Nov 13, 2007)

> Crumpp - I forgot to ask whether you have have curves presented several power available/altitude profiles of say the Fw 190A8 vs the P-51D? At first observation it seems like these are normalized to Sea Level??



Hi Bill,

Both aircraft have curves for different configurations. The P51D is calculated for the TO weight 9611lb clean configuration overloaded fighter without the rear fuselage tank installed. The FW-190A8 is for a TO weight of 4272Kg termed "Fluggewicht A" on the ladeplane or clean configuration overloaded fighter. There is also one chart of the FW-190A8 in "Fluggewicht B" with ETC501 rack and the 115 liter Zusatzkraftstoffbehälter im rumpf.

Both aircraft are also depicted at combat weight as the USAAF defined it, 60% internal fuel, full ammunition, and consumables.

The speeds are listed in Knots Equivalent Airspeed. Altitude will change the velocity specific performance occurs but not the conclusion or shape of the curve. It is standard to use KEAS in these kind of estimates. All you have to do to convert to TAS is multiply the KEAS by SMOE found on the Atmospheric Table. This corrects for density at altitude.

KEAS is Indicated airspeed with the aircrafts Instrument Position Error Correction and a correction for the compressibility of air.

As you know, there is not nor was there ever a universal or standard method for application of compressibility. By converting the airspeed from IAS, we eliminate this as a factor in our performance estimate. Even today engineering firms set their own standards for the point we move from treating air as an incompressible liquid to a compressible gas. So once the Position Error Correction is accounted for I applied a universal standard for compressibility error onset at 200KTS. This way the playing field is leveled and we are not inducing error due to different firms standards for compressibility.

All the best,

Crumpp


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## Crumpp (Nov 13, 2007)

> Of course it! How silly of me, I knew that.



LOL!


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## drgondog (Nov 13, 2007)

Crumpp said:


> Hi Bill,
> 
> Both aircraft have curves for different configurations.
> 
> ...



Thanks for taking the time - I've been out of flight mechanics for too long.


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## FLYBOYJ (Nov 13, 2007)

Great info Crumpp!


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## Crumpp (Nov 13, 2007)

drgondog said:


> Thanks for taking the time - I've been out of flight mechanics for too long.



The analysis works up to 1st gear FTH. It does not include second gear effects although given a good engine chart it would be entirely possible to do an analysis.

Although we use power available, the prediction actually uses thrust production as a function of Thrust Horsepower and velocity with an assumed propeller efficiency of 85%.

I used 85% as it is considered the norm for propeller aircraft predictions. I do have good thrust horsepower data on the Focke Wulf series. It shows an Np depending on the advanced ratio from the low 60's to the mid 90's. I do have some data on the P51's propeller as well. It shows a similar trend in Np.

So assuming an Np of .85 is not going to change the conclusions of the prediction. There is no specific performance conclusions that can be made from any of these predictions. In the realm of significant digits though, the prediction is accurate for determining trends in performance.

Specific performance is far beyond the scope of one man who has to feed a family. It would take an engineering team with mounds of data and computer time to do that.

We can accurately say that the P51 series and the FW190 series are close enough that pilot skill makes all the difference and that aircraft configuration is a major contributing factor.

Two clean aircraft in similar loading configuration at or below FTH gives the FW190A8/D9 series a slight advantage at low to mid velocity. At high velocity the P51 series holds a slight advantage. Roll rate would be more important between these two aircraft as the aircraft which establishes the turn first will widen its advantage. Here again, at low velocity the FW190 wins out and the P51 series wins out at high velocity with the mid range leaving the two aircraft equal.

If the configurations were dissimilar, then the clean fighter would hold the advantage. 

*We cannot make a blanket statement that either aircraft design is superior to the other in horizontal maneuvering.*

Offhand, At 35K the V-1650-3 equipped P51 series would hold a wider advantage but the V-1650-7 equipped P51 series would be very close.

I could run an analysis for you but will have to add it to my list of "things to do" after the Bf-109/Spitfire analysis..

You can also see by examining such aircraft as the Zeke 52 and P47D-22 some interesting trends. Although the Zeke 52 can easily outturn the P47 as it can reach a high Nzmax at some very low velocities, the P47 is the superior fighter. If the P47D-22 stays in its best turn velocity range, the Zeke 52 cannot touch it. It simply does not have the power available at velocity. The P47D-22 for example can sustain 2.75G’s at 250KEAS while the Zeke 52 can only fly wings level at 250KEAS.

It is easy to see why the IJNAF did not retain air superiority in the Pacific.

All the best,

Crumpp


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## Crumpp (Nov 13, 2007)

Thank you FlyboyJ. I hope everyone finds it of value and it lends some insight into the scientifically achievable performance of these aircraft.

All the best,

Crumpp


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## Soren (Nov 13, 2007)

According to your chart the Dora-9 holds a clear advantage over the P-51D at all speeds, which is entirely correct according to most sources.


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## Crumpp (Nov 13, 2007)

> According to your chart the Dora-9 holds a clear advantage over the P-51D at all speeds, which is entirely correct according to most sources.



Certainly if we are flying a Dora-9 using C3 fuel and MW50. The more common B4 with the Oldenburg system was a much closer match.

I caution you not to read into these charts. They are not predicting specfic performance. For example all we can conclude is that at 300KEAS the FW-190D9 clean configuration overload fighter variant with C3 and MW50 had a turn advantage over the P51D clean configuration overloaded fighter. We cannot say that it was could pull .74g's more than the P51. All we can say is in the realm of significant digits, the FW190D9 C3 was advantaged but not by a large margin.

Consider too just how many pilots could take advantage of this level of superiority. 

All the best,

Crumpp


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## Sgt. Pappy (Nov 13, 2007)

Coming from a video game-based community, I can't really say much that is of true value, but from what I've learned from the Aces High II flight models, the F4U is quite superior to the Mustang in all but speed and zoom/sustained climb. Compared to the 190-A5 for example, it dives better, zooms better, and turns tighter. The 109K-4 is likely to eat the F4U-1 series (that is the F4U-1, -1A, etc) alive but the contemporary of the K-4 is the F4U-4 which is more or less on par with the Kurfurst, IMO. It has been said that the Kurfurst is better in everything but roll but the deployment of the highly efficient flaps of the F4U in addition to the lower wingloading allows it to get the Corsair just as maneuverable as the wing-slatted 109.

The slotted flaps of the Corsair offer it far greater maneuverability than both the P-51 and the 190 due to a much higher Clmax and its higher power loading affords it better acceleration. I don't consider range to be a very important factor in fighters; after all, fuel load never helped bombers dogfight so why would it help fighters? 

Anyhoo, here's a good link that might be interesting: The Math Behind Turning


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## Soren (Nov 13, 2007)

Crumpp said:


> Certainly if we are flying a Dora-9 using C3 fuel and MW50. The more common B4 with the Oldenburg system was a much closer match.
> 
> I caution you not to read into these charts. They are not predicting specfic performance. For example all we can conclude is that at 300KEAS the FW-190D9 clean configuration overload fighter variant with C3 and MW50 had a turn advantage over the P51D clean configuration overloaded fighter. We cannot say that it was could pull .74g's more than the P51. All we can say is in the realm of significant digits, the FW190D9 C3 was advantaged but not by a large margin.
> 
> ...



Copy that Crumpp.

However considering the lift-loading of the FW-190 was lower as-well we can safely assume that the FW-190 can pull more G's. The light stick forces of the Fw-190 series, esp. in elevator control, also made sure it was far more maneuverable at high speed.

According to NACA the 23000 series airfoils from 15 - 9% thickness ratio had an average free flow CLmax of around 1.60. This is much higher than the laminar flow airfoil on the P-51.


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## Crumpp (Nov 13, 2007)

> However considering the lift-loading of the FW-190 was lower



I don't think this is correct, Soren. The Dora has higher wingloading at TO weight than the P51D series. 

The Dora has more power available though as it has lower drag than the Anton variants while increasing thrust production.

You are correct on the higher Clmax. Clmax required of the P51D series is 1.50 and the Clmax required of the Dora-9 is 1.58 if these aircraft are to reach the stall speeds provided by the manufacturer.



> here's a good link that might be interesting:



That is pretty much the same methodology I used.

All the best,

Crumpp


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## Soren (Nov 13, 2007)

Don't know the stall speeds of each a/c, however I do know that the Dora-9's landing speed was 167 km/h and that the P-51's landing speed is 170 km/h.

The Dora-9 also has a much shorter take-off run, both to point of take-off and to clear a 20m high object, which it actually does on a shorter distance than it takes the P-51D to clear a 15m high object.


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## drgondog (Nov 14, 2007)

Crumpp said:


> The analysis works up to 1st gear FTH. It does not include second gear effects although given a good engine chart it would be entirely possible to do an analysis.
> 
> *I felt this to be true - which is why I asked the question earlier.. what was running through my mind was a.) Hp/Thrust as function of altitude - each fighter with a different profile , .b) prop efficiency at recommended versus max rpm, c.) relative energy losses beteen the two ships in high G level turn at different altitudes - not only as function of induced drag but the overall airframe wing/body combination - your profile does an excellent job of consolidating relative merits w/o going throug a full blown performance analysis*
> 
> ...



Thanks again Crumpp


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## Soren (Nov 14, 2007)

The "high" control forces of the Bf-109 at high speeds could easily be dealt with with a little two hand pull, so there should be no restraint in pitch. However roll rate did get affected at high speed, the forces being higher in this area as-well as being harder to counteract.


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## Glider (Nov 14, 2007)

I think we need to understand the definition of high speeds. In the 109 life started to get scary at around 700-720km/h (around 435-450mph) speeds at which the P51D was still fairly easy to manoevre

So at very high speeds the P51 has a significant advantage.


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## Kurfürst (Nov 14, 2007)

> Date :- 28th October 1941
> Ref : - AFDU/3/19/44
> 
> *TACTICAL TRIALS - Me.109F AIRCRAFT*​_
> ...


_
_

As I understand, low control forces are advantagous for high instantanous manouvers, ie. brief snap turns, but they provide no advantage in sustained turns, in fact, below a certain level of control force, it`s much more difficult to ride the stall - and get the optimum sustained turn rate - due to the control`s sensitivity.


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## AL Schlageter (Nov 14, 2007)

_Flying Limitations of the Me 109 G (from: Technical Instructions of the Generalluftzeugmeister, Berlin, 28th August 1942.)

Reference Me 109 - wing breakages. Owing to continually recurring accidents caused by wing breakages in Me 109 aircraft attention is drawn to the following:

(1) The maximum permissible indicated airspeeds in the different heights are not being observed and are widely exceeded. On the basis of evidence which is now available the speed limitations ordered by teleprint message GL/6 No. 2428/41 of 10.6.41 are cancelled and replaced by the following data:

Up to 3 km	(9,842 ft.)	750 km/h.	(466 m.p.h.)
At 5 km	(16,404 ft)	700 km/h.	(435 m.p.h.)
At 7 km	(22,965 ft)	575 km/h.	(357 m.p.h.)
At 9 km	(29,527 ft)	450 km/h.	(280 m.p.h.)
At 11 km	(36,089 ft)	400 km/h.	(248 m.p.h.)

These limitations are valid for the time being for all building series including the Me 109 G. A corresponding notice is to be placed upon all air-speed indicators in aircraft.

(2) Yawing in a dive leads to high one-sided wing stresses which, under certain circumstances, the wing tip cannot support. When a yawing condition is recognised the dive is to be broken off without exercising force. In a flying condition of yawing and turning at the same time correction must be made with the rudder and not the ailerons. The condition of wing tips is to be examined and checked with TAGL. Bf 109 Nos. 5/41 and 436/41.

(3) Unintentional unlocking of the undercarriage in a dive leads also - especially if only one side unlocks - to high wing stresses. Observation and the carrying out of TAGL. No. 11/42 and the following numbers is, therefore specially important.
Note. Trouble has been experienced owing to undercarriage unlocking in a dive and a modification has been brought out to prevent this.

.......The dive speed limits listed above are also to be found in Vorläufige Fluggenehmigung BF 109 G-2 and G-6

Dive limitations from: Bf 109 G-2, G-4, G-6 Bedienungsvorschrift, June 1943 edition

Dive: Adjust trim in such a way that the airplane can be held in a dive. *The elevator forces and tailplane loads become great at high speeds*. The tailplane adjustment must work perfectly; otherwise shifting of the tailplane is not possible.
Sturzflug: Trimming so einstellen daß das Flugzeug durch Drücken im Sturzflug gehalten werden kann. Die Höhenruderkräfte und Flossenbelastungen werden bei hoher Fahrt sehr groß. Hemmung der Flossen verstellung muß einwandfrei arbeiten; sonst ist Selbst verstellung der Flosse möglich.

Maximum diving speed 750 km/h. Hard aileron manipulation while diving leads to failure, particularly when pulling out. Höchstzulässige Sturzfluggeschwindigkeit 750 km/h. Harte querruder betätigung im Sturz und besonders beim Abfangen führt zum Bruch._


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## Kurfürst (Nov 14, 2007)

Nice flamebait.


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## Crumpp (Nov 14, 2007)

> We cannot make a blanket statement that either aircraft design is superior to the other in horizontal maneuvering.



Hi Bill,

Certainly we cannot make a blanket statement as to specific performance. We can however predict general trends but only as to what the engineering will allow. We also have no method to factor the effects of pilot skill.



> As I understand, low control forces are advantagous for high instantanous manouvers



Hi Kurfurst,

From the point of view of the pilot low control forces at high speed are advantageous. To the engineer they are dangerous and higher stick force per G is desirable to keep the pilot from killing himself.

Both the P51 and the Bf-109 exhibited stability and control issues when approaching their q-limits. This is common in WWII aircraft and IMHO, stability and control is where we find the largest differences in these aircraft. It was still a science in its infancy.

As I understand it, the Bf-109's developed a dutch roll when nearing the q-limits. A 13mm extension to the tail solved it allowing the q-limits to be raised in the "tall tail" 109's. 

The P51D series exhibited longitudinal stability and control issues. The aircraft would begin to porpoise. Design changes to the empennage improved the longitudinal stability but did not allow for a q-limit increase.

The low stick force per G of both the P51 series and the FW-190 series is a very good way for the pilot to kill himself. Several Luftwaffe documents warn of this as well as the P51D series POH. 

All the best,

Crumpp


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## Crumpp (Nov 14, 2007)

I think the 109's is already posted in the thread.









All the best,

Crumpp


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## HoHun (Nov 14, 2007)

Hi Al,

>Technical Instructions of the Generalluftzeugmeister, Berlin, 28th August 1942.)

Thanks a lot! Where did you find this gem? 

Let me try to re-translate this sentence since there is a slight inaccuracy in the above translation:

"Sturzflug: Trimming so einstellen daß das Flugzeug durch Drücken im Sturzflug gehalten werden kann. Die Höhenruderkräfte und Flossenbelastungen werden bei hoher Fahrt sehr groß. Hemmung der Flossenverstellung muß einwandfrei arbeiten; sonst ist Selbstverstellung der Flosse möglich."

'Dive: Adjust trim so that the aircraft can be held in the dive by pushing on the stick. The elevator forces and tailplane loads become very high at high indicated airspeeds. The friction brake of the tailplane adjustment drive has to work flawlessly, else the tailplane can change incidence by itself [driven by the aerodynamic loads].'

>"Höchstzulässige Sturzfluggeschwindigkeit 750 km/h. Harte Querruder betätigung im Sturz und besonders beim Abfangen führt zum Bruch."

That's interesting, too. ('Maximum permissble dive speed 750 km/h. Harsh aileron deflection in the dive and especially on pull-out leads to airframe failure.')

I found a description of this effect (caused by wing warping induced by the aerocdynamic forces on the ailerons) in Mike Crosley's "Up in Harm's Way" - he was a Seafire pilot in WW2 and a test pilot after the war, and they found that aileron-induced wing failure was a reason for some then unexplained losses they had in the war.

I have always suspected that the Messerschmitt must have suffered from the same problem as it has the same single-spar wing construction as the Spitfire, but I couldn't find anything definite on this topic before, so thanks for confirming my suspicion! 

Regards,

Henning (HoHun)


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## Kurfürst (Nov 14, 2007)

Even _the P-47_ was prone to wing failures to such combined elevator+aileron induced stresses - there`s a NACA paper on the IIRC, I`ve read it a while ago. The paper also tells why : WW2 aircraft wings were not stressed for such _twisting _ loads. Pullot yes, rolling yes, for rolling during pullout twisting the wings - no. The Spitfire neither - I wonder when Mike will palce that part below next to the 109 limitations he quotes.

This is tactical advise to the RAF Spit pilots, how to get around the negative G problems with a roll-and-dive manouvre. Seems to me exactly the same content as the German manual.







I am afraid Mike was a bit picky on that subject (too).


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## AL Schlageter (Nov 14, 2007)

Kurfürst said:


> This is tactical advise to the RAF Spit pilots, how to get around the negative G problems with a roll-and-dive manouvre. Seems to me exactly the same content as the German manual.


Confused Kurfurst?

Neg G was with regards to the carb cutting out.


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## Soren (Nov 14, 2007)

LoL, read the report before making stupid statements like that AL !

The report is about structural issues, it has NOTHING to do with the issues surrounding the carburators.


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## drgondog (Nov 14, 2007)

HoHun said:


> Hi Al,
> 
> >Technical Instructions of the Generalluftzeugmeister, Berlin, 28th August 1942.)
> 
> ...


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## drgondog (Nov 14, 2007)

Crumpp said:


> Hi Bill,
> 
> *We cannot make a blanket statement that either aircraft design is superior to the other in horizontal maneuvering. *
> 
> ...



Crumpp - gentle LOL - I left your quote in bold as above to provide lead in to 8th AF general directives about relative merits of Fw190 and P-51. I quite agreed with it as well as your above follow on comment. 

When I took my degrees in Aero, both aerodynamics and flight mechanics, while theoretically sound, were not an exact science in the 60's - by definition they sure weren't precise in the 30's and 40s when these ships were designed. 

I imagine it is much better now with the compute power available but modelling is still an art as much as science.

Regards,

Bill


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## Crumpp (Nov 14, 2007)

q-limits are also called the flutter limits.



> *Wing structures are akin to a 'tuning fork' extending from the fuselage.* When a tuning fork is tapped the fork vibrates at a particular frequency, the stiffer the structure the higher its 'natural' frequency. The natural frequency of a wing or tailplane structure may apply another limiting airspeed to flight operations – related to structural instabilities: flutter and wing divergence.
> 
> When the airflow around a wing or control surface is disturbed by aerodynamic reactions, turbulence or pilot inputs, the structure's elastic reactions may combine as an oscillation or vibration of the structure (possibly evident just as a buzz felt in the controls) which will quickly damp itself out at normal cruise speeds. At some higher speed — the critical flutter speed — where the oscillations are in phase with the natural frequency of the structure the oscillations will not damp out but will resonate, rapidly increasing in amplitude. (Pushing a child on a swing is an example of phase relationships and amplification). *This condition is flutter and, unless airspeed is very quickly reduced, the severe vibrations will cause control surface [or other] separation within a very few seconds. *





> Wing divergence refers to a state where, at the very low angles of attack of high speed where the nose-down pitching moment is already very high, pressure centres develop pushing the front portion of the wing downward and the rear portion upward. This aerodynamic twisting action on the wing structure, while the rest of the aircraft is following a flight path, further decreases the aoa and compounds the problem; finally exceeding the capability of the wing/strut structure to resist the torsional stress and causing the wing to separate from the airframe – with no warning! This could be brought about if a down gust is encountered at high speed.



http://www.auf.asn.au/groundschool/flutter.html

The limits of all of these aircraft are set for very good reasons. They are all subject to the same physics and have much more in common with each other than they do differences.



> Both were fixed with the kits and TO's mentioned by Crumpp



Exactly. The design teams for all of these aircraft addressed the problems which arose. The failure is on the reader who looks at such difficulties and concludes "Ah-ha! my favorite airplane was better than that!"

Facts are it probably suffered from similar issues as well. These are simply the results of engineering at the edge of human knowledge. As the level of knowledge was about the same you can expect the problems to be about the same.

All the best,

Crumpp


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## Soren (Nov 14, 2007)

Hows work progressing on the addition of the Bf-109 Crumpp ? (Looking foward  )

Btw, I don't feel we finished our debate on the stalling speeds of the Fw-190 P-51, whats your thought on this ?


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## HoHun (Nov 14, 2007)

Hi Kurfürst,

>WW2 aircraft wings were not stressed for such _twisting _ loads. Pullot yes, rolling yes, for rolling during pullout twisting the wings - no. 

Actually, rolling pull-outs induce high stress for all aircraft, not only WW2. I dimly remember reading that at one point the civilianized T-34 fleet was grounded after an accident of this sort, for example. 

However, the Bf 109 and the Spitfire with their single-spar wings were more sensitive against this than other WW2 aircraft. That both lose aileron effectiveness at high diving speeds is the first sign of wing twisting - for the Spitfire, Crosley points out that above some speed, the aileron response actually reversed. 

So if you used aileron trying to correct in a dive, the aircraft would actually roll to the opposite direction. If you fed in more aileron intuitively in an attempt to correct, the wing would twist further, increasing the roll - tempting the pilot to add yet more aileron. If he did, the wing might come off, if he didn't, he would be diving at top speed at an oblique angle, partially out of control. Pretty bad situation ...

Regards,

Henning (HoHun)


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## drgondog (Nov 14, 2007)

Crumpp - as an anecdotal aside I was an Aero (Fluid Mechanics and Structures) that worked at Skunk Works and Bell Helicopter before pursuing the all mighty dollar in Computer services.. but was the 'modeller' for the first NASTRAN airframe structural model (allegedly) accepted by US Army on the AH-1 Cobra in 1970.

The only reason I bring this up is that for every assumption I made about using rods and shear panels to simulate longerons/stiffeners and skins (instead of beams and plates in the NASTRAN model kit) I had to do the 'hand analysis' in report form so the contract officers could follow the logic..

As laborious as that process was I wonder how far the computer modelling has progressed in combining aerodynamic predictions in say, a relaxation methodology, with the matrix decompositions of flight mechanics - and then progress to account for aerdynamic deformations from limit to ultimate loads?

Your teaser about an indicial gust promted the stream of conciousness

Regards,

Bill


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## Crumpp (Nov 14, 2007)

Hi Henning,

Off topic - I still haven't downloaded Open Office to check out your Hurricane analysis. I will get that done soon as I am very interested in your outcome!

As you say, asymmetrical loading is not a good thing for any airframe and is a problem all aircraft can experience.

Soren,

I don't understand what the debate is on the P51 and FW190 stall speeds

All the best,

Crumpp


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## Kurfürst (Nov 14, 2007)

HoHun said:


> Hi Kurfürst,
> ...
> However, the Bf 109 and the Spitfire with their single-spar wings were more sensitive against this than other WW2 aircraft. That both lose aileron effectiveness at high diving speeds is the first sign of wing twisting - for the Spitfire, Crosley points out that above some speed, the aileron response actually reversed.
> 
> ...



I don`t think this - aileron reversal due to wing twist - was a particular problem on the 109 at least. It had fairly high aileron reversal speeds, similar to the USAAF`s two-spar pursuit aircraft, noted in the report quoted below. Perhaps due to it`s box spar configuration, I can only guess, but generally a box spar is fairly good resisting twisting loads, effectively it`s a single, very wide spar in the middle. 






*RAE Technical note 1001* (comparison Mustang/Spitfire ailerons, August '42) notes a deduced aileron reversal speed of *510 mph Vi for the Spitfire* and *820 mph Vi for the Mustang*. The 850 mph IAS computed by Material Command for the 109F is rather close to the Mustang`s, ie. a two-spar design, taking into account the margin of error with these calculations.

On the Spitfire, I can see why it wing twist was such a problem with the original wing. The whole D-chamber torsion spar was in the leading edge, and strong as it may be, it provided almost no rigidity for the structure furhter aft, especially as the wing was fairly big and deep - which would explain why it had fairly low aileron reversal speeds until the wing`s redesign (did the 20 series have a new spar design?).


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## Crumpp (Nov 14, 2007)

> As laborious as that process was I wonder how far the computer modelling has progressed in combining aerodynamic predictions in say, a relaxation methodology, with the matrix decompositions of flight mechanics - and then progress to account for aerdynamic deformations from limit to ultimate loads?



Hi Bill,

Things are moving toward using computer simulation exclusively. There have been quite a few advances in computer algorithums for solving the Euler and Navier Stokes equations for example. It is still the realm of the big time firms though.

The little guys are still using saw horses and sandbags.

Do you have a copy of David Lednicer's computational fluild dynamics evaluations of the Spitfire, P51, and FW190 series? He used Vasero to analyze the designs with some very good agreement and insight. I can give you a copy if you do not have it already.

All the best,

Crumpp


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## drgondog (Nov 14, 2007)

Crumpp said:


> Hi Bill,
> 
> Things are moving toward using computer simulation exclusively. There have been quite a few advances in computer algorithums for solving the Euler and Navier Stokes equations for example. It is still the realm of the big time firms though.
> 
> ...




Crumpp - I do not have a copy and would love it if not too much trouble..

As to solving Navier Stokes - it was only a figment of imagination in context of IBM 360/50 and CDC 6600 computers of the day in the airframe biz when I was dabbling. I actually thought about doing my Doctoral Dissertation on modelling cloud formation which would have required heavy doses of NS.. but stopped short of pursuing when 'family count' built up.

Now that I am retired I have started to investigate pursuing the PhD (Who knows why? LOL)

Thanks, as always


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## AL Schlageter (Nov 14, 2007)

Soren said:


> LoL, read the report before making stupid statements like that AL !
> 
> The report is about structural issues, it has NOTHING to do with the issues surrounding the carburators.


You read what was said Soren. 

"_*This is tactical advise to the RAF Spit pilots, how to get around the negative G problems with a roll-and-dive manouvre.*_" 

This was the maneuver (roll and dive) done to get around the carb cut out problem.

The only way one could get NEG G force was if an outside maneuver was done for it to be structural.

Now what is this about stupid statements?


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## Crumpp (Nov 14, 2007)

The excerpt appears to warn Spitfire pilots against asymmetrical loading of the airframe during the maneuver.


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## Soren (Nov 14, 2007)

Exactly Crumpp, however AL seems unable to figure that out.

About the stalling speeds, do you have the figures for the FW-190 P-51 ?


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## 16KJV11 (Nov 14, 2007)

Soren said:


> Exactly Crumpp, however AL seems unable to figure that out.
> 
> About the stalling speeds, do you have the figures for the FW-190 P-51 ?



For what it's worth:
Wikipidia has the P-51D's stall speed at 100 MPH and the FW 190 prototype stall speed at 127 MPH.


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## Hunter368 (Nov 14, 2007)

Crumpp said:


> The excerpt appears to warn Spitfire pilots against asymmetrical loading of the airframe during the maneuver.




Sorry (Soren), but Crumpp can you explain that a little better.......I am not too proud to say I don't understand what you are saying.

What Al is saying makes sense to me, but then again I have no experience in the field. I need to dummies version of what you are saying and what Soren knows already.


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## Glider (Nov 15, 2007)

Crumpp said:


> The excerpt appears to warn Spitfire pilots against asymmetrical loading of the airframe during the maneuver.



What I find interesting is what it doesn't say. It doesn't say not to do the maneuver, it doesn't say do not do it above a certain speed.

What it does say is that it should be practiced, which is fair enough and that it can be carried out at high speed. 

Just a question but would the leaf spring design of the Spits wing spar help or hinder as it gave the structure some 'give' in its design. 
Part of me says that it would hinder by making it more liable to twist, but part of me says that it would help as the plane would depart from normal flight without structural failure enableing the pilot to recover.

Any ideas on this welcome.


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## Glider (Nov 15, 2007)

PS one thing the thread is about the later 109G which was heavier than the F and this wouldn't have helped in its ability to take stresses.


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## Soren (Nov 15, 2007)

16KJV11 said:


> For what it's worth:
> Wikipidia has the P-51D's stall speed at 100 MPH and the FW 190 prototype stall speed at 127 MPH.




Hehe 127 mph is not the stall speed, the landing speed was lower than that. The stall speed of the P-51D with flaps and gear retracted is 109 mph IIRC, and the FW-190 around 102 - 105 mph under the same conditions.


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## Kurfürst (Nov 15, 2007)

Stress factors of the late 109G were practically the same as the 109F. Dive limits of the 109K were even increased by 100 km/h.


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## Soren (Nov 15, 2007)

The new wheel covers and retractable tail-wheel undoubtedly allowed this increase in the dive speed limit. At 850 km/h the K-4 has the same dive speed limit as the FW-190.


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## AL Schlageter (Nov 15, 2007)

Soren said:


> The new wheel covers and retractable tail-wheel undoubtedly allowed this increase in the dive speed limit. At 850 km/h the K-4 has the same dive speed limit as the FW-190.


Dive limits 109G
Up to 3 km	(9,842 ft.)	750 km/h.	(466 m.p.h.)
At 5 km	(16,404 ft)	700 km/h.	(435 m.p.h.)
At 7 km	(22,965 ft)	575 km/h.	(357 m.p.h.)
At 9 km	(29,527 ft)	450 km/h.	(280 m.p.h.)
At 11 km	(36,089 ft)	400 km/h.	(248 m.p.h.)

So the 109K could be dived to 528mph *under* a height of 3km (9845').

No Soren, it is you is who is having trouble. Now if Kurfurst had said, 
"_care has to be exercised with the roll-and-dive maneuver to get around the negative G problems _" 
instead of 
"_how to get around the negative G problems with a roll-and-dive maneuver._"

Do you see the difference?

Where is the rest of the report? Selective editing?

Btw, when was the thread title changed to *Spitfire vs. BF 109G,K or FW 190's*

I checked out your site Kurfurst and could not find the following. Why is that?

_1.)Boost 1,8ata with B4 fuel
Reason for the meeting were the problems in “field” and at the serial production facility “Genshagen” because of the “white flame” effect during the use of the
Higher output. First it is shown by Hr. Dr. Scherenberg how the “white flame”
followed by burned pistons, develop. Because of the results of the engine knocking test the lower quality of the fuel is the main reason for the problems.
DB has allready solved the problem with adjusting the ignition timing by 5°(???) .
This allowes the use of “Sondernotleistung” and the 1.45 and 1.80ata settings.
But because of later ignition , 50PS are lost during the “Sondernotleistung”,
Where the 1,45 ata setting doesn’t lose power.
DB although mentions the problems with the bad fit of the valvesitrings or
the plug thread , that where reasons for the glow-ignition too. But because
of improovments in the production these failurs are said to be canceled.
All agreed and the decision was done, that all engines should get the new ignition time. The lose of power is not so critical. But, because of hints from DB (DaimlerBenz), there should be test flight with 5 planes within all alts, but especially above rated alt, to get knowledge about the power loose above rated alt.

END SHEET ONE

This will be done at II/JG11. It is asked, if the ignition timing can be set on old value
if better fuel quality is back. Answer is delayed till it is for sure that only better fuel is used, and if it is shown, that later ignition does have no influence on the planes perfromance. DB mentions that the later ignition point although is better for the plugs that have a thermal problem at all.
It is mentioned too, that the performance lose will be decrease with increasing engine run time , means with less oil lose. It indicates too, that new engines with less oil usage are better in performance than the ones with at first high usage and the lower usage of oil. From the troop should be taken 1 engine with 15-20h for oil consumption and performance tests to be done in Genshagen. Because the b4 fuel is mostly used in the east, the order for the new ignition point/time should get out asap by…

2.)1.98 boost with c3 fuel
the first report shows, that the test with the 1.9, and 1.98 boost had negative results.
Then a telegram from Rechlin was shown (they tested 4 engines) that criticized the
clearing of the Sondernotleistung by Gen. Ing. Paul direct from the company to A.Galland bevor sufficient tests were done. Rechlin although defend themselves, that
they did NOT give the new boost free for the Troop. (looks like some thought they did). DB on the other hand shows their positive test results for the 1.9 , 1.98 usage.
They say, that the clearance for the 1.98 boost was given with the same TAGL (?)
(think a kind of order) as the 1.8 ata boost was cleared..both on the same day!.

SHEET THREE

It was then decided (after hearing all the reports) than currently only II/JG11 should test the 1.98 boost and that the 1.9ata engine test should be finished when the engines failed. (so no more test after them). The JG should then only get 1.8 ata engine supplies. Heavy punnishment is threaten when this order is not followed. The 1.98 clearance decission may only come from department 4 of general staff.
It is suggested that some recon planes should be equiped with 1.98 boost. Decission was not done. To disburden the current 1.98 and 1.9 engines it is suggested to give them the new ignition time too. So, all engines flowen with the sondernotleistung will
Be set to the new ignition point/time.

The JG’s in field complain about the plug failurs. Especially in the last time the number of failurs increased. DB reports about improoved plug modells and better
quality control e.g. with x-ray controlling. Again DB points out that the cooling of the
109 is insufficient and wishes that the LW will solve this problem asap. This was mentioned by Gen.-Ing Paul and arrangements where done instandly.
DB points out that the performance of the “cell” (fuselage/wings) is extremely bad,
and even worser J. It makes no sense to increase the power output of the engine when on the other side the plane quality is decreasing dramatically. Is is reported that a coparison of a 109 with a mustang was arranged for Mr. Sauer, but he failed to come.
The result of the comparison was, spoken of produktion quality only, shocking
for the 109._


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## AL Schlageter (Nov 15, 2007)

Who has a drawing showing the construction of this box spar on the 109? I can only see an I-beam type main spar.


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## Crumpp (Nov 15, 2007)

> Crumpp can you explain that a little better.......I am not too proud to say I don't understand what you are saying.



An example of assymetrical loading is when you combine both aileron input and elevator as the memo recommends. It also reminds the Spitfire pilot that doing so significantly reduces the amount of load the aircraft can safely handle.



> Asymmetric aerodynamic loads such as combined rolling and pitching reduce the maximum airframe load allowable by perhaps 30%.



Fly real fast

All the best,

Crumpp


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## drgondog (Nov 15, 2007)

AL Schlageter said:


> Who has a drawing showing the construction of this box spar on the 109? I can only see an I-beam type main spar.



AL- IIRC, the main spar was around 45% chord, and supplemented by a leading edge "C" box and another spar at the flap intersection point on the chord. The 109G wing was stiffened over the 109F by increasing the skin thickness over main to aft spar. 

Anectdotally (I haven't seen the reports) this solved the high G turn wing failures experienced by the 109F.

Anecdotally again, I have seen several references to both 109F and G and Spit (through XII) control reversal issues due to torsion at tip caused by aileron deflections at high speed.

Kurfurst - that was a nice report from the Brits - but would add that neither flutter nor aeroelasticity were 'sciences' during WWII - particularly in regions of compresssibility.

Having said that, the ability to calculate limit and ultimate loads in symmetrical conditions was pretty good as long as the pressure distributions were well understood. 

In the case of a P-51 in a .78-81 dive the concept of the ammo door 'bulging', as stiff as it originally was, and creating a locally higher cambered, thicker wing came as a "suprise" 

That is why, as much as I have enjoyed the analytical discussions, that I tend to fall back on wind tunnel and flight test to evaluate the 'real' from the theoretical. 

I was delighted to see reports of VSAERO computer modelling recently which showed the pressure distribution comparisons between P-51, Fw 190A8 and D-9 and Spit IX (and compared to wind tunnel results). 

Computational aerodynamics has come a LONG way since I was practicing and would have been very useful in improving all the designs.


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## drgondog (Nov 15, 2007)

Soren said:


> Hehe 127 mph is not the stall speed, the landing speed was lower than that. The stall speed of the P-51D with flaps and gear retracted is 109 mph IIRC, and the FW-190 around 102 - 105 mph under the same conditions.



The zero sink rate flight speed of a clean 51D is about 110 IAS - which means at that speed it loses no altitude in level flight. 

The Stall speed - clean- is about 80 +/- IAS.

The 51 typically rolls slowly to right in a level flight stall and immediately recovers (if you have altitude) by simply letting go of the stick.


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## Crumpp (Nov 15, 2007)

> The 109G wing was stiffened over the 109F by increasing the skin thickness over main to aft spar.



Hi Bill,

Excellent point. As a former structure guy, I am sure you will agree with the following and is exactly why you made the point on the skins.

It is common in these type of discussions to look at design change and make assumptions that frankly cannot be made.

Everyone,

The German duralumin alloy had a lower cupric content than the US duralumin. This meant is some ways, the German duralumin was stronger but in other ways weaker.

Generally speaking the German duralumin had a higher tensile strength and much better resistance to corrosion. The US duralumin had a higher shear strength and was more vulnerable corrosion.

The German construction also relied on thicker skins. In some places, the FW-190 wing skins for example are 2cm thick.

*Point is that there is little to choose in the results.* Both sides aircraft construction resulted in airframes which had the same ultimate load factors. The construction techniques reflect the base materials chosen for the airframes.

Trying to compare strengths based on the shape of the I-beam is not going to get anyone very far.

It is a leap of logic that cannot be made given the facts behind the engineering. 

All the best,

Crumpp


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## davparlr (Nov 15, 2007)

renrich said:


> My reference show the P51 D with a sea level vmax of 367 mph, the P51B was slightly faster at SL. The F4U 4 was fastest of all at SL(US fighters) with Vmax of 380 mph. Same reference shows the P51D is introduced into the 8th AF in March of 1944. Same reference shows F4U4 could climb to 20000 ft in 6.8 minutes. Another reference shows the FW190D9 took 7min 6sec to climb to 19685 ft. The F4U4 was a significantly better climber.



In May, 1944, both North American estimates and AF flight test show that the P-51B with 150 grade fuel, pulling 75" Hg, could exceed 380 mph at SL (without wing racks).

http://www.wwiiaircraftperformance.org/mustang/na-p51b-150grade-level.jpg 

http://www.wwiiaircraftperformance.org/mustang/p-51b-24771-level-blue.jpg


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## drgondog (Nov 15, 2007)

Crumpp said:


> Hi Bill,
> 
> Excellent point. As a former structure guy, I am sure you will agree with the following and is exactly why you made the point on the skins.
> 
> ...



Crump - Agreed with one minor departure. 

As a structures guy I want the main spar as close as possible to the Center of Lift- nominally at 25%, so that I am not adding a Lift Force to the existing Moment by moving the main spar, to say at 45% Chord, away from Center of lift.. like the 109. 

In effect that 109 wing was a small, eccentric beam (leading edge) at zero chord, big beam and skin at 45% and another small beam at flap line. So the Center of Lift was approximately mid way beteen leading edge (small beam) and main spar with a big freaking hole in the bottom in the worst place - called a wheel well.

I can make that wing stiff in bending by increasing the structure (and weight) with thicker skins to give me more cap size for tension and compression (and shear) but as I get further out toward the tip, building a torque box with decreasing sectional thickness is a problem and the simple lift in level flight is creating an additional torque to aero moment.

I would love to see exactly what the analysis looked like... particularly for the asymetric load of a turn in a diving pullout


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## Glider (Nov 15, 2007)

Certainly there were warnings to German pilots that if a yaw developed in a dive the wing tips tended to come off. Instructions were given that the wing tips should be checked so it would appear that the weakness is one that would build up over time, as opposed to one off catastrophic failures


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## drgondog (Nov 15, 2007)

Glider said:


> Certainly there were warnings to German pilots that if a yaw developed in a dive the wing tips tended to come off. Instructions were given that the wing tips should be checked so it would appear that the weakness is one that would build up over time, as opposed to one off catastrophic failures



Interesting - in most cases a structural failure in Yaw would occur in tail area - either at the point of vertical stabilizer/fuselage spars or the Rudder itself. Usually the source of 'do not roll in a high speed dive' or snap roll or sideslip warnings


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## Soren (Nov 15, 2007)

drgondog said:


> The zero sink rate flight speed of a clean 51D is about 110 IAS - which means at that speed it loses no altitude in level flight.
> 
> The Stall speed - clean- is about 80 +/- IAS.



Exactly at what alt is this Bill and from where do you have this ?? 

The reason I'm asking is because the official figures are much higher.

This is from the POH:




As you can see the P-51D's stall speed in level flight was around 106 mph clean.

I don't have the official figure for the FW-190, I was hoping Crumpp would provide that, my guess is its lower though, esp. considering the much shorter take off run and distance to clear a 20m high object.


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## Crumpp (Nov 15, 2007)

> Certainly there were warnings to German pilots that if a yaw developed in a dive the wing tips tended to come off. Instructions were given that the wing tips should be checked so it would appear that the weakness is one that would build up over time, as opposed to one off catastrophic failures



AFAIK,

This does not show up in any of the high speed trials. That being said, any of these aircraft will suffer catastrophic structural failure if the limits are exceeded.

Hence we see the P51, Spitfire, and Bf-109 structural failures.



> As a structures guy I want the main spar as close as possible to the Center of Lift- nominally at 25%, so that I am not adding a Lift Force to the existing Moment by moving the main spar, to say at 45% Chord, away from Center of lift.. like the 109.



The Center of Lift is located at the main wing spar in the Bf-109G. I can send you the ladeplan and the Ersatzteilliste. You might be thinking of the rearward CG limit. Remember that has to be just forward CoL if we want a controllable aircraft.

All the best,

Crumpp


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## Crumpp (Nov 15, 2007)

> my guess is its lower though



The FW-190A8's is about 110mph. The stall speed I used in my analysis are 89.5KEAS for the P51 and 94.4KEAS for the FW-190A8.

All the Best,

Crumpp


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## Glider (Nov 15, 2007)

Crumpp said:


> AFAIK,
> 
> This does not show up in any of the high speed trials. That being said, any of these aircraft will suffer catastrophic structural failure if the limits are exceeded.
> 
> ...



I hate asking this as it shows my age but what does AFAIK mean?

Re the reference to the wing tip failures, it was part of the Technical Instructions from Generalluftzeugmeister Berlin, 28th August 1942 so I have no reason to doubt its accuracy.

This would imply to me that it was a more common problem on the 109 as this was a general warning issued to all units. 
I am not aware of similar warnings being sent to all Spitfire or P51 units.

Certainly I could be wrong on this and if anyone has a similar warning issued to allied units, I am happy to change my view.


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## Soren (Nov 15, 2007)

Crumpp said:


> The FW-190A8's is about 110mph. The stall speed I used in my analysis are 89.5KEAS for the P51 and 94.4KEAS for the FW-190A8.
> 
> All the Best,
> 
> Crumpp




Roger, what about the Dora-9's then ?


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## lesofprimus (Nov 15, 2007)

AFAIK = As far as I know...


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## Crumpp (Nov 15, 2007)

> Re the reference to the wing tip failures, it was part of the Technical Instructions from Generalluftzeugmeister Berlin, 28th August 1942 so I have no reason to doubt its accuracy.



Just as the P51's instructions found during the investigation into its wing failures.

Just as the Spitfire's longitudinal instability prompted similar warnings when plane started breaking up in flight.

The Spitfire's instructions go so far as to caution the pilot not to fly without bracing himself against the cockpit to ensure his stick inputs are very precise.

All of these were fixed in all of these designs. Including the Bf-109. 

The Bf-109 developed a Dutch roll. A common stability issue even today. Fly a Pitts S-1 if you want to see some good Dutch roll. Normally this is a benign condition however any airframe pushed to the q-limits is going to come apart. Does not matter if it is a Bf-109, P51, Spitfire, or an SR-71.

Here is a page from the high speed trails. The results of this testing prompted a design change raising the q-limits of the Bf-109. Adding 13mm to the tail increases directional stability dampening the Dutch roll.

*However even the small tail Bf-109's Mach number is unremarkable for a WWII fighter.*

The small tail Bf-109's mach limit is placarded higher than the P51D's. Not that placard mach limits mean much in the WWII fighter. If you want to see that start converting British Airspeeds to the mach number listed. One day I am going to find Supermarine’s compressibility error standards in the National Archives, LOL.





Here is the P51D/K limit of Mach .75 with the elevator modification to correct the longitudinal instability:





Facts are all of the aircraft were limited to the vicinity of mach .8 simply due to the propeller. All of them would suffer catastrophic airframe failure if the q-limits were exceeded.

All the best,

Crumpp


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## Crumpp (Nov 15, 2007)

> Roger, what about the Dora-9's then ?



94.4KEAS 

All the best,

Crumpp


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## Glider (Nov 15, 2007)

Crumpp said:


> The Bf-109 developed a Dutch roll. A common stability issue even today. Fly a Pitts S-1 if you want to see some good Dutch roll.
> Crumpp



We use something similar in a Glider when on a winch launch and the cable is to fast. To tell the winch operator that the launch is too fast you kick the rudder left and right, the secondry control effects ensure that there is plenty of yaw.
If your taking someone up on their first flight, it always causes deep gulps from the front seat.


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## Kurfürst (Nov 15, 2007)

Glider said:


> This would imply to me that it was a more common problem on the 109 as this was a general warning issued to all units.
> I am not aware of similar warnings being sent to all Spitfire or P51 units.
> 
> Certainly I could be wrong on this and if anyone has a similar warning issued to allied units, I am happy to change my view.



... that`s a faulty conclusion based on insufficent information. We know there was an instruction for the 109F wingtips. Do we know the 109G still had this problem? How we do the Mustang and Spitfire (La7, Yak3, Typhoon etc.) did not have similiar problems? They are less well documented? Of course. The less details we dig up on a plane, the fewer skeletons we find in the cupboard. But that doesn`t effect the actual number of skeletons overall. They are there, even if we don`t know about it.

BTW, ever wondered why the 'pointed', ie. tall vertical stabiliser was introduced to the Spitfire..? Stabiliser fin to the p51d..? Tall tail to the 109?

These aircraft had more in common than not. Designers kept bumping into the same limits, no matter the country. Physics are universal.


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## drgondog (Nov 15, 2007)

Soren said:


> Exactly at what alt is this Bill and from where do you have this ??
> 
> The reason I'm asking is because the official figures are much higher.
> 
> ...



Page 29 of the "Pilot's Flight Operating Instructions AN 01-60JD-1" has the reference to Zero Sink speed - clean. 

Multiple references are made to this including the instruction to not start climb until flaps are up and airspeed at least 110IAS... and do not side .slip the Mustang below 110 IAS, etc..

Stall speed is contained in Appendix II and varies with load but I have flown the airplane several times at 80-90 mph at 5000 feet to coax it into a clean stall, notably because my dad 'insisted' that I learn how easy it is to recover from. The bird would have weighed in the 8900+ weight range.

You were looking at 106mph/10,000 feet in your Power Off Stall chart and failed to notice (?) that the stall speed in that chart was down to 94 mph for 8,000 feet and continues to drop with increased density.

Crumpp's figures are`'correct' for good assumptions in performance calculations.


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## drgondog (Nov 15, 2007)

Crumpp said:


> The Center of Lift is located at the main wing spar in the Bf-109G. I can send you the ladeplan and the Ersatzteilliste. You might be thinking of the rearward CG limit. Remember that has to be just forward CoL if we want a controllable aircraft.
> 
> All the best,
> 
> Crumpp



Crumpp - ?? 

I made an assumption based on drawings I have seen of the 109 that the main spar is around 45% chord - not so? or, just as intriguing the Center of Lift actually at 45%??


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## drgondog (Nov 15, 2007)

Kurfürst said:


> ... that`s a faulty conclusion based on insufficent information. We know there was an instruction for the 109F wingtips. Do we know the 109G still had this problem? How we do the Mustang and Spitfire (La7, Yak3, Typhoon etc.) did not have similiar problems? They are less well documented? Of course. The less details we dig up on a plane, the fewer skeletons we find in the cupboard. But that doesn`t effect the actual number of skeletons overall. They are there, even if we don`t know about it.
> 
> BTW, ever wondered why the 'pointed', ie. tall vertical stabiliser was introduced to the Spitfire..? Stabiliser fin to the p51d..? Tall tail to the 109?
> 
> These aircraft had more in common than not. Designers kept bumping into the same limits, no matter the country. Physics are universal.



There were no wintip issues with 51 or control reversal issues due to aileron loads causing too much twist in wing.

Having said this, the P-51 had sveral 'skeletons', all were well documented and none remain as skeletons... as you (and Crumpp) said - they all had problems and all were fixed.

The big ones for the 51 were a.) wheel door uplock failing to keep landing gear where it belonged in a dive, b.) bad batch of heat treated bolts for engine mounts, c.) increasing yaw as speeds increased from .75 to .81 Mach, d.) structural failure of Tail/aft fuselage due to asymmetrical loads at high speeds (i.e rolling in dive, snap roll at high speed), e.) ammo door deflection at high speeds causing a local increased lift and spar failure in high speed diving pullout.

To the best of my knowledge Kurfurst, there is no conspiracy to keep those shameful secrets hidden?


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## Soren (Nov 15, 2007)

drgondog said:


> Page 29 of the "Pilot's Flight Operating Instructions AN 01-60JD-1" has the reference to Zero Sink speed - clean.
> 
> Multiple references are made to this including the instruction to not start climb until flaps are up and airspeed at least 110IAS... and do not side .slip the Mustang below 110 IAS, etc..
> 
> ...



What are you talking about Bill ??! 

The stall speeds are given for different weights, NOT different altitudes! 

What the chart says is that the P-51D stalls at 106 mph at SL at 9,700 lbs ! At 10,000 lbs its 108 mph at SL. There's no way the P-51D is ever going to fly at 80 mph clean, the real stalling speed is WAY higher than that!

Btw, is it me or are you saying you actually fly the P-51 ?? - suspiciously late to come forth with this IMO.


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## Crumpp (Nov 15, 2007)

> Btw, is it me or are you saying you actually fly the P-51 ?? - suspiciously late to come forth with this IMO.



When your father is a P51 Ace, you think he might take you flying?

All the best,

Crumpp


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## drgondog (Nov 15, 2007)

Soren said:


> What are you talking about Bill ??!
> 
> The stall speeds are given for different weights, NOT different altitudes!
> 
> ...



You are right about the chart Soren - I was braindead on the quick glance at your chart.

As to a/c command time in the 51 - You haven't been paying attention. You have made more than a few 'not true comments' that I corrected based on my own experience with the ship. I have also commented that my own experience with cross wind landings does not co-incide with Manual just because it has a wide track gear! 

I have 100 dual and 56.6 solo in a P1D-25 and -30.. I think I first mentioned it in June timeframe in a conversation with Joe about preferred landing speeds (I favored 110+ IAS Power on at 2700 rpm and 15-20 degrees flaps depending on how fast I wanted the sink rate.) 

And Crumpp is correct on stalling speeds although I am reasonably sure he is talking about a bird at near max gross or at least combat load.- and yes the 51 stall speed for 8000-8500 pounds is somewhere in the range of 80-90 mph clean, power on, depending on a lot of factors... but much less than 110 IAS.


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## drgondog (Nov 15, 2007)

Crumpp said:


> When your father is a P51 Ace, you think he might take you flying?
> 
> All the best,
> 
> Crumpp



G - LOL - I'll tell You the story -it's worth it. Via email. The net is "there's nothing wrong with a fix - if you are in on it"

The USAF auctioned a lot of 51's when they got out of the biz in 1957-1958 and dad bought one.

He got a 51D-25 that had been completely overhauled, and included a spare 1650-7 with less than 25hrs on it. He traded that to Cavalier in return for a two seat TF-51D conversion..

He was one hell of a fighter pilot but perhaps an even better instructor. I miss him still and it's been 28 years.

My last time in the bird was back in 1985. If I was a biilionaire I would buy off the FAA docs and have one today.

Regards,

Bill

PS - both Jeff Ethell and I got our pilot's license before we got a driver's license - go figure. And Jeff's dad Irv was a squadron CO when my father was Gp CO of 35th in Japan - we grew up together, starting in Japan in 1948 - and I miss him.


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## Crumpp (Nov 15, 2007)

> I made an assumption based on drawings I have seen of the 109 that the main spar is around 45% chord - not so? or, just as intriguing the Center of Lift actually at 45%??



Hi Bill,

The AC has to be forward of the CG as you know. The limits of the CG are measured from Bulkhead 1 not from the LE of the wing. The main spar is located 1003.2mm from the LE and the most rearward CG location on the Bf-109G2 is 69.2cm from Bulkhead 1 <firewall>.

As you know, the most rearward portion of the CG has to in front of AC. The AC is in the vicinity of the spar were it should be as far as I can tell.

So I am not confusing you. Center of Lift and Aerodynamic Center are interchangeable terms today. You are probably used to Center of Pressure calcs where M = Lx.

Center of Pressure is seldom used today. The math gets hokey. As we approach zero lift mathematically our x reaches infinity and the Cp moves backward to infinity. This is of course impossible. You’re probably thinking Cp is Center of Lift instead of AC. It used to be when we did Cp calcs.

AC is the point where all the torques of the Aerodynamic Forces are located.

To Soren’s credit, Bill, there are plenty of folks who prowl these kinds of boards whose sole motivation is to up their game score and live out their ace fantasy. There is more than one BS artist around.

So readers will be able to follow what we are discussing.

Aerodynamic Center

All the best,

Crumpp


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## drgondog (Nov 15, 2007)

drgondog said:


> Page 29 of the "Pilot's Flight Operating Instructions AN 01-60JD-1" has the reference to Zero Sink speed - clean.
> 
> Multiple references are made to this including the instruction to not start climb until flaps are up and airspeed at least 110IAS... and do not side .slip the Mustang below 110 IAS, etc..
> 
> ...



correction made as noted


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## 16KJV11 (Nov 15, 2007)

Soren said:


> Hehe 127 mph is not the stall speed, the landing speed was lower than that. The stall speed of the P-51D with flaps and gear retracted is 109 mph IIRC, and the FW-190 around 102 - 105 mph under the same conditions.



Like I said, "For what it's worth".


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## FLYBOYJ (Nov 15, 2007)

Soren said:


> Btw, is it me or are you saying you actually fly the P-51 ?? - suspiciously late to come forth with this IMO.


Bill has stated on several occasions that he and his dad flew in P-51s.(together)


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## FLYBOYJ (Nov 15, 2007)

drgondog said:


> both Jeff Ethell and I got our pilot's license before we got a driver's license - go figure. And Jeff's dad Irv was a squadron CO when my father was Gp CO of 35th in Japan - we grew up together, starting in Japan in 1948 - and I miss him.


I always enjoyed his books and seeing him on the history channel. I was deeply saddened when he was killed...


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## Glider (Nov 15, 2007)

Kurfürst said:


> ... that`s a faulty conclusion based on insufficent information. We know there was an instruction for the 109F wingtips. Do we know the 109G still had this problem? How we do the Mustang and Spitfire (La7, Yak3, Typhoon etc.) did not have similiar problems? They are less well documented? Of course. The less details we dig up on a plane, the fewer skeletons we find in the cupboard. But that doesn`t effect the actual number of skeletons overall. They are there, even if we don`t know about it.
> 
> BTW, ever wondered why the 'pointed', ie. tall vertical stabiliser was introduced to the Spitfire..? Stabiliser fin to the p51d..? Tall tail to the 109?
> 
> These aircraft had more in common than not. Designers kept bumping into the same limits, no matter the country. Physics are universal.



The instruction that I referred to in my previous posting was specifically for the Me109G so yes I do believe that the problem existed in the 109G.

Of course any aircraft then or now that exceeds its design limits is in danger of structural failure, that is obvious.

The difference here is that the German authorities had to issue a reminder to all German units that started

_Owing to continually recurring accidents caused by wing breakages in Me109 aircraft attention is drawn to the following_

Then it lists various items including the item on wing tips. Now this is a document issued to units after that have been equipped and trained on the aircraft over and above the normal pilots notes.

The fact that the authorities had to issue such a reminder implies to me that the problem was greater on the 109 than other aircraft, as I have never heard of such a reminder being issued to other airforces or aircraft. After all, if the problem was the same on all aircraft and the Germans were being more communatitive than other nations, why didn't they issue similar reminders for all their 190's, 110's etc?

You will recall that JG26 in its list of pilots lost to accidents, treated wing failure as another type of accident, again something I have never heard of in any US or British record. Another indication that it was more common in German aircraft.

I would be the first to agree that this isn't definite proof but the circumstancial evidence builds up the more you look into it.


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## Crumpp (Nov 15, 2007)

> He was one hell of a fighter pilot but perhaps an even better instructor. I miss him still and it's been 28 years.



Yes he was and he is missed. Men of his caliber and generation are a precious dwindling resource.

Glider,



> treated wing failure as another type of accident, again something I have never heard of in any US or British record.



How do you explain the USAAF documents?

How do you explain the RAF warnings?



> Now this is a document issued to units after that have been equipped and trained on the aircraft over and above the normal pilots notes.



Just like the RAF and USAAF documents. 



> why didn't they issue similar reminders for all their 190's, 110's etc?



They did....



> Another indication that it was more common in German aircraft.



This is an airplane issue not a cultural defect. The Germans were not nor are they incompetant as a race.

Glider, IMHO, comments like this are a slap in the face to every guy who fought in the skies over Europe. I am sure you did not think of it that way when you wrote it. The Luftwaffe was not some push over organization flying half-baked airplanes. Both Allied and Axis flew the best technology mankind had to offer. The Nazi's were defeated because good men went forth everyday and risked all of their tommorrows in a hard won fight.

All the best,

Crumpp


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## Soren (Nov 16, 2007)

Sorry about your dad Bill.

At 8000-8500 lbs, power on, 80-90 mph sounds about right. You didn't say that before though, so I got confused.

And sorry that I sounded rude before.


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## Kurfürst (Nov 16, 2007)

Glider said:


> The instruction that I referred to in my previous posting was specifically for the Me109G so yes I do believe that the problem existed in the 109G.Of course any aircraft then or now that exceeds its design limits is in danger of structural failure, that is obvious.
> 
> The difference here is that the German authorities had to issue a reminder to all German units that started



Then read again and look at the date. It`s been issued after service experience with the 109F, at about the time the units were starting to receive their first 109Gs (which had reinforced wing structure, I might add). 

Such reminders to all units were issued by all airforces in the dozen during the war. It`s the first step in fixing an newly found problem.

_Owing to continually recurring accidents caused by wing breakages in Me109 aircraft attention is drawn to the following_



Glider said:


> Then it lists various items including the item on wing tips. Now this is a document issued to units after that have been equipped and trained on the aircraft over and above the normal pilots notes.



And...? It`s a technical addendum, one of the thousends issued during the war from the slightest matters like what grease is to be used in winter till the maintaince of the spark plugs.



Glider said:


> The fact that the authorities had to issue such a reminder implies to me that the problem was greater on the 109 than other aircraft, as I have never heard of such a reminder being issued to other airforces or aircraft. After all, if the problem was the same on all aircraft and the Germans were being more communatitive than other nations, why didn't they issue similar reminders for all their 190's, 110's etc?



And that is the fallacy of your logic. You`ve seen a snipped of a technical instruction about the _109 series_. For some odd reason, you assume that no such exist for other aircraft types, as you haven`t seen it. 
It doesn`t exist then. 

But that`s just an illogical assumption about no such thing being issued in other airforces, or for other types. See below ?












Another one from 1941, Mk I/V








Glider said:


> You will recall that JG26 in its list of pilots lost to accidents, treated wing failure as another type of accident, again something I have never heard of in any US or British record. Another indication that it was more common in German aircraft.



No, it`s an indication of the same logical fallacy. You haven`t seen it, then it doesn`t exist. But they do... a guy some time ago, collected_ some_ from Spitfire : The History`s listing of Spitfire serials and fates from the original service cards of the individual aircraft. I won`t list all.

Mar 39...Mk I....K9838...Structural failure in dive. 
Jan 41...Mk I....N3191...Both wings broke off in dive. 
Jul 41...Mk I....X4354...Port wing broke off in dive. 
Aug 41...Mk I....X4381...Starboard wing broke off in dive. 
Mar 41...Mk I....X4421...Both wings broke off in dive pullout. 
Jul 41...Mk I....X4662...Stbd wing broke off in dive pullout. 
Jun 41...Mk I....X4680...Wings/tail broke off in dive pullout. 
Nov 42...Mk I....X4621...Failed to recover from dive. 
Apr 43...Mk II...P7352...Broke up in dive. 
Sep 41...Mk II...P7522...Both wings broke off in dive. 
Jun 43...Mk V....BL531...Both wings broke off in dive. 
Feb 42...Mk V....AA876...Disintegrated in dive. 
Jul 43...Mk V....BL389...Pilot thrown from aircraft in dive. 
Jan 43...Mk IX...BS251...Structural failure in dive. 
May 43...Mk IX...BS385...Structural failure in dive. 
Aug 43...Mk IX...BS441...Disintegrated in dive. 
Oct 46...Mk IX...PL387...Disintegrated in dive. 
Jan 48...Mk XVI..SL724...Crashed after recovery from dive. 
Sep 48...Mk XVI..TD119...Crashed after recovery from dive. 
Aug 42...Mk I....N3284...Broke up in flight. 
Aug 41...Mk I....N3286...Broke up in flight. 
Sep 40...Mk I....P9546...Structural failure in flight. 
May 42...Mk I....P9309...Lost wing in flight. 
Apr 43...Mk I....X4234...Lost wing in spin. 
Sep 42...Mk I....P9322...Broke up in flight. 
Aug 43...Mk I....R6706...Aileron failure which led to crash. 
Jan 43...Mk I....X4854...Starboard wing broke off in flight. 
Nov 40...Mk II...P7593...Stbd wing and tail broke off in flight. 
Dec 41...Mk II...P8183...Port wing broke off in flight. 
Jun 42...Mk II...P8644...Starboard wing broke off in flight. 
May 41...Mk II...N8245...Structural failure in flight. 
Feb 44...Mk II...P7911...Flap failure which led to crash. 
Sep 42...Mk V....AD555...Flap failure which led to crash. 
Mar 44...Mk V....BL303...Flap failure which led to crash. 
Dec 41...Mk V....BL407...Structural failure suspected. 
Jun 42...Mk V....AB172...Structural failure in flight. 
Mar 43...Mk V....AA970...Structural failure in flight. 
Jun 43...Mk V....BL290...Port wing broke off in flight. 
May 43...Mk V....BR627...Port wing failed in spin. 
Oct 41...Mk IV...AA801...Structural failure in flight. 
Feb 43...Mk IX...BS404...Structural failure in spin. 
Feb 45...Mk IX...MH349...Wing failed during aerobatics.

etc.

The British recorded structural failures occuring just like the Germans and everybody else.



> I would be the first to agree that this isn't definite proof but the circumstancial evidence builds up the more you look into it.



What _'circumstancial evidence'_? You`ve seen a _single_ extract from the hundreds of technical instructions issued for the 109 during the war. By some odd logic, you claim no similiar thing was issued for other aircraft or by other air forces.

_That`s circumstancial evidence?_ 

I`d say it`s a small piece of the puzzle, it doesn`t say what happened after, and how they dealt a problem that occured under some circumstances, that they appearantly found and knew well on later subtypes. 

Go ahead and do some in-depth research on other aircraft, and when you have done your reading, and have a solid base for comparison, come back and tell us wheter they are different or not.

I recommend you read the book _Spitfire : The History_. It`s a great in-depth research of the Spitfire`s development. Here`s a spoiler, it speaks almost entirely of the technical difficulties the designers had to overcome, and a lot about structural issues, too. The more you read of the aircraft, the more skeletons you`ll find in the cupboard. The more you read about other aircraft as well, the more you realize the problems were very similar. And the more you read, the more you realize how little you know... for example, a friend sent me a list about aircraft related material in a national archive. It`s over 600 pages long, and it`s only has brief titles and references to it. 99.9% of it are unknown to me. If I`d ever be able to read all of it, I am sure I`d be bound for a lot of surprises.


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## drgondog (Nov 16, 2007)

Soren said:


> Sorry about your dad Bill.
> 
> At 8000-8500 lbs, power on, 80-90 mph sounds about right. You didn't say that before though, so I got confused.
> 
> And sorry that I sounded rude before.



Soren - I appreciate the comment. no big deal

Let me make something clear about my 'experience'. I flew a low time, peace time, late model ship in excellent condition. I never (intentionally) over stressed the airframe, did not do any dives exceeding .72 to maybe .74, did not do any 4-5g turns chasing another airplane - and will never represent that I have.

But I do have a good feel for the airplane even though it has been 40+ years since I last solo'd in one.

I had a great instructor who taught me the 'don't do's" early on - and I'm sure was anxious when he 'turned over the keys' for the first solo.

And last, only one of 21 air aces in his group shot down more 109s than he did - Henry Brown... but he definitely respected the airplane

Regards,

Bill


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## DerAdlerIstGelandet (Nov 16, 2007)

drgondog said:


> Soren - I appreciate the comment. no big deal
> 
> Let me make something clear about my 'experience'. I flew a low time, peace time, late model ship in excellent condition. I never (intentionally) over stressed the airframe, did not do any dives exceeding .72 to maybe .74, did not do any 4-5g turns chasing another airplane - and will never represent that I have.
> 
> ...



You certainly are blessed to have been able to fly one of these great warbirds. Closest I have come to it was a backseat right in a T-6.

Do you have any pics of your dad from the war with his P-51 and some of you when you were flying it? Would be cool to see them.


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## drgondog (Nov 16, 2007)

FLYBOYJ said:


> I always enjoyed his books and seeing him on the history channel. I was deeply saddened when he was killed...



Joe - I found out from his dad who called me after the accident.. he was there and watching when Jeff stalled the P-38 out and watched his son get punched out of the cockpit when the nose wheel crashed through.

I haven't talked to Irv since the accident (4-5 years ago??)

Jeff helped me think through the type of book I wanted to write on the 355th and we were talking about doing a Kent Miller style Fighter Pilots of the 8th book when he checked out on me.

You know, every time I hear someone state that 'flyin is safer than drivin' it makes me chuckle. When we came back from Japan and were at Eglin during the F-86D, F89, F-100A test programs it seemed like someone was going in every week (over stated of course - but not too much)

Regards,

Bill

Reactions: Agree Agree:
1 | Like List reactions


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## drgondog (Nov 16, 2007)

DerAdlerIstGelandet said:


> You certainly are blessed to have been able to fly one of these great warbirds. Closest I have come to it was a backseat right in a T-6.
> 
> Do you have any pics of your dad from the war with his P-51 and some of you when you were flying it? Would be cool to see them.



Chris - I don't have any pics of the TF-51D conversion, for some reason I don't recall him ever taking one? or even if we had a camera then - but I have a ton of him during the great patriotic war - I posted some of them in the photo section here and of course my avatar.

http://www.ww2aircraft.net/forum/aircraft-pictures/355th-fg-pics-9563.html



I have photos of six of his 7 Mustangs during the war. I sent one taken by base PRO at Johnson AFB near Tokyo of Jeff, me, Irv Ethell and dad next to his 51..to Irv after Jeff went in with the P-38.

I had a fair amount of time in the At-6 before solo in P-51. As I recall, the 51 seemed easier to fly but I can't tell you why specifically


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## DerAdlerIstGelandet (Nov 16, 2007)

Thats right Bill. I remember you posting those now. 

Thanks again though.


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## Glider (Nov 16, 2007)

Kurfürst said:


> Then read again and look at the date. It`s been issued after service experience with the 109F, at about the time the units were starting to receive their first 109Gs (which had reinforced wing structure, I might add).


I am only reporting what it said, which referred to the 109G not F.



> Such reminders to all units were issued by all airforces in the dozen during the war. It`s the first step in fixing an newly found problem.


This wasn't fixing a problem, this was reminding people of structural limitations that caused enough accidents that they were treated as ordinary accidents.



> _Owing to continually recurring accidents caused by wing breakages in Me109 aircraft attention is drawn to the following_
> And...? It`s a technical addendum, one of the thousends issued during the war from the slightest matters like what grease is to be used in winter till the maintaince of the spark plugs.


Nope, it wasn't, I repeat it was reminding people of structural limitations that caused enough accidents that they were treated as ordinary accidents.



> And that is the fallacy of your logic. You`ve seen a snipped of a technical instruction about the _109 series_. For some odd reason, you assume that no such exist for other aircraft types, as you haven`t seen it.
> It doesn`t exist then.


I haven't seen any other example and still haven't seen one that covers an entire type of aircraft. However I did say that I was happy to change if I saw an example.



> But that`s just an illogical assumption about no such thing being issued in other airforces, or for other types. See below ?



The documents are very interesting and show a component weakness in some aircraft which is rectified with new parts, a common situation then and now.

The list of failures is again interesting but you are making a huge case out of nothing. Of course there were structural failures, but out of 28000 ish examples rapidly built and often flown by inexperienced pilots in combat its only to be expected. 

I have never said that allied aircraft didn't suffer failures, I have only said that I had never seen them referred to as an ordinary accident and such a blanket warning issued.
The list is interesting, a large proportion are types that were obsolete at the time of the accident and almost certainly in the hands of training units.

But I promise I will read the book


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## renrich (Nov 16, 2007)

Seems odd to me that anyone who has been a regular on this forum would not be aware that Bill has actually flown a P51 and that his father was a USAAF pilot in WW2. Over the last few months I have read his posts referring to those facts on a number of occasions. Bill, your statement about the P51 seemingly being easier to fly than a AT6 lends backup to a thread I started a few days ago on the SNJ. Also, your statement about "someone going in every day" says a lot about people who scoff at George Bush's service in the TANG flying F102s. My hat is off to anyone who flew in the military especially in the early jet days.


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## drgondog (Nov 16, 2007)

renrich said:


> Bill, your statement about the P51 seemingly being easier to fly than a AT6 lends backup to a thread I started a few days ago on the SNJ. Also, your statement about "someone going in every day" says a lot about people who scoff at George Bush's service in the TANG flying F102s. My hat is off to anyone who flew in the military especially in the early jet days.



My saddest memory as a kid was when my best friend's father Mac McQuirter was flying a Mother ship B-17 controlling a trailing B-17 target drone and was hit by mistake from another friend of my father, Art DeBolt, with rockest from an 86D in an all weather radar approach.

Mac ket the ship in control while the crew got out but the B-17 blew up before he got out - over the Gulf of Mexico.

I saw a lot of those growing up. Fighters are not 'safe' in any sense of the word.. I remember the hoorah when some crashes occurred with the F-111 and I kept asking myself 'what in the world are you talking about?'


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## AL Schlageter (Nov 17, 2007)

Glider, it only shows the end result but not the reason why the plane was in a dive which could be because of, for example, battle damage, the pilot was wounded, the pilot passed out do to the lack of oxygen, the dive limit speed was exceeded.

I came across this post awhile back when searching for info on the Spitfire,

_I don't want to hijack this thread but I feel the need to put the record straight on this one. The last thread concerning the Spitfire's dive speed was contaminated by_ (member's name deleted) _poison pen regarding the Spitfire's structural integrity and I see his contention that it was 'weak' is gaining currency here- which is just what he intended.

I thought I remembered reading an interview on this subject many years ago- and finally found it in a yellowed copy of Alfred Price's 'Spifire At War' (published 1974). It's germane to this discussion (as my teacher used to say) because the person being interviewed is none other than Mr Eric Newton who spent the war with the Air Accident Investigation Branch. He was still employed by them as an investigator in 1974- the time of the interview- so presumably still had the facts at his fingertips. This body was, and is, independent of the RAF.

Mr Newton was called in to investigate Spitfire crashes which could not be immediately attributed to pilot error (the same crashes which are detailed in Morgan and Shacklady). He says:

"Out of a total of 121 serious or major accidents to Spifires reported to us between the begining of 1941 and the end of the war, 68 involved structural failure in the air. Initially the most common reason for such failures, with 22 instances in 1941 and 1942, was aileron instability. The symptoms were not at all clear cut: the aircraft were usually diving at high speed when they simply fell to pieces. Only after one of the pilots had survived this traumatic experience and parachuted successfully were we able to find the cause. During his dive he saw both of his ailerons suddenly flip up, producing an extremely violent pitch- up which caused the wing to fail and the aircraft to break up. In collaboration with RAE we did a lot of tests and found that aileron up- float was made possible by stretch in the control cables; in those days tensioning was a hit or miss affair with no compensation for temperature. On our recommendation the RAF introduced a tensometer which ensured accurate tensioning of the controls; this, and the simultaneous introduction of metal surfaced ailerons ('42/'43), cured almost all the cases of aileron instability in the Spitfire.

The next most serious cause of structural failure in the Spitfire was pilots overstressing the airframe. She was extremely responsive on the controls and one must remember that in those days there was no accelerometer to tell the pilot how close he was to the limit. So it was not difficult to exceed the aircraft's 10G ultimate stress factor (what was the 109's?- Berkshire) during combat or when pulling out from a high speed dive; during the war we were able to put down 46 major accidents to this cause, though undoubtedly there were many other occasions when it happened and we did not see the wreckage. Incidentally, if there was a structural failure in the Spitfire it was almost inevitably the wing that went; the fuselage was far less likely to fail first (the same for most low wing monoplane fighters?-except the Typhoon?- Berkshire).

I once asked a very senior RAF officer why the accelerometer- technically a simple instrument- was not introduced during the war. He replied that he was sure it would have an adverse effect on the fighting spirit of the pilots (same was said re the parachute in WW1!- Berkshire).

Whether that would have been so I cannot say. But I do know that when they finally introduced the accelerometer into service in the Hunter in 1954, and began educating the pilots on structural limitations and the dangers of overstressing, accidents to this cause virtually ceased.

After structural failure the next largest category of accidents proved on investigation to have followed loss of control by the pilot (36 cases). Of these 20 occured in cloud and could be put down to pilot error; one must remember that in the rush to get pilots operational instrument training was not up to peacetime standards. A further 13 accidents were shown to have been caused by oxygen starvation; the oxygen system had been used incorrectly with the result that the pilot had passed out and the aircraft had crashed. As a result of our investigations the system was modified to make it easier to operate.

The remaining 3 accidents in the loss of control category were initiated by the pilot pulling excessive G and blacking himself out.

Engine failures and fires contributed a further 17 accidents, and the remainder could be put down under the 'miscellaneous' heading (long story here about fuel leaks and explosions on the ground- Berkshire)

As I have mentioned we investigated a total of 121 Spitfire accidents during the war. The causes did not always fit simply into neat categories mentioned above. For example, a pilot might lose control in cloud and his aircraft then broke up in the ensuing dive due to aileron instability- in that case the accident would have been listed under two categories. There were one or two accidents caused by the light- weight plastic bucket seats fitted to some batches of Spitfires. The trouble was they were not strong enough and if there was a heavy pilot who pulled a bit of G they tended to collapse- on to the elevator control runs which ran underneath. We soon had that type of seat replaced.

In the nature of my work I tend to concentrate on an aircraft's failings and ignore its good points; but how safe was the Spitfire? I think the figures speak for themselves; a total of more than 22,000 were built, and we were called in on only 130 occasions- and in not all of those was the Spitfire at fault. If one considers that she was not a simple trainer built for ease of handling, there can be no doubt that the Spifire was a remarkably safe little aircraft."

To summarise:
There were 121 Spitfire crash investigations between 1941 and May 1945 involving serious structural failure:
22 aileron instability
46 pilot overstressed airframe
20 pilot error in cloud
13 misuse of oxygen system- pilot error
3 pilot blacked out
17 engine failure/fire

(22,000 produced)

I shall refrain from calculating percentages to show what an incredibly low percentage of Spitfires were destroyed by structural failure/ engine failure for the reason outlined by Mr Newton. Nevertheless, there is absolutely nothing here to suggest that the Spitfire had some kind of endemic weakness._


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## DerAdlerIstGelandet (Nov 17, 2007)

renrich said:


> Seems odd to me that anyone who has been a regular on this forum would not be aware that Bill has actually flown a P51 and that his father was a USAAF pilot in WW2.



I never said I did not know his father was a fighter pilot and that he also flew the P-51. I knew that from the very beginning when he joined the forum. All I said was that I did not remember if I had seen the pics or not.

Thats a big difference.


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## lesofprimus (Nov 17, 2007)

I think he was referring to Soren Chris, not u...


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## Juha (Nov 17, 2007)

IMHO Bf 109G structure was OK, IIRC Finnish AF suffered only one known structural failure during its combat use of G-2s and G-6s in 1943 – 44. Of course the number of planes was very small if we compared it to numbers used by LW, RAF, USAAF or VVS. Finns seemed to think that the heaviness of controls in high speed was intentional to protect pilots from structural failures. On the other hand Daimler-Benz 605A didn’t endear itself to Finnish pilots, there were many catastrophic engine failures in 1943 even if the possibility of use of 1,42 ata emergency power was disabled in FAF’s Bf 109Gs.

Juha


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## Soren (Nov 17, 2007)

If I had known beforehand that Bill's dad was a WW2 fighter pilot I wouldn't have said what I did now would I Renrich ? I don't read every new post on this forum everytime I visit, I simply don't have the time, so even though I do try to check every day I far from read every new post.

The reason for my confusion was in part Bill's response to the stall speed table I presented, and that I never before had heard his father was a WW2 fighter pilot so I thought it abit late to come forth with - but he came forth with that from the beginning of his membership I just learned, so nothing odd there.


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## drgondog (Nov 17, 2007)

Soren said:


> If I had known beforehand that Bill's dad was a WW2 fighter pilot I wouldn't have said what I did now would I Renrich ? I don't read every new post on this forum everytime I visit, I simply don't have the time, so even though I do try to check every day I far from read every new post.
> 
> The reason for my confusion was in part Bill's response to the stall speed table I presented, and that I never before had heard his father was a WW2 fighter pilot so I thought it abit late to come forth with - but he came forth with that from the beginning of his membership I just learned, so nothing odd there.



Soren - we are fine. Let me summarize what I think I learned from my father's experience as Mustang pilot, an ace and a Command pilot with close to 9,000 hours in 40 different a/c.

Relevant to my discussions with you, he a.) flew the two seat 109 and 190 at Gablingen - post war when he was CO of the 355th, b.) flew the 'resident' Fw190D-9 with about 20 hours both in familairization and rat races with P-51s, c.) shot down the second highest total of Me 109s in the 355th, second only to the top ace Henry Brown, had 2300 hrs, highest in 355th FG due to long experience as instructor.

His comments were Anecdotal as he flew no test profiles, and his experience with the 109s were 'I won and here is why', not that Mustang was far superior. In fact he would be first to tell you that he capitalized on 51 strength and 109 weakness in his six victory/one probable/two damaged record.

My experience in a 51 does NOT qualify me as an expert, but I do have more time in one than a young fighter pilot flying his first combat mission. In the case of my father he shot down his first a/c on D-Day after completing a grand total of 2 1/2 hours in the aircraft prior to that day - maybe 6 hours total.

Hopefully, you don't feel a need to apologise and I don't need to justify my 'impressions' or recollections as long as I preface them with the factual background.

Regards,

Bill


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## Crumpp (Nov 17, 2007)

> after completing a grand total of 2 1/2 hours in the aircraft prior to that day - maybe 6 hours total.



Bill,

I am certainly not looking to have you justify your memory.

Am I misunderstanding this? Surely you don't mean your father had 2 /12 hours time in Operational type aircraft. According to the USAAF training regiment, fighter pilots sent to operational units received between 125-200 hours experience flying operational type aircraft. IIRC, the P40 was the most common Operational Type Training aircraft with some P47's and P51B's spread around. Are you sure your Dad was not meaning he flew in either the P51*D* or that particular aircraft for his 2 1/2 hour experience?

It would be interesting to know if your father experience was different and how that came to be.

Sounds like he might have had a similar experience to Oskar Bösch. He flew the Bf-109 from the beginning of the war and had several hundred hours experience in them by the time he transferred to an FW-190 equipped unit. There he received 40 minutes of ground instruction and a 20 minute flight doing three touch and go's. He then flew his first combat mission in the type.

This is contrast to the post - 1943 Luftwaffe pilots who received 25-35 hours total flying time in operational type aircraft before being posted to a combat unit.

All the best,

Crumpp


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## Glider (Nov 17, 2007)

Al, Many thanks for your posting, much appreciated


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## Soren (Nov 18, 2007)

Bill,

Glad to hear it, as I was way too quick to pull the trigger back there for which I definitely feel the need to apologize.

And Salute to your father and all the other brave souls the world over who risked their life for their country loved ones back then


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## DerAdlerIstGelandet (Nov 18, 2007)

lesofprimus said:


> I think he was referring to Soren Chris, not u...



Yeah I figured that out, and we worked it out in a PM. This Flu has been killing me and I have not been able to shake it for the last week.


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## drgondog (Nov 19, 2007)

Crumpp said:


> Bill,
> 
> I am certainly not looking to have you justify your memory.
> 
> ...



No BS on this Gene. He had 1755 hours in Training Command, volunteered for AVG, etc before finally getting out into a B-26 outfit - was ready to go to (th AF as a replacement when his application for Fighters (same time as B-26) came in. He had 160.15 hours in P-40 and 40.55 as a/c in B-26 by time he went to England on May 25, 1944. Zero time in 51. He was a Captain at the time.

Fighter school in P-40's at Tallahassee, ETO replacement pool at Goxhill and Clay Kinnard intervened and had him transferred after 4 hours (i missed 1.5 in his logbook) to 355th FG after 5 days total elapsed time at Goxhill. He and Clay went to school together and were extremely close friends. Clay puuled some stings to get dad into 355th.

On D-Day he flew his first mission of 3.15 hrs Area Patrol, then flew the second Area Patrol when he got his first score on same day. So in all, 4.0 and three landings before xfer and 3.15 on first mission.. I should have looked more closely so I missed the extra 1.5

He was still Captain but 354 Squadron CO after 55 days, a major for six weeks, and Lt. Col and Group Exec of 355FG on October 26, 1944

He was not typical.

Regards,

Bill


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## Crumpp (Nov 27, 2007)

Thanks Bill for the reply on the board and the emails. I have enjoyed corresponding with you.

Here are the other estimates I promised.

Here is the Nzmax estimates that were requested on the Spitfire Mk IX and the Bf-109F/G/K series.

All the estimates are at take off weight, clean configuration overloaded fighter variant.

Here is the Spitfire Mk IX Merlin 61:






Here is the Bf-109F4 1.42ata:






Here is the Spitfire Mk IX Merlin 70:






Here is the Spitfire Mk IX Merlin 66 +18:






Here is the Bf-109G2 1.42ata:





Here is the Bf-109G6 1.42ata:






Here is the Bf-109G14ASM 1.8ata:






Here is the Spitfire Mk IX Merlin 66 +25:





Here is the Bf-109G10 1.8ata:






Here is the Bf-109K4 1.8ata:





Here is the Bf-109K4 1.98ata:





Enjoy!

All the Best,

Crumpp


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## Kurfürst (Nov 28, 2007)

Great stuff, Crumpp, it looks very reasonable values to me ! 8) 

Is this for SL or?


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## Soren (Nov 28, 2007)

Excellent Crumpp, very good work!

The figures look very realistic and corresponds with what I expected. (Did an analysis myself which agrees very much with your charts as-well)

Again thanks!


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## Soren (Nov 28, 2007)

I think its at 10,000 ft Kurfürst, looks to be so.


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## lesofprimus (Nov 28, 2007)

Wow, some serious work Crumpp.... Now, what I'd like to see, is a composit of all the graphs u made, different colors representing each plane... THAT would be huge...


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## Soren (Nov 28, 2007)

That would indeed be great Les.


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## Crumpp (Nov 28, 2007)

The speeds are Knots Equivalent Airspeed so they are easy to convert to any altitude. The engine is data is good up to 1st stage/gear FTH.

The engine data is easy to change to whatever altitude we want.

Glad to be of help!

All the best,

Crumpp


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## Crumpp (Nov 28, 2007)

My charting skills in xls are not the best. I need to figure it out and then I will combine the lift lines and multiple charts.

Then it will be very useful!

All the best,

Crumpp


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## HoHun (Nov 28, 2007)

Hi Crumpp,

>My charting skills in xls are not the best. I need to figure it out and then I will combine the lift lines and multiple charts.

I'd recommend Gnuplot. It's free, and it works just like you'd expect. You could do it in Excel, but that's hundreds of clicks in an awkward interface.

gnuplot homepage

Here is an example script:

set terminal png
set output "test.png"
set xlabel 'Speed [km/h]' 
set ylabel 'Altitude [km]' 
set label
set xrange [500:700]
set yrange [0:10000]
set xtic 20
set ytic 1000
set grid xtic ytic
set key box bottom spacing 1 samplen 1
plot \
'F4U-1D.txt' using 2:1 w l lt 1 lw 2 title 'F4U-1D',\
'F4U-1D_2.txt' using 2:1 w l lt 1 lw 2 title 'F4U-1D 2nd sample'

Here is the content of the F4U-1D.txt file (note the "using 2:1" applied to this file, meaning speed is on the x-axis and altitude on the y-axis). The file "F4U-1D_2.txt" is basically the same but supposed to contain different figures.

---cut-------------

0.00	576.02
579.12	567.98
4693.92	648.43
5273.04	640.38
6065.52	658.08
7620.00	637.16
9144.00	614.64

---cut-------------

Regards,

Henning (HoHun)


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## Crumpp (Nov 28, 2007)

Thanks Henning!

I downloaded it and will play with it. I like some of the features it has especially the error range plots. You could show the normal performance variation of a design.

All the best,

Crumpp


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## HoHun (Nov 28, 2007)

Hi Crumpp,

>I downloaded it and will play with it. I like some of the features it has especially the error range plots. You could show the normal performance variation of a design.

Glad you like it 

Be warned that there is an error in my sample script: I left an extra "," behind the second line that will mislead Gnuplot to expect more graph specifications that I actually provided.

I'll edit that out, but only after I have mentioned it here so you know about the changes. It could be terribly confusing if you had already copied the flawed script and I'd make the edit without telling you! 

Regarsd,

Henning (HoHun)


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## Crumpp (Nov 28, 2007)

Thank You!


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## Soren (Nov 30, 2007)

Another great fighter to add is the Ta-152 H-1, with its highly efficient high AR wing it was a formidable turnfighter. The high AR made sure that the L/D ratio was very high, and coupled with the high CLmax of the NACA 23000 series airfoil this made for a lot of lift for a minimum amount of drag.

Ta-152H-1 wing AR: 8.94.

L/D ratio = Lift to drag ratio.

The more lift you have pr amount of drag the better, and the less your energy loss is going to be in maneuvers, and the higher the AR the higher the L/D ratio. 

Higher AR wings also have the advantage of producing a higher amount of lift pr. area in the first place - forgetting about the L/D ratio.

*L/D ratio at an AR of 4:*






*L/D ratio at an AR of 9:*





As you can see the wing with an AR of 9 has over twice as high a L/Dmax and optimum CL.


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## Glider (Nov 30, 2007)

One question about the TA152H as a high altitude fighter. Those wings could I think have been a significant problem as very high altitudes.

I have only flown a glider a couple of times at high altitude and I was briefed about the absolute requirement of being careful about the airspeed I flew at. The difference in airspeed between encountering a stall and a shock stall was very small, around 10 knots and the VNE was also impacted. For obvious reasons any form of manoevering had to be very smooth and slow.
I know that this isn't specific issue with gliders, the Lockheed U2 had similar problems and I would have thought the 152 must have followed as there isn't a magic cure for this, even today.

I have no access to any tests undertaken by the 152 and was wondering if this problem had ever some up.


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## Soren (Nov 30, 2007)

Glider, a glider (  ) is a different beast than a powered a/c. Also I'm wondering why you would ever be warned about a shock stall in a glider as they don't often reach their critical mach number  I can see why the U2 jet had this problem though, but the Ta-152H wouldn't be susceptible to this unless in a very high speed dive.

High AR wings are necessary for high altitude fighters as a very efficient and high lift wing is needed at high altitudes in order to preserve a good degree of maneuverability. 

PS: The AR of a glider's wing is usually around 12-14.


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## FLYBOYJ (Nov 30, 2007)

It's not a matter of the glider (or powered aircraft) hitting its critical mach number, its a matter of exceeding Vne based on TAS at altitude. The Ta-152H like any other aircraft could be affected by this. One would have to look at the aircraft's Vne, service ceiling, maximum speed and calculate that in a hypothetical setting at altitude.


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## Glider (Nov 30, 2007)

Soren said:


> Glider, a glider (  ) is a different beast than a powered a/c. Also I'm wondering why you would ever be warned about a shock stall in a glider as they don't often reach their critical mach number  I can see why the U2 jet had this problem though, but the Ta-152H wouldn't be susceptible to this unless in a very high speed dive.
> 
> High AR wings are necessary for high altitude fighters as a very efficient and high lift wing is needed at high altitudes in order to preserve a good degree of maneuverability.
> 
> PS: The AR of a glider's wing is usually around 12-14.



We were carefully briefed because people didn't want us to die, and I was willing to listen, as I didn't want to die. Simple really.

I am very aware of a gliders wing and how to fly them. I am interested as to your assumption that the 152 wouldn't be susceptible to shock stall and VNE problems, when ALL other aircraft that I know of with this wing configeration, both then and now are. 
There is no magic formula and if you flew on that basis then you would be in serious trouble very quickly.


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## Soren (Nov 30, 2007)

I know FLYBOYJ, however a glider has a much much lower Vne than any respectable WW2 piston engined fighter, so comparing the two is pretty ridiculous. 

*Glider,*

As to why I think the Ta-152 wasn't susceptible to shock stall unless in a high speed dive: Simple, look at the top speed of the aircraft, 760 + km/h in straight flight, and the Vne is 850 km/h. - Hence why no such problems were ever registered or noted by any Ta-152 pilot.

That the U2 experienced problems with shock stall is understandable, its a jet aircraft with long slender straight wings - not a good combination in all situations. The U2 mind you also had a higher wing AR of 10.6, and gliders usually have a wing AR of 12-14.


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## Crumpp (Nov 30, 2007)

Hi guys,

Soren you are correct in that the high aspect ratio of the Ta-152H series is the key to it's high altitude performance.

However what both Glider and FlyboyJ are telling you is correct too.

While there are multiple reasons why we can establish a design Vne, the two major reasons are q-limits and mach limits.

Q-limits are also termed our "flutter limits" and generally form our lower altitude restrictions. Our designs harmonics are such that the aircraft structure will most likely fail. There are generally two zones of restriction placed on the aircraft. First is the area of damage and second restriction is at the failure point. 

Now some might erroneously think this gives a pilot license to violate the damage zone. It does not, for damage to an airframe will obviously weaken the structure. One harmonic or loading condition that would not normally cause damage to an intact airframe may now cause total failure in the damaged one at a much lower loading or different harmonic. 

At high altitudes though the mach limits are our major restriction. 

*As FlyboyJ points out, our high TAS due to density effects means we are traveling at a higher mach number for the same Equivalent Airspeed.*

M = VTAS/a
a = a<sl> * SQRT (theta)

Velocity in TAS divided by local speed of sound.

Local speed of sound equals the speed of sound at sea level multiplied by the square root of the temperature ratio.

For example, lets take an aircraft traveling at 250KEAS at sea level and see how mach changes between sea level and FL33 or 33,000 ft.

250KEAS at sea level = 250KEAS * SMOE(1) = 250KTAS

250KTAS/661.74KTAS = Mach .37

That same 250KEAS at FL33 becomes:

250KEAS*SMOE(1.7291) = 432.28KTAS

432.28KTAS/581.85KTAS = Mach .74

At mach .74 a subsonic airfoil most definitely is experiencing shock build up and supersonic flow. We are beginning to experience divergence effects on both our drag and lift forces.

Some of the effects of force divergence are:

1.	An increase in Cd for a given Cl <our L/D _shape_ is changing>
2.	A decrease in CL for given AoA <L/D curve change>
3.	Change in the pitching moment as the Aerodynamic Center shifts <stability and control points shift>

So even though the aerodynamic forces on the aircraft are exactly the same at altitude and 250KEAS, the Mach number is much higher.

This is an environmental effect that all aircraft have to deal with at high altitudes. High aspect ratio wings are ideal because they develop low induced drag and higher efficiencies in high CL low velocity flight. As you have seen from our airspeed computations, aircraft at high altitudes will spend the majority of their time at Equivalent Airspeeds that represent the low velocity flight realm to the aerodynamic forces due to mach restrictions of the environment.

All the best,

Crumpp


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## Soren (Nov 30, 2007)

I know all this very well Crumpp, but you can't compare a glider to a fighter a/c.

The Ta-152H would ofcourse experience shock stall before an a/c with more stubby (lower AR) wings, but at 760 km/h there were no problems, and since the Vne was 850 km/h I'd expect no such problems until then. The U-2 is a jet aircraft of very low drag so the Vne can be reached quickly by this a/c, and thus problems with shock stall would've been very apparent to the engineers when designing the a/c, they knew it was going to have problems at very high speeds.

PS: I noticed Glider said he was warned about shock stall when released at high altitude, which I understand, I missed that part to begin with. Starting at high alt you have to be careful when descending in a glider, no doubt.


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## FLYBOYJ (Nov 30, 2007)

Soren said:


> I know all this very well Crumpp, but you can't compare a glider to a fighter a/c.
> 
> The Ta-152H would ofcourse experience shock stall before an a/c with more stubby (lower AR) wings, but at 760 km/h there were no problems, and since the Vne was 850 km/h I'd expect no such problems until then.


Only if the OAT was such that TAS will remain in sync to the operating limitation of 850 Vne. Also consider that prior to exceeding Vne you're in a "caution" range where any abrupt maneuvers or turbulence can damage the aircraft. Just because you're at altitude at 700 km/h doesn't mean you're pulling 3 or 4 Gs.


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## Soren (Nov 30, 2007)

Roger that FLYBOYJ and no objections from me about that either. 

My point is that at all the normal flight envelopes of WW2 fighters the Ta-152 wouldn't be experiencing any problems with shock stall, but approach the Vne of 850 km/h and then we can begin to talk about the possibility of a shock stall.


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## Crumpp (Nov 30, 2007)

Hi Soren,

I wasn't trying to come across as a know it all or talk down to you. Just to explain the effect to all of high AR wings on a subsonic airfoil and why they are important to high altitude performance whether you are in a glider or a fighter. The reason for that explanation is so that there are no misunderstanding's in the conversation.

I apologize if I came across as talking down to you.

Nobody is putting out any wrong information. What glider is saying is very true AND what you are saying is very true.

Our mach characteristics are primarily dictated by _airfoil_ choice. Critical mach is a function of the Coefficient of pressure of the airfoil section and the free stream mach number. Shock stall is a function of critical mach number.

Getting the most out of our airfoil choices at a given aerodynamic force is affected by Aspect Ratio and is a property of the _wing_ design. At high altitudes we want a _wing_ that performs well at low velocity aerodynamic forces if we use a subsonic _airfoil_.



> Just because you're at altitude at 700 km/h doesn't mean you're pulling 3 or 4 Gs.



Absolutely. AT 700kph and 33,000 feet, we are traveling at ~210KEAS and mach .65 using NACA 1922 standards. Just hazarding a big guess, I imagine a Ta-152H can still quite well especially in comparision with a design that is not optimized for high alititudes.

All the best,

Crumpp


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## Glider (Nov 30, 2007)

Soren said:


> PS: I noticed Glider said he was warned about shock stall when released at high altitude, which I understand, I missed that part to begin with. Starting at high alt you have to be careful when descending in a glider, no doubt.



'When released at high altitude' Ouch that hurt. It took me about 2.5 hours to get up there and about 3.5 to come down again.

I retire bruised


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## delcyros (Dec 1, 2007)

Aerodynamically, gliders and the Ta-152 do both have high aspect ratio wings and beside other things follow the same principles. I second Gliders experiences.


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## Crumpp (Dec 1, 2007)

> Just because you're at altitude at 700 km/h doesn't mean you're pulling 3 or 4 Gs.



To give the readers an idea of the effects on the Ta-152, critical mach for the NACA 23015.3 is ~ mach .655 in level flight.

Changing this to CLmax drops our critical mach to ~mach .5.

So at a velocity of 700kph at 33,000 feet we are just a fraction below the critical mach but our maneuvering is limited.

Of course everyone understands that all aircraft are effected by this not just the Ta-152. Airfoil choice will determine the critical Mach number.

Our High Aspect Ratio wings on the Ta-152 will do much better when the equivalent airspeed drops to the low velocity realm than a Lower Aspect ratio wing on the same design. 

A short Aspect ratio wing is optimized for high velocity equivalent airspeeds and will not do well at all at high altitude because of mach limits in comparison.

All the best,

Crumpp


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## Soren (Dec 1, 2007)

*Crumpp,*

We agree completely.

And no worries, you didn't come across as a know it all or as trying to talk down to me in any way, so no need for any apologies. 

*Glider,*

Many apologies, I didn't know you went up there all by yourself, kudos to that!

Hope that eased the bruising


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## Glider (Dec 1, 2007)

The wife has told me to quit sulking. No worries.


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## Soren (Dec 1, 2007)

Wives can be so strict!


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## Soren (Dec 1, 2007)

Ta-152H-1 performance:

Top SL speed: 580 - 597 km/h
Top speed: 752 - 760 km/h at 12.5 km

Time to Climb 10km (32,808 ft): 10.1 min

Service ceiling: 15.1 km (49,540 ft)

Take Off Roll: 295m (967 ft)
Take Off distance to clear 20m high object: 495m (1,624 ft)


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## Soren (Dec 5, 2007)

Crumpp,

How much into jet-propulsion are you ? Would you be able to produce a similar chart for the Me-262 sometime in the future ?


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## Crumpp (Dec 5, 2007)

> How much into jet-propulsion are you ? Would you be able to produce a similar chart for the Me-262 sometime in the future ?



Thrust producer theory is a standard part of the curriculum for the degree Soren.

I would have to modify or create a new spreadsheet but it can be done.

I really haven't had anytime to even look at combining the charts or use Henning's program.

It's Christmas time, annual time, and airplane insurance time at my house.

All the best,

Crumpp


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## Soren (Dec 6, 2007)

Roger that Crumpp, I understand completely, a very busy time for me too.

Merry Christmas !


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## piperboy66 (Jul 1, 2010)

Why don't we ask/read about what the Fleet Air Arm guys who flew them in the North Atlantic think/thought about that? !We flew them too! In fact, in both the Atlantic and Pacific - the last VC of the war was to a Canadian flying off HMS Formidable for sinking a japanese destroyer........


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## wwii:)aircraft (Dec 6, 2010)

I would agree in saying that the corsair overpowered the G-6 seing that it was much faster, at higher speeds was more maneuverable and always could out dive the bf 109; not to mention the corsair was a muchh more stable gun platform and we already know how effective the 6x .50cals were against the bf 109 (in the P-51). But when you move onto 1944 when you have variants such as the G-14, DB605AS powered bf 109s, and then the K the F4U-1D not only is either match or overpoered in speed but the bf 109s rate of climb is also enhanced.


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## davebender (Dec 6, 2010)

I think it's safe to assume 3cm mine shells would put a Corsair down for the count. So both aircraft have enough firepower to destroy the opponent. Whoever hits first will win.


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## AlfaKiloSierra (Aug 23, 2019)

The performance relies greatly on altitude. At 15000ft the Bf 109 K even with only 1.8 ata outruns F4U-1 by some nearly ten miles per hour [1] [2]. Look at that chart closely and the F4U is about even with the 109 at its supercharger critical altitudes. That was speed,

climb. [3] [1] shows that Bf 109 K climbs slightly better, but significantly better at around 12000ft. The F4U-1 pilot should seek to fight somewhere near any of its supercharger critical altitudes, and not at its supercharger gear switch altitudes. As for turn rate, the F4U-1 looks better by wing loading, but I cannot find proof that it indeed turns better.

Note: I used the F4U-1 because I cannot find any report of a 2.0ata Bf 109 K, and if I do, I'll bring up the F4U-4 to compare to it.

[1] Spitfire Mk XIV versus Me 109 G/K 
[2] http://www.wwiiaircraftperformance.org/f4u/50030-level-final.jpg 
[3] http://www.wwiiaircraftperformance.org/f4u/50030-climb-final.jpg


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## FLYBOYJ (Aug 23, 2019)

AlfaKiloSierra said:


> The performance relies greatly on altitude. At 15000ft the Bf 109 K even with only 1.8 ata outruns F4U-1 by some nearly ten miles per hour [1] [2]. Look at that chart closely and the F4U is about even with the 109 at its supercharger critical altitudes. That was speed,
> 
> climb. [3] [1] shows that Bf 109 K climbs slightly better, but significantly better at around 12000ft. The F4U-1 pilot should seek to fight somewhere near any of its supercharger critical altitudes, and not at its supercharger gear switch altitudes. As for turn rate, the F4U-1 looks better by wing loading, but I cannot find proof that it indeed turns better.
> 
> ...



Just a tip - be advised that this thread has been inactive for almost 9 years. Some of the original posters may still be around, others may be long gone. Nothing wrong with resurrecting an old thread but you may not get a response if you direct your response to a specific post.

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