# P-40 vs. ME-109



## Elvis (Mar 15, 2008)

Sort of another "Which would win that fight" question.

I just realized that I've never seen anything written on how these two planes stacked up against each other.

I know they had to have met at one point or another during the war.

Anyone got any kind of kill ratio's they want to post, or pit performance figures against these two?

Seems like an almost even match, to me, if the _correct_ varients were pitted against each other.



Elvis


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## HoHun (Mar 15, 2008)

Hi Elvis,

>Seems like an almost even match, to me, if the _correct_ varients were pitted against each other.

Hm, I remember reading a comment by a P-40 pilot who flew the type over North Africa - he said something like "constant vigilance and mutual support were our only hope".

A clean P-40N-1 at 3000 rpm, 57" Hg boost, might be able to compete with a Me 109G-2 below 3000 m speed-wise, but its higher weight would mean that it still would be disadvantaged in every aspect concerning energy, i. e. climbs and sustained turns.

Maybe you are thinking of the P-40F, but the data I have seen indicate that even at +10.36 lbs/sqin, 3000 rpm (choice of units shows this is from a Commonwealth test , it would not be competitive against a Messerschmitt Me 109 variant later than the Emil. Though it had a two-speed supercharger, the early Packard Merlins were not quite as powerful as their Rolls-Royce powerplants yet.

Regards,

Henning (HoHun)


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## slaterat (Mar 15, 2008)

A couple good books on this topic are "Kittyhawks Over the Sands" and "Kittyhawk Pilot" both by Michel Lavigne and James "Stocky" Edwards. Edwards was a Canadian ace with 20 or so kills in the Desert Airforce. 
Kittyhawk Pilot , Edwards biography, was published in 83 so it would be hard to find but copies of Kittyhawks Over the Sands are still available. Both books are excellant with lots of first hand accounts and cross referencing of kills /claims.

Slaterat


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## Elvis (Mar 15, 2008)

Ok, so it sounds like this is almost a lost cause.

Thanks for your comments.
Much appreciated.

--------------

Slaterat,

Thanks for the recommendations.
I'll look for those at the local bookstore.



Elvis


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## renrich (Mar 15, 2008)

I believe that Marseille(may have spelled that wrong) enjoyed a lot of success against P40s in N Africa. If I remember correctly the day he allegedly had 17 kills several were P40s. Other LW pilots probably had good success against P40s also.


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## claidemore (Mar 15, 2008)

The other area the Bf109 met P40's was on the Eastern Front. 
Here's an excellent link about Lend-lease planes in Russian service. The interview iwth Kulakov is particularly good, he flew P40's against 109s. There is another online interview story of a Russian P40 pilot but I can't remember where it is. 

Articles

Those interviews of Russian pilots I find very enlightening. 

Theres some good stuff about P39s in there as well. 

Claidemore


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## Graeme (Mar 15, 2008)

Australia's 3 Squadron operated Kittyhawks and Tomahawks with success in North Africa, but I don't know the final Bf 109 tally...


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## claidemore (Mar 15, 2008)

James _Stocky _Edwards, RCAF, flew Kittyhawks with 260 Squadron RAF in North Africa. He got 13 or 14 kills with the P-40 before switching to Spitfires with 417 Squadron. He's credited with shooting down 51 kill ace Otto Schulz, and it's also possible that he shot Marseille down. 

Edwards was on the deck, running for home, came over a hill and saw a 109 and put a burst into it but didn't stick around to see what happened. A day or two later they heard Marseille had gone down where _Eddy _had shot at the 109. The story was Marseilles engine quit, he bailed out and was killed. Edwards was alone at the time, nobody saw him shoot, so he was never credited and Luftwaffe maintains it was a flying accident. 

Last I heard Edwards was still live and kickin near Vancouver B.C. 

Here's his take on P-40s. 



> On the P40 series:
> 
> "... not an easy aircraft to fly properly and as a result, we lost a good number of pilots while training."
> "In the first few months after conversion to Kittyhawks, all the squadrons lost heavily to the 109s."
> ...



a Utube link with some RAF,RAAF, RNZAF P40 footage. 


_View: https://www.youtube.com/watch?v=Q9CwP_JMI2A_


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## Wildcat (Mar 15, 2008)

Graeme said:


> Australia's 3 Squadron operated Kittyhawks and Tomahawks with success in North Africa, but I don't know the final Bf 109 tally...



From the excellent book "Desert Warriors, Australian P-40 pilots at war in the Middle East and North Africa 1941-1943" By Russell Brown. I added the confirmed 109 kills up as 49 plus a half kill shared with another squadron for 3 sqn RAAF.
For 450 sqn RAAF, I got 26 109's destroyed out of 49 enemy a/c destroyed by this squadron in North Africa.


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## Graeme (Mar 15, 2008)

Wildcat said:


> From the excellent book "Desert Warriors, Australian P-40 pilots at war in the Middle East and North Africa 1941-1943" By Russell Brown. I added the confirmed 109 kills up as 49.75 for 3 sqn RAAF.
> For 450 sqn RAAF, I got 26 109's destroyed out of 49 enemy a/c destroyed by this squadron in North Africa.



Well we knocked quite a few 109's out of the sky! Thanks Wildcat! Been away for a while mate? Enjoying the heat? What weather you get, we get in a day or so


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## Wildcat (Mar 15, 2008)

Graeme said:


> Well we knocked quite a few 109's out of the sky! Thanks Wildcat! Been away for a while mate? Enjoying the heat? What weather you get, we get in a day or so



Nah, just been working alot lately. I work outdoors so this heat is killing me!


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## pbfoot (Mar 16, 2008)

claidemore said:


> James _Stocky _
> Last I heard Edwards was still live and kickin near Vancouver B.C.
> 
> Here's his take on P-40s.
> ...


He along with the surviving AVG pilots and any other P40 jocks they can scrounge will be at Geneseo this year along with 11 p40'S this year Vintage Wings is bringing a P40 in with his markings from 260 Sqn .
1941 Historical Aircraft Group Museum in Geneseo, NY
Curtiss P-40 Kittyhawk


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## Elvis (Mar 16, 2008)

Hey, maybe not such a "lost cause" after all!
Thanks to everyone involved for the comments thus far.

----------------------------------

Graeme,

I've got a program on VHS that I taped off the TV back in the mid 90's, concerning a P-40 that was found in Canada in the 80's (IIRC) and restored by an Aussie named Cole Palen (sp?).
The show delved into the restoration of the plane, and had a good bit about the P-40's role with the RNZAF and RAAF during the war.
Part of the program talked a little about 109's as well, and Bobby Gibbes is interviewed, at the unveiling of a (then) newly restored 109.
Wish I had an extra VCR, I'd make a copy for you.
Maybe one of these days, I'll have someone dupe all these movies I taped on VHS back in the 90's, down to DVD and have an extra one made for you (...and kool kitty, too).


Elvis


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## Elvis (Mar 16, 2008)

...and you can say what you want about the Allison, but man, 
_View: https://www.youtube.com/watch?v=Glr8jOzuVuM_.



Elvis


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## Wildcat (Mar 16, 2008)

Elvis said:


> I've got a program on VHS that I taped off the TV back in the mid 90's, concerning a P-40 that was found in Canada in the 80's (IIRC) and restored by an Aussie named Cole Palen (sp?).
> The show delved into the restoration of the plane, and had a good bit about the P-40's role with the RNZAF and RAAF during the war.
> Part of the program talked a little about 109's as well, and Bobby Gibbes is interviewed, at the unveiling of a (then) newly restored 109.
> Wish I had an extra VCR, I'd make a copy for you.
> ...




G'day Elvis, that program is available on DVD, probably be able to get it through EZYDVD, that's were I got my copy from. That Kittyhawk was owed by Col Pay, who was unfortunately killed a few months back. His latest P-40 is painted as one flown by Bobby Gibbes, who also passed away a few months back aswell.
The book I mentioned above shows 16 Australians achieved ace status whilst flying P-40's in the desert. Of these Andrew Barr is credited with 5 109 kills (from a total of 12 victories), Bobby Gibbs with 5 + 1 shared 109 kills (1 not officially recorded) and Clive Caldwell with 10 109 kills (from his total of 27+3 shared).


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## Elvis (Mar 16, 2008)

Wildcat,

Thanks for the updated info and the correction on Col Pay's name (turns out Cole Palen was associated with The Old Rhinebeck Aerodrome).
Sorry to hear of the passing of both those gentlemen.



Elvis


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## phoenix7187 (Mar 16, 2008)

I'll add these 2 things 70% of pilots that got shot down in WWII did know they were under fire. Second The P-40 was an out dated before it entered service. The RAF used it in the support roll not so much fighter roll (yes some were due to necessity) It really wasn't up to air war in the ETO. From what I know about the P-40 I would want to take it into combat against 109F or better. your just asking to be another hash mark on some 109's rudder.


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## claidemore (Mar 16, 2008)

I get a kick out of how most articles about the P40 start: 

"The United States was 'forced' to put the P40 into mass production because it was the 'best' fighter they had." 

It's always worded like an apology. Why not write it: 

"The United States put their best fighter into mass production, the Curtiss P-40!"

Soviet lend-lease P-40s were used against various models of the 109 ranging from the Emils to 109G6's. They certainlly weren't able to dominate the 109s, very few planes did, but they did hold their own. 

In one of the Soviet P40 pilot interviews he goes on quite a bit about the interviewers 'obsession' with max speed. He points out that in combat max speed was seldom attained,(when it was it was usually in a dive where the P40 held an advantage) and wasn't a critical factor in a fight. Acceleration was more important than max speed in his opinion and according to him the P-40 could accelerate quickly enough to catch a 109 before it's higher max speed could pull it out of range.

From _Wiki_:


> The P-40 was generally considered roughly equal or slighly superior to the 109 at low altitude, and inferior at high altitude. Though this varied depending on the specific variants, the P-40 usually had an edge over Bf 109 in horizontal maneuverability, absolute dive speed, and structural strength; was roughly equal in firepower, slightly inferior in speed and outclassed in rate of climb and operational ceiling



_Wiki _has 239 Wing RAF in the Western Desert as claiming 283 kills vs 100 losses. Thats almost a 3-1 claim/loss ratio. If you cut the kills in half for over claiming and you still have a 1.4/1 positive kill ratio. Against F and G model 109s thats pretty good. 

BTW, I consider the shark nosed Kityhawks in RAF desert camo paint scheme to be one of the most visually appealing fighters of WWII. 

Claidemore


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## Soren (Mar 16, 2008)

Claidemore,

The P-40s didn't just shoot down fighters - something which is often forgotten when talking kill/loss ratios.

As for the topic; The Bf-109 is the best hands down. Can't think of an area besides roll rate where the 109 wasn't better than the P-40.


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## claidemore (Mar 17, 2008)

Soren said:


> Claidemore,
> 
> The P-40s didn't just shoot down fighters - something which is often forgotten when talking kill/loss ratios.
> 
> As for the topic; The Bf-109 is the best hands down. Can't think of an area besides roll rate where the 109 wasn't better than the P-40.



True, they didn't just shoot down fighters, but most of the stuff they were shooting at shot back.  But you are right, that kill ratio would be against all types of planes. 

I agree that the 109 was a better plane overall. 

Advantages of the P40 near as I can tell: 
a) firepower, 6 x.50 mg compared to 1x20mm and 2 x7.92 in the F and G2 109s.(the two wingpod guns would give the advantage to the 109G2 here)
b) roll rate as you pointed out, so it gets into a turn quicker
c)turn rate, P40 pilots said they could turn better than the 109, and the RAE test show the P36 Hawk turning better than the 109. Since the P40 has more horsepower available, it should turn as good or better than the P36. 
d) max dive. maybe
e) visibility from the cockpit
f)range, 650 miles compared to 550?
g)wider landing gear, safer on takeoff and landing


The 109 was faster, climbed better, possibly had dive advantages, and had better high alt performance. I'd say the 109 cockpit layout was better too, the P40 cockpit always looked confusing and cluttered to me.


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## HoHun (Mar 17, 2008)

Hi Claidemore,

>In one of the Soviet P40 pilot interviews he goes on quite a bit about the interviewers 'obsession' with max speed. He points out that in combat max speed was seldom attained,(when it was it was usually in a dive where the P40 held an advantage) and wasn't a critical factor in a fight. 

Hm, to give a rough indication: At 6 km and up, the Me 109G-2 probably cruised around 50 km/h faster than the P-40 could do at emergency power. This limits the tactical options of the P-40 pilot considerably ...

In fact, if there is one universal, overriding trend in WW2 fighter design, it's the trend towards higher top speeds at the expense of manoeuvrability. Obviously, top speed was what combat experience showed to be critical, even if the mileage of individual pilots varied  (In assessing the interview, you also have to take into account that a pilot necessarily focuses on the strengths of his aircraft because that's what he needs to do to survive.)

"Though this varied depending on the specific variants, the P-40 usually had an edge over Bf 109 in horizontal maneuverability"

With two aircraft using a very similar airfoil, having a similar wing loading and a similar power output, I really wonder how the one that's heavier than its opponent by a ton got the reputation of superior "horizontal maneurability"  No way!

Regards,

Henning (HoHun)


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## claidemore (Mar 17, 2008)

Hi Henning,

I get a wingloading of 35.5 lbs/sq ft for P40k (Kittyhawk III)and 39 lbs for a 109G2. Thats figuring 6800 lbs for the 109 and 8400 for the P40, 1600lbs heavier (pretty close to a ton). I've seen lighter and heavier weights for the 109 even on the same document.
I get a P40K @1325hp and 109G2 @1335 (1.42ata) and 1455 takeoff power. 
Haven't found a stall speed for P40 yet. 

I might be mistaken about the RAE tests, I can't seem to find it now, and I might be confusing them with the Rechlin tests against a Curtiss,Spit and Hurricane. Don't know if the Curtiss referred to is a Hawk 75 (radial) or a Tomahawk. In any case, the Rechlin test says: 



> Before turning fights with the Bf 109 E type, it must be noted in every case, that all three foreign planes have significantly smaller turning circles and turning times.


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## Glider (Mar 17, 2008)

This was a radial Curtis


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## claidemore (Mar 17, 2008)

Glider said:


> This was a radial Curtis



Agreed. I checked the date on the Rechlin test, and it's almost impossible for Luftwaffe to have a Hawk 81 or Tomahawk at that time. Has to be a French Hawk 75A.


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## renrich (Mar 17, 2008)

Some info on the P40, all in the Med. Flew 67059 sorties, had 553 losses, not a bad ratio but intensity of combat probably not as great as in Europe. The P40 had 592 kills in the Med, so losses to kills were about even. These, I believe, are all sorties by AAF pilots.


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## Soren (Mar 17, 2008)

claidemore said:


> Hi Henning,
> 
> I get a wingloading of 35.5 lbs/sq ft for P40k (Kittyhawk III)and 39 lbs for a 109G2. Thats figuring 6800 lbs for the 109 and 8400 for the P40, 1600lbs heavier (pretty close to a ton). I've seen lighter and heavier weights for the 109 even on the same document.



The 109 has got automatic LE slats, that's the deciding difference, hence why it turns much better than the P-40. Marseilles for one shot down quite a few Spitfires, Hurricanes P-40's in turn fights, cause he was not afraid of the slats unlike the British test pilots and some of the early Emil pilots. 



> I get a P40K @1325hp and 109G2 @1335 (1.42ata) and 1455 takeoff power.



Hence why the Bf-109 has a MUCH better sustained turn rate.

As for the stall speed of the 109G-2, it's 145 km/h clean flaps gear up.



> I might be mistaken about the RAE tests, I can't seem to find it now, and I might be confusing them with the Rechlin tests against a Curtiss,Spit and Hurricane. Don't know if the Curtiss referred to is a Hawk 75 (radial) or a Tomahawk. In any case, the Rechlin test says:



And it must be stated that this test was not only carried out with an Emil which had frequent problems with its slats jamming and behaving oddly in flight, it was also in 1940, a period where there weren't many experienced pilots in the type. The German test pilot in this case was as vary about the slats as the British test pilots were when they flew it.

The problems only occured in tight turns though, and not in a slow speed straight stall, in which the slats on the Emil worked very well. The stall speed of the Emil is 61 mph flaps gear down and 75 mph clean gear flaps up.

All the problems with the slats were addressed with the introduction of the F series, and from there'on the Bf-109 could did comfortably engage in turning fights with the Spitfire and win.


*Erwin Leykauf, German fighter pilot, 33 victories.*
_"During what was later called the 'Battle of Britain', we flew the Messerschmitt Bf109E. The essential difference from the Spitfire Mark I flown at that time by the RAF was that the Spitfire was less manoeuvrable in the rolling plane. With its shorter wings (2 metres less wingspan) and its square-tipped wings, the Bf 109 was more manoeuvrable and slightly faster. (It is of interest that the English later on clipped the wings of the Spitfire.)
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. This is how I shot down six of them." _

*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 Bf109 could manouver better in turnfight than LaGG, Yak or even Spitfire."_

*Herbert Kaiser, German fighter ace. 68 victories.* 
_"Personally, I met RAF over Dunkirk. During this battle not a single Spitfire or Hurricane turned tighter than my plane. I found that the Bf 109 E was faster, possessed a higher rate of climb, but was somewhat less manouverable than the RAF fighters. Nevertheless, during the campaign, no Spitfire or Hurricane ever turned inside my plane, and after the war the RAF admitted the loss of 450 Hurricanes and Spitfires during the Battle of France." In the desert there were only a few Spitfires, and we were afraid of those because of their reputation from the Battle of Britain. But after we shot a couple of them down, our confusion was gone."_

*Pierre Clostermann, Spitfire pilot.*
_"I tried to fire on a '109' that I spotted in the chaos. Not possible, I couldn't get the correct angle. My plane juddered on the edge of a stall. It was comforting that the Spitfire turned better than the '109'! Certainly at high speed - but not at low speed."_


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## slaterat (Mar 17, 2008)

I can find hundreds of quotes of Spitfires and Hurricanes easily outurning
109s. I can also find quotes from German aces saying they never turned against spits or Hurricanes. Both German and RAF testing confirmed that the 109 was inferior in the turn.

Slaterat


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## Elvis (Mar 18, 2008)

Watched the feature on the P-40 I referred to earlier, that had Col Pay and Bobby Gibbes in it.
According to an interview of Gibbes, upon the unveiling of Pay's (then) newly restored P-40 (Gibbes attended the ceremony), Gibbes said the P-40 had better dive speed than a Spit, and (when flown properly) could turn with the Spit.
Considering how good of a showing the Spit made against the 109, it could be said that the P-40 _could've_ had similar results against the 109 that the Spitfire did.
Gibbes also mentioned that the six 50's of the P-40 was better armorment than the eight 303's of the Spit.
He also talked quite highly of the 109, but didn't mention any comparitives between it and the P-40.


Elvis


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## Kurfürst (Mar 18, 2008)

*Soviet figures for P-40, 109G turn times*, 1000m.

P-40C 18 secs
P-40E 19,2 secs
Bf 109F-2 19,6 secs (this one was in pretty rough shape, so..)
Bf 109G-2 20 secs, 290 m radius

Bf 109E 
from Mtt report, 0 m : 18,92 secs, 203 m
from *Baubeschreibung für das Flugzeugmuster Messerschmitt Me 109 mit DB 601 *: 170 m w/o flaps, 125 meter with flaps. Turn time not given.

*Messerschmitt Me. 109 Handling and Manoeuvrability Tests BY M. B. MORGAN, M.A. and D. E. MORRIS, B.SC.*
_
When the Me.109 was following the Hurricane or Spitfire, it was found that our aircraft turned inside the Me.109 without difficulty when flown by determined pilots who were not afraid to pull their aircraft round hard in a tight turn. In a surprisingly large number of cases, however, the Me. 109 succeeded in keeping on the tail of the Spitfire or Hurricane during these turning tests, merely because our Pilots would not tighten up the turn suficiently from fear of stalling and spinning.

...

The gentle stall and good control under g are of some importance, as they enable the pilot to get the most out of the aircraft in a circling dog-fight by flying very near the stall. As mentioned in section 5.1, the Me.109 pilot succeeded in keeping on the tail of the Spitfire in many cases, despite the latter aircraft's superior turning performance, because a number of then Spitfire pilots failed to tighten up the turn sufficiently. If the stick is pulled back too far on the Spitfire in a tight turn, the aircraft may stall rather violently, flick over on to its back, and spin. Knowledge of this undoubtedly deters the pilot from tightening his turn when being chased, particularly if he is not very experienced._


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## Elvis (Mar 18, 2008)

kurfurst,

Thanks for the informative post, but the only thing I see that whole report really saying is that unexperienced pilots were most likely easier target for more experienced pilots, because they weren't as secure in the performance of their planes.
Kinda funny, because that conclusion would seem like "common knowledge", but now they have PROOF.  

Thanks for the turning figures between the 109 and the P-40, as well.



Elvis


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## Kurfürst (Mar 18, 2008)

Well, obviously between two identical planes its pilots experience that matters, between two different planes however, stall characteristics can be important, ie. how easy it is to push the aircraft to its limits, or in different words, what are the limits for pilots of different skills. 

Good stall characteristics and foolproof handling was one of the 109s fortes for sure. The Spitfire was not so ideal in this respect because of the utter sensitivity of the controls in pitch. I dont know about the P40 in this regard.


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## HoHun (Mar 18, 2008)

Hi Kurfürst,

>Soviet figures for P-40, 109G turn times, 1000m.

>P-40C 18 secs
>P-40E 19,2 secs

Ah, these are the figures I had in mind when I mentioned the P-40 being "a ton heavier".

I've attached the scan of the Soviet data ...

My calculations show the circle time for the Me 109G-2 to be 19.6 seconds at 2600 rpm/1.3 ata compared to the Soviet 20 s.

However, the circle time for the P-40C I calculate as 19.6 s, which is not surprising considering its lower power and higher weight, and the P-40E - which adds another 450 kg of mass - in my calculation comes out at 22.7 s at 3000 rpm/44" Hg, which is worlds apart from the 19.2 s given in the Soviet table.

To give an idea of the proportion: Even if I use the engine power data for the V-1710-81 at 3000 rpm/57" Hg, which yields about 200 HP more at 1 km than the V-1710-39 of the P-40E at 3000 rpm/44" Hg, I still get a circle time of 20.8 s ...

Accordingly, I don't consider the Soviet data on the P-40 variants realistic. Weight really means something in a turn! 

Regards,

Henning (HoHun)


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## claidemore (Mar 18, 2008)

Is the Soviet data tested or calculated?

Claidemore


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## HoHun (Mar 18, 2008)

Hi Claidemore,

>Is the Soviet data tested or calculated?

I know they did quite a bit of turn rate testing, but if that applies to the P-40s listed in the scan, I don't know.

The Soviet data can be be a bit inconsistent at times - for example, I couldn't figure out what their top speed figures mean, as the altitudes given don't match the altitudes you'll find in US documents on aircraft and engine.

With regard to the Soviet turn rate data, there is a set of diagrams listing quite a number of fighter aircraft, but if you use two of these sets to establish the weight of the listed fighters, you'll end up with two different figures for half of the types.

Accordingly, my confidence in the informative content of these Soviet tables and diagrams is somewhat limited.

Regards,

Henning (HoHun)


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## Hunter368 (Mar 18, 2008)

Agreed, I have always found Russian test results........questionable.


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## claidemore (Mar 18, 2008)

There's a few things I've learned about the Soviets and their fighters. 

Soviets were always concerned with maneuverability, and as you pointed out HoHun, they did a lot of turn time tests. Most of the pages describing the various Soviet pilots at Alexandre Savines' _Russian Aviation Museum_ website include turn time figures. Interestingly,(and dissapointingly) they don't list turn times for the P40 on this site. They list the P40C at 3424kb (7532lbs) loaded weight which is a little higher than some sources, but have the P40K at 8400 lbs, which agrees with other sources. I found the figures listed on this site to be pretty reliable when I was researching the Yaks. 

Russian Aviation Museum

The Russians also were notorious for burning out engines in their lend-lease fighters, operating them at max power continuously. This is often quoted as part of the reason for their success with the P39. 

I know that some of the P40s in Soviet service had guns removed or replaced, though the practice was not universal. Don't know if those two things might factor into the turn time numbers they got or not. 

Here's a little quote about the P40s in Soviet service from the 'lend lease site';



> In conclusion, one fact should be noted: three Twice HSU (of 27) in Soviet aviation fought in the Kittyhawk: B. F. Safonov, P. A. Pokryshev (22 personal victories and 7 in group), and M. V. Kuznetsov (22 + 6). Pokryshev and Kuznetsov flew the Kittyhawk for more than a year. Many pilots became aces and HSU while flying the P-40, achieving good combat scores. A number of regiments gained their guards status while flying the P-40. On the whole this aircraft fought well, though the conceptual errors that were built into it significantly reduced the sphere of its effective employment.



And a couple quotes from Nikolai Golodnikov, who flew P40s with 2GvSAP



> We completely abandoned the defensive circle as soon as they re-equipped us with the P-40. The P-40 was equal to the Bf-109F and therefore we had no reason to resort to the defensive circle. No reason at all.
> 
> The Tomahawk and Kittyhawk had different armaments. The Tomahawk had four machine guns—two synchronized heavy machine guns in the nose and a pair in each wing. I have already forgotten the caliber of the wing-mounted machine guns, because we immediately removed them. Perhaps they were standard [they were .30 caliber—JG].
> The Kittyhawk did not have [nose-mounted] synchronized machine guns. It had only six (three in each) wing-mounted heavy machine guns. We removed two of these machine guns immediately, leaving four.
> ...


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## Zarathos (Mar 18, 2008)

claidemore said:


> Soviets were always concerned with maneuverability



May I disagree? Since 1938, when Polikarpow screwed the I-180 and new constructors started to create fighters, Soviet tactics turned away from manoeuvrability. They were more concered since then with speed. And even pre-1938 Soviets were not making "more manoeuvrable" fighters, but they followed the concept of two fighters: interceptor and dogfighter (duo I-16/I-15).

Shortly pre-war it changed and Russians started to make faster and faster fighters at all cost - best example is Yak-3 which was the fastest USSR fighter, but it was so light, that it had tendece to fall apart at higher g-forces. Of course, Russians were interested in turn times and done a lot of tests, but Germans done the same with captured airplanes, and Brits, and US. Find weak spot and tech fighter pilot to exploit them. I have somewhere notes from Polikarpov fighter tactic book, and most manoeuvers were based around high-speed and vertical manoeuvers, not around horisontal manoeuvrability.



> I found the figures listed on this site to be pretty reliable when I was researching the Yaks.
> 
> Russian Aviation Museum



Yes, it is quite good, but it's better to check the data presented there, because some of it is not taking into consideration some... problems of Russian tech. For example - the max speed of Ła-5FN on sealevel is listed with boost, while M-82 engines were not able to engage the boost at such low altitueds. Another example is 655 km/h as max speed of Yak-3. It's also true, but at such speeds any turn with g-force higher then 4g if I good remember resulted in wings flying in one direction and hull in another.

Not to mention, that both max speeds were for prototype or test fighters which were (usualy) made properly. Normal fighters had in most cases troubles with reaching those numbers.

And so on...


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## HoHun (Mar 18, 2008)

Hi Claidemore,

>The Russians also were notorious for burning out engines in their lend-lease fighters, operating them at max power continuously. This is often quoted as part of the reason for their success with the P39. 

Hm, I've heard about that, too, and it seems to match Allied practice in the Pacific (though it was not really maximum power, but actually long-term use of power settings above "maximum continuous"). However, I also remember an interview with a Soviet P-39 pilot who said that he only once or twice used the full 57" Hg boost pressure of his Allison ...

>I know that some of the P40s in Soviet service had guns removed or replaced, though the practice was not universal. 

It would make sense ... though I'm not sure there was enough of a weight saving to justify the high turn rates listed in the scan I posted.

The P-40C would need to be down to about 3100 kg to achieve the 18 s for 360 degrees at 1000 m figure ... the P-40E to 3635 kg. That's a 290 kg for the P-40C and a 205 kg saving for the P-40E compared to the weights listed above.

From a P-40N weight and balance chart, it had 4 12.7 mm MGs for a total of 320 lbs and an ammunition supply of 940 rounds for a total of 280 lbs. If the weights and ammunition capacity per gun were the same of the P-40E, the Soviets would have saved 300 lbs by removing one pair of machine guns and their ammo - or 136 kg. That's not yet enough to reach our target of 205 kg, but of course, they might have tested with a reduced fuel load, too - perhaps that was actually representative for the way they flew in combat, too.

Regards,

Henning (HoHun)


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## Soren (Mar 18, 2008)

Did you use a CLmax of 1.70 for the Bf-109 in your calculations HoHun ?

I'm asking since this is the tested value for the F series.






With that in mind it's quite clear than the Bf-109 G-2 at 2,890 kg easily out-turns the P-40C, E M.


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## Soren (Mar 18, 2008)

The P-40 also featured an airfoil with a slightly lower Clmax than the NACA R2 (Modified Clark Y airfoil) used by the 109. This airfoil was the same as the Spitfire's, the NACA 2200 series, in this case 2215 at the root and 2209 at the tips.


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## kool kitty89 (Mar 18, 2008)

The best all around performer of the "standard" P-40s would have been the P-40M, which was the same as the P-40K except it had a V-1710-81 engine (same as the P-51A and P-40N). This would not be including the lightened P-40L (short range) or the P-40N's with reduced armament. The Tomahawks of the AVG were a special exception with non-standard (up to 220 higher HP than standard) engines allowing 370 mph top speed and along with there lighter weight (P-40B configuration, though converted from P-40C) would have been the best true "dogfight" performing P-40s.

That aside the wing loading of the P-40M would be similar to the P-51A (albeit the P-40 had a higher CL) and power loading would be slightly worse. Thus climb would be similar (slightly less) and turn rate would likely be slightly less than the P-51 though radius would likely be better. The P-51A was also ~40 mph faster than P-40M. The V-1710-81 had max 1,200 hp takeoff (limited to prevent over boost) and WEP from 5,000-10,400 ft was 1,480 hp. Critical altitude for 1150 hp Mil power was ~18,000 ft. Thus altitude performance was similar to the Merlin engined P-40s, but with much better low alt performance.

I haven't seen many specific figures (with altitudes, load, and power settings listed) for the P-40M or the N of similar configuration, but the P-51A info is here: http://www.wwiiaircraftperformance.org/mustang/p-51a-1-6007.jpg Mustang (Allison Engine) Performance Trials

The only real statistics with a good range of info for the P-40M I've seen is in the historical performance info from the Il-2 flight simulator. I can post them later, but I'm not sure of the accuracy. (though from the comparisons I've seen most data is quite accurate and all values which were calculated and not test data are listed as such)


The P-39 would have been much more closely matched to the 109 up to 15,000 ft than the P-40 was with a better turn rate, power loading, and initial climb than most P-40s. Hoever the MAX range of the P-39 was about 50% less than the P-40, though still better than the 109. (with 91 imp gal drop tank the P-39 could manage ~1050 mi, while the p-40 could manage ~1,600 mi at optimum cruise) The range difference is a major reason (along with its ruggedness and the fact that someone taler than 5'8" could fly it) that made the P-40 more successful in the PTO than the P-39. Plus the armament was better suited for dogfighting.


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## Soren (Mar 18, 2008)

The Bf-109 G-2 is a better turn fighter than the P-39 if both a/c are flown to the absolute limits, seeing the 109 features a high lift wing and lower power-loading. 

The std. evading tactic for German 109 pilots was a hard climbing turn, something no VVS fighter could follow.


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## kool kitty89 (Mar 18, 2008)

I said the P-39 was a closer match not equal or better. Also if the USAAF had the 109 it would not have been as useful as the P-40 was as it lacked the range for many missions the P-40 did. (it could manage a combat radius of at least 500 mi with a 91 imp gal drop tank iirc)

Also any comparisons made with the P-36 from british trials would not be valid for the P-40 as it would have been lighter than even the P-40B! In british tests (the model had a 1,200 hp R-1820 or R-1830, and 6x .303 guns) it was found that it could out maneuver the Spitfire Mk.I, lighter controls at high speed, shorter takeoff, slightly better turn rate, and better dive, but the Spitfire had a ~40 mph advantage in top speed allowing it to break off at will. The P-36 also had a lower critical altitude with ~16,000 ft for the R-1820, while the single-speed supercharged R-1830 models were rated fr only ~11,000 ft.


An interesting comparison though would be the standard P-40B and the Bf 109E. Granted the P-40 would still be outperformed above 15,000 ft, but below it was quite comparable and it still managed a decent range of 730 mi normal. (no external stores could be carried) Along with this it had a maximum speed of 352 mph and an initial climb rate of 2860.

See: Curtiss P-40B


Soren what figures do you have for the 109's range with or w/out drop tanks.


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## Soren (Mar 18, 2008)

Max rang for the G series was 600 + miles with a drop tank, the K series could go further because of its cleaner design.

Hohun are you there ??


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## kool kitty89 (Mar 19, 2008)

The P-40M was supposedly capable of reaching 20,000 ft in 7.5 min and a speed of 362 mph at that altitude. These figures seem acurate since the P-51A could manage 20,000 ft in ~6.9 min according to the chart. Max speed should have been reached at 10,400 ft (crit alt for 1,480 hp) as did the P-51A. The P-51A managed 415 mph at this altitude and 408 mph at 17,500 ft. (crit alt for Mil power) So the P-40M proably did ~375 mph at 10,400 ft.

And on range, the late P-40N's had 3x hardpoints capable of carrying bombs or drop tanks. With 3x drop tanks a maximum ferry range of 3,100 mi was possible.


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## kool kitty89 (Mar 19, 2008)

I've also seen (Soviet I think, again from Il-2 sim performance archive) figures on the P-39N/Q which list a turn time of 18-19 sec at 10,000 ft. The P-40E/M were listed for 20-22 sec. Times P-40B/C were not listed.


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## kool kitty89 (Mar 21, 2008)

Correction, the turn times should all be at 1,000m (3,280 ft) and the P-40E was listed at 19.5 sec. (though this may be with a reduced armament and most Soviet tests seem to be at half fuel load to simulate combat conditions)

The P-39N-1 was 19 sec, Q (with full armament) 19.5 sec, and Q-10 (w/out gun pods and with a 4-blade prop) was 18-19 sec.


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## HoHun (Mar 21, 2008)

Hi Koolkitty,

>most Soviet tests seem to be at half fuel load to simulate combat conditions

Do you have any information on the circumstances of the Soviet tests? That would be most fortunate!

Regards,

Henning (HoHun)


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## kool kitty89 (Mar 21, 2008)

I think the fuel load was mentioned earlier on this thread. Possibly on this site as well: Russian Aviation Museum

Other than that the only specific info on the tests are that they were performed at 1,000 m.

The last few figures of turn times I posted are from the test data in the info secion available in the Il-2 flight sim. I'm assuming they're Soviet as the game is designed in Russia (1C Company - Wikipedia, the free encyclopedia) and focuses on the Eastern front. And the fact that turn times are listed for a good number of fighters. (somthing the Russians were known for)


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## Juha (Mar 22, 2008)

Hello
according to Finnish tests, flown by a late 109G-2 (MT-215), the fastest 360deg turn was 22sec at the optium speed of 360kmh. But it was possible to turn 360deg in 18sec if the speed was allowed to decrease from 450kmh to 330 kmh during the turn.

Juha


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## claidemore (Mar 22, 2008)

Juha said:


> Hello
> according to Finnish tests, flown by a late 109G-2 (MT-215), the fastest 360deg turn was 22sec at the optium speed of 360kmh. But it was possible to turn 360deg in 18sec if the speed was allowed to decrease from 450kmh to 330 kmh during the turn.
> 
> Juha



Thanks for the info Juha. I've read and re-read the Finnish report (English version) at Kurfursts site, and I don't see any turn time tests there. Is this information on the Finnish version there, or on another test that I haven't read?

The Finnish 109G6 manual lists a 180 degree turn at 400kmh as 13 seconds, so 26 seconds for a 360 turn. Surprising how much difference there was in turn rate for that heavier plane. 

Claidemore


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## Elvis (Mar 22, 2008)

You know, one thing no one's mentioned yet, is how the Russians thought outside of the box, concerning performance improvements to the the P-40's they used.
While everyone else was increasing the power of their drivetrains (i.e., engines/props), the Russians decided to work with what they had, concerning the P-40's, and instead, lighten the load a little, to better match the power/thrust they had at hand.
The only other aircraft I can think of, off hand, that goes with that train of thought would be F8F, which used the same engine as the F6F, and (possibly) the P-63.

Kudos to the Russians, for seeing another way of upgrade the performance of an airplane.




Elvis


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## kool kitty89 (Mar 22, 2008)

Well when the US and Brits were complaining 2x .50's and 4x .30's of the P-40B/C/Tomahawk were too weak the Russians were stripping it down to just the 2x .50's! But if you look at russian a/c of the same period they had similar armaments. In fact very few Russian fighters had wing guns.

In terms of concern for maneuverabillity and light armaments, the Russians were similar to the Japanese, granted most Russian planes were a good deal tougher and better armored. (and the Soviets had some of the best overall guns of the war)


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## Juha (Mar 22, 2008)

Hello Claidemore
the info is from Suomen Ilmailuhistoriallinen Lehti, Finnish Journal of Aviation History, all text in Finnish only. That part of the article is based on the test reports of the tests flown by Kokko in MT-215. So there are more test reports than that on performance tests published on Kurfürst's site. I personally haven't seen the original reports.

Juha


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## HoHun (Mar 22, 2008)

Hi Juha,

>That part of the article is based on the test reports of the tests flown by Kokko in MT-215. 

Thanks a lot! Is there more information on the circumstances of the test? For example, altitude would be very important. It would also be interesting to hear if Kokko used flaps for optimum turn rate ...

Regards,

Henning (HoHun)


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## Juha (Mar 22, 2008)

Sorry HoHun
I already packed the journal away into attick, but there wasn't much more details. IIRC flaps were not used, altitude wasn't mentioned but there was a graph based on theoretical calculations which match well with the actual tests according to the writer. And according to the graph the time of 360deg turn was almost constant from sea level to appr. 2000m then begin to grow. I personally would have liked more info on the actual tests but there isn't. If you want, I can recheck the graph, it isn't much trouble, but as i wrote it is based on theoretical calculations, not on actual tests. The only concrete info from the actual tests are the times and speeds I gave earlier and that in the 18sec turn a/c had to be rolled almost to 90deg.

Juha


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## Juha (Mar 22, 2008)

Hello again, HoHun
I tried another solution. The writer, Jukka Raunio, have written at least 3 books on Finnish made a/c and a/c used by FAF during the WWII from pilot's point of view, the 2nd, Lentäjän näkökulma II, is on the main fighters of FAF during the WWII, and in it he wrote that the turning tests of MT-215 were flown at 1000m. On the 360 deg turn at 360kmh: the a/c was rolled to 70deg and the G-force was 3. Nothing on use of flaps.


Claidemore
in MT-215, at 1000m, 180deg turn took 10sec when the speed at the beginning was 450kmh and at the end 380kmh and if continued to 360deg, time was 18sec and end speed 330kmh. Source: the above mentioned book.

Juha


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## joy17782 (Mar 22, 2008)

i personaly love both planes but i think the me 109 has the edge, as i would also say the german airmen were better , but the fact of the matter is if i had my choice i would fly the p -40 , its the american thing too do


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## claidemore (Mar 22, 2008)

Juha said:


> Hello again, HoHun
> I tried another solution. The writer, Jukka Raunio, have written at least 3 books on Finnish made a/c and a/c used by FAF during the WWII from pilot's point of view, the 2nd, Lentäjän näkökulma II, is on the main fighters of FAF during the WWII, and in it he wrote that the turning tests of MT-215 were flown at 1000m. On the 360 deg turn at 360kmh: the a/c was rolled to 70deg and the G-force was 3. Nothing on use of flaps.
> 
> 
> ...



Thanks Juha. 18 seconds for the G2 is very good, definately a match for most of the Soviet planes it was up against. It also gives some credence to Sorens positon that the 1944 AFDU trials of a 109G2 vs various allied planes doesn't show the 109 up to its potential. 

The turn time of the 109G6 of 26 seconds, also supports the pilot reports of Mustang pilots etc. outturning 109s in 1943 and 44. 

Claidemore


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## Kurfürst (Mar 23, 2008)

claidemore said:


> Thanks for the info Juha. I've read and re-read the Finnish report (English version) at Kurfursts site, and I don't see any turn time tests there. Is this information on the Finnish version there, or on another test that I haven't read?



I am absolutely positive there are other tests around with MT 215, but that`s all I have on it what you see on my site.



> The Finnish 109G6 manual lists a 180 degree turn at 400kmh as 13 seconds, so 26 seconds for a 360 turn. Surprising how much difference there was in turn rate for that heavier plane.
> 
> Claidemore



IIRC the Finnish manual`s figures are not for turn times, but for something else, like safe approach possibilities on landing or something like that.. I am too lazy to look it up. 

Differences between the G-2 and G-6 were rather marginal, especially in weight (+60 kg or so), so I don`t expect too much of difference in turn.


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## Elvis (Mar 23, 2008)

Not to get off the subject, but does anyone know if any P-40's that the Russians used had the Allisons replaced with Klimov V-12's, at any time, and if so how was performance affected?

Just curious.




Elvis


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## Juha (Mar 23, 2008)

Hello claidemore
Notice that the second half of full circle is faster, in G-2's case when the speed was allowed to drop, full circle took 10+8secs, so on G-6 at most 13+11=24secs and as Kurfürst wrote, the G-6 figure might well be uncomparable to the MT-215 figure. I'm not avare same level of testing of G-6 than G-2 by the FAF, that in itself doesn't mean much.

Secondly, I don't know the criteria of Soviet tests, was the times for turns during which the speed was allowed to decay or turns when speed was kept constant. 

Finnish Bf-109G pilots tended to think that the new Soviet fighters (Yak-9s and La-5s) were better in horizontal fight than Bf 109G, at least at lower levels, even by very experienced like Capt. Puhakka, who was regarded as very skillful pilot and one of our top aces.

Juha


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## Elvis (Mar 23, 2008)

kool kitty89 said:


> Well when the US and Brits were complaining 2x .50's and 4x .30's of the P-40B/C/Tomahawk were too weak the Russians were stripping it down to just the 2x .50's! But if you look at russian a/c of the same period they had similar armaments. In fact very few Russian fighters had wing guns.
> 
> In terms of concern for maneuverabillity and light armaments, the Russians were similar to the Japanese, granted most Russian planes were a good deal tougher and better armored. (and the Soviets had some of the best overall guns of the war)


Kool Kitty89,

My apologies. I just realized my last post omitted comments on your response to my other post, so please allow me to indulge you, here...

Quite true.
It seems like many of the "lesser" countries that participated tended to arm their fighters lightly, and yet, a number made a pretty good showing of themselves..
Take the Italian fighters, most of which I believe were only armed with two 7.7mm machine guns. Yet, they did ok.
I believe the Romanian IAR 80 was also lightly armed, yet did quite a bit of damage (or protection, however you want to look at that) at Ploesti.

Its like, which do you take - 2x 7.7 + 1x 20mm (109) or 2x .50 cal (P-40) ?

...and here's another question for you to ponder...

Do you think the P-40 could''ve benefitted from a larger prop?



Elvis


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## HoHun (Mar 23, 2008)

Hi Juha,

>in it he wrote that the turning tests of MT-215 were flown at 1000m. On the 360 deg turn at 360kmh: the a/c was rolled to 70deg and the G-force was 3. Nothing on use of flaps.

Thanks! My results calculated result for a Me 109G-2 at 3023 kg (like MT-215) are in fact 2.97 G at 360 km/h, so that matches the test result quite well (assuming this was a sustained turn at 2600 rpm/1.32 ata).

However, it's possible to directly calculate the lift coefficient for that situation - and it comes out as just 0.98. As an optimum turn is flown at the maximum lift coefficient, which for the Me 109 is probably around 1.5, the Finnish test result actually doesn't represent the optimum combat turn.

By reducing speed and flying a tighter turn at the maximum coefficient of lift, the same MT-215 should have been able to achieve a time of 19.2 s for a 360 degree circle at 1000 m altitude (according to my calculation).

Excellent that the Finns have recorded the exact conditions of the turn - all too often, you find that test results and calculation yield a differenct figure, which in the absence of detailed data can be hard to explain! 

Regards,

Henning (HoHun)


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## Juha (Mar 23, 2008)

Hello HoHun
yes, to my understanding when the speed was kept constant and without any info on altitude lost it means sustained turn. Raunio mentioned "kaasu auki" which I interpret "full throttle" even if exact translation to full throttle is "kaasu täysin auki". And in FAF the max power used in 109G-2s was 2600rpm/1.32ata.

Yes we Finns are lucky that we have writters like Raunio, who had made his career in aviation industry and in same time have had intrest to went through massive amount of archival material and wrote books on technical aspects of those old planes.

Juha


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## claidemore (Mar 23, 2008)

LOL Juha. After I wrote that post about the G6 at 26 seconds, I also thought that we could knock two seconds off as in the case of MT-215, with a resultant time of 24 seconds. Great minds do think alike! 

In the Finnish 109G6 manual they give a time of 14 seconds at 450kmh for 100 degrees. I wonder if that is a typo or misprint, and should read 180 degrees? Since these times are 6 to 8 seconds more than with a G2, would I be safe assuming they are for sustained turns? 

Anybody got any inkling as to whether the Soviet turn tests were sustained turns or optimal turns?

Claidemore


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## kool kitty89 (Mar 23, 2008)

Elvis said:


> Take the Italian fighters, most of which I believe were only armed with two 7.7mm machine guns. Yet, they did ok.
> I believe the Romanian IAR 80 was also lightly armed, yet did quite a bit of damage (or protection, however you want to look at that) at Ploesti.
> 
> Its like, which do you take - 2x 7.7 + 1x 20mm (109) or 2x .50 cal (P-40) ?
> ...



Nearly all Italian fighters were carring at the least 2x 12.7 mm guns at the start of the war. (except some CR.42's that may not have been refitted) many were suplemented by wing guns as well (sometimes 7.7 mm) and most late war planes had either an engine mounted 20mm gun or 2x wing mounted cannons.

The IAR 80 first had only 4x 7.92mm guns the 80A had 6x, the 81 had 4x + 2x 20mm guns. 

The P-40E's were sometimes refitted with Kilimov engines, with some modifications. (new spinner, and maybe different prop) Performance would have been similar due to similar power, but I think the V-1710s of the P-40E had better altitude performance though. (the Kilimove was best below 10,000 ft, but the Allison was decent up to ~15,000 ft iirc)

The P-40E had a larger 3-bleded prop than the P-40B/C/Tomahawk, and this was fine up to the P-40K (and moreso with the M/N), but with the K's more powerful engine a larger (4-bladed) prop should have been fitted. Same goes for the P-40M/N which had the same V-1710-81 as the P-51A which had a better prop. (earlier Mustangs had 3-blade props) THe P-39N/Q could have used better props too, but it wasn't 'till very late model P-39Q's that they got 'em.


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## HoHun (Mar 24, 2008)

Hi Juha,

>And in FAF the max power used in 109G-2s was 2600rpm/1.32ata.

Roger that, that's what I used for the 19.2 s @ 1000 m sustained turn result, too.

>Yes we Finns are lucky that we have writters like Raunio, who had made his career in aviation industry and in same time have had intrest to went through massive amount of archival material and wrote books on technical aspects of those old planes.

Absolutely! Without the data on speed and G rate, a detailed analysis of the Finnish tests would not be possible 

Looking at my calculation again, I noticed that the 360 km/h turn is actual an "optimum" turn in a way too, as it's the turn that yields the highest sustained G rate. So it appears that the speed of 360 km/h might not have been chosen randomly, but in fact was carefully selected to produce a specific result.

The question of the "quickest sustained turn" would yield a different answer - according to my calculation, the Messerschmitt would have to fly at just 285 km/h at a slightly lower G rate to achieve minimum turn time, the aforementioned 19.2 s for 360 degrees.

Regards,

Henning (HoHun)


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## Juha (Mar 24, 2008)

Hello HoHun
” Looking at my calculation again, I noticed that the 360 km/h turn is actual an "optimum" turn in a way too, as it's the turn that yields the highest sustained G rate.”

Thanks for the info. I don’t understand much on aerodynamics but I have always being a little amiss on the 360kmh speed, I have felt that it was too high, feeling that appr. 300-310kmh would have been more likely "optimum" speed.

Juha


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## HoHun (Mar 24, 2008)

Hi Juha,

>I don’t understand much on aerodynamics but I have always being a little amiss on the 360kmh speed, I have felt that it was too high, feeling that appr. 300-310kmh would have been more likely "optimum" speed.

Your intuition was very good in that regard! 

I'll have to think on the issue for a while, but my spontaneous impression is that it's a good idea to test for best sustained G rate if you have a G meter available because it will give excellent control of the conditions of the turn.

It's more difficult to try and actually fly the aircraft at the maximum lift coefficient - it could either enter the stall region with shuddering and abrupt loss of lift, making the current turn sub-optimum, of if the aircraft has a "soft" stall transition (like for example the Spitfire), you might fly at sub-optimum coefficient of lift without even noticing.

If you keep airspeed and G rate constant (and G rate at the maximum), you still have a good margin before you stall, and while you don't get the optimum turn rate, I believe the difference to the optimum turn rate will be almost identical for most WW2 propeller fighters. (That's the bit I'll still have to think about.)

In other words, flying for best G rate seems like a good test flight technique that will give accurate results that can be compared well with results from other aircraft that have been measured using the same technique.

This almost makes me suspect that the Finns routinely tested fighter aircraft for turn rate, as the technique seems to be designed with comparability in mind. Do you perhaps know if there are similar figures for the other fighter types flown (or perhaps even captured) by the Finnish Air Force?

Thanks again for the Finnish test results, I feel I'm learning something new about WW2 era flight testing at the moment! 

Regards,

Henning (HoHun)


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## Elvis (Mar 25, 2008)

kool kitty89 said:


> Nearly all Italian fighters were carring at the least 2x 12.7 mm guns at the start of the war. (except some CR.42's that may not have been refitted) many were suplemented by wing guns as well (sometimes 7.7 mm) and most late war planes had either an engine mounted 20mm gun or 2x wing mounted cannons.
> 
> The IAR 80 first had only 4x 7.92mm guns the 80A had 6x, the 81 had 4x + 2x 20mm guns.
> 
> ...


Hey Kool Kitty89,

Looks like I need to research my Italian fighters a little more.
I've always been under the impression they were pretty lightly armed and only with 7.7's (or 7.9's?) in the nose.
...and I found that IAR article later on. Sorry about that, my bad.

Thanks for answering my question about the Klimov re-engine.

You say that the Prop got larger starting with the P-40E.
Do you happen to know what those diameters were?
I remember a book that was in the school library of the elementary school I attended. I believe it was written in '46 and was a catalogue of a whole bunch of aircraft used up through WWII.
Of the specs, I remember many listed prop diameters, and I remember the P-51's being listed as around 10.5', but the P-40's was less than 10'.
Variations were not listed and that was presented as "this is the diameter of the prop for this airplane" with no mention of whether they were referring to the "A" or "B" or "whatever" version.




Elvis


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## kool kitty89 (Mar 25, 2008)

I was wrong about the P-51A, it had a 3-blade prop, but it should have had a 4-blade one and so should the P-40M/N (and probably K) as the V-1710-81 was producing similar power as the P-51B's Merlin. (the prop change would explain the gain in climb of the P-51B as it was heavier and had no significant power advantage below 13,000 ft)

The Diameter didn't change much on the P-40E (I think the D got it too, but there weren't too many P-40D's anyway). The main change was a broader chord iirc.


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## Juha (Mar 25, 2008)

HoHun
Thanks a lot for Your enlightening explanation.
I only have copies on 2 short flight test reports, on LaGG-3 (3pages) and on Pe-2 (2pages). They are more like summaries and didn’t have numerical representations on turning abilities.

From Raunio’s book there are some, but not as exact than on 109G-2.

Brewster Model 239
Sustained 180deg at 350kmh (IAS) at 2000m 7sec, no wonder that Finns liked the plane.

Morane-Saulnier M.S. 406
instantaneous/temporary (meaning unsustained) 360deg, speed at the beginning 320kmh (IAS), under 16sec, G-force at the beginning 4G, radius 265m.

Gloster Gladiator Mk. II
at low level 360sec sustained 10-11sec, radius 90m

Polikarpov I-153
at low level 360sec sustained 12 sec and radius 110m

There was a more detailed report on LaGG-3, a copy of which was given also to Swedes, who passed it to British and it was published in Flight(?) during the war and reprinted in Aeroplane maybe early 2000s. I have a copy of the Aeroplane, I cannot recall that in it there was exact info on turning times, but cannot be sure. IIRC it was more on structures and systems.

Juha


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## Glider (Mar 25, 2008)

This may be of interest. Its the 'official' record for the 325 Gp which was equipped with the P40 for a time and breaks down the losses/claims by the type of aircraft it was equipped with at the time.

Can I make it clear that I am not saying that I believe these figures, its just something I found that people may want to look at.

Ops Summary


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## FLYBOYJ (Mar 25, 2008)

kool kitty89 said:


> I was wrong about the P-51A, it had a 3-blade prop, but it should have had a 4-blade one and so should the P-40M/N (and probably K) as the V-1710-81 was producing similar power as the P-51B's Merlin. (the prop change would explain the gain in climb of the P-51B as it was heavier and had no significant power advantage below 13,000 ft)



I bet if you did the math you would probably find a 3 bladed prop was used for a reason.


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## drgondog (Mar 25, 2008)

Elvis said:


> You know, one thing no one's mentioned yet, is how the Russians thought outside of the box, concerning performance improvements to the the P-40's they used.
> While everyone else was increasing the power of their drivetrains (i.e., engines/props), the Russians decided to work with what they had, concerning the P-40's, and instead, lighten the load a little, to better match the power/thrust they had at hand.
> The only other aircraft I can think of, off hand, that goes with that train of thought would be F8F, which used the same engine as the F6F, and (possibly) the P-63.
> 
> ...



The 51H was another example where weight reduction was foremost. The expereimental XP-51G and J were by far the best performers of the series, but the H was very close in production versions.
 
By AF standards of the time it should have had another designation than P-51because only about 11 parts were truly common (allegedly) between D and H.. It was 'cleaner', had more internal fuel in wings, less in fuse tank, smaller tires, designed to 11 G versus 12G for 'Utimate' and was about 900 pounds lighter with a more powerful engine.

A lot of 8th AF pilots that flew the B's in combat removed the two out board 50's and ammo to lighten the D by some 300 pounds. That should have improved roll, turn, acceleration, climb, range and top speed to a small degree


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## kool kitty89 (Mar 25, 2008)

FLYBOYJ said:


> I bet if you did the math you would probably find a 3 bladed prop was used for a reason.



Maybe, but they still had the same HP. (with normal boost limitations of the Merlin) Top speed probably wouldn't change, but climb probably would. (like with the P-47's paddle prop, no change at high speed, but climb and initial acceleration did)



Juha said:


> From Raunio’s book there are some, but not as exact than on 109G-2.
> 
> Brewster Model 239
> Sustained 180deg at 350kmh (IAS) at 2000m 7sec, no wonder that Finns liked the plane.
> ...



7 seconds?! it was a good turner, but that's just unrealistic, especially when you compare the biplane figures. Are you sure it wasn't 17 sec?


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## Juha (Mar 25, 2008)

Hello
as it stands, 7sec for 180deg, especially mentioned that it went to turn clearly faster than Hawk 75A (P-36), so 360deg probably appr 13 sec.

Juha


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## HoHun (Mar 25, 2008)

Hi Juha,

>From Raunio’s book there are some, but not as exact than on 109G-2.

Thanks a lot, at least it shows that the Finns did indeed consider turning capabilities to be important, and that they routinely tested at least some of the aspects of turning. I think that these figures are not directly comparable probably means that we have only some bits of the reports, not that the Finns didn't test systematically.

>There was a more detailed report on LaGG-3, a copy of which was given also to Swedes, who passed it to British and it was published in Flight(?) during the war and reprinted in Aeroplane maybe early 2000s. 

Ah, that's a good lead - maybe Micdrow in his extensive research on the Flight site has seen something on the LaGG?

Regards,

Henning (HoHun)


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## claidemore (Mar 25, 2008)

Can't remember if I got this off this site or another, but here it is. 

Pdf of article on LaGG 3. 

Claidemore


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## FLYBOYJ (Mar 25, 2008)

kool kitty89 said:


> Maybe, but they still had the same HP. (with normal boost limitations of the Merlin) Top speed probably wouldn't change, but climb probably would. (like with the P-47's paddle prop, no change at high speed, but climb and initial acceleration did)


If you change a prop (pitch, blade count, etc.) you gain and loose. What you make up in climb, you're gonna loose in speed, what you make up in speed, you loose in fuel consumption and so on. Matching props to the airframe/ engine combo is an exact science and sometimes compromise is the end result.


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## kool kitty89 (Mar 25, 2008)

Juha said:


> Hello
> as it stands, 7sec for 180deg, especially mentioned that it went to turn clearly faster than Hawk 75A (P-36), so 360deg probably appr 13 sec.
> 
> Juha




 Sorry missed the 180 degrees, but why 13 sec and not 14 for 360*?

The B-239 was certainly agile though, and could certainly out "dogfight" the Hurricane I. (though the Hurri had much better performance above 10,000 ft, the Finn's Brewsters' engines being rated for low altitude)


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## Soren (Mar 26, 2008)

FLYBOYJ said:


> If you change a prop (pitch, blade count, etc.) you gain and loose. What you make up in climb, you're gonna loose in speed, what you make up in speed, you loose in fuel consumption and so on. Matching props to the airframe/ engine combo is an exact science and sometimes compromise is the end result.



100% true!


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## Juha (Mar 26, 2008)

Hello Claidemore
because 1st half of full turn takes more time that the 2nd half, but because Finns reported that 239 went into turn clearly quicker than Curtiss Hawk 75 which was a good turner. maybe 13½ sec is nearer to truth.

HoHun
"I think that these figures are not directly comparable probably means that we have only some bits of the reports, not that the Finns didn't test systematically."

Probably Finnish test got more scientific as time passed. In 1942 it became clear that the new fighter, Myrsky, would be too slow to be used as first line fighter and Finns began to design a faster fighter, Pyörremyrsky, with DB605A engine. My guess is that Bf 109G-2 was seen as very interesting a/c for thorough testing to get basic data for modern high speed fighter. Finns went to roomier, bigger wing solution.

Finns were very pleased with Brewster Model 239 and planned to built 90 "copies" of it, called Humu (new, wooden wing, different fuel tank system, war booty M-63 engine etc), so they probably tested 239 thorougly.

MS 406 was also much tested, because Finns modified it for war booty M-105P engine, so called Mörkö-Morane. Main reason for this project was that MS 406 was underpowered and clearly too slow and too poor climber. So maybe the turning ability of MS 406 was not test as thorougly that 239 and 109G.

Juha


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## kool kitty89 (Mar 26, 2008)

Yeah, (on the prop issue) plus there's the fact that the Merlin P-51 would be operating with much higher powers at altitude as well.


THe Humu turned out to be a bust though, too heavy and much slower than the B-239. It also came even later than the Mirsky, which was considerably faster than the B-239.


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## drgondog (Mar 26, 2008)

kool kitty89 said:


> Yeah, (on the prop issue) plus there's the fact that the Merlin P-51 would be operating with much higher powers at altitude as well.
> 
> 
> THe Humu turned out to be a bust though, too heavy and much slower than the B-239. It also came even later than the Mirsky, which was considerably faster than the B-239.



KK- As Joe said - it's more complicated... 

Prop design is all about rotating 'wings'.. more props in the disk (usually) mean more thrust and more drag, ditto increasing pitch to take a bigger bite (higher local angle attack) but getting more drag and requiring more torgue, keeping the diameter to point below tip speed>high transonic, keeping the prop at smaller diameter but greater RPM so my airplane can take off and land w/o stubbing a prop, resonance issues based on natural frequency of the blades, etc, etc..

As you speculated "where do I want my best performances at (pick one - long range cruise?, high thrust at altitude where the density/drag is lower?, etc, etc)


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## Hunter368 (Mar 26, 2008)

Damn I need a note book to write this all down, good day guys. Lots of great information and facts today.


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## FLYBOYJ (Mar 26, 2008)

drgondog said:


> KK- As Joe said - it's more complicated...
> 
> Prop design is all about rotating 'wings'.. more props in the disk (usually) mean more thrust and more drag, ditto increasing pitch to take a bigger bite (higher local angle attack) but getting more drag and requiring more torgue, keeping the diameter to point below tip speed>high transonic, keeping the prop at smaller diameter but greater RPM so my airplane can take off and land w/o stubbing a prop, resonance issues based on natural frequency of the blades, etc, etc..
> 
> As you speculated "where do I want my best performances at (pick one - long range cruise?, high thrust at altitude where the density/drag is lower?, etc, etc)


Just for the discussion - I had to choose a prop for our Supercubs - one that would pull at a high altitude (the academy is 6000' MSL) and at the same time limit noise and be efficient enough so we could fly our cubs cross country. After 3 weeks of research I had a headache for a week and didn't even want to see a propeller!


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## kool kitty89 (Mar 26, 2008)

Sorry, by yeah, I was agreeing with Joe that it's more compicated than I was initially thinking. I was just pointing out that, despite similar power up to ~10,000-12,000 ft there would also be more consideration of power at high altitude with the Merlin. (at 18,000 ft the V-1710-81 dropped to ~1,100 hp)


Also it may not have been the prop that resulted in the P-51B's better climb at low alt (obviously at high alt as well), but that it seems that it used the full 1,485 hp at 10,000 ft while the P-51A tests were limited to 1,320 hp at a similar altitude. (in the speed tests full hp was used) If pushed to full WEP the P-51A would probably climb at least as well as the P-51B from 3,000 ft to 11,000 ft. (below 3,000 ft power would limited by overboost)

P-51 Mustang Performance
Mustang (Allison Engine) Performance Trials


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## drgondog (Mar 26, 2008)

FLYBOYJ said:


> Just for the discussion - I had to choose a prop for our Supercubs - one that would pull at a high altitude (the academy is 6000' MSL) and at the same time limit noise and be efficient enough so we could fly our cubs cross country. After 3 weeks of research I had a headache for a week and didn't even want to see a propeller!



ROFLMAO - just go fast forward and try to figure out what kind of rotor you need to put on a completely divergent system from your entire design experience - one in which you go from two blade semi articulate to four (or more) blade, rigid rotor for a new attack helicopter RFP - and we lost to the Apache.

There is art, and science. The good news is you can try a lot of differnt designs after you make your decision - to fine tune the analytics. A major benefit to test versus 'analyze' when involved in the Arcane.

I have never done any analysis on a conventional prop other than class work.


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## drgondog (Mar 26, 2008)

kool kitty89 said:


> Sorry, by yeah, I was agreeing with Joe that it's more compicated than I was initially thinking. I was just pointing out that, despite similar power up to ~10,000-12,000 ft there would also be more consideration of power at high altitude with the Merlin. (at 18,000 ft the V-1710-81 dropped to ~1,100 hp)
> 
> *KK- it is complicated making design trade offs, because every 'positive' advantage usually has a negative somewhere else. For the Merlin at least one of the parameters was established - namely the best thrust RPM was 3000rpm. At least one 'given' was available before going to the rest of the considerations.*
> 
> ...



Remember 'time to climb to 20,000 feet is not possible to calculate simply by using rate of climb - it was different for different altitudes as the Merlin was exercising power available in low blower, kicking over to high blower and then climbing at a different rate (slower as the power/thrust available continued to fall off)


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## kool kitty89 (Mar 26, 2008)

Ok, but I didn't say anything about time to altitude. (there are figures there for that too though)

For some reason the climb power is different from the high speed test's power too. 

For the V-1710-81 "normal" takeoff power was 1,200 hp. According to those tests throttle was limited up to 10,400 ft. (even in WEP, though 1,480 hp could be acheived above 3,000 ft at partial throttle) If the Boost limitations had been removed with 100/150 octane avgas,, max power output should have been increased significantly.


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## Juha (Mar 27, 2008)

Hello kool kitty
you have very good knowledge on FAF a/c. Yes, Humu project was stopped after one prototype was flown, it has survived and can be seen at Keski-Suomen Ilmailumuseo. Main reason to its slowness was that M-63 gave less power than expected. 

Myrsky was some 30kmh faster than Model 239, at least its Pilot’s Notes gave max speed as 515kmh, IIRC. IIRC max speeds of protos were 530-535kmh. But it was slow for its day as first line fighter, even without serious flutter problem IMHO it would not have been ready for sqn service before the beginning of 44, and because of the flutter problem it began combat sorties as recon fighter in Aug 44 and IIRC flew only 66 combat sorties before armistice with SU in 4th Sept 44.

Juha


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## kool kitty89 (Mar 29, 2008)

One of the major problems with the Mirsky was the construction (wood+steel tubing), which had structural problems as well as maintence issues. (particularly in wet environments). It was a decent a/c but it came a bit late for it's performance. Considdering what the Finns had to work with otherwise it was pretty good, though not as high performing as their 109's, and probably not as agile as the B-239. (due to higher wing loading) It was a nice plane (good lokng IMO) with a concentrated armament of 4x 12.7 mm cowl guns. Visibility was also about as good as the Brewster with the clear rear decking.

But again were getting a little of topic.


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## drgondog (Mar 29, 2008)

kool kitty89 said:


> Ok, but I didn't say anything about time to altitude. (there are figures there for that too though)
> 
> For some reason the climb power is different from the high speed test's power too.
> 
> For the V-1710-81 "normal" takeoff power was 1,200 hp. According to those tests throttle was limited up to 10,400 ft. (even in WEP, though 1,480 hp could be acheived above 3,000 ft at partial throttle) If the Boost limitations had been removed with 100/150 octane avgas,, max power output should have been increased significantly.



The only reason I mention it is that virtually all engine/propeller designs were geared for the strike zone they wanted best thrust.

All of the best engines had one form or another of 'sawtooth' hp output as a function of altitude .. some aircraft climbed to altitude at a speed and climb angle different from another. So from a math standpoint, the calulations are step functions also.

Ditto turn performance... particularly in the case of an aircraft losing energy and speed. It ain't enough to apply static L/D/Gravity free body diagrams as the vectors change as a function of AoA and flight path and thrust available for the manuever. 

All must be integrated as a function of rate of change (and time) of several variables..As you and several others have noted - a plan view of a high G turn would look like a like a curvelinear path (not a circle) in which both the rate of change of velocity and 'theta' would be integrated as a function of time. The radius of the turn would be lower on the back half of the circle than on the high energy side.

Some may perceive the analytical solution as simple.. but it never has been for serious students of the 'problem'.. and certainly not for me.


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## kool kitty89 (May 9, 2008)

I found some info on the P-40's (Hawk 75 actually) stall characteristics in a British comparison test.

They said that the stall was fairly mild but there was no warning until the stall hit and the wing drooped. The stall was easily and quickly corrected. This makes me think there was relatively little washout on the P-40's wing.


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## FLYBOYJ (May 10, 2008)

kool kitty89 said:


> They said that the stall was fairly mild but there was no warning until the stall hit and the wing drooped. The stall was easily and quickly corrected. This makes me think there was relatively little washout on the P-40's wing.


That's typical of of almost any stall, using right rudder to counter the wing drop (power on stall). If the P-40 is stalled at an extremely nose high attitude (power on) there is a possibility it could flip on its back and tumble - I read that in some pilot reports and that also might be mentioned in the -1.


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## kool kitty89 (May 11, 2008)

But there is no buffetting at the stall onset either, the RAF testers said it came on with less warning than the Spit, although the actuall stall was relatively mild and easy to correct.

In the case of the 109 the slats gave very mild stall characteristics on the F and later models. (the Emil and earlier models had slats that were sensitive to dirt and pron to jamming under high G conditions, they also opened very rapidly and caused the ailerons to snach and the a/c to shudder; the new slats were reliable and simply gave a "clunk" on full deployment)


And there's lot's on the P-40 performance and engines here: Perils P40 Archive Data


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## claidemore (May 11, 2008)

From the Tomahawk 1 manual:



> STALLING
> 15. The stalling characteristics of this aircraft are good. At minimum speed the stall is gentle and there is some buffeting and pitching before the wing, generally the right, drops gently, followed by the nose.
> 
> At high speed the machine can be stalled as a result of the coarse use of the elevators producing high acceleration loadings, but due warning is received, particularly on the high speed turn, by a shuddering of the aircraft, and loads of over 5g. can be applied to 180 to 200 m.p.h. without the aircraft stalling.
> ...



Note that the P40 could pull 5 g at 180mph, while the 109 E was stalling at 3 g at that speed, according to RAE tests. 

My understanding is that the LE slats in the F G 109s also caused aileron snatching, enought to disturb aiming. The difference between them and the ones on the Emil was that they didn't jam and were more reliable, opening simultaneously, rather than one at a time. 

The problem with high lift devices, is that they are devices, and so the opportunity exists for them to malfunction. Willy M didn't use the KISS system when he chose that wing.


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## kool kitty89 (May 11, 2008)

According to Kfurst and Soren, the F's (at least the late F's) and all G and later models slats extended gradually and smoothly with a 'clunk' being heard and felt in the stick when fully extended, no directional changes occured.
These slats were of the same mechanism as on the Me 262 and F-86, and I don't remember any report of jostle/jolt etc occuring durring slat deployment on those a/c.


And on the stall; from R&M2379-curtiss H.75 Spitfire Gloster f5 aileron test.pdf (posted on the 109 v. Zero thread iirc):


> There is good all-round control down to the stall, at which wing drops sharply without any pronounced stall warning.


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## HoHun (May 11, 2008)

Hi Claidemore,

>Note that the P40 could pull 5 g at 180mph

Hm, at which weight? The G rate appears to be a bit on the high side - I have the P-40 maximum coefficient of lift as 1.45 (from Peril's data), and that would require a weight of no more than 3180 kg at 200 mph (the upper limit of the range given in your quote).

>while the 109 E was stalling at 3 g at that speed, according to RAE tests.

Hm, if you you refer to the Spitfire-vs.-Me 109 turning diagram dated 19-11-1940, it shows about 3 G at 200 mph TAS, but I believe it would actually have be read at the 200 mph IAS reading for a comparison, and there it gives about 4.5 G for the Emil. The latter figure is also in fairly good agreement with my calculations.

Regards,

Henning (HoHun)


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## kool kitty89 (May 11, 2008)

That's for the Tomahawk I (evquivelant to the P-40 -no letter) wiout armor or self-sealing and only 1x .30 in each wing.
see: Curtiss P-40



> Weights were 5376 pounds empty, 6787 pounds gross, and 7215 pounds maximum


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## Elvis (May 11, 2008)

From reading the descriptions posted by Kool Kitty, it sounds to me like the LE slats on the earlier versions of the 109 were spring powered, while later versions may have been hydraulically powered.

Would that be a correct assumption?

Interesting posts. Keep it coming, guys.




Elvis

P.S. Kk - Thanks for the link to Peril's.


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## Soren (May 11, 2008)

> the F's (at least the late F's) and all G and later models slats extended gradually and smoothly with a 'clunk' being heard and felt in the stick when fully extended, no directional changes occured.
> These slats were of the same mechanism as on the Me 262 and F-86, and I don't remember any report of jostle/jolt etc occuring durring slat deployment on those a/c.



Exactly, just as explained countless times by now by both the vets and the guys who fly the birds today.


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## kool kitty89 (May 11, 2008)

Elvis the operated by airpressure, see: http://www.ww2aircraft.net/forum/polls/allied-tests-captured-bf-109-s-12456.html



Kurfürst said:


> > Quote:
> > Originally Posted by Soren
> > Dave Southwood, 109 pilot:
> > "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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## billswagger (Jan 24, 2010)

Soren said:


> Claidemore,
> 
> The P-40s didn't just shoot down fighters - something which is often forgotten when talking kill/loss ratios.
> 
> As for the topic; The Bf-109 is the best hands down. Can't think of an area besides roll rate where the 109 wasn't better than the P-40.



I think the only weakness of the P-40 in this match up would be ceiling. The areas of turn, and top speed might go one way or the other but its repeatedly reported that the P-40 was an above average turner. 

Even the RAF considered the Tomahawk to be superior to the Hurricane , and Hurricanes could out turn 109s under 10,000ft. 

Then take these two examples of when the 109 and P-40 met over Italy in 1943:


"On 1 July 1943, 22 P-40s made a fighter sweep over southern Italy. Forty Bf-109s surprised the checker-tails, engaging them at moderate altitude where the P-40 performed best. After an intense dogfight the Germans lost half their force while only one P-40 failed to come back.

A similar event took place on the 30th of the same month in which 20 P-40s were bounced by thirty-five 109s. The Germans limped home after losing 21 of their own while the checker-tails came through with only one loss. The Germans lost 135 aircraft (ninety-six of which were 109s) to the pilots of the checkered-tail P-40s while shooting down only seventeen of the 325th."
The P-40 Warhawk and the A6M Zero, Patrick Massol.

I think, for whatever reason, the P-40 has a flawed reputation as a fighter. The Japanese also ranked it as their number one advesary in low altitude combat. 


I thinks its ability as a high altitude fighter limited its use in the ETO, and perhaps because of this reason the 109 might be the more formidable fighter, however match ups under 20,000ft are more likely to put the contemporaries on even footing, and perhaps lower level dogfights might've even gone in favor of the P-40. 




Bill


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## Glider (Jan 27, 2010)

I was able to have a look at Fighters over Tunisia in the Library last week and I couldn't find a US Pilot who didn't think that the P40 was totally outclassed by the Me 109. I don't pretend to have read the whole book just looked at bits that interested me and then concentrated on the conclusions.

Some quotes I jotted down 
a) Page 392 discussing P40 vs Spit V Wing Commander Benham
During mock dogfights I was able to outfly 3 x P40 in a single Spitfire VB

b) Page 403 John Bradley 33rd Fighter Group on P40F
He describes the plane as being obsolete for what it was asked to do _(as a fighter)_

c) Page 407 Brig Harrison Thyng CO 309 Squadron 31st Fighter group
Preferred the Spitfire to all other Allied fighters and considered the P39/P40 to be no match for the 109 F/G or the 190

d) Page 413 Capt Ron Whittaker 57th Fighter Group P40F
Considered the P40 to be outclassed by the German Fighters.

I must emphasise that I only had the book for about 30 mins and by no means read it all but there was a common theme that the Spit V was considered to be better than the US fighters and the Spit IX to be at least as good as the 190 and better than the Me109.
The only exception being that the P38 was better for range which shouldn't be a suprise.


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## renrich (Jan 28, 2010)

This has been pointed out before but the P40's major drawbacks were it's especially poor rate of climb and poor high altitude performance. In a fight at lower altitudes where it's very good rolling abilities and decent turning characteristics stood out it could be pretty formidable. The fighters it was likely to meet in ACM could mostly all outclimb it which was quite a handicap.


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## Glider (Jan 28, 2010)

All I can say is that wasn't the picture I had from my brief look at the book. I saw no caveats such as at altitude we were in trouble or at low altitude we were able to hold our own. It was always along the lines of the P40 being totally outclassed.


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## renrich (Jan 28, 2010)

Glider, if a fighter has a poor rate of climb and not very good performance above 12000 feet and was in the ETO being flown possibly by low time pilots, then I suspect that it would not have a good record and might be considered a dog. However, according to Dean in AHT, the P40" had few equals among US fighters in maneuvering at altitudes below 15000 feet" and "they were particularly good in roll." The problem was though the Axis fighters would not usually fight where the P40 could use it's advantages. Those same handicaps applied in the PTO especially against the A6M. Even the P40 at lower altitudes could not do well against the A6M in a turning fight.


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## Glider (Jan 28, 2010)

I would love to say that I am going to buy the book but have you seen the second hand prices!! Scary. UNfortunately it was the British Library which is one you cannot take things out on loan from.

Next time I go there I will try and have a better look. To help me narow the search down, is there a unit that was renowned for doing well with the P40. If I concentrate on that first I may well get a more even picture.

Thanks


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## Wildcat (Jan 29, 2010)

Glider said:


> Next time I go there I will try and have a better look. To help me narow the search down, is there a unit that was renowned for doing well with the P40. If I concentrate on that first I may well get a more even picture.



3 RAAF and 112 RAF both had around 200 kills each with the P-40, probably the two most prominent in the Desert.


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## Glider (Jan 29, 2010)

Wildcat. Thanks for this, I cannot promise, but I should be able to have another look next Wednesday.


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## NZTyphoon (Jan 29, 2010)

Wildcat said:


> 3 RAAF and 112 RAF both had around 200 kills each with the P-40, probably the two most prominent in the Desert.



Hi Wildcat (just listening to Australia thrashing Pakistan in the one day cricket...), Have you got or read Geoffrey Pentland's *The P-40 Kittyhawk in Service* (Kookaburra 1974)? This has some really solid info on Tomahawks and Kittyhawks in Australian service, in North Africa and the Pacific (from 75 Sqn's defence of Port Moresby to the end of the war) - there is also some information on the USAAF units defending Darwin. It is well worth finding a copy for anyone interested in the RAAF.


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## Glider (Jan 29, 2010)

With a bit of luck the British Library will have a copy of that as well. I will see what I can find.


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## Wildcat (Jan 29, 2010)

I haven't got that book, but it's now on the to get list! Cheers.
For an excellent book on RAAF P-40 pilots and squadrons in North Africa, you can not go past Russell Brown's superb "Desert Warriors". It's a day by day account of all the actions fought by Australian P-40 units in the desert, listing all losses and victories against German and Italian records. truely an excellent book.


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## billswagger (Feb 1, 2010)

Using Google books you can thumb through the great books mentioned above, or at least preview some passages but i think your gonna have to look at more information to make any kind of conclusion. Getting a RAF pilot's interpretation of the P-40 in contrast to his Spitfire is going to be a bit loaded. 

In my reading of the P-40b, it seemed to have been more successful in the PTO and CBI.

What i find interesting about the MTO is that the P-40F was used, featuring the Packard Merlin found in the P-51D. 
The engine was tested and rated to 55", however in my reading the pilots could and would push it to 65" in emergency situations which allowed them to out run 109s at some altitudes.

One pilot describes throwing the throttle forward while evading a 109. He noticed the boost pressure was above 60", and he thought he heard a knocking sound so he throttled it down to 55". He then realized the knocking sound was 20mm cannons exploding into his wing, and throttled it back up over 60". 

I can't say much for the P-40s performance over the 109, only that it could turn with it, and dive with it, but more importantly was that it could reach further with the range that it had.

Tactically that means you can climb higher and further, for example, using rough figures:

If a Spitfire must fly under 10,000ft to reach the target area and be able to return, and the P-40 can climb to 20,000ft and still reach the target area, who has the tactical advantage? 
I think the match up was more closely drawn in situations under 15,000ft. Tactically the 109s lacked the range of the P-40, meaning attack missions were often lower than what their ceilings suggests. Most people don't even look at range, just speed and climb figures but range is very important in gaining a tactical advantage, 

Perhaps on the order of 109 supremacy, the 109s were also met with situations when attacking a middle altitude formation only to have high altitude top cover saddle in on them. The P-40s had a ceiling of 29,000ft but probably could only function decently as a fighter below 20,000ft. This doesn't mean the P-40s weren't capable of using altitude for a tactical advantage,

There are also many P-40 pilots in the PTO who know a well kept secret that it actually out turned a P-38, however, as the war in the Pacific went on the only war bird that could make it to the target areas was a P-38.

I haven't found anything that says the P-40 was outclassed, but i am still reading. 


Bill


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## Njaco (Feb 1, 2010)

Glider said:


> I would love to say that I am going to buy the book but have you seen the second hand prices!! Scary. UNfortunately it was the British Library which is one you cannot take things out on loan from.
> 
> Next time I go there I will try and have a better look. To help me narow the search down, is there a unit that was renowned for doing well with the P40. If I concentrate on that first I may well get a more even picture.
> 
> Thanks



I think the 352d FS "Checkertail Clan" did well with the P-40 in the MTO.


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## Colin1 (Feb 1, 2010)

billswagger said:


> If a Spitfire must fly under 10,000ft to reach the target area and be able to return, and the P-40 can climb to 20,000ft and still reach the target area, who has the tactical advantage?
> 
> The P-40s had a ceiling of 29,000ft but _probably_ could only function decently as a fighter below 20,000ft.
> 
> This doesn't mean the P-40s weren't capable of using altitude for a tactical advantage


I don't think the P-40 was terribly familiar with life at 20,000ft

Make that definitely, I don't think many P-51 pilots looked out of the roof of their canopies to see P-40s 4,000ft above their best altitude; 29,000ft was an if-only from the first P-40 to the last of the line.

Do you have any anecdotal evidence or combat reports to support this view?


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## billswagger (Feb 1, 2010)

Colin1 said:


> I don't think the P-40 was terribly familiar with life at 20,000ft
> 
> Make that definitely, I don't think many P-51 pilots looked out of the roof of their canopies to see P-40s 4,000ft above their best altitude; 29,000ft was an if-only from the first P-40 to the last of the line.
> 
> Do you have any anecdotal evidence or combat reports to support this view?



P-40 top cover was flown lower than their ceilings, if thats what you thought i was suggesting. 

Its merely a demonstration of ability. I doubt a Mustang pilot would look above to see a P-40, instead the P-40 at 28,000ft would look up to see a P-51 at 38,000ft, if the mission required. 
The reality of the MTO was having a reliable plane to fly top cover at the ranges required. The P-51 was still found to be somewhat fallible and teething out some engine problems at that time. 
There were also situations where the Spitfire was used as top cover if the range permitted. 

Much of my reading on the P-40 has been dispersed over a couple months from various sources. There is no one detailed account but a general picture can be gathered. It was also spelled out more specifically in a book about the 57th. 

Bare with me, as i don't have the passage readily available, but if its tantamount that you need it, i can probably get it. 

I would urge you to read about it more yourself, particular if want to get a better picture of how the plane was used in combat. 

I think the age of TnB faded into BnZ tactics where dive characteristics, and roll were seen to be favorable designs. 


Then take these two examples of when the 109 and P-40 met over Italy in 1943:


"On 1 July 1943, 22 P-40s made a fighter sweep over southern Italy. Forty Bf-109s surprised the checker-tails, engaging them at moderate altitude where the P-40 performed best. After an intense dogfight the Germans lost half their force while only one P-40 failed to come back.

A similar event took place on the 30th of the same month in which 20 P-40s were bounced by thirty-five 109s. The Germans limped home after losing 21 of their own while the checker-tails came through with only one loss. The Germans lost 135 aircraft (ninety-six of which were 109s) to the pilots of the checkered-tail P-40s while shooting down only seventeen of the 325th."
The P-40 Warhawk and the A6M Zero, Patrick Massol.


Bill


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## Shortround6 (Feb 1, 2010)

billswagger said:


> What i find interesting about the MTO is that the P-40F was used, featuring the Packard Merlin found in the P-51D.


It was rather different Packard Merlin. A two speed supercharger WITHOUT a SECOND STAGE and WITHOUT INTER-COOLER as used in the P-51B-D. 



billswagger said:


> The P-40s had a ceiling of 29,000ft but probably could only function decently as a fighter below 20,000ft.




The "ceiling" or service ceiling of most planes was the altitude at which the climb rate dropped to100ft per minute. This is also an indication of the excess power available after level flight is achieved. Please note that "Climbing speed" is where this excess power is available. not max level speed. 

MAX. ceiling is the altitude at which the plane cannot climb anymore and Max speed is the same as stall speed which also means the airplane cannot turn or maneuver as the extra drag will cause the airplane to stall.

An airplane with a service ceiling just a few thousand feet higher than another aircraft might, at an altitude a few thousand feet below plane "B"s service ceiling have double the rate of climb, a much better ability to either maintain speed or height in a turn. 

The P-40 F might be able to effectively fight 3-5000ft higher than a P-40E but that does not mean it can fight at the same altitudes (24,000-30,000ft) as some Spitfires and the 109s.


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## billswagger (Feb 1, 2010)

Shortround6 said:


> It was rather different Packard Merlin. A two speed supercharger WITHOUT a SECOND STAGE and WITHOUT INTER-COOLER as used in the P-51B-D.
> 
> 
> 
> ...



thanks for reminding me of that. 

The ceiling of the F was actually 34,000ft, but as I mentioned was not an effective fighter above 20,000ft, although out put of the one stage two speed Merlin was still 1120hp (@20k ft), I simply see them using the altitude for a tactical advantage diving on climbing 109s, or 109s that are pursuing a formation at medium altitude (15,000ft)

I think its important to recognize what level speed figures mean, and the altitudes they are achieved at. The Merlin Mustang was significantly faster not only because of its engine advances but because it could climb higher into the thinner air. 
I'd be surprise to see how the Merlin Mustang and P-40F match up in level speed at 15,000ft.

Erik Shilling contends the P-40 was faster, but i might question his biased. Still it illustrates a point about level speed and altitude. I might clarify, the Mustang was faster at 15k, but i have to recognize that it was also rated for over 60" of manifold pressure. Not looking to argue, just simply raising the question of a P-40 merlin output at 65". 

Note: the power plant of the 109F-3 also produced 1300 hp, and previous F-1 and F-2 variants were closer to 1200hp. (SL)

Above 20,000ft, the P-40s short comings become more recognizable and for obvious power to weight reasons but i might argue that at lower altitudes the P-40F and 109s were better matched in speed. Recognize that max speed of the 109 was attained above 22,000ft. Level Speed advantage would diminish with altitude, and where engine HP output was similar. 

Hopefully. I'm not repeating what people already know. 

At 20,000ft range of the P-40F was as follows:
clean -----------------------------700 miles
43 imp gal drop tank.-- ------875 miles
141.5 imp gal tank, ----------1500 miles. 

A loose comparison with the 109F puts its range at 710km (440 miles) at 16500 ft alt. 
and closer to 600 miles range with a drop tank (note: no reference to altitude)

There are many 109 variants, and forgive me if i haven't detailed their ability extensively, really my intent was to show the superior range of the P-40F with contemporary 109s which would've been 109E/Fs and early G models. 

\\



Bill


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## Colin1 (Feb 2, 2010)

billswagger said:


> I'd be surprised to see how the Merlin Mustang and P-40F match up in level speed at 15,000ft


No surprises I'm afraid

P-40F around 352mph @ 15,000ft
P-51B around 415mph @ 15,000ft


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## billswagger (Feb 2, 2010)

Interview with L.Kulakov

This is an interview with Leonid Sergeevich Kulakov, posted in the begining of the thread. 

He flew the Kittyhawk as well as the Cobra and the Yak.

His thoughts on the Kittyhawk were that it was excellent in the horizontal and even out turned Yak7s, however the Yak was much better in the vertical because of its speed. He could not compare the cobra well to the kittyhawk because he never had to dogfight in a cobra. 
He simply said the cobra was faster, 

Apparently, the Kittyhawk also offered excellent visibility and he contends that as long as he was able to see his adversary he was able to evade them. This probably in't saying much, but i think it shows that the plane was still formidable if flown properly. 

His opponents were often 190 and 109s flying much higher and faster than himself. 


Bill


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## Vincenzo (Feb 2, 2010)

good read, need to take in consideration the him talking of training biplace Yak 7


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## billswagger (Feb 2, 2010)

Vincenzo said:


> good read, need to take in consideration the him talking of training biplace Yak 7



I didn't catch that, he mentions training in a Yak7, and i have to think he also flew a single seater.
I'm certain the Yak out performed the Kittyhawk in many ways i just thought that was an interesting remark. If i had the choice i would still take the Yak. 



Colin1 said:


> No surprises I'm afraid
> 
> P-40F around 352mph @ 15,000ft
> P-51B around 415mph @ 15,000ft



Indeed.

Look at level flight characteristics of contemporary 109s at 5000m (16404ft):

F-2 362mph (592kph)

F-4 387mph (623kph)

G-1 365mph (588kph)

G-2 366mph (590kph)

As you can see the speed advantage is reduced significantly at medium altitudes. 
The reality was such that 109s would often avoid the conflict if possible and instead speed away and climb to a position of advantage, however 109s caught from above or by surprise had to endure a dogfight, which i tend to think gave the advantage to the 109 in the vertical and the advantage to the P-40 in horizontal. It would not surprise me if the P-40 was also faster in the dive given the higher weight of the plane and being the power output of the two planes were very similar at these altitudes. 
In level flight or extended climbs the P-40 was likely to see the 109 pull away, barring overheating or engine problems. 
The P-40 was also able to retain more speed out of dives, because of weight, and power, although turns would quickly bleed off any speed advantage. 
109s probably still faired best to keep the fight vertical, where if the P-40 chose to follow, would lose any advantage in repeated loops. I don't believe the 109 could turn with a P-40 unless the chase was at higher speeds where speed and rate of turn are more effective than radius. Its possible the 109 may match the P-40 in many turns, on paper, but the reality of energy in a dogfight when making such turns is that the plane that bleeds off speed faster would be able to make the tighter turn. 


Bill


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## Vincenzo (Feb 2, 2010)

specifically he tell that in training never flew alone in yakovlev, late he never talking to fly with yakovlev.

soem notes on 109 speed 
at time of P-51B the F-2 can go a 612 km/h but was hard find one for the 51 i think, also the speed of F-4 maybe highest in late 43 the engine was cleared for WEP (using american termonology) the speed of G-1 in Rechlin test was 622 km/h at 5 (and w/o wep, and at time of 51 the wep was cleared)


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## billswagger (Feb 2, 2010)

> =Vincenzo;631381]specifically he tell that in training never flew alone in yakovlev, late he never talking to fly with yakovlev.



Oh, i took that to mean he never flew Yaks with out other Yaks. My bad. 

As for G-2 speed, it may have been faster, but the graph (in German) rated speed a bit lower specifically in the 4000m-6000m range from what appeared to be overheating. 
http://www.kurfurst.org/Performance_tests/109G1_messung601e605a/files/Blatt8.jpg

It may have gone faster in short bursts and overheating would've been limited with the introduction of MW50. As far as i know that didn't begin to appear in production 109s until mid to late 1943. 

This is also a test on a captured 109G2 of the MTO, although it gives no specific figures at 5000m. 
Kurfrst - Bf 109G/trop Middle East trials: Dimesnions, Weights and Performance

There is probably a margin of error on any published figures for most aircraft anyway. 
To quibble over a small difference in numbers is insignificant. It isn't to say that the P-40 was faster in level speed, only that at medium altitudes the speed disadvantage was within 10-30mph depending on variant. Also i'm not attempting to mislead you, in that the 109 could fly faster and higher. Higher = faster which is generally seen as a huge advantage. 
If range permitted, I know tactically it was better for German planes to elude lower altitude fights so they could climb to a vantage point. From reading more of the interviews on that website, it appears that was a very common tactic of the German/Russian air war. 



Bill


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## Vincenzo (Feb 2, 2010)

you take the comparison test with 601 and 605 engine this is not a production fighter configuration, the test of rechlin you can find ever in kurfuerst page at Kurfrst - Rechlin E`Stelle Erprobungsnummer 1586, ,the plane of G2 trop has, within other trouble, a hole in the prop...
why looking a enemy test or a special purpouse test when there are the official flight trials available?


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## billswagger (Feb 2, 2010)

duplicate


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## billswagger (Feb 2, 2010)

Vincenzo said:


> why looking a enemy test or a special purpouse test when there are the official flight trials available?



Well, i can't look at a test in 43 to see how a fighter performed in 42. 
Even flight trials are done to measure an increase in performance, and aren't always best for comparison reasons, but that is all we have short of actually flying the planes ourselves. 
And noteably, there are flaws in the data of most tests which have to do with limitations in instrumentation. For that reason i mention a margin of error +/- 10mph (16kph).
Nothing i'm saying is doctrine, simply my educated opinion. 

Even with this said, production variant 109s tested and rated in early 43 would not have seen combat til mid 43/late 43. And by then the P-40 was being phased out with P-47s and P-51Bs. 

Its not really a relative discussion of speed in this context, simply put, the 109 was faster, however speed advantage was reduced with altitude. 

BTW, the speed at 15,000ft by the P-40F of 352mph, was achieved at 48" of boost. It was ran in combat up to 55" and according to some pilots could achieve over 60" of boost in emergencies. 

Australian pilots reported pushing 70"s of boost using their Allison driven Kittyhawks. (P-40E) with out problems, yet you see more published numbers on speed indicated when they were used at 42" of boost. 

http://www.raafwarbirds.org.au/targetvraaf/p40_archive/pdfs/Allison 1710-39 abuse.pdf

You can see how much power the Allison was capable at lower altitudes where supercharging was not such an issue as it was in thinner atmosphere. The horsepower is considerably higher. 

The Merlin was better at altitudes of 10-15k ft, where i have to wonder what speeds could be produced using higher boost pressures. 

Perils P40 Archive Data


So speed and advantage is a bit difficult to nail down with discussion of test flights alone,

Bill


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## Vincenzo (Feb 3, 2010)

billswagger said:


> Well, i can't look at a test in 43 to see how a fighter performed in 42.
> Even flight trials are done to measure an increase in performance, and aren't always best for comparison reasons, but that is all we have short of actually flying the planes ourselves.
> And noteably, there are flaws in the data of most tests which have to do with limitations in instrumentation. For that reason i mention a margin of error +/- 10mph (16kph).
> Nothing i'm saying is doctrine, simply my educated opinion.
> ...



do you know modification on G1 or G2 that give speed up from early production and late??
and why compare a 42 gustav neither P-40F or P-51B fightning in '42?
difference also from a aircraft and other can give also difference in performance.
a bit pessimistic on timing on lw plane, no they are fastest, they aren't US planes that must pass the ocean.
i've laready reading in this forum info on overboosted P-40 but (i still not read the links) i think this give best a lower altitude (lower of 15'k)


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## Kurfürst (Feb 3, 2010)

Official specifications for Bf 109G-1(as well as -2/-3/-4):

Kurfrst - Mtt. AG. Datenblatt, Me 109 G - 1. Ausfhrung

Range figures for Bf 109F/G:


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## billswagger (Feb 3, 2010)

Vincenzo said:


> and why compare a 42 gustav neither P-40F or P-51B fightning in '42?



The majority of operations for the P-40F was from mid 42 to mid 43, but the plane was used into 44 as it was being phased out. 
Prior to that, the P-40E was used in North Africa. 

Contemporary fighters would've been the 109E/F/G and Macchi 202s. The time table suggests that 109F was the predominant fighter with many Es still in operations. 




> i've laready reading in this forum info on overboosted P-40 but (i still not read the links) i think this give best a lower altitude (lower of 15'k)



Most of what i've seen for overboosting is related to the Allison engined (P-40E). It was not as efficient at 15k as the Merlin engine found in P-40Fs. 
The rated boost was 52" for take off and 48" as combat power. Though my reading suggests pilots pushed the Merlin to 65". I'm not sure how that translates to horsepower or speed but it does suggest a substantial improvement above using 48". I also have to wonder how long they could fly overboosted and if engine problems occurred. 

Bill


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## billswagger (Feb 3, 2010)

[


Kurfürst said:


> Official specifications for Bf 109G-1(as well as -2/-3/-4):
> 
> Kurfrst - Mtt. AG. Datenblatt, Me 109 G - 1. Ausfhrung
> 
> Range figures for Bf 109F/G:




I've been looking for those. Do you have figures on the 109Fs specifically the R types used as long range fighters?
Possibly even early Gs or G-2s?

These look to be late war figures. 

A brief search pegs the F with service range of 800miles with tank, but im not sure how accurate that is. 

Also do you happen to know what altitude those ranges occurred?


thanks

Bill


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## Milosh (Feb 3, 2010)

Interesting graphic.

Has the Spitfire IX fast cruise speed at almost 365mph (no external fuel tank) while the 109G's fast cruise speed is approx. 300mph.


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## Vincenzo (Feb 3, 2010)

Milosh said:


> Interesting graphic.
> 
> Has the Spitfire IX fast cruise speed at almost 365mph (no external fuel tank) while the 109G's fast cruise speed is approx. 300mph.



what graphic?

in the table are 331 for LF IX and 321 for gustav...


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## billswagger (Feb 3, 2010)

So far everywhere i've looked the mention of max range with a tank is 600-800miles depending on 109 variant. 
Specifically the numners i see are 1000km, and its repeated over several sources. 
They also site Rechlin
I also have to ask if the fuel injection offered better fuel economy, but i'm not able to decypher those figures looking at German sources. 


I don't doubt other configurations offer better range, perhaps two tanks.


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## Glider (Feb 4, 2010)

The following are the list of combats that RAF 112 squadron had in Tunisia which should give a fair indication as to how well the P40 did against the Me109. All details from Fighters Over Tunisia

23rd Dec 2 x P40 lost 2 x P40 belly landed 1 x Me109 claimed
11th Jan 1 x P40 lost and 1 x P40 belly landed
5th Feb 1 x P40 l1 x P40 lost and 1 x P40 belly landed, 1 x Me109 claimed
27th Feb 1 x P40 lost. 1 x Me109 Probable claimed
7th March 1 x P40 Badly damaged
8th March 7 x P40 lost (1 pilot returned) 2 x Me109 1 x Ju87 claimed
22nd March 1 x Me109 as a probable claimed
19 April 1 x Me109 claimed
20 April 1 x Ju88 claimed

Also did the same for 68th Fighter Squadron of 33rd Fighter Group
12th Dec - 1 German claimed no type given
19th Dec - 1 x He111 claimed
21st Jan - 1 x P40 lost
3rd Jan - 2 x P40 lost
4th Jan - 3 x P40 lost 1 x P40 damaged
8th Jan - 1 x Me109 and 2 x Fw190 claimed (1 German actually lost and 1 Damaged), 2 x P40 lost
11th Jan - 1 x P40 lost 1 x Me109 claimed (but no actual losses recorded)
12th Jan - 1 x Ju88 1 x Me109 claimed
13th Jan - 1 x Beaufighter shot down, 2 x Ju88 shot down (note these were seperate incidents)
15th Jan - 1 x P40 lost
17th Jan - 1 x P40 lost
30th Jan - 1 x P40 lost on GA mission
24th Mar - 5 x P40 lost 5 x Me109 claimed but only one Me109 (Richard Wolfmier) actually lost
29th Mar - 3 x Me109 claimed plus 3 x Me109 claimed by 60th FS. 4 x Me109 actually lost for 1 x P40 lost from 58th FS
31st Mar - 1 x P40 lost and 1 x P40 damaged, 7 x Me109 claimed but none lost
4th Apr - 2 x P40 lost 2 x Me109 claimed but none lost
5th Apr - 1 x P40 lost, 1 x Mc202 and 1 x Me109 claimed
7th Apr - 1 x P40 lost on GA mission
10th Apr - 4 x Mc 202 claimed
23rd Apr - 1 x P40 lost on GA mission
4th May - 2 x P40 claimed 2 x Me109 claimed but no losses to either side
7th May - 1 x p40 lost to AA fire.

Note the 33rd FG unit received a Distinguished Unit Citation for action on 15 Jan 1943 but this must have been on the 13th Jan as that was the oly time they went against a large number of German Bombers destoying 12 in total.

According to German Records


Total German Claims 965

Total German Losses
Combat - 182
Accident -68
AA fire - 23
own AA fire - 3
Own Fighter - 2
Total 278

Generally speaking there is little here to say that the P40 could hold its own in combat against the Me109.


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## Kurfürst (Feb 4, 2010)

billswagger said:


> [
> 
> 
> I've been looking for those. Do you have figures on the 109Fs specifically the R types used as long range fighters? Possibly even early Gs or G-2s? These look to be late war figures.
> ...


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## Kurfürst (Feb 4, 2010)

Milosh said:


> Interesting graphic.
> 
> Has the Spitfire IX fast cruise speed at almost 365mph (no external fuel tank) while the 109G's fast cruise speed is approx. 300mph.



Except the table does not give cruise speeds at all  only max. range, and max. endurance - and the two do not occur at the same speeds.

Spitfire IX LF max speed is given as http://www.spitfireperformance.com/spitfire-lfix-ads.jpg 328 mph by the British datasheet. Bf 109G (DB 605A) fast cruise speeds were 595-600 km/h according to German datasheets (373 mph).


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## billswagger (Feb 4, 2010)

Glider said:


> The following are the list of combats that RAF 112 squadron had in Tunisia which should give a fair indication as to how well the P40 did against the Me109. All details from Fighters Over Tunisia
> 
> 23rd Dec 2 x P40 lost 2 x P40 belly landed 1 x Me109 claimed
> 11th Jan 1 x P40 lost and 1 x P40 belly landed
> ...



I have a hard time distinguishing anything from loss records alone. It does tell a tail, but their is no indication of combat numbers flown, for example 20 me109s vs 10P-40s, or 20P-40s vs 15 me109s. 

You get a different indication depending on the material, but no question the P-40 was the underdog. 



Bill


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## Glider (Feb 4, 2010)

I understand what you are saying which is why I concentrated on following two of the most experienced allied units for the whole of the period. By doing that, any temporary advantages such as for instance who had the bounce or the larger numbers in a particular combat would be evened out. 
Its always easy to find one particular action and put far more importance into it than it warrants.


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## billswagger (Feb 5, 2010)

RAF 112 squadron was equipt with Kittyhawk III (P-40Ks) which used a more powerful Allison engine, but perhaps did not retain the altitude performance of the Merlin found in the P-40Fs. 
Interesingly the Ks could fly a 500mile range with a bomb load, and a total of 1600 miles ferrie range. 

The numbers indicated by the 68th seem to indicate they did a bit better, and on some days were quite victorious. 
Maybe something to do with experience in the aircraft, or perhaps the use of different variant. (warhawks, aka P-40F-5-CU)

Bill


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## Glider (Feb 5, 2010)

Either way the 109 was comfortably ahead in both cases.


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## Wildcat (Feb 5, 2010)

For interests sake, here are the figures posted in "Desert warriors" by Russel Brown. P-40 victories in North Africa - 

112 RAF - 118.5 victories for 38 operational losses

3 RAAF - 139.5 victories for 34 operational losses

450 RAAF - 49 victories for 28 operational losses.

Note - 36 of 112's and 65 of 3 RAAF's victories were achieved whilst flying Tomohawks, the rest on Kittyhawks. Operational losses included aircraft lost to AA fire, bomber return fire etc.

Going through the list of individual pilot claims for 3sqn RAAF, I count 50 Bf109's destroyed, similary for 450 RAAF I count 27 Bf109's being destroyed by it's pilots. The book doesn't list the individual claims for the pilots of 112 sqn.


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## Nikademus (Feb 5, 2010)

From Shores' Fighters over the Desert , I calculated the following:

168 x Tomahawk for 47 x Bf-109
223 x Kittyhawk for 97 x Bf-109
11 x P-40F for 4 x Bf-109

summary: 402:148 (3.7:1)

From Shores' Fighters over Tunisia:

62 x Kittyhawk for 25 x Bf-109
58 x P-40F for 33 x Bf-109

summary: 120:58 (2.1:1)


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## Glider (Feb 6, 2010)

I can only assume that Desert Warriors used the claimed figures. Some of these claims were clearly way over the top. Not mentioned in my list was one unit that claimed 21 Me109's in one combat over Sardinia in P40's. 

Its important not to accuse anyone of misleading people but claimed figures are always very misleading.


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## billswagger (Feb 6, 2010)

Glider said:


> Its important not to accuse anyone of misleading people but claimed figures are always very misleading.




Then why did you bring them up.  j/k

I think there is a tendency to over claim, maybe a damaged aircraft for a loss, for example. Happens on both sides which makes these sort of things a bit fuzzy to discuss. I saw a German documentary with subtitles, and they showed some P-40s getting shot at. You see a tracer round strike the plane and then he rolled out of the turn, perfectly intact. "THAT PLANE IS DESTROYED" says the subtitle. Probably propaganda more than anything. 

I just look at the performance of the aircraft and the margin between some variants was not that far apart. 

Consider the P-40K, and P-40F were the better powered versions over the P-40E and B models which perhaps help them contend better. The USAAF even concedes to the fact that the P-40F was probably the best suited for combat against the German fighters because of its better altitude performance. 

Something i dont understand is that if the Spitfire was the obvious better performer, what reason did they have to continue making P-40s? Just seems they could've contracted through an American company and produced a crap load of Spitfires instead. 
I'm sure there is as much politics surrounding that question as there is trying to site combat claims and losses. 


The Checkertails (325th) were a proficient fighter group in the P-40s, and so was the 318th. You might read up on them too. 


Bill


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## riacrato (Feb 6, 2010)

How do you know he was perfectly intact? People think the majority of air to air kills resulted in giant fireballs, which is not true. Especially not in these earlier scenarios when most fighters still relied to some degree on rifle calibre machine guns.

But Glider is right, the only way to get a half decent picture of any individual combat is to look at the loss figures for each side rather than the claims made.

And if Brown's figures are indeed claims made by P-40s that were not cross-checked, that would be quite ironic, because in his book he is quick to mention that JG27 claims don't match loss records for RAF and RAAF.


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## Hop (Feb 6, 2010)

> Except the table does not give cruise speeds at all only max. range, and max. endurance - and the two do not occur at the same speeds.



No, they give cruise speeds. How can they be giving max enurance when they give 2 different figures? For example, is max endurance on the Spitfire IX with no tank 1.1 hours or 1.6 hours?

In fact max endurance was much longer. The Spitfire IX manual gives fuel consumption figures down to 30 gallons an hour, with an 85 gallon fuel tank, how could endurance be 1.1 or even 1.6 hours?


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## billswagger (Feb 6, 2010)

i guess what i mean by intact is that no wings or tail pieces came off, and their was no smoke or fire. In fact, the plane flew out of frame. 
Its probably something you'd need to see for youself before you can speculate. You'd probably agree that the plane was not destroyed as the subtitled suggests. 

Its not really the point i was getting at. Combat records are full of propaganda and biased. Getting reliable unbiased research still draws questions from skeptics too. 


Now back to my other question. 

why not build more Spitfires since it was the better performer? Why continue to build P-40s?

American industry was perfectly cable of mass producing the Spitfire if an agreement could be made. Instead P-40s were built up until 43.


Bill


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## riacrato (Feb 6, 2010)

Milosh said:


> Interesting graphic.
> 
> Has the Spitfire IX fast cruise speed at almost 365mph (no external fuel tank) while the 109G's fast cruise speed is approx. 300mph.



I don't know about you but I calculate ~321 mph for Bf 109 G and ~332 mph for Spitfire IX LF fast cruise speed from that graph. And it still _could_ be that the two figures apply to different speeds.


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## billswagger (Feb 6, 2010)

Hop said:


> In fact max endurance was much longer. The Spitfire IX manual gives fuel consumption figures down to 30 gallons an hour, with an 85 gallon fuel tank, how could endurance be 1.1 or even 1.6 hours?



Endurance figures often include take off, climb to 10,000ft, and military output or max throttle for 10 minutes, sometimes 20 minutes to simulate combat output. Every country probably does this slightly different and usually cruise setting and altitude are specified along with consumption and combat load. 


Bill


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## Clay_Allison (Feb 6, 2010)

billswagger said:


> Then why did you bring them up.  j/k
> 
> I think there is a tendency to over claim, maybe a damaged aircraft for a loss, for example. Happens on both sides which makes these sort of things a bit fuzzy to discuss. I saw a German documentary with subtitles, and they showed some P-40s getting shot at. You see a tracer round strike the plane and then he rolled out of the turn, perfectly intact. "THAT PLANE IS DESTROYED" says the subtitle. Probably propaganda more than anything.
> 
> ...



I don't think that the U.S. was capable of making Spitfires under license effectively. They were an expensive and complicated aircraft with a lot of sub-assemblies as I understand it.


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## billswagger (Feb 6, 2010)

Clay_Allison said:


> I don't think that the U.S. was capable of making Spitfires under license effectively. They were an expensive and complicated aircraft with a lot of sub-assemblies as I understand it.



The Packard Merlin was license built and look what innovations it was able to add to the Spitfire, specifically the dual impellers and the use of indium to help prevent corrosion. It also incorporated a more advanced supercharging system that was later retrofitted to existing Merlins and late production Spitfires. 


Referencing a combat pilot, Charles Dills, who flew the P-40E, F, K, M, N and L as well as the P-47, and P-51, says that the P-40 is under rated.
His notion is that at the start of the war there was little time to engineer changes or rework designs for specific improvements. The US was burdened with supplying its air forces with enough fighters to be effective in air campaigns. As you know, first impressions are lasting impressions, however he does say the early P-40s were the lightest and that the K model was the best compromise for weight and power. 
He later adds he would rather a P-40 in combat than a P-47, but there is no other aircraft like an A-36A which he preferred for close ground support. 

Interesting tid biit, although anecdotal 

Bill


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## Colin1 (Feb 6, 2010)

Clay_Allison said:


> I don't think that the U.S. was capable of making Spitfires under license effectively. They were an expensive and complicated aircraft with a lot of sub-assemblies as I understand it.


There were no issues with US aircraft manufacture in fact, European observers commented on the high build quality. The initial problem with US fighters was suitability for role (in the ETO).

If Lockheed could turn out a relatively complex aircraft like the P-38 then I don't think a Spitfire would have posed many more problems.

Packard took on the Merlin for licence production successfully and even started feeding back improvements, I would consider the powerplant to be one of the most complex subsystems of a WWII fighter, I'm just not seeing any banana skins anywhere else in the overall manufacture of the platform; the semi-elliptical wing was becoming apparent with the P-47 and NAA were getting to grips with compound curve aeronautical design.

Where are you envisaging the problems as being?


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## Shortround6 (Feb 6, 2010)

billswagger said:


> The Packard Merlin was license built and look what innovations it was able to add to the Spitfire, specifically the dual impellers and the use of indium to help prevent corrosion. It also incorporated a more advanced supercharging system that was later retrofitted to existing Merlins and late production Spitfires.
> 
> Bill



where are you getting that from?

R-R designed and built the two-stage supercharger. The design was given to Packard who was already building a single stage (impeller) version. It is true that Packard designed and used a different supercharger drive/gear change than R-R. 

Any evidence that a more advanced supercharger system was retrofitted to existing engines?


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## Shortround6 (Feb 6, 2010)

Colin1 said:


> There were no issues with US aircraft manufacture in fact, European observers commented on the high build quality. The initial problem with US fighters was suitability for role (in the ETO).
> 
> If Lockheed could turn out a relatively complex aircraft like the P-38 then I don't think a Spitfire would have posed many more problems.
> 
> ...



I believe it was US policy NOT to build foreign designs. THE US built NO British tank designs, Few, if any, small arms and only a few escort type war ships. The Idea being that if England was conquered the US wouldn't be stuck with a bunch of factories tooled up to produce weapons that didn't suit US requirements. 
Some of the requirements may have had little practical difference in the end but they did exist. For instance the Spitfire may not have been built to the US load factor for a pursuit fighter. Yes, we wound up flying them and I am not saying that the the Spitfire didn't do an excellent job in combat but at the time these decisions were made (and it takes at least a year to tool up a factory and get real numbers rolling out the door, not a ceremonial "1st production" aircraft) the British planes didn't meet US requirements or standards.


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## Timppa (Feb 6, 2010)

>



I have problems accepting the values.
For example AHT gives for P-51 with drop tanks combat radius of 700 miles at 25,000ft and 750 miles at 10000ft.

Combat radius is calculated by taking account of:
- warm-up and take off
- climb at normal rated power (distance covered in climb is not included)
- fast cruise (210mph ias=315 mph tas)
- combat, 5mins emergency power and 15min in military power
- fast cruise back
- 30mins reserve ( min cruise power)

The table above gives only 590 miles radius calculating fast cruise only without the above considerations ?


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## Kurfürst (Feb 6, 2010)

I am thinking that the British report's figures assume a Mustang III without the rear fuselage tank perhaps.


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## JoeB (Feb 6, 2010)

Nikademus said:


> From Shores' Fighters over the Desert , I calculated the following:
> 
> 168 x Tomahawk for 47 x Bf-109
> 223 x Kittyhawk for 97 x Bf-109
> ...


"Desert" was written with pretty complete specific German claims (from Hans Ring, Shores' co-author) and Allied claims and losses, but not complete German losses. The text will often say 'so and so shot down Bf109' when it apparently really means 'so and so claimed Bf109, we don't have the actual German losses for this particular case'. This is what Frank Olynyk, author and expert on US victory credits and contributor to some of Shores' books, told me. I started to count up case by case the combats in 'Desert' but was confused by the wording about many combats, and gave up getting an accurate result once I heard that answer. Assuming you were counting all those ambiguous references to Bf109 losses (I don't know how to make judgement calls distingushing them), I think we can assume the 109's ratio was better than those counts. From what I've heard it's also true of "Tunisia" and that's why Shores plans to write updated books on both campaigns.

Joe


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## Nikademus (Feb 7, 2010)

> =JoeB;633142
> Assuming you were counting all those ambiguous references to Bf109 losses (I don't know how to make judgement calls distingushing them), I think we can assume the 109's ratio was better than those counts. From what I've heard it's also true of "Tunisia" and that's why Shores plans to write updated books on both campaigns.
> 
> Joe



no. I don't count ambiguous references. I only counted the verified losses per the source. "Verified" means the source states that the plane/pilot in question went down. I never count "claims" listed in Shores books for some of the reasons you cited, it would make the totals too subjective. I've developed a pretty consistant system in the 11+ Shores books collected, along with other authors who document specific air battles. Perfect? no.....which is what i always list my figures as "estimates." 

If anything the ratio is more likely to be more kind to the Allied side though it is also possible that some German losses might have been missed. Shores is not perfect and neither am i. FoT[unisia] is a good example. Shores admits from the get go that one problem in using the Deutsches Dienststelle WAST in Berlin as the primary source on German losses is that it's based on daily German casualty lists. To be recorded into this list one has to have been injured to some degree. If a German pilot bailed out or crash landed and then walked or was driven back to his unit....he might not have ended up in the list.

As such....as Shores says, its more than probably that a % of the claims made by Allied pilots in "Tunisia" were legit. Nevertheless for consistancy purposes.....i did not count the claims unless verified by the German sources just as i do for his other books and other authors such as Lundstrom.


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## JoeB (Feb 7, 2010)

Nikademus said:


> no. I don't count ambiguous references. I only counted the verified losses per the source. "Verified" means the source states that the plane/pilot in question went down. I never count "claims" listed in Shores books for some of the reasons you cited, it would make the totals too subjective. I've developed a pretty consistant system in the 11+ Shores books collected, along with other authors who document specific air battles. Perfect? no.....which is what i always list my figures as "estimates."
> 
> If anything the ratio is more likely to be more kind to the Allied side though it is also possible that some German losses might have been missed. Shores is not perfect and neither am i. FoT[unisia] is a good example. Shores admits from the get go that one problem in using the Deutsches Dienststelle WAST in Berlin as the primary source on German losses is that it's based on daily German casualty lists. To be recorded into this list one has to have been injured to some degree. If a German pilot bailed out or crash landed and then walked or was driven back to his unit....he might not have ended up in the list.
> 
> As such....as Shores says, its more than probably that a % of the claims made by Allied pilots in "Tunisia" were legit. Nevertheless for consistancy purposes.....i did not count the claims unless verified by the German sources just as i do for his other books and other authors such as Lundstrom.


In trying to count by my method, I gave up as end of 1941 in 'Desert' with ? for the German side in most cases, and many cases where the narrative said 'shot down' not 'claimed' about Axis losses but gave no further details. Just as one random example flipping around, not a 109 but pg. 70, 28 Nov 1941 it says: "Lt. Moolman shot down a Bf110', not 'claimed', but there are no details which Bf110. The impression I've gotten from someone who knows Shores is that in the early book, he meant 'claimed and taken as valid lacking contradictory info', because there were so many holes in the German loss data he had (and he had little at all about the Italians back then, 1969). And he was just developing his style, and finding out how complete a story could be told, I personally suppose, also. 

I don't have 'Tunisia' but based on the general picture in 'Fw190 in North Africa' by Arthy and Jessen, a much more recent book (Tunisia was published in 1975), written using primary sources and German published works which became available more recently, a less than 2:1 kill ratio of Bf109's v USAAF/French P-40F's in Tunisia seems remarkably favorable to the P-40's. I assume its possibly a result of confusion of the narrative style of Tunisia v Shores' later books, which makes some Allied claims sound like actual German losses, which perhaps were not.

So, I am not raising this as criticism of Shores generally or books presenting opposing air combat accounts generally, and surely not of you, but a problem with those particular books. Though even in general of course the interesting question is where the info in such books comes from originally and how gaps in it are treated in the narrative or footnotes (which unfortunately Shores/his publishers have seldom included in any of his writing). I've looked into Shores' et al sources for 'Bloody Shambles' for example, on Japanese side, which tends to be what's contentious, and feel pretty comfortable how that book deals wit that info and the gaps in it. Similarly Lundstrom. I haven't done the same kind of poking into Desert or German sources generally, but from what I've heard and ambiguities as I see it in the text, I think we can compute less accurate quantiative results from that book compared to others' of Shores and of same genre by some other authors.

Joe


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## drgondog (Feb 7, 2010)

Kurfürst said:


> I am thinking that the British report's figures assume a Mustang III without the rear fuselage tank perhaps.



You are right, the RAF did not use the aft fuse tank - at least not as far as I know.


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## Nikademus (Feb 7, 2010)

> I don't have 'Tunisia' but based on the general picture in 'Fw190 in North Africa' by Arthy and Jessen, a much more recent book (Tunisia was published in 1975), written using primary sources and German published works which became available more recently, a less than 2:1 kill ratio of Bf109's v USAAF/French P-40F's in Tunisia seems remarkably favorable to the P-40's.



Not when one considers the different conditions by which the USAAF P40's operated in Tunisia. According to pilots in JG77, they found that while they could still pick off Kittyhawks fairly easily, it was found that American Warhawks were flown with a skill that prevented their losses from ever reaching the levels suffered by some RAF units. The level of committment of the American P40's was also less in Tunsia than that seen in 'Desert' under the Commonwealth.


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## billswagger (Feb 10, 2010)

I was unable to find specific charts for roll rates of the 109, but much of what i've read on contemporary Spitfires says they were about the same.

Remarkably, the high speed rate of roll for both planes (spit and 109) drops off considerably above 300mph (IAS). 

The 109E takes about 2 seconds to roll 45 degrees at 300mph and about 4 seconds to roll 45 degrees at 400mph. 
Spitfire Mk I versus Me 109 E


I'm not sure how the F and G stand in this category, but i would think the airframes are very similar. 
Maybe someone could shed some light here perhaps a roll chart of the different variants. 


Now on to the P-40.

Its max rate of roll is achieved at 285mph (ias) where it rolls at 110 degrees per second. (10,000ft)
That would be about 220 degrees in two seconds. 
Whats interesting is that it was tested against other planes using 30 lbs of stick force, however maximum deflection was attained with just 19.5 pounds of stick force. 

I might think the P-40 to be a very effective fighter in the roll axis even at high speeds, in fact very little effort would be required to maneuver in this regard in comparison to the 109 and Spitifre. 

http://www.raafwarbirds.org.au/targetvraaf/p40_archive/pdfs/Allied AC rollrate.pdf

It was also mentioned that although heavier stick forces were felt with the Spitfire and Hurricane, they had lighter and more responsive stick movements at lower deflections. In other words, 5lbs of stick force would get you more roll from a Spitfire than a P-40, but 30lbs of stick force would not match the roll performance of the P-40 using less than 20lbs of stick force at speeds above 160mph. 

The article also goes on to describe the P-36 and mechanical differences to the P-40. In effect, the P-40 stick travels a little further but with less force in comparison to the P-36. 

A side note:

Also found the P-40D was fitted with 20mm cannons but never used operationally.



Bill


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## Clay_Allison (Feb 10, 2010)

It will never cease to amaze me that the USA never got their 20mm cannons to work, with so many viable options to fix them.


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## brandle (Feb 10, 2010)

Interesting comment there Clay, any reason why they didnt push the 20mm, I was fortunate many years ago to talk with a German pilot who flew 109,s and he said "the machine can be a technical marvel, but if the pilot is not then why have it made" I think that comment boils down to the machine is only as good as the pilot.


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## Clay_Allison (Feb 10, 2010)

brandle said:


> Interesting comment there Clay, *any reason why they didnt push the 20mm*, I was fortunate many years ago to talk with a German pilot who flew 109,s and he said "the machine can be a technical marvel, but if the pilot is not then why have it made" I think that comment boils down to the machine is only as good as the pilot.


arrogantly refusing to use the suggestions the British made on how to make the Hispano work, also seemingly zero interest in exploring cannon options outside of the Hispano. Probably a lot of people taking the ".50s are good enough" line and dragging their feet on progress, regardless of the fact that the M2 weighed a ton and didn't have any HE rounds.


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## DerAdlerIstGelandet (Feb 10, 2010)

I do not believe the the US was ever in need of the 20mm. The .50s were more than enough to bring down 109s and 190s. The German's needed heavier weapons that were more suited for killing bombers. If the US would have had to contend with large streams of heavy bombers, they certainly would have used heavier armament.


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## Clay_Allison (Feb 10, 2010)

DerAdlerIstGelandet said:


> I do not believe the the US was ever in need of the 20mm. The .50s were more than enough to bring down 109s and 190s. The German's needed heavier weapons that were more suited for killing bombers. If the US would have had to contend with large streams of heavy bombers, they certainly would have used heavier armament.


Firepower/Weight ratio on the M2 is pathetic. It's a very heavy gun for what it delivers, weighing 2/3 as much as the hispano for 1/3 the destructive power, the power/weight ratio on the ammo actually sucks since it relies on lead rather than high explosive.

If we had a lighter .50 like the Berezin UB or MG 131 I'd be fine with it. The M2 is a ground weapon, heavy and rugged and square. It is mediocre in the air at best.


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## DerAdlerIstGelandet (Feb 10, 2010)

Clay_Allison said:


> Firepower/Weight ratio on the M2 is pathetic. It's a very heavy gun for what it delivers, weighing 2/3 as much as the hispano for 1/3 the destructive power, the power/weight ratio on the ammo actually sucks since it relies on lead rather than high explosive.
> 
> If we had a lighter .50 like the Berezin UB or MG 131 I'd be fine with it. The M2 is a ground weapon, heavy and rugged and square. It is mediocre in the air at best.



I agree with you that it was not the best choice, but it served its purpose just fine. For an Air Force whos main adversary was a single engined fighter, having a fighter with 8 .50s did the job just fine. There was no need to have 20mm or highter to counter the fighter threat. 

To use a lighter version of the weapon obviously would have been better, but as I said there was no need for the USAAF to fit its fighters with heavy caliber weapons.

That is all I am saying...


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## Clay_Allison (Feb 10, 2010)

DerAdlerIstGelandet said:


> I agree with you that it was not the best choice, but it served its purpose just fine. For an Air Force whos main adversary was a single engined fighter, having a fighter with 8 .50s did the job just fine. There was no need to have 20mm or highter to counter the fighter threat.
> 
> To use a lighter version of the weapon obviously would have been better, but as I said there was no need for the USAAF to fit its fighters with heavy caliber weapons.
> 
> That is all I am saying...


2x20mm cannons would provide the same firepower as a 6x.50 battery at a huge weight savings (about half the total weapons weight), that's what I'm saying. Also, 4x20mm on the heavy fighters (like the P-47, F6F, F4U, P-38 ) would have been a big force multiplier when attacking ground targets.


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## renrich (Feb 10, 2010)

This topic has been argued on this forum for years and Chris has nailed it as far as I am concerned. All things considered, the 50 BMG was the correct weapon for use in American fighters. The US mostly used it's fighters against Axis fighters and the reliability, flat trajectory, large amount of ammo carried which gave a lot of firing time, the hitting power of the cartridge against lightly armored AC, the large numbers of 50 BMGs carried along with the high rate of fire,(compared to cannon) which made it easier to get hits, all contributed to the efficacy of the 50 BMG. It was simpler in terms of logistics also. The bombers carried mostly 50s and the fighters also. Undoubtedly, for the expert marks man, a few cannon with a lower rate of fire and shorter firing time, would have been more lethal but most pilots were not expert gunners. This has not been discussed here before, AFIK, but I read in Shaw, 
"Fighter Combat, Tactics and Maneuvering," that many less than stellar gunners from the US, in WW2, had their guns harmonised, rather than to converge at around 300 yards, had them adjusted to give somewhat of a box pattern, a lttle like a shotgun at an appropriate range. A few hits from a 50 BMG on an enemy fighter was often enough to damage or disable that fighter. The F4U1B and later the F4U4B, as well as some F6Fs came from the factory with four or two 20 MMs but apparently they were not viewed as an improvement. The later F4U5N which was a night fighter to be used against bombers all had four 20 mms.


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## billswagger (Feb 10, 2010)

There's a couple other factors at play regarding the 20mm and the M2. 
I think in the time frame we are speaking of, (allied) cannons were slower firing both in rate and velocity which tended to favor the M2 for air to air combat other than hitting bigger targets like bombers. You can look at weight of fire statistics and all the jargon that accompanies such comparisons but the fact remains if you can't hit what you're shooting at then the HE rounds are less effective. 
You can have six streams of bullets fireing at a higher rate and losing less velocity than 2 streams that fire at a lower rate and lose more velocity. So not only do you have more streams of bullets but better arch and range for air to air combat. 

Difference is that when a couple HE rounds land they do much more damage, but I have to think that it also came down to the fact that most aircraft were vulnerable to machine gun fire alone. 

I agree if the US had to face a heavy bomber threat then cannons would've seen more service. I dont think the P-40 could ever be decribed as an interceptor so maybe thats why the idea of cannons was left alone. 


I was hoping to get back on topic, perhaps if someone had some roll rate figures for the 109, particularly the F or early G series so at least so the comparison can pertain to the P-40,
So far much of the roll performance suggests very poor roll response at higher speeds along with low elevator authority because of the 109s short stick throw, however numbers are not too specific other than what i found at SpitfirePerformance.com


Bill


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## Clay_Allison (Feb 10, 2010)

billswagger said:


> There's a couple other factors at play regarding the 20mm and the M2.
> I think in the time frame we are speaking of, (allied) cannons were slower firing both in rate and velocity which tended to favor the M2 for air to air combat other than hitting bigger targets like bombers. You can look at weight of fire statistics and all the jargon that accompanies such comparisons but the fact remains if you can't hit what you're shooting at then the HE rounds are less effective.
> You can have six streams of bullets fireing at a higher rate and losing less velocity than 2 streams that fire at a lower rate and lose more velocity. So not only do you have more streams of bullets but better arch and range for air to air combat.
> 
> ...



Early in the war the M2 was firing at 450-500 rpm, unless I'm mistaken, I don't think the AN/M2 was available until mid-war.

None of that changes the fact that the M2 was unforgivably heavy (38 Kg). German 13.1(16.6 kg), Japanese 12.7(23kg), and Russian 12.7(21.5 kg), Italian 12.7(29Kg) were all lighter and all had HE ammo.


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## Shortround6 (Feb 10, 2010)

Clay_Allison said:


> Early in the war the M2 was firing at 450-500 rpm, unless I'm mistaken, I don't think the AN/M2 was available until mid-war.
> 
> None of that changes the fact that the M2 was unforgivably heavy (38 Kg). German 13.1(16.6 kg), Japanese 12.7(23kg), and Russian 12.7(21.5 kg), Italian 12.7(29Kg) were all lighter and all had HE ammo.



The Early and mid war .50s could fire at about 600rpm (not much different than the Hispano) in free firing installations. The synchronized guns however were down near 400-450rpm as you say. I don't believe there were many late war synchronized guns (P-63?).

The extra weight of the American .50 did allow for higher velocity compared to the axis guns which did make defection shooting easier.


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## renrich (Feb 10, 2010)

To me the following is a pretty good analogy of the cannon-50 BMG topic. A hunter who hunts doves will probably choose size seven and a half shot shell. The reason he does that is that he knows that a few solid hits with 7.5 shot will bring down a dove. A hunter who hunts geese will probably choose size two shot shell because a few solid hits with a size 2 will bring down a goose. Those size twos will bring down a dove also but the pattern is not very dense and a dove can fly though a pattern of twos at thirty yards and only lose a few feathers. Conversely size 7.5 shot will bring down a goose but the range has to either be very close, before the pattern opens up, so that a bunch of solid hits are made or else a lucky pellet hits a vital place. The pattern of a seven and a half is dense enough at thirty yards or even a little further that a dove cannot fly through the pattern without taking some hits.

Now the 20 mm cannon has a ROF of about ten rounds a second, so if a four cannon armed fighter fires a two second burst. he has sent 80 rounds down range at the target. A lucky hit with any of those rounds can bring down a fighter but more probably it will take several hits to be lethal. The 50 BMG has a ROF of about 15 rounds per second and a six gun fighter in a two second burst will then send 180 rounds down range at the target. The 50 BMG round is not as lethal as the 20 mm but still one lucky hit can bring down a fighter and he is far more likely to get hits with 180 rounds in the target vicinity than with only 80 rounds. The fighter is like the dove, which does not take a lot of lead to bring down. On the other hand a bomber is much more rugged, like a goose, and also a much bigger slower target, like a goose. It takes more killing but the pattern does not have to be as dense because the target is slow and big. Another factor is that the P51A with four 20 mm cannon carried 125 rounds per gun which gave it a firing time of 12.5 seconds or slightly more than six two second bursts. The P51D with six 50 BMGs carried 313 rounds per gun which gave it a firing time of 20.9 seconds or slightly more than ten two second bursts. The argument favoring the 50 BMG for fighter versus fighter combat seems clear to me.


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## DerAdlerIstGelandet (Feb 10, 2010)

I agree, and that is why I said that the armament was perfect for what the USAAF needed. If heavy bombers had been the main target, then the armament would have been adjusted accordingly. Just look at how the Bf 109s armament evolved from the beginning of the war when the LW was on the offensive fighting mostly against fighter opposition, to the mid to later war years when it was mostly up against the large allied heavy bomber streams.


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## renrich (Feb 10, 2010)

This is beside the point but I know that adding all the cannon, some of them in gondolas, degraded the performance a little of what were essentially small, light fighters in the BF109 and the FW190, but I wonder how the recoil of those weapons affected the fighters, especially of a cannon on one side only jammed. Seems as if there would be a pretty severe yaw component.


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## Clay_Allison (Feb 10, 2010)

renrich said:


> To me the following is a pretty good analogy of the cannon-50 BMG topic. A hunter who hunts doves will probably choose size seven and a half shot shell. The reason he does that is that he knows that a few solid hits with 7.5 shot will bring down a dove. A hunter who hunts geese will probably choose size two shot shell because a few solid hits with a size 2 will bring down a goose. Those size twos will bring down a dove also but the pattern is not very dense and a dove can fly though a pattern of twos at thirty yards and only lose a few feathers. Conversely size 7.5 shot will bring down a goose but the range has to either be very close, before the pattern opens up, so that a bunch of solid hits are made or else a lucky pellet hits a vital place. The pattern of a seven and a half is dense enough at thirty yards or even a little further that a dove cannot fly through the pattern without taking some hits.
> 
> Now the 20 mm cannon has a ROF of about ten rounds a second, so if a four cannon armed fighter fires a two second burst. he has sent 80 rounds down range at the target. A lucky hit with any of those rounds can bring down a fighter but more probably it will take several hits to be lethal. The 50 BMG has a ROF of about 15 rounds per second and a six gun fighter in a two second burst will then send 180 rounds down range at the target. The 50 BMG round is not as lethal as the 20 mm but still one lucky hit can bring down a fighter and he is far more likely to get hits with 180 rounds in the target vicinity than with only 80 rounds. The fighter is like the dove, which does not take a lot of lead to bring down. On the other hand a bomber is much more rugged, like a goose, and also a much bigger slower target, like a goose. It takes more killing but the pattern does not have to be as dense because the target is slow and big. Another factor is that the P51A with four 20 mm cannon carried 125 rounds per gun which gave it a firing time of 12.5 seconds or slightly more than six two second bursts. The P51D with six 50 BMGs carried 313 rounds per gun which gave it a firing time of 20.9 seconds or slightly more than ten two second bursts. The argument favoring the 50 BMG for fighter versus fighter combat seems clear to me.


If I'm going dove hunting with 7.5 shot, I'd rather not take a 25 pound shotgun to shoot it with.


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## billswagger (Feb 10, 2010)

so better the lighter gun and not hit anything?

You might run out of ammo before you actually hit a dove. 


any 109 roll charts?

mentions this is the best the pilots could achieve and dependent on pilot strength.








This report is based on 30lbs of stick force. 
http://www.raafwarbirds.org.au/targetvraaf/p40_archive/pdfs/Allied AC rollrate.pdf

Bill


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## renrich (Feb 11, 2010)

So you use a full choked 10 gauge punt gun because it weighs a little less than your inproved cylinder 12 gauge?


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## Clay_Allison (Feb 11, 2010)

renrich said:


> So you use a full choked 10 gauge punt gun because it weighs a little less than your inproved cylinder 12 gauge?


I think the analogy broke down somewhere. I'd use a Berezin UB or MG-131 (or similar lighter gun) rather than an M2.


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## Demetrious (Feb 11, 2010)

Clay_Allison said:


> I think the analogy broke down somewhere. I'd use a Berezin UB or MG-131 (or similar lighter gun) rather than an M2.



You go to war with the guns you've got. Which is, in fact, why the P-40 was used in the Second World War at all after the first months of 1941- the Curtiss-Wright factory was available NOW, and they needed fighters NOW, not in three months after the factory was re-tooled to produce Spitfires. 

The reason the Americans got away with using the M2 is because they were in the habit of cramming hideously powerful engines into their airframes anyways, so the extra weight didn't hold down their more successful designs. The planes that would have benefited the most from the weight reduction- early-war underpowered birds like the Warhawk or the Wildcat- never would have gotten them, since the pressure on American forces was the most dire then, and co-operation between America and the Soviet Union was still gearing up- and given who was bearing the brunt of the enemy's attention, the aid was flowing one way. 

As for the P-40 in North Africa, I find it odd that so many people doubt it's effectiveness. I'd expect a 1:1 kill ratio against the 109. Most of the combat was at low level, where the P-40s naturally aspirated Allison was in it's element, and the P-40 had a marked advantage over the Bf-109 in turn and roll rates. The 109, for it's part, had superior climb/vertical performance and acceleration. These performance disparities generally counter each other. Firepower was a wash; the 109 was a fragile aircraft so the Warhawk's .50s were more then sufficient, and the 109s cannons were less effective against the incredibly durable P-40.

This analysis, of course, pertains to early war- the Emil versus the Kittyhawk, for example. Both aircraft received substantial upgrades as the war progressed; the Warhawk usually doesn't get enough credit for it's horsepower upgrades since those numbers are usually given for power at 10,000 feet, and as intelligent minds on this forum have told me, the power drop-off is dramatic even at that modest altitude. So later P-40s generating 1,325 HP at sea level would be right back to 1,000 HP by the time they were at 10K. 

I don't know if the Gustav was ever deployed to North Africa, or if the campaign there was over by the time it was developed, but if memory served the Gustav was a dramatic improvement over earlier 109s- the turn performance was greatly effected by the improved engine power and other modifications, IIRC. If anybody knows more about that, I'd love to hear it.


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## renrich (Feb 11, 2010)

If the foreign weapons are so desirable, it is a wonder we have not been copying and producing them here in the US instead of still producing the M2, (since the 1920s) The F86 was still armed with a version of the M2 in the 50s and did fairly well. As Demetrious said, we went to war with what we had. I would have like to have seen the Garand chambered for something on the order of a very slightly downsized 270 Win but understand why Mac Arthur insisted we stay with the 3006.


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## Vincenzo (Feb 11, 2010)

Demetrious said:


> As for the P-40 in North Africa, I find it odd that so many people doubt it's effectiveness. I'd expect a 1:1 kill ratio against the 109. Most of the combat was at low level, where the P-40s naturally aspirated Allison was in it's element, and the P-40 had a marked advantage over the Bf-109 in turn and roll rates. The 109, for it's part, had superior climb/vertical performance and acceleration. These performance disparities generally counter each other. Firepower was a wash; the 109 was a fragile aircraft so the Warhawk's .50s were more then sufficient, and the 109s cannons were less effective against the incredibly durable P-40.
> 
> This analysis, of course, pertains to early war- the Emil versus the Kittyhawk, for example. Both aircraft received substantial upgrades as the war progressed; the Warhawk usually doesn't get enough credit for it's horsepower upgrades since those numbers are usually given for power at 10,000 feet, and as intelligent minds on this forum have told me, the power drop-off is dramatic even at that modest altitude. So later P-40s generating 1,325 HP at sea level would be right back to 1,000 HP by the time they were at 10K.
> 
> I don't know if the Gustav was ever deployed to North Africa, or if the campaign there was over by the time it was developed, but if memory served the Gustav was a dramatic improvement over earlier 109s- the turn performance was greatly effected by the improved engine power and other modifications, IIRC. If anybody knows more about that, I'd love to hear it.




Unlucky for P-40 pilots the rate was over 2:1, the data were posted some day ago in this forum.
Emil versus Kittyhawk maybe a possible engagement, but at time of Kittyhawk came, early 42, the Friederich was already avaialble.
Yes Gustav was deployed, one also captured and tested from british


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## billswagger (Feb 11, 2010)

> So later P-40s generating 1,325 HP at sea level would be right back to 1,000 HP by the time they were at 10K.



The P-40F still produced 1050hp at 20,000ft. Later variants of the P-40 like the K and M also used better powered Allisons which allowed for better outputs up into the mid 20k ft region. 
The fact remained that up in the thinner air above 20k climb rates sank for all birds but considerably more for the heavier planes. Any power loss at altitude would hinder the P-40 much more than the Spitfire or 109. 


Bill


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## Clay_Allison (Feb 11, 2010)

Demetrious said:


> You go to war with the guns you've got. Which is, in fact, why the P-40 was used in the Second World War at all after the first months of 1941- the Curtiss-Wright factory was available NOW, and they needed fighters NOW, not in three months after the factory was re-tooled to produce Spitfires.
> 
> The reason the Americans got away with using the M2 is because they were in the habit of cramming hideously powerful engines into their airframes anyways, so the extra weight didn't hold down their more successful designs. The planes that would have benefited the most from the weight reduction- early-war underpowered birds like the Warhawk or the Wildcat- never would have gotten them, since the pressure on American forces was the most dire then, and co-operation between America and the Soviet Union was still gearing up- and given who was bearing the brunt of the enemy's attention, the aid was flowing one way.
> 
> ...


We had 20 years to develop a purpose built aircraft gun and didn't pay any attention to it except for the M4 37mm cannon, which doesn't compare well to other contemporary heavy AC cannon.

"Going to war with what you have" only applies to us and not Germany, who developed AND mass produced the Mk 108 during the war? 

The US military just didn't consider the guns on an aircraft to be important, they stuck something from the ground forces on it and upped the rate of fire a little. 

Designing a gun is not that hard, maybe 1/500th the complexity of an engine and 1/1000th the complexity of an aircraft. That's the reason that individual men design guns and huge teams design planes. That's also the reason that once a good gun is designed, it continues to be an effective weapon for 100 years. The M1911 is still a very good gun nearly 100 years since its development by J.M. Browning. Nobody is flying even an F-86 into combat tomorrow or any time soon.

Tell any good gun company with a good designer on staff to design a longer, lighter, more linear HMG for aircraft and promise the winner first dibs on putting as many as they can produce into every plane in the inventory. I can guarantee you that Winchester, Remington, Colt, or somebody would come up with something.


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## renrich (Feb 11, 2010)

The M2 weighed around 70 pounds, was 54 inches long and had a ROF of 800 to 900 RPM. The 20 mm cannon weighed 129 pounds, was 78 inches long and had a ROF of 600 RPM. 70 pounds does not seem excessive for a weapon of that power and reliability. How much weight could be saved by a redesign. If 10 pounds per gun were saved times six guns that would only be 60 pounds. There could be that much difference in pilot weight. Methinks there is hair splitting going on.


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## Clay_Allison (Feb 11, 2010)

renrich said:


> The M2 weighed around 70 pounds, was 54 inches long and had a ROF of 800 to 900 RPM. The 20 mm cannon weighed 129 pounds, was 78 inches long and had a ROF of 600 RPM. 70 pounds does not seem excessive for a weapon of that power and reliability. How much weight could be saved by a redesign. If 10 pounds per gun were saved times six guns that would only be 60 pounds. There could be that much difference in pilot weight. Methinks there is hair splitting going on.



The MG 131 weighed 36 pounds. The US had, what, six times as many gun manufacturing companies as Germany? We couldn't possibly come up with a weapon half as efficient? That's 234 pounds difference over a six gun battery. That's a whole pilot (larger than average).


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## billswagger (Feb 12, 2010)

The AN/M2, the aircraft version of the gun, was both lighter and more efficient in rate of fire than whats been quoted so far. 
It weighed closer to 64lbs as an aircraft gun. 
I'm not sure why they couldn't have built it as light as the German 131, but it seems there might have been some ballistic advantages for such guns mounted in the wings. 
http://www.warboats.org/stonerordnotes/ANM2HB R4.html


I doubt 30lbs dif was enough to justify weight changes when the gun was proving itself to be effective in the air, at high altitudes and on the ground,
Not just in the capacity to fire at longer ranges but also reliable. 
" Nevertheless, the aircraft gun is still around today because no other cannon-sized gun [.60 (15mm) and larger] can compete with it for simplicity, reliability, and cost-effectiveness. "
when your aircraft weighs close to 10,000lbs loaded, there is little difference 100lbs would make especially if it meant having a less accurate or less reliable weapon. 

EDIT: not implying the German weapon is less reliable, but if I'm not mistaken it fired a smaller casing. 

The 109 already being a light aircraft with moderate horsepower probably got much of its performance by remaining a light aircraft. 
Its really a crappy comparison because they weren't loading 6 or 8 Mg131s in the wings of the 109 with the complexities of harmonization and convergence. The 109 was armed with a pair of MGs and a nose cannon. I wonder how reliable and efficient the MG 131 would be as a six gun installation. 

I think less than 30lbs difference is splitting hairs when you look at the bigger picture not just caliber and firing time. 

Cannons, as the US were concerned, were not an effective air to air weapon until they matched velocity and firing time of the M2.
They didn't get the late war Hispano going until 1945, and even then it could not be used at higher altitudes with out jamming. 

I also think the US had the capability to load their planes with 20mm, but the truth is the US never really had to deal with a heavy bomber threat where the HE round would've been more useful. 
50 caliber did its job in the air and on the ground. 

Bill


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## tomo pauk (Feb 12, 2010)

In a context of major war, a cannon that can substitute 3, or 2 HMGs for a cannon is a great thing. USA produced some 100 000 fighter planes for ww2. Assuming they had 5 HMGs per plane, that's 500 000 all together. Not just producing them, it takes more time/effort/money to mount harmonise those 500K, then 200K of cannons that could do their job.
If the US necked-up their .50 M2 to 18-19mm (as shown by Germans, Russians and Japanese), their 'new' weapon would be a fraction more expensive then original M2. Plus, the plane would have to haul some 100-300 kg less guns ammo, a great thing for any WW2 fighter - F4-F and P-40 would benefited mostly in this example.

As for 'not wanting the cannon until it has the MV as HMG', I don't think it's valid. 
If anything, US pilots were well trained, and their planes had great sights, so the cannon with 10-15% less MV would be equally as usefull. Again, as shown by German, Russian and Japanese pilots (majority was less trained and their planes had less sophistical sights).


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## tomo pauk (Feb 12, 2010)

DP


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## renrich (Feb 12, 2010)

I agree that the average pilot weighed a lot less than 234 pounds. After all, the P39 was designed for a five foot eight inch pilot. TP, no matter how well trained the average pilot was in all the US air forces, the fact remains that the vast majority were no better than average gunners. The Navy and Marine pilots were well trained in deflection shooting but the really good gunners were the exception. The 50 BMG gave them all a better opportunity to get some hits because it could put more rounds into the pattern and because of longer firing times. Being only an average gunner was not confined to the US airmen. I believe that Bubi Hartmann has been quoted as saying that he tried to get so close that he could see nothing through the windscreen but the enemy plane before pulling the trigger.
The weights I have quoted for the guns are from Dean's "America's Hundred Thousand" and I assume they are accurate. I have read that the 50 BMGs in the wings of WW2 fighters were anchored at the rear of the gun but were more free floating near the muzzle. I don't really understand that but I wonder if the mechanism used to mount the guns in the wings was not very important also and if the weight of the mounting apparatus varied according to the type of gun. Could it be that a light but heavy recoiling weapon required a more robust but heavier mounting?


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## tomo pauk (Feb 12, 2010)

Sure enough, more bullets mean more hits, so 4 HMGs have advantage vs. 2 cannons. 
But there are some issues about that: Me-109*, most of Japanese* Russian planes were equipped with 1-2 cannons (add a pair of LMGs, but that's a minor addition to firepower), yet they served admirably. Another is that, even if enemy plane receives 5-10 hits from HMG, those need to hit where it hurts to make a kill. Much less is needed with cannon hits. One more thing: if the target receives a bullet, it knows it's been hit and can react accordingly. But if it receives a shell, target is dead. This is important since I've read many times that 3/4 of planes were killed without knowing they're target.

As for recoil, guess that a gun mount that could handle the recoil of 2-4 HMGs could handle the recoil of 1-2 cannons. RAF experience with wing-mounted cannons is also positive from 1941 on.



*MG-FF and early Japanes cannons had low eneregy and low ammo supply, and even so they were major players


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## DerAdlerIstGelandet (Feb 12, 2010)

Sorry, but it still comes down to arming your aircraft for the threat it is going to encounter. The .50 was enough to counter the 109 and 190 and other LW or Japenese aircraft. Had the US been up against bombers, they would have surely armed them with heavier weapons.


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## Clay_Allison (Feb 12, 2010)

DerAdlerIstGelandet said:


> Sorry, but it still comes down to arming your aircraft for the threat it is going to encounter. The .50 was enough to counter the 109 and 190 and other LW or Japenese aircraft. Had the US been up against bombers, they would have surely armed them with heavier weapons.


You still don't get that I'm talking about the gun and not the caliber (ammunition)? (although I think the .50 should have had HE ammo like every other .50 in the war). The M2 was not an aircraft gun.


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## DerAdlerIstGelandet (Feb 12, 2010)

Clay_Allison said:


> You still don't get that I'm talking about the gun and not the caliber (ammunition)? (although I think the .50 should have had HE ammo like every other .50 in the war). The M2 was not an aircraft gun.



I get exactly what you are saying. I do however not agree with you. I think the .50 was just fine for taking on the German fighters. I think that maybe a better weapon could have been designed, but the .50 was already built and ready to use. For an army that is trying to win a war of attrittion and needs to build a large army quickly, it was the way to go. Why waste time with R&D, when you can use something you already have?


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## Clay_Allison (Feb 12, 2010)

DerAdlerIstGelandet said:


> I get exactly what you are saying. I do however not agree with you. I think the .50 was just fine for taking on the German fighters. I think that maybe a better weapon could have been designed, but the .50 was already built and ready to use. For an army that is trying to win a war of attrittion and needs to build a large army quickly, it was the way to go. *Why waste time with R&D, when you can use something you already have?*


Why didn't we just go to war with the P-40 for the rest of the war? Why develop anything better?


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## Shortround6 (Feb 12, 2010)

The American .50 cal used much more powerful ammunition than the German MG 131. 

The American Ammunition had a muzzle energy of about 17,800 joules per round compared to about 9,600 joules per round for the German 13x64B ammunition. This requires a somewhat larger (the empty case is 35mm longer than the German) and heavier gun, although perhaps with not quite difference between the two guns. 

The Russian 12.7mm was even more powerful but the gun's light weight was purchased, in part, because of a much lower gun "life". This is not Barrel life but the life of the receiver and reciprocating parts. You can argue over the wisdom of designing/building guns with an expected life of 10,000rounds or better for combat planes but it was a real difference in design and weight. 

The American (and Russian) .50s had shorter times of flight, higher impact velocity/energy and flatter trajectory which made air to air gunnery much easier. So much so that the US spent large sums of money and time trying to develop even higher velocity cartridges and guns during the war as the T17 series.


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## Clay_Allison (Feb 12, 2010)

High Explosive weighs less than lead. Seems like HE rounds would achieve both a higher MV and a higher lethality.


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## Shortround6 (Feb 12, 2010)

Clay_Allison said:


> Why didn't we just go to war with the P-40 for the rest of the war? Why develop anything better?


The planning (drawings, tooling, production allocations and such) for most American fighters,and bombers was either completed or in advanced stages at the time of Pearl Harbor. 

For instance there were 773 P-47Bs and Cs on order in Sept. of 1940 even thought the first prototype didn't fly until May of 1941. The first Production P-47 came off the line Dec. 21 1941. What do you want to do?
Stop production of the P-47 and spend months retooling the the Republic factory to build P-40s because you are NOW at war?


Fighter aircraft are a combination of things. You need an airframe/engine combination that will give you at least adequate performance and you need sufficient armament to bring down the enemy aircraft once you are in firing position. The .50 provided adequate armament even if it wasn't superior.


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## Shortround6 (Feb 12, 2010)

Clay_Allison said:


> High Explosive weighs less than lead. Seems like HE rounds would achieve both a higher MV and a higher lethality.



HE also has a density much closer to wood than metal. Look at even a German Mine shell. What percentage of shell weight is HE? the fuse is going to weigh a certain amount unless you get into some rather bizarre and questionable safety issues. With the stress of high velocity firing the shell walls have to be stronger (thicker) to stand the strain leading to less volume for the HE. With a near constant wall thickness the larger diameter shell will always show a much higher percentage of volume for HE content than a smaller diameter shell.

Light shells for caliber also act like Ping-Pong balls. High intital velocity but slow down really quick.


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## Clay_Allison (Feb 12, 2010)

Shortround6 said:


> HE also has a density much closer to wood than metal. Look at even a German Mine shell. What percentage of shell weight is HE? the fuse is going to weigh a certain amount unless you get into some rather bizarre and questionable safety issues. With the stress of high velocity firing the shell walls have to be stronger (thicker) to stand the strain leading to less volume for the HE. With a near constant wall thickness the larger diameter shell will always show a much higher percentage of volume for HE content than a smaller diameter shell.
> 
> Light shells for caliber also act like Ping-Pong balls. High intital velocity but slow down really quick.


That's reasonable, yet there must be some reason why every other 12-13mm gun had them.


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## DerAdlerIstGelandet (Feb 12, 2010)

Clay_Allison said:


> Why didn't we just go to war with the P-40 for the rest of the war? Why develop anything better?



That is beyond the point. Now you are just nit picking.  The point is the .50 was just fine for the job.



Shortround6 said:


> Fighter aircraft are a combination of things. You need an airframe/engine combination that will give you at least adequate performance and you need sufficient armament to bring down the enemy aircraft once you are in firing position. The .50 provided adequate armament even if it wasn't superior.



Thank you...


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## Clay_Allison (Feb 12, 2010)

I wouldn't be complaining so much if early war American planes weren't so overweight. It wouldn't have killed them to stress the plane to 10 Gs rather than 12, lighten the armament, supercharge the engine a little better, and make them fly like fighters instead of ground pounders. A little attention to a lot of small details could have saved lives.


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## Shortround6 (Feb 12, 2010)

Clay_Allison said:


> That's reasonable, yet there must be some reason why every other 12-13mm gun had them.



Did the Russian 12.7 have HE rounds?

The Italian and Japanese did but their rounds were only a bit more powerful than the German round. And as a bit of comparison they carried explosive charges of about 1-2 grams. 20mm HE shells carried 6-10 grams with the German Mine shells roughly doubling that (20 grams).

American .50 API rounds carried about as much incendiary material as the Axis 12.7-13mm projectiles carried HE.


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## Shortround6 (Feb 12, 2010)

Clay_Allison said:


> I wouldn't be complaining so much if early war American planes weren't so overweight. It wouldn't have killed them to stress the plane to 10 Gs rather than 12, lighten the armament, supercharge the engine a little better, and make them fly like fighters instead of ground pounders. A little attention to a lot of small details could have saved lives.




Or traded lives.

A plane stressed to 10 Gs might not be able to take as much punishment as the one stressed to 12 Gs. So fewer pilots are saved by their "sturdier" aircraft. Granted fewer of them might have been shot up as bad if they had more speed and maneuverability to begin with but that plan didn't wind up working so well for the Japanese did it?

Lighter armament? Few kills or cripples for the same number of firing opportunities? More enemy pilots and planes escaping to fight another day? Or does the added speed an maneuverability translate into more firing opportunities to compensate? enough more?

edit: American planes were also over weight because they housed more internal fuel than most of their contemporaries. Shorter range/endurance in the Pacific might not do much for firing opportunities or for pilot survival on over water flights.
end edit:


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## Clay_Allison (Feb 12, 2010)

> Lighter armament? Few kills or cripples for the same number of firing opportunities? More enemy pilots and planes escaping to fight another day?



I mean armament that weighs less, like 4 light cannon over 6 heavy machine guns. We discussed in another thread how the Japanese 20mm Ho-5 cannon was based on the Browning MG and carried a lot more punch at slightly lower unit weight than the M2. The 50 BMG necked up to 20mm could have been roughly equivalent to having MG 151/20s.

4 light 20mm cannons would be lighter armament, but more powerful.


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## renrich (Feb 12, 2010)

I never saw combat but fired an M2 on the range at Fort Hood and believe me it is an effective weapon. That round will tear an old deuce and one half to pieces and I can only imagine what it would do to a WW2 aircraft, especially a fighter. The fact is that four gun P51B and Cs and four gun Wildcats were very effective in both theatres. Four gun Martlets served with the FAA and were effective aginst JU88s and FW200s and Eric Brown called the armamament of the Wildcat "very powerful."


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## billswagger (Feb 12, 2010)

Clay, i think a lot of what you're missing is the context of the weapons you're describing.

The US was developing alternatives to the 50 caliber. The 14.7mm caliber was a late war development that never saw fruition. 20mm was also being worked on. 50 caliber did its job. 

As i said before the 20mm was not seen as an effective or reliable in the eyes of the US for air to air combat. This had a lot to do with MV and firing time but also a majoirty of the these cannons suffered problems at altitude. There was a report that well documented both these findings on this forum. It did not mean there was not a need or a demand for a higher caliber, just simply put, the 1941 hispano was not fit for US operations. The British made use of it, however, they were also defending home land from invading bombers. I read that many of these cannons still had problems and Spitfire pilots still felt more confident flying with 303s. 

The US also refused to use HE rounds with their browning because the trade off in range was not worth the result. You need a denser heavier round to maintain better velocity. The 50 caliber was preferred in part not only because of its range but at high speeds the projectiles maintained much of their velocity. 20mm cannons took most of the war to match the velocity capable of the 50s and still were not fit for high altitude missions. 

I hate seeing comparisons to cannon weilding planes because in the context of the war, Germans were using cannons on heavy bombers, Japanese cannons were considered low velocity weapons and only useful at short range. A Yak has 9-12 seconds of trigger time, compared to P-47D 30 seconds. Which plane could hover over roadways for half the day shooting at anything that tries to drive on them?

Point is each weapon has a roll, and making blanket statements about gun weight and ammo has little to do with their use. 


Bill


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## Shortround6 (Feb 12, 2010)

Clay_Allison said:


> I mean armament that weighs less, like 4 light cannon over 6 heavy machine guns. We discussed in another thread how the Japanese 20mm Ho-5 cannon was based on the Browning MG and carried a lot more punch at slightly lower unit weight than the M2. The 50 BMG necked up to 20mm could have been roughly equivalent to having MG 151/20s.
> 
> 4 light 20mm cannons would be lighter armament, but more powerful.



Lower unit weight? I think the Japanese cannon weighed 6-8kg more than American .50cal aircraft gun.

The total weight would be lower than six .50s including ammo but I think the weight savings is not as much as you might think. the Japanese 20mm ammo is around twice as heavy per round as .50 cal ammo. an even swap for weight (not including links) gives 221 rounds of 20mm HE ammo per gun (AP was somewhat heavier) for the four Japanese cannon. Not bad but not much of weight loss either. Trading ammo for weight loss means less firing time. 

It is also about 4.7mm bigger in diameter of the case body compared to a .50cal which means the Japanese round as around 50% more case capacity per unit of length. A necked up .50 cal would have considerably less performance than the Japanese cartridge.


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## tomo pauk (Feb 12, 2010)

Hi, billwager, some questions disagreements:



> As i said before the 20mm was not seen as an effective or reliable in the eyes of the US for air to air combat.



When the USAAC/USN established that?



> 20mm cannons took most of the war to match the velocity capable of the 50s and still were not fit for high altitude missions.



1. Hispano shells were any bit as fast as .50
2. Is the speed of .50 better asset then destructive power of medium-velocity 15-20mm cannon shell? 
3. Is it only the US Hispano-derivarive susceptible to the adwerse effects of high altitude, or the othe cannons suffered from it?



> Germans were using cannons on heavy bombers,



Poland, Norway, Low countries, France, Battle of Britain, Mediterrranean, the whole Russian front were void of heavy bombers, yet Luftwaffe used cannons there too 



> A Yak has 9-12 seconds of trigger time, compared to P-47D 30 seconds. Which plane could hover over roadways for half the day shooting at anything that tries to drive on them?



If the P-47D had 4 cannons instead of 8 HMGs, the firing time would remain the same, end fire power would be upped.



> Point is each weapon has a roll, and making blanket statements about gun weight and ammo has little to do with their use.



Cannons were used for same role as MGs in fighter planes of WW2 - to kill the enemy plane. Cannons were better for the job.


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## Markus (Feb 12, 2010)

The ideal kind of gun IMO largely depends on what you are shooting at.

a)unprotected A/C: rifle caliber machine guns will do just fine
b)protected single and twin engine A/C: heavy machine guns
c)four engine heavy bombers: cannons

Since the USAAF did not have to worry about c) the admittedly more powerful 20mm cannon was not necessary.


With regard to the (over)weight of pre-war designs like the P-40 and F4F I wonder why the US mostly kept the six gun armament. At 70lb per gun, 0.3lb per round and IIRC 450 rds/gun a Wildcat could have lost 410lb and retained more than enough firepower as the performance of the four-gun Wildcats before Midway shows.


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## renrich (Feb 12, 2010)

The P51 with four cannon had a firing time of 12.5 seconds, the P51B had a firing time of 21 seconds. The P47, with a full load of ammo had a firing time of aound 28 seconds. The F6F when equipped with two 20 mms had a firing time of 22.5 seconds and that was with 225 rounds per gun. Why do you think the P47 could carry enough 20 mm cannon rounds to equal the 28 seconds firing time? 20 mm ammo weighs more and takes up more space than 50 BMG ammo. Belted 20 mm ammo could weigh as much as .766 pound per round whereas the max weight of 50 BMG was .311 pound per round. With 8 MGs the P47 is more than twice as likely to hit the target as with four cannon and that does not even take into account the longer firing time. On top of that, railroad locomotives are probably more likely to be put out of service by 50 cal rounds than by 20 mm rounds and trucks don't need to be hit by 20 mms as 50 BMGs will do the job just as well, just like with fighters. Another issue with explosive cannon shells is that a certain percentage of them will be duds and not do as much damage as the solid round of the 50 cal.


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## Vincenzo (Feb 12, 2010)

premise i'm agree that .50 it's enough for shoot down enemy SE fighters, imho also less powered HMG are enough but
little comparation
2 Hispanos (600 rounds), late model, versus 8 .50 Browning (2400 rounds)
they have comparable MV and ROF (the hispanos are a bit low in both)
a hispano weight around 30% more that a .50 so over 150 kg less for the hispanos
the hispano ammo weight it's around 3 time of .50 ammo (for true less) so over 80 kg less for hispanos
time of fire it's for both ~25"
you've in air around 4 time .50 round that 20mm but the 20mm power it's over 4 time of that .50 (i can tell 4 and 1/4 or also 4 and 3/4) so the 20mm hitting only 1/4 of time of .50 but give almost 10% more damage in total, and you've a plane 230 kg lightest.


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## billswagger (Feb 12, 2010)

tomo pauk said:


> Hi, billwager, some questions disagreements:
> 
> When the USAAC/USN established that?



I'm not sure exactly when, this was early in the war when Hispanos and 50s were weighed against each other.
I'd site sources but this is knowledge gained through collective reading. 




> 1. Hispano shells were any bit as fast as .50,


This is debatable but what i think most people don't realize is that muzzle velocity is measured in the first few feet of fire.
Cannon rounds slow down faster at high speeds, or at least thats what was found early on. 


> 2. Is the speed of .50 better asset then destructive power of medium-velocity 15-20mm cannon shell?



If it takes 10 50 calibers rounds to do the same job as 4 20mm shells then no, however speed and rate of fire gives you better odds that your 50 calibers are going to land. I'm not implying 10 rounds of 50s are equal to 4 20mm shells, rather each combination is capable of destroying a plane. 

It was also determined that cannons (not sure of the caliber) had an effective range of 250y, where 50 caliber had an effecitve range of 850y. That's in level flight. In turns it was suggested the range of the 50 is reduced to 250yards. 
I can only question where that leaves cannons. 

The Luftwaffe detirmined it takes an average of 20 20mm shots to down a B-17. They also figured that at a 2% hit rate means they would need to fire 1000 rounds. So the other option was to increase firing time. The way to do that is to add more guns. Thats why some vairiants of the 190 include 4 wing cannons and two in the cowling. 

We see lighter configurations on German fighters intended for air to air combat or dogfighting, MGs are typically part of that arrangement although cannons were also used for shots at closer range. 



> 3. Is it only the US Hispano-derivarive susceptible to the adwerse effects of high altitude, or the othe cannons suffered from it?


There is no real difference, IMO. They were the same gun just manufactured in different places and expected to fit and work in different airplanes. I think the British used it because they needed it, but the US didn't because it wasn't up to their standards.
The altitude problem was more an issue of gun heating, (late war) because as far as i know, the Tempest mk V was able to make use of them, but then again the Tempest stayed under 26k ft for the most part. 

There is a report that out lines more of this discussion if you search for it on this forum. 



> Poland, Norway, Low countries, France, Battle of Britain, Mediterrranean, the whole Russian front were void of heavy bombers, yet Luftwaffe used cannons there too



Good point. 
I guess I'm reffering to heavier installations, but it is worth noting that the 109 and 190 both used MGs to the end of the war. 
More of a point to how a gun and its ammo is designed for the roll. You don't use 50 calibers to shoot down heavy bombers you use cannons.


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## Shortround6 (Feb 12, 2010)

Some of this depends on ammunition. The 20mm Hispano guns are more effective than the the .50 and in later years fired a combination API round that equaled the penetration of the .50 API round but carried 10 times the incendiary material.

Mission--- bomber intercept vrs bomber escort. A shorter firing time can be accepted because the interceptor will be over home base and can land to rearm an engage bombers on the way out or intercept a later attack. Bombers are usually bigger and tougher. For bomber escorts running out of ammo on the outward leg is a problem. There targets are usually single engine fighters or at worst twin engine fighters. Their goal is a little different to. Goal of a bomber interceptor is to destroy the bomber or at least get it to turn back before dropping bombs. Goal of a bomber escort is to keep enemy interceptors for doing the same to the bombers they are protecting. Shooting down the enemy is nice and keeps them from flying another day but merely damaging and interceptor and driving it away doesn't have quite the same consequences as damaging a bomber that still makes it to the target area. 

The US should have been able to do better in regards to aircraft armament but to claim they weren't trying or at least thinking about it doesn't go with the facts.
Pre-war they had investigated a 23X139mm cartridge and four different guns to fire it. They had also tested the 23mm Madsen cannon and a French 25mm gun. Then we have the 37mm gun fitted to Aircobras, Aircudas and in one instance the top turret of the XB-19. It was also specified in a number of experimental aircraft like the XP-67 and the XP-54.

Good aircraft guns aren't quite as simple a device as some would like to think. It usually took a number of years from prototype to squadron use. There are reports of a German MG 151 in Spain in 1938 yet it took another 3-4 years to get it into squadron service with the only alternative the not so satisfactory MG/FF.


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## Glider (Feb 12, 2010)

Its easy to get sucked into a long debate about the types of ammunition different rates of fire and effective ranges and I am not against this in any way but sometimes its easier to stand back and look at the question in simplistic terms.
We know that the USN compared the 0.50 M2 against the 20mm Hispano II and summerised it as saying that the Hispano was three times more effective that the M2.
They would have done the test using all sorts of paramaters and criteria way beyond I could come up with and as a rule of thumb its a comparison worth remembering.

It also makes sense as it makes the normal 6 x .50 carried in so many US aircraft equal to the 2 x 20 carried in the Spitfire (ignoring the ineffective 4 x 303), both were effective against fighters and other Axis aircraft but would have needed beefing up had they been forced to face B17 type aircraft. 
Its worth remembering that 2 x 20mm plus some MG's was a pretty common payload for a number of fighters and its unlikely that all those nations and designers would have made the same mistake. Generally these 20mm were not as powerfull as the Hispano II but were obviously effective enough.

The 2 x 20mm may have been more efficient as it was lighter than 6 x .50 but the US aircraft were able to carry this and have a performance to take on the opposition, so did it matter? 
It did on the F4F4 but that is a much smaller aircraft and basically was overloaded. It needed to be lightened and the result was the FM2 which worked well.


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## tomo pauk (Feb 13, 2010)

Thanks for the opinions, bill. I've found some stuff I disagree with:



billswagger said:


> ...
> (Me: Hispano is as fast as .50 BMG):
> This is debatable but what i think most people don't realize is that muzzle velocity is measured in the first few feet of fire.



Guess it makes no difference if the MV is measured at muzzle, or during the 1st meter - the difference is under 5% still, ie. negligible.



> Cannon rounds slow down faster at high speeds, or at least thats what was found early on.



That's a generalization, and a moot point anyway. If a 20mm, 140g projectile has 880m/s initial velocity (= Hispano), it would not lose any speed when compared with .50 BMG (50g @ 900 m/s). Now we could take medium velocity German, Russian and Japanese cannons: those would be slower indeed, but no complains about that in respective air forces using them.
...




> It was also determined that cannons (not sure of the caliber) had an effective range of 250y, where 50 caliber had an effecitve range of 850y. That's in level flight. In turns it was suggested the range of the 50 is reduced to 250yards.
> I can only question where that leaves cannons.



Isn't that a little dubious that .50 had 3,5 greater effective range 



> The Luftwaffe detirmined it takes an average of 20 20mm shots to down a B-17. They also figured that at a 2% hit rate means they would need to fire 1000 rounds. So the other option was to increase firing time. The way to do that is to add more guns. Thats why some vairiants of the 190 include 4 wing cannons and two in the cowling.



While I agree about what you've said about German tests (thugh it was 2-5%, depending who shots), I disagree about what you say of remedies for the problem. Germans moved to 30mm, since it takes only 3-5 such shells to kill a bomber. The other benefit for having one-two bigger vs. more smaller cannons was that Me-109 could become a good bomber-killer with a single cannon (Fw-190 even better one with 2 such cannons), while the shortcoming was low MV, thus requiring a close-in shot. Benefit is also that it's way less expensive to produce/mount/maintain 1 MK-108, then 3-4 MG-151/20 in lieu.



> We see lighter configurations on German fighters intended for air to air combat or dogfighting, MGs are typically part of that arrangement although cannons were also used for shots at closer range.



German fighters carried 2 cannons from day one of WW2, while in cowls of both 109 190 13mm guns were barely crammed in, so I'd say they stucked with MGs because of necessity, not because MGs were preferred. Both Bf-109F and early Fw-190 were criticized by Germans for not having armament as heavy as Bf-109E, or contemporary Spitfire Mk-V. 



> There is no real difference, IMO. They were the same gun just manufactured in different places and expected to fit and work in different airplanes. I think the British used it because they needed it, but the US didn't because it wasn't up to their standards.



When I talk 'cannons', I mean 'all-world' cannons, not only anglo-american products 
The issue about US-produced Hispanos was that their product was mismanaged (in one or other way), not that all canons were not good.



> The altitude problem was more an issue of gun heating, (late war) because as far as i know, the Tempest mk V was able to make use of them, but then again the Tempest stayed under 26k ft for the most part.
> 
> There is a report that out lines more of this discussion if you search for it on this forum.



Gun heating was sometimes the issue, but many RAF Luftwaffe planes did used their cannons high above


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## Shortround6 (Feb 13, 2010)

billswagger said:


> Cannon rounds slow down faster at high speeds, or at least thats what was found early on.



That rather depends on the particular MG bullet cannon shell and the particular MG bullet.
Two things affect how fast a projectile loses velocity.
1. It's shape, how pointy is the nose and shape of boattail, if any. It's form factor.
2. How much it weighs in relation to it's frontal area. It's sectional density.
With 12.7-13mm bullets going from 33-34grams to 46-48 grams we can see that they varied quite a bit as did 20mm projectiles which ranged from 79 grams to 130 grams. 
In the case of the American .50 vrs the 20mm Hispano the /50 cal bullets had better shape but poorer sectional density. Consider that while ground level test firing may give one result with the air at 20,000ft offering about half the resistance the difference at that altitude would be much less. 



billswagger said:


> It was also determined that cannons (not sure of the caliber) had an effective range of 250y, where 50 caliber had an effecitve range of 850y. That's in level flight. In turns it was suggested the range of the 50 is reduced to 250yards.
> I can only question where that leaves cannons.



Without knowing which cannon this statement means nothing. It could refer to the American 37mm cannon with it's MV of 610m/s. The trajectory on this was bad enough that the XP-54 was designed with a mechanism to tilt the 37mm guns in relation to the .50cal guns to keep the point of impact the same at various ranges. But then this is not the 20mm Hispano is it?



billswagger said:


> We see lighter configurations on German fighters intended for air to air combat or dogfighting, MGs are typically part of that arrangement although cannons were also used for shots at closer range.



The German MG 131 was designed to fit into spaces (or at least require little more room) than the MG 17 fit into. It used lighter, poorer shaped bullets and it's MV was 120-160m/s lower. A better match for the German cannon but not really in the same class as the American .50.



billswagger said:


> There is no real difference, IMO. They were the same gun just manufactured in different places and expected to fit and work in different airplanes. I think the British used it because they needed it, but the US didn't because it wasn't up to their standards.



According to Tony Williams there was a difference. He claims the British never used American made guns in operational aircraft but converted a number of them to AA guns. Aparently the American made guns were not up to British standards.


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## billswagger (Feb 13, 2010)

tomo pauk said:


> Thanks for the opinions, bill. I've found some stuff I disagree with:
> 
> 
> 
> Guess it makes no difference if the MV is measured at muzzle, or during the 1st meter - the difference is under 5% still, ie. negligible.



Not so negligable when fireing at higher speeds. The 50 caliber was found to have a flatter trajectory than the 20mm and while flying at 300+IAS that was a huge advantage over cannon shots that slowed down faster.

I don't doubt that late war 20mm Hispano was on par with 50 caliber MV and trajectory. 



> Isn't that a little dubious that .50 had 3,5 greater effective range



It should be more for both, but the context of "effective range" is defined as looking through a gunsight in the cockpit of a plane, as oppose to looking down the barrel or through a scope. 
Shots of 50 caliber remained inside the site ring for 850yards. Shots of cannon fire remained inside the site ring for 250yards. 
Cannon is a general word used to describe HE rounds, which included 20mm. The early war Hispano was not the best for maintaining velocity but it was on par with other cannons. 

I actually was looking at some ballastic features of the 20mm, 50 caliber, and a 14.7mm. A lot of the trajectory is not only related to the projectile size and weight but the amount of propulsion composition in the casing. A 14.7mm weapon fired with a similar composition of a 20mm has a better trajectory and range. I would not confuse heavier round better range and trajecorty unless its also fired with more energy.


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## billswagger (Feb 13, 2010)

Shortround6 said:


> According to Tony Williams there was a difference. He claims the British never used American made guns in operational aircraft but converted a number of them to AA guns. Aparently the American made guns were not up to British standards.



Its a question of history and sources then, because even the British cannons were riddled with problems.
Also the 20mm Hispano was used along side 303s initially. They were reserved for bombers, where records indicate 4000 rounds of 303s being spent on individual aircraft. The 20mm was a necessity even if it jammed half the time. 

The Americans were focused on getting higher MV and firing times from the gun, but couldn't get a reliable configuration that matched the capability of the 50 caliber weapon until 1945. Wasn't even possible until 1944, and combat ready by 1945. 
They did have other installations of the 20mm, as well as the 37mm. but were not as popular as the 50 caliber for the air war. 


Bill


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## tomo pauk (Feb 13, 2010)

Bill, the early Hispanos (French, UK MK.II) had greater MV then late-war Mk.V, so their drop was actually smaller. If you could point out a reliable source about bullet drop, it would be cool. Until then, I'll stick to the" heavier the bullet - flatter the trajectory" mantra (provided that MV and drag coefficients are nearly the same)


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## renrich (Feb 13, 2010)

I would be very surprised if the 20 mm had as good a ballistic coefficient or sectional density as did the 50 BMG. The 50 BMG was outstanding in both regards. Snipers have used the 50 BMG to make kills at one mile and that was with the M2. The table in "America's Hundred Thousand" shows the 20 mm to have a slightlly higher MV than the 50 BMG but and I am guessing, because I don't know the BC of the 20 mm round, I think the 50 BMG round would soon catch and surpass the 20 mm. Another however is though that the difference in trajectory of both rounds is probably not tactically significant because ranges were generally in the 300 yard area and pinpoint accuracy was not necessary or possible. The British were not able to equip their bombers with the 50 BMG, although it would have been desirable to do so, because of a shortage of the guns, until near the end of the war, according to a book I have. I suspect that the Spitfire would have gotten 50 cals in late 40, 41, o4 42, if they had been available. The Eastern front had no heavy bombers but it did have Russian medium bombers and ground attack planes that were heavily armored. In the early war, the German fighters had cannon because the MGs mounted were the puny 30 cals. Later those 30 cals were supplanted by the German version of the 50 cal, likewise on the A6M. The facts are that the M2 and it's round were available, tested, reliable and were found to be more than adequate for the job of knocking down the opposition during WW2. I wonder how many of us on this forum have tried to read extensively about aerial gunnery in WW2 and have reflected on how difficult it must have been to get any hits at all on an EA. The 50 BMG equipped fighters with four, six or eight guns, with a high ROF and relatively long firing times, gave American pilots a better chance to get hits and obtain local air superiority over enemy fighters. That is the bottom line.


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## billswagger (Feb 13, 2010)

tomo pauk said:


> Bill, the early Hispanos (French, UK MK.II) had greater MV then late-war Mk.V, so their drop was actually smaller. If you could point out a reliable source about bullet drop, it would be cool. Until then, I'll stick to the" heavier the bullet - flatter the trajectory" mantra (provided that MV and drag coefficients are nearly the same)



There is a ww2 article on this forum that goes into all those details but i'm unable to locate it. 

Just to use an example:

Same gun fires 20mm and 14.5mm.

The effective range of the 20mm is >1500m 
the 14.7mm effective range is >2300m

The muzzle energy is nearly the same yet you get more range out of the 14.7mm.

There are also many variants of the Hispano and the Mk V was the only one that matched firing time and the velocity of the M2. 
A plane diving on its target at 400+mph also needs to pull deflection and sometimes at ranges where the 50 cal was percieved as better because it retained its energy where the 20mm fell away. 

It is hairsplitting, if you figure a pilot is good enough to anticipate where his shot needs to be with sufficient gunnery training. But there are other reasons for using the 50 caliber over the 20mm. 


The Big One...

The 20mm is, however, recognized as the smallest projectile capable of the biggest pop. So for HE rounds, 20mm is going to be the most efficient.

You could probably Youtube this gun and get more qualified information. 


Bill


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## Vincenzo (Feb 13, 2010)

sure that a 14.5 at 1080 m/sec has more range of 20 at 720 m/sec, but the .50 it's not the 14.5 and the german 20 mm is not the hispano 20 mm. put the 50 and the 20x110 at 890 and 830 m/sec and easy that the range difference it's limited and useless in air fight not fight at so long range 300 meters are already good range, so pratically there is no large difference also with a 20x82 at 720 m/sec.


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## riacrato (Feb 13, 2010)

I'm with Tomo: Given the same bc and the same mv the gun firing the heavier bullet will have a flatter trajectory. Heavier rounds bleed of speed slower than lighter rounds that is a fact. Of course the ballistic coefficient is also important, but so far I've not seen any evidence suggesting its role is as important as combination of the other factors. If someone has conclusive evidence that proves otherwise feel free to show.

The Mechem is a bad example to prove your point as the MV is 300 m/s faster for the 14.5mm version. Or to put it relative, it is 1.5x that of the 20mm version. Which is actually interesting as the 14.5mm has also almost exactly 1.5x the range. I know its not really a linear connection but you could speculate that both rounds fired at the same mv would likely have very similar range. Also, being an anti-material sniper rifle, i guess effective range has another definition here than it has with aircraft mounted guns.


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## Shortround6 (Feb 13, 2010)

The Hispano 20mm did not have the ballistic co-efficiency of the .50 cal. The 20mm Hispano rounds had a poorer shape but they did have a higher sectional destiny which helped balance things out.

See this bore sighting chart for a P-38

http://www.zenoswarbirdvideos.com/Images/P-38/38BSC.gif

While the 20mm has a bit more arc to it's trajectory but staying within a few inches of the 50cal from 0 to 500yds means that for practical purposes there really wasn't any difference.


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## tomo pauk (Feb 13, 2010)

Since Vicenco pointed out the flaws in 14,5mm vs. 20mm comparison, I'll add that Russians necked-up their 14,5mm to 23mm and use (along with half of the world) the new cartridge from from 1944 'till today. As aircraft weapon's cartridge, indeed


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## renrich (Feb 13, 2010)

What you just said, riacrato, is not really true but the 20mm round may not have the same BC because of it's shape. If the two projectiles have the same BC then their velocities and trajectory down range will stay the same. An example: 45 cal 500 grain round nose bullet, BC is .297. MV is 2500 fps, zeroed at 200 yards, ar 500 yards the bullet has dropped 76 inches. 35 cal 250 grain round nose bullet, BC is .296. Zeroed at 200 yards, at 500 yards the bullet has dropped 75 inches. All info from Hornaday Handloading Guide. Heavier rounds do not necessarily bleed off speed more slowly than lighter bullets. It depends on, essentially how streamlined the bullet is. The 20 mm projectiles I have seen pictures of have a blunter tip than the 50 bmg has and the ojive looks "fatter" and thus not as streamlined. I would be surprised if the BC was as high. The 50 BMG has a BC in the area of .700 or so, I think.


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## billswagger (Feb 14, 2010)

I can't really get into complicated discussions on bullistist nor have the time to back up what i know with every article i've ever read. 

Trajectory has more to do with speed than weight. A faster bullet has less drop. Agreed, heavier bullets hold speed better if they have similar BC, mV In effect they have less arch over the length of the shot as the lighter round slows down. 303s had a flatter trajectory than the 50 caliber until they slowed down. 

Now there is a significant difference at firing a gun from a stand still position than at 300mph. Consider for a moment that bullets travel at supersonic speeds where slight variations in coefficients makes for dramatic differences over the range of the shot even at 300 and especially over 500 meters. Then factor in deflection and turning. 

The 20mm was found to slow down faster than the 50 caliber. This effects arch, (faster bullets less arch) Agreed, heavier bullet has more mass and penetrates armor better. 

I have to agree that the 20mm did not have the same BC as the 50 caliber. 

What effected it more as a gun platform for long range shots at high speeds was this fact of speed (retention), and firing time. It still made a great gun for shots at closer range and at moderate deflections. It was still shunned for its reliability issues. 



Bill


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## Shortround6 (Feb 14, 2010)

billswagger said:


> 303s had a flatter trajectory than the 50 caliber until they slowed down.



what 303 had a higher velocity than the American .50?



billswagger said:


> Now there is a significant difference at firing a gun from a stand still position than at 300mph. Consider for a moment that bullets travel at supersonic speeds where slight variations in coefficients makes for dramatic differences over the range of the shot even at 300 and especially over 500 meters. Then factor in deflection and turning.



True, but since ALL bullets fall at the same speed (32ft/sec^2) we can assume that two bullets with close to the same initial velocity that have the about the same trajectory will have similar times of flight to the distances shown in the trajectory chart. This also means they had similar ballistic co-coefficients.


billswagger said:


> The 20mm was found to slow down faster than the 50 caliber. This effects arch, (faster bullets less arch)



It may very well have but it didn't slow down enough to make much practical difference and any normal air to air range.

Please look at the P-38 sighting-in and trajectory chart I posted a link to. staying within 6in and usually less of the .50 cal bullets to 500yds (and/or beyond) means it could not have been that bad. Either your 250 yd figure applies to some other gun than the 20mm Hispano or this sight-in Chart is bogus.



billswagger said:


> It was still shunned for its reliability issues.



Only by the US. The British guns seem to have worked a lot better.


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## Markus (Feb 14, 2010)

Question(s): At what actual ranges did fighter pilots open fire? IIRC between 200 and 300 yards. Does a small difference in velocity and drop even matter at such a short distance? And was armour penetration even an issue for cannon shells? I thought they were supposed to destroy the airframe with their explosive charges, not punch through armor like a machine gun bullet.


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## Shortround6 (Feb 14, 2010)

Markus said:


> Question(s): At what actual ranges did fighter pilots open fire? IIRC between 200 and 300 yards. Does a small difference in velocity and drop even matter at such a short distance? And was armour penetration even an issue for cannon shells? I thought they were supposed to destroy the airframe with their explosive charges, not punch through armor like a machine gun bullet.



Small differences in the velocity and drop from the guns of single firing aircraft are not going to matter.

Larger differences will matter as in the American 37mm at 2000fps and the cowl mounted .50s at 2800fps+.

With the target moving at 450-600fps having the shells/bullets arrive even at the same point in space but at different times doesn't do much good.

If one sides fighter planes have guns that have a shorter time of flight to distance "X" by say, 20% than the other sides then the first side will have an overall advantage in deflection shooting and perhaps in range.

Of course if the difference between the different sides armament was only 5% then it might be too small to notice.


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## billswagger (Feb 14, 2010)

Shortround6 said:


> Please look at the P-38 sighting-in and trajectory chart I posted a link to. staying within 6in and usually less of the .50 cal bullets to 500yds (and/or beyond) means it could not have been that bad. Either your 250 yd figure applies to some other gun than the 20mm Hispano or this sight-in Chart is bogus.



I saw it, and it shows bore sighting. The 20mm needed more velocity to have the same trajecory as the 50. 
It slowed down faster, and did make a significant difference for air to air combat because as the plane gets faster more air resistance slows the bullet and drag coeficients increase dramatically. Looking at bore sighting doesn't always reveal this fact.
I find it odd they didn't use 20mm for all of the P-38s guns. Could it have been the ballistics properties i'm talking about. 

And the british had jamming issues with this gun, but they made it work for what they had to do. They did fix these issues by the Mk V Spit but the amount of problems seems to be down played because the Spitfire saved Britain. 

The point of the discussion is really irrelevant when shooting at 200m range, it is splitting hairs (there said it again) and level shots and slow speed fights at these ranges make little difference,


However a P-47 diving over 400 mph and firing at 30 degrees deflection is going to favor the flatter trajectory (speed retention). 
You just figure at 200m, 200mph a couple degrees drop is of little consequence but at 400mph in a turn those effects are augmented. Those couple degrees could now be as much as 5 or 10 degrees at higher speed and augmented more so by the degree of the turn and the speed. 
So the P-47 pilot may have to pull an additional 10 degrees (maybe more) to correct for speed loss of using 20mm over the 50 cal. And i call it speed loss to not be confused with trajecory which i think refers more to a calibers characteristics when fired at lower speeds and moderate deflections.



Bill


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## riacrato (Feb 14, 2010)

renrich said:


> What you just said, riacrato, is not really true but the 20mm round may not have the same BC because of it's shape. If the two projectiles have the same BC then their velocities and trajectory down range will stay the same. An example: 45 cal 500 grain round nose bullet, BC is .297. MV is 2500 fps, zeroed at 200 yards, ar 500 yards the bullet has dropped 76 inches. 35 cal 250 grain round nose bullet, BC is .296. Zeroed at 200 yards, at 500 yards the bullet has dropped 75 inches. All info from Hornaday Handloading Guide. Heavier rounds do not necessarily bleed off speed more slowly than lighter bullets. It depends on, essentially how streamlined the bullet is. The 20 mm projectiles I have seen pictures of have a blunter tip than the 50 bmg has and the ojive looks "fatter" and thus not as streamlined. I would be surprised if the BC was as high. The 50 BMG has a BC in the area of .700 or so, I think.



you're right I mixed up bc and form factor.

bill, I thought the M2 had a slightly_ faster _mv than the Hispano. In any case, the difference both in mv and ballistic performance is very, very slim.


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## Shortround6 (Feb 14, 2010)

billswagger said:


> I saw it, and it shows bore sighting. The 20mm needed more velocity to have the same trajecory as the 50.
> l




It also gives the trajectory figures to 500yds. How many inches above and below the line of sight. 

With the 20mm starting 3in below the lower .50 cal guns it rises to meet the .50 cal at 300yds and doesn't fall below the .50 until after 400yds and is all of 1in low at 500yds. 

Does it have the same trajectory as the .50? NO
Is it loosing velocity faster than the.50? YES 
Is it going to make any practical difference under 600yds? *NO*
Trajectory difference are less than the normal dispersion of the guns/ammo.

The higher above sea level the firing takes place the less difference there is between the two. With the air density at 20,000 being about half that a sea level they will both slow down less but over a given distance the change should not be as great as at lower altitudes. Given that initial velocity's are only 3-7% higher than the 20mm for the .50 I am just not seeing the huge disadvantage for the 20mm Hispano.

By the way, thanks for this one, it sure made me laugh.

"And the british had jamming issues with this gun, but they made it work for what they had to do. They did fix these issues by the Mk V Spit but the amount of problems seems to be down played because the Spitfire saved Britain."

Since the MK V came out in the Spring of 1941 even if we tack on about 8 months it means the British had the problem solved BEFORE PEARL HARBOR

And of course all those squadrons equipped with cannon armed Beaufighters, Mosquitoes, Typhoons, Hurricanes and other aircraft played down their problems with the Hispano to help save the Spitfires reputation.


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## Jabberwocky (Feb 14, 2010)

billswagger said:


> Its a question of history and sources then, because even the British cannons were riddled with problems.
> Also the 20mm Hispano was used along side 303s initially. They were reserved for bombers, where records indicate 4000 rounds of 303s being spent on individual aircraft. The 20mm was a necessity even if it jammed half the time.
> 
> The Americans were focused on getting higher MV and firing times from the gun, but couldn't get a reliable configuration that matched the capability of the 50 caliber weapon until 1945. Wasn't even possible until 1944, and combat ready by 1945.
> ...



"Riddled" is hardly the right term.

The Hispanos went through a relatively protracted pre-war development process with the French Air Force, and then a somewhat more truncated development with the RAF, but, after initial failures in combat trials during the Battle of Britain, they were considered a very effective and reliable weapon.

The Hispano Mk I, which displayed much problem with jamming was quickly replaced by the more reliable Mk II, and used as the RAF's basic fighter armament from 1941 onwards.

The problems with the Mk I were in several areas. Lightly struck caps caused problems with misfires, the canted over installation, particularly in the Spitfire, combined with a less than satisfactory feed mechanism for the 60 round snail magazine, also lead to jams. Another problem with the Mk I was again tied to the installation, was the wing mountings were initially to light to handle the recoil. Wing flexing was also a problem which lead to jamming. Both of these were tied to the Mk I's origin, in the form of the French HS 404 'moteur cannon' and the differing installation requirements that such a gun had.

The Hispano Mk II sorted out many of these problems, particularly the magazine feed and modifications to the chamber, firing pin and extractor spring, to reduce mis-fires and poor cartridge ejection.

In mid 1942, the Hispano Mk II was tested against the US 20mm M1 and AN-M2, firing 5,000 rounds. The RAF gun averaged about 1 stoppage in 275 rounds. The three US guns average 1 stoppage every 60, 39, and 27 rounds respectively, and none of them were able to complete the full 5,000 round test before destructive failure.

By 1943, testing showed reliability of US 20mm cannon had improved, but the RAF never used any of their imported US 20mms in combat. Even the 20 mms coverted to AAA guns went straight into storage.


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## billswagger (Feb 14, 2010)

Shortround6 said:


> It also gives the trajectory figures to 500yds. How many inches above and below the line of sight.
> 
> With the 20mm starting 3in below the lower .50 cal guns it rises to meet the .50 cal at 300yds and doesn't fall below the .50 until after 400yds and is all of 1in low at 500yds.



Tell me what the angle for each gun's bore site is in relation to the line of site? 
Bore site charts are used to set convergences not compare trajectories. You need to fire both guns at the same angles to make this comparison relevant. Its not really the best source for what your trying to show. 

I understand altitude and pressure density, but when your bullet is traveling at 2-3 mach, air is still pretty freckin dense. 

The 20mm is over a quarter inch wider than the 50 cal, so i'm trying to figure how you would think their coeficient would be similar. 

The .50 M2 bullet weighed 46g giving an SDR of 0.406 (therefore) BC = .54 
The 20mm Hispano weighed 130g giving an SDR of 0.462 (therefore) BC = .31

COMBATSIM.COM ARCHIVE FORUM : Ballistic coefficients
This guy explains what all the numbers mean better than i can. 

But basically what this means is the 50 caliber is nearly 42% more efficient at holding its velocity than the 20mm was.
I hardly consider that similar. 

All else being equal, bullets that have the same BC would follow the same trajectory path. You might notice the 7.92mm had a BC of .30 


And the nonsense about the Spitfire was a just a joke, mate.  

Bill


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## Demetrious (Feb 15, 2010)

billswagger said:


> But basically what this means is the 50 caliber is nearly 42% more efficient at holding its velocity than the 20mm was.
> I hardly consider that similar.
> l



Would that make the .50 caliber superior at armor-penetration at ranges of over 200 yards?


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## riacrato (Feb 15, 2010)

billswagger said:


> But basically what this means is the 50 caliber is nearly 42% more efficient at holding its velocity than the 20mm was.
> I hardly consider that similar.


42% gives a false idea of accuracy as one half of the formula is "guesstimated". Only a small error in this guesstimation will lead to very different results. Academic approaches are nice and all but the empirical results as indicated by the bore sighting chart simply show that for all practical purposes there is no difference in effective range. As mentioned the trajectory differences are below normal ammo and gun induced dispersion.


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## billswagger (Feb 15, 2010)

Demetrious said:


> Would that make the .50 caliber superior at armor-penetration at ranges of over 200 yards?



For the purposes of WW2, it depends on the rounds used. HE rounds explode on impact so armor penetration is not really their intended purpose. AP 20mm was shown to be more consistent and more effective up to 400 yards. 


Armor penetration in mm


================
Browning 50 cal 
================

APM1(RA/40) :

20 @ 200 yards
18 @ 400 yards
16 @ 600 yards

APM2

22 @ 200 yards
19 @ 550 yards
10 @ 1300 yards

(SLAP) modern M2 (light armor piercing, doesn't apply to WW2)

34 @ 550 yards
23 @ 1300 yards

=============================
20mm Hispano 
=============================
Ball Mk 1

12 @ 200 yards
10 @ 400 yards

HE Mk 1

8 @ 200 yards


AP MkII.Z

27 @ 200 yards
24 @ 400 yards


The 20mm being a heavier round also would show more consistency at various angles. The steeper the angle, the less effective 50 caliber becomes by comparison.




Bill


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## billswagger (Feb 15, 2010)

riacrato said:


> 42% gives a false idea of accuracy as one half of the formula is "guesstimated". Only a small error in this guesstimation will lead to very different results. Academic approaches are nice and all but the empirical results as indicated by the bore sighting chart simply show that for all practical purposes there is no difference in effective range. As mentioned the trajectory differences are below normal ammo and gun induced dispersion.



The boresite chart simply indicates the convergence range. The guns are fired at different angles so that corresponding arc meets in the convergence zone. Its good information but doesn't indicate effective ranges for either round only that they can be paired and converged in a way illustrated on the chart. 

Indeed its splitting hairs at 200 yards, but at 400mph and turning the differences in ballistic properties are augmented. 
I don't know how accurate Tony Williams guestimate is, but he is an ammo expert and written several articles as well as a book.
Methods used to indicate form are not far off from his method, and his numbers are valid and consistent with other data. 








Find the 20mm Hispano round. 

Hint: its the one with the blunt tip. 


more info:

This guy did 4 months of research and explains his methodology. 
http://members.cox.net/rg_lunatic/gunpage/index.htm

The charts indicate velocity at different ranges and the blue squares indicated mach 1.5 speed. Simply put, the bullet experiences higher amounts of drag the longer it travels above the speed of sound, in turn most speed loss occurs in the first few hundred meters. Speed of sound changes with altitude, so these are sea level indicators. 

His chart says the 20mm slows to about 705m/s at 250m, where the 50 caliber slows to 695m/s at 400m. This indicates a loss of over 150m/s from the distance to the muzzle. (best case)

150 m/s = about 335 mph. 

i'm sure you can see where this is headed when planes travel from 200-400mph in a combat scenario. These figure don't factor in the speeds at which the plane firing is going. It would only complicate matters, but the point is illustrated further. 

http://members.cox.net/rg_lunatic/gunpage/Ballistic_Methodology.htm
His methods. 
Here he points to historical data which suggests the 20mm retains 48 percent less velocity than the 50 caliber at 600m.


Bill


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## riacrato (Feb 15, 2010)

billswagger said:


> The boresite chart simply indicates the convergence range. The guns are fired at different angles so that corresponding arc meets in the convergence zone. Its good information but doesn't indicate effective ranges for either round only that they can be paired and converged in a way illustrated on the chart.


Duh of course they are fired at different angles. The point is that the difference in trajectory is MINIMAL, you continue to ignore that. The chart you provide, if accurate, indicates that the difference in time to reach x, is less than 10% for all x below 500m. Anything beyond that range is unrealistic to achieve with a decent hit probability given the combat conditions and the crude gunsights, _especially_ if the target is a single engined fighter. And you can quit pointing to the blunt nose of the 20mm ammo. We all know that and the web site you quote "guesstimates" kind of like I did that the form factor is less important for the ballistic performance when compared to the sectional density. The qualities of having a good form factor apparently are not as important for aircraft cannons, which would also explain why virtually all WW2 era aircraft cannon designs didn't give that much attention even though the manufacturers that built them were very well able to build streamlined bullets (Germany, Russia, France, UK...). Even among modern cannons there are many (like the M61) with very "dirty" shaped ammunition.

It's obvious you have your mind dead set on the .50, so I will just leave it at that. But I would be curious: There are a number of USAAF fighters that were equipped with 20mm Hispanos, most notably the P-38. Was there ever a report that P-38 pilots complained about the lack of range of that cannon or its lack of felt accuracy in a turn fight (reliability issues aside) when compared to the M2? Imo the M2 had its advantages even in the air-to-air role, primarily as a defensive weapon for bombers where the range advantage over German cannons was more important than the destructiveness or efficiency. The simple fact that a German fighter pilot was usually always under fire upon starting his attack run matters.

As an offensive gun however it was just acceptable. I don't believe the USAAF ever thought it to be perfect for its task as some people here argue or else they would not have multiple projects to get a 20 mm to work, going as far as trying to copy the MG151.


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## renrich (Feb 15, 2010)

This discussion has been had before and it seems to me that the various advocates for the aerial cannons and the 50 BMG are mostly talking past one another. To me, any attempt to prove that the 50 BMG was NOT inferior to the 20 mm or for that matter the 37 mm or 30 mm if all guns firing those projectiles were roughly equal in reliability, is futile. Those cannon rounds were more destructive than the 50 BMG. The MGs mainly relied on kinetic energy or sometime incendiary effect for their destructiveness and when the cannon shell exploded it was more destructive. However, the 50 BMG was a very destructive bullet because of it mass and velocity and many many EA were destroyed by the 50 BMG. Someone earlier made the point though that the German fighters and British fighters armed with cannon did not go on long escort missions because they did not have the range. They also were being used often to shoot down four engined heavy bombers or well armored Russian ground support bombers, or in the case of the British fighters the only alternative to the cannon was the rifle caliber guns. Since those fighters were in the air only a short time they did not need a lot of ammo. The fact is that hits in fighter versus fighter combat were hard to obtain and the large number of guns carried by US fighters and the high rates of fire made hits a little easier to obtain and the long firing times, (compared to cannon equipped fighters) meant that US fighters on long escort missions could still contniue to be armed when a cannon equipped fighter would have been out of ammo. Perhaps the best armed US fighter was the few F6Fs that carried two, hopefully, reliable 20 mm cannon with 225 rounds for each gun and four 50 BMGs with 400 round each. When the 20
mms were exhausted he still had four effective guns with some ammo left. However that F6F had a big thick wing to carry all those guns and ammo and one wonders how much it's performance was degraded by the additional weight.

Was the 20 mm round more destructive than the 50 BMG? YES
Could the US fighters carry more guns and more ammo if they were 50 cals instead of 20 mms? YES
Did the more numerous 50 cals with a higher ROF enable the US fighters to get more hits? YES
Did the longer firing times of the US fighters because of being equipped with 50 cals enable them to still be lethal on long missions? YES

Those seem to be the salient and unarguable points.


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## Shortround6 (Feb 15, 2010)

billswagger said:


> Tell me what the angle for each gun's bore site is in relation to the line of site?
> Bore site charts are used to set convergences not compare trajectories. You need to fire both guns at the same angles to make this comparison relevant. Its not really the best source for what your trying to show.



The angle of the bore doesn't really matter in this case does it?

I am not trying to prove that the 20mm was better or equal to the .50 in a purely theoretical case. I am trying to prove that at normal air combat ranges the .50 didn't have enough of an advantage to get all worked up about. Unpleasant as that may be for some .50 cal fans.

since the chart shows that up until 500yds the 20mm trajectory can be made to match the .50 cal trajectory within 3in or less I would say the chart does help show what I am talking about. 

It certainly is a lot more on point than your statement from post #219

"It was also determined that cannons (not sure of the caliber) had an effective range of 250y, where 50 caliber had an effecitve range of 850y."

or from #224

"Shots of 50 caliber remained inside the site ring for 850yards. Shots of cannon fire remained inside the site ring for 250yards."



billswagger said:


> The 20mm is over a quarter inch wider than the 50 cal, so i'm trying to figure how you would think their coeficient would be similar.



Not sure what you mean by this one. For lead round balls the ballistic co-efficient goes up with an increase in caliber. Same with any similarly shaped projectile, as in different diameters but similar shapes including length to dia. ratio, the larger diameter projectile will always have a higher BC.


billswagger said:


> The .50 M2 bullet weighed 46g giving an SDR of 0.406 (therefore) BC = .54
> The 20mm Hispano weighed 130g giving an SDR of 0.462 (therefore) BC = .31
> 
> COMBATSIM.COM ARCHIVE FORUM : Ballistic coefficients
> ...



I have a lot of respect for Mr. Williams but in this case he is (and admits) he is using estimates. For instance he uses the same form factor for the German 20mm and the Hispano. While there may not be a huge difference there is a difference:

http://www.quarry.nildram.co.uk/20mm1.jpg

I have some some figures that I am not real happy with but I will give them to you.

Time of flight to 600yds for a .50 cal 753gr/2900fps is 0.72sec, angle of departure is 14 min, remaining velocity is 1950fps. Retained velocity is 67%

Time of flight to 1000yds for a .50 as above is 1.32sec, angle of departure is 30 min, remaining velocity 1575fps. Retained velocity is 54%

For a prewar 20mm cannon with a 2000gr/2750fps round the 600yd time of flight is 0.84sec, angle of departure is 17 minutes, remaining velocity 1650fps. Retained velocity is 60%

For 1000yds the numbers are time of flight 1.71sec, angle of departure 42min and remaining velocity 1210fps. Retained velocity is 44%

Please note that these figures are from "Automatic Arms" by Johnson and Haven except for the percentage of retained velocity which is mine. 
While the .50 shows a marked superiority in flight times, angle of elevation and retained velocity at 1000yds the margin of superiority at 600yds is nowhere near as great. 

If somebody has better figures please bring them out. 

I would note that at 600yds if a .50cal and a 20mm were fired at the same instant the 20mm's 1st shell would arrive hard on the heels of the .50cal's second bullet if free firing and just a bit ahead of a synchronized .50 cal's 2nd bullet.

At distances below 600yds the differences are going to get smaller. 




billswagger said:


> And the nonsense about the Spitfire was a just a joke, mate.



Good Joke then, I said it gave me a good laugh.


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## billswagger (Feb 15, 2010)

riacrato said:


> Duh of course they are fired at different angles. The point is that the difference in trajectory is MINIMAL, you continue to ignore that. The chart you provide, if accurate, indicates that the difference in time to reach x, is less than 10% for all x below 500m. Anything beyond that range is unrealistic to achieve with a decent hit probability given the combat conditions and the crude gunsights, _especially_ if the target is a single engined fighter. And you can quit pointing to the blunt nose of the 20mm ammo. We all know that and the web site you quote "guesstimates" kind of like I did that the form factor is less important for the ballistic performance when compared to the sectional density. The qualities of having a good form factor apparently are not as important for aircraft cannons, which would also explain why virtually all WW2 era aircraft cannon designs didn't give that much attention even though the manufacturers that built them were very well able to build streamlined bullets (Germany, Russia, France, UK...). Even among modern cannons there are many (like the M61) with very "dirty" shaped ammunition.
> 
> It's obvious you have your mind dead set on the .50, so I will just leave it at that. But I would be curious: There are a number of USAAF fighters that were equipped with 20mm Hispanos, most notably the P-38. Was there ever a report that P-38 pilots complained about the lack of range of that cannon or its lack of felt accuracy in a turn fight (reliability issues aside) when compared to the M2? Imo the M2 had its advantages even in the air-to-air role, primarily as a defensive weapon for bombers where the range advantage over German cannons was more important than the destructiveness or efficiency. The simple fact that a German fighter pilot was usually always under fire upon starting his attack run matters.
> 
> As an offensive gun however it was just acceptable. I don't believe the USAAF ever thought it to be perfect for its task as some people here argue or else they would not have multiple projects to get a 20 mm to work, going as far as trying to copy the MG151.




Its obvious you use erroneous conclusions.  

Trajectory is minimal? Is the chart to scale? Does it give the angles?
I don't expect you to answer that, I've already admitted its an apples to apples comparison under 300 yards. 

Not really trying to drill the point so much as share what i know. 

I guess what i was getting at was the 50 calibers ability to maintain velocity at higher speeds, and USAAF recognized this over the 20mm. 
Somewhere in the comparison of muzzle velocities and coefficients i was intending to show that the bullet has better effective range. Hopefully what i've shown gets through to you. Effective range is the ability to hit the target and do damage. 

As for the bore site chart. I simply disagree about its use to show similar effective range for 50 caliber and 20mm. Your more than welcome to beat me up about it, but it doesn't change the facts about the ballistic behaviors of each weapon. 
P-38s had the advantage of the nose mounted armament which made calibration easier. I don't doubt P-38 pilots ever complained about range. With proper trajectory and calibration you could probably get an effective range of 1000yards. 
Point is, your gonna have an insane arc. Geez, they could probably set the trajectory of the 50 cal to hit at over 2000 yards. Oh wait, thats called a sniper rifle. 
When the target goes into a turn at higher speeds, you'd need to pull more lead and at higher speeds thats where the 50s have a better chance of hitting. The closer the target the less difference it makes. 

If you think they have the same effective range, show me something other than a boresite chart from a P-38. 




Bill


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## Vincenzo (Feb 15, 2010)

renrich said:


> Was the 20 mm round more destructive than the 50 BMG? YES
> Could the US fighters carry more guns and more ammo if they were 50 cals instead of 20 mms? YES
> Did the more numerous 50 cals with a higher ROF enable the US fighters to get more hits? YES
> Did the longer firing times of the US fighters because of being equipped with 50 cals enable them to still be lethal on long missions? YES
> .



1 agree
2 but if we take in consideration the more damage of 20 mm the US fighters with 20mm can carry more effective weaponry with same time of firing.
3 yes but the hit of 50 give less damage of hit of 20mm so this indifferent (with just proportion)
4 with same time of firing the US fighter can use 20mm ever if we take in consideration the just proportion (damage delivered to target)


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## billswagger (Feb 15, 2010)

Shortround6 said:


> The angle of the bore doesn't really matter in this case does it?
> )



If your firing in a straight line at zero mph, probably not much at all. In turns at high speed, i would think ballistic behaviors are gonna tell you a bit more info. 

An aircraft moving at 300mph at 10,000ft fires into a headwind. You'd have to have atmospheric conditions to get exact figures but it would make a difference if the coefficient of the 20mm is 40 percent worse. 

Your numbers on velocity correlate with most other numbers i've seen which seem to pin the difference in velocity loss at 29 percent for the 50 caliber, and 43 percent for the 20mm. 43-29 = 12 , 12/29 = 48 percent (600m) Ball round data

The faster the plane gets the more distance the bullet needs to travel to the target its shooting. So a shot at 300meters may infact may need to travel through another 75 meters of air to hit a moving target. 
You start to see how a bullet that's 40 percent less efficient would start to show at combat speeds and ranges. 
You could adjust trajectory for accuracy but it doesn't make up for velocity loss where a tenth of second is enough to make your shot miss by a significant margin.

I can't help think of race cars that travel at 200mph, When they show the lead car as having a 0.10 second lead, and the gap that appears to the trailing car. You could probably fit a Mustang or two between them. 

"A round that doesn't hit its target is never effective. "


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## Shortround6 (Feb 15, 2010)

billswagger said:


> You could adjust trajectory for accuracy but it doesn't make up for velocity loss where a tenth of second is enough to make your shot miss by a significant margin.



Well, lets look this then. At 600yds the 20mm round is .12 seconds behind the .50. Close enough to " a tenth of second"?

But then the second round out of a syncro-ed .50 is the same time behind or more. These guns are fired in bursts after all. Some pilots may have started shooting behind the target and "traversed" (turned tighter) to bring the bullet stream/s through the target and then ahead to get the correct lead. Others may have over lead and then loosened their turn a bit to let the target run into the stream of bullets, Some tried to use tracers to correct aim but that doesn't work so well at 600yds does it? Tracer tells you were you shooting 3/4 of a second ago. 

comparing the times it looks like the 20mm may need about 16% more lead than the .50. Of course if you are defection shooting at 600yds you are either very, very good or hoping for a whole lot of luck.

As the range shortens the difference gets smaller. At range "X" (20mm needs 10% more lead) could you really tell if you were leading the target by 66ft rather than 60 ft?

The .50 will show an advantage, but it only shows a big advantage at ranges beyond normal air to air combat ranges that were common in WW II. 

As for this "Is the chart to scale? Does it give the angles?"

It doesn't have to be to scale does it?
Since there is a chart that lists the exact below and above line of sight distance for the trajectories in inches for every 50 yards of range out to 500yds. 

I have given you angles of elevation for both 600yds and 1000yds. But they may be nominal angles which assume bullet rising and then falling to the same plane as the muzzle of the weapon and not take into account the difference in hight between the sight and the barrel. 

Angles for the bore sight chart are useless. barrels will vibrate differently from each other when fired and have different points of impact using the same nominal bore alignment ( as in optical or laser bore sighting) which is why nobody but a fool doesn't test fire a weapon to confirm point of impact in relation to sights. once you have a known point of impact for a barrel you can then bring the barrel up either the "correct" number of minutes or you can use a short range sight in chart (like 1000in) and when the guns point of impact coincides with the proper point on the chart/target you will automatically have the desired arc/trajectory for the sight/ranges desired.


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## billswagger (Feb 15, 2010)

Yeah, i agree with what you are saying. 

What your still missing is the point that the faster the plane moves the more the bullet needs to travel to get to the target and
you also have more air resistance acting on the coefficients of the bullets. 

A test fire from a stationary gun is not likely to show this accurately but the differences in trajectory would probably correlate similarly to speed shot from as it does range. 

So it would be apples to apples at 180mph and 200 meters range, but at 400 mph and 300 meters range you might see greeter differences than whats depicted on the chart. (augmentation)

Part of the reason the 50 caliber gets its praise is for its ability to hold speed at higher mach numbers. 

I could throw altitude and mach effects into the equation but i think that might be splitting flea hairs. 

To digress a bit, i know that an angles fight often involved getting in a snapshot that would do the most amount of damage in the least amount of time. The 20mm is better suited for this but would be limited by rate of fire and firing time. 

At higher speeds, and in energy fights, the goal is similar however efficiency of the shot needs to insure it will hit the plane.
At higher speeds, it is not always possible for the fight to develop to a point where the pilot can shoot at closer range.
As you know ammo loads are critical to compensate for deflection shooting. 


Bill


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## renrich (Feb 16, 2010)

SR, those are very interesting numbers you have posted. Many thanks. Those numbers raise an interesting question. In a P38, with the one 20mm and the four 50 cals, if the pilot was trying a full deflection shot at 400 yards, (very unlikely) against an EA traveling 350 mph, the rounds from the 50 cals would hit in the same vicinity but the 20mm rounds would hit further away longitudinally. Correct?


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## billswagger (Feb 16, 2010)

To get back on topic i found a short read on Google books that goes into the handeling charcteristics of the 109. 

Its a decent read because it gives several perspectives and also distinguishes RAF reports from propaganda.

The commonality i see in most reading regarding the 109 is its poor elevator response at higher speeds as well as its decrease rate of roll. 
At speeds above 250mph it becomes difficult to fly and maneuver well and dives at 400mph could be difficult to recover from. 

The Putnam Aeronautical Review - Google Books

starts with Handling and reads to the next page. 


In comparison of the P-40, although under powered at higher altitudes was able to maneuver more effectively at higher speeds. 
Increased maneuverability allows for tactical superiority since a broader range of maneuvers can be used. 

This is not a full proof approach to what fighter would come out on top, but rather illustrates the apparent disadvantages the 109 had where the P-40 could be successful in a combat scenario between many aircraft. 

I don't see how the Thach Weave would not also apply to 109 being that it was particularly successful against the Zero which also suffered in high speed maneuvers.

The short coming of course would be the climb and altitude issue. It just seems tactical advantage would need to be in place before the 109 had the chance to escape and climb to a position of advantage. (many vs many)

While some of the bombing campaigns took place over parts of Italy and Sicily, it was learned that 109s were dispatched on average of about 15 minutes before the bombers got over their targets. 
P-40s had the range to fly to the target area ahead of the bombers awaiting for 109s attempting to take off or climb to intercept bombers. 

109s attempting to dive away had little maneuverability if being pursued by a faster diving plane, P-40s included. 


Bill

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## billswagger (Feb 16, 2010)

renrich said:


> SR, those are very interesting numbers you have posted. Many thanks. Those numbers raise an interesting question. In a P38, with the one 20mm and the four 50 cals, if the pilot was trying a full deflection shot at 400 yards, (very unlikely) against an EA traveling 350 mph, the rounds from the 50 cals would hit in the same vicinity but the 20mm rounds would hit further away longitudinally. Correct?



Depends on the deflection angle and also the speed of the aircraft being shot at. Steeper angle would mean greater separation even at 200 yards, but having pin pointed accuracy with an HE round is not as critical. You only need hit the wing once or twice and the plane will have trouble remaining in the fight. 

You also have to couple that with rate of fire. 

Deflection shooting at 300-400 yards was quite common on 50 caliber load outs. (20-30 degrees)
In reading combat accounts, a pilot pulling deflection is usually closing at higher rates of speed. You have an aircraft moving at over 400mph toward its target, while the target is slower but banking and/or turning to avoid being hit. The bullet that gets there the fastest wins. 

Its really the difference between hitting the nose or hitting the tail. Or hitting a wing and not hitting a wing. 
No doubt experience would compensate for any corrections needed to compensate for deflection. 

Its apples to apples in the end. 


Bill


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## renrich (Feb 16, 2010)

Bill, if you will notice, I said full deflection, which means the attacker begins to fire at 90 degrees to the target. Only USN trained pilots spent much time in full deflection gunnery because of issues like visibility over the nose, so my question is somewhat academic. However, the P38, unlike most other fighters had good visibility over the nose. The question is only interesting because the P38, like all fighters with all armament closely grouped, had a very good concentration of projectiles. But if one projectile is traveling more slowly than the other four then that concentration would suffer. An example might be that four rounds hit in the cockpit area and the 20mm round might hit further back on the fuselage. The question is how much further back? For a very fine discussion of Aerial Fixed Gunnery and deflection shooting, go to Appendix 2, Lundstrom, "The First Team."


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## riacrato (Feb 16, 2010)

renrich said:


> SR, those are very interesting numbers you have posted. Many thanks. Those numbers raise an interesting question. In a P38, with the one 20mm and the four 50 cals, if the pilot was trying a full deflection shot at 400 yards, (very unlikely) against an EA traveling 350 mph, the rounds from the 50 cals would hit in the same vicinity but the 20mm rounds would hit further away longitudinally. Correct?


If my math skills don't betray me (which they usually do), at 400 metres, full deflection, EA flying at 350mph (563.3 km/h), the 20mm bullets would hit about 4.69 metres aft of the .50 calibre bullets.

I took metres since I'm to lazy to convert the chart into yards.


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## NZTyphoon (Feb 16, 2010)

drgondog said:


> You are right, the RAF did not use the aft fuse tank - at least not as far as I know.


At the moment I only have Gruenhagen's book which gives figures of:

P-51 B/C/D Internal Fuel wing/fuselage tanks 500 miles combat, 1,200 miles ferry
+ 75 gal drop tanks 880 miles combat, 1,830 miles ferry
+110 gal drop tanks 1,000 miles combat, 2,120 miles ferry


The ranges for Mustangs with wing tanks is given as:
Mustang I, P-51, A-36, P-51 A/B/C is 400 miles combat, 900 miles ferry


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## renrich (Feb 16, 2010)

riacrato, thanks for your calculations. Don't worry about converting meters to yards as they are so similar. That is a big difference, almost 15 feet between the strike of the 50 cals and 20mms. It could easily mean a hit with one and a miss with the other.


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## riacrato (Feb 17, 2010)

Well there is a slight difference at that range, 400 yards is about 366 m.

But anyways while there is certainly a difference in point of impact (~4.7m), let's be realistic:

1- at that range you would have to lead the target by about 82 m with a 50 cal, as opposed to 86.7m for the hispano. could you tell the lead difference of 82 vs 86.7 m? So a fighter with 6x50cal would have to lead about 5.7 % less than a fighter armed with 4x Hispano at that extreme range. I suggest someone who can pull off the former can likely pull off the latter.

2- is this a realistic scenario: Full deflection at 400m vs a fast aircraft (at the upper limit of typical dogfight speeds, if not beyond)?



If anything that shows that mixed armaments of cannons and mgs are less optimal when it comes to dogfighting, well known. Still at typical deflection shot scenarios I think the differences between the two guns are minimal.

EDIT: Forget what I wrote, my calculations would only be valid if the attacker is flying at 0 km/h. for an aircraft flying at x km/h the lead for both aircraft would be smaller and the difference between 50cal and Hispano slightly larger. I am too lazy at the moment to try to calculate the values again


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## Vincenzo (Feb 17, 2010)

riarcrato what's difference for a 200 meters range?


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## Demetrious (Feb 17, 2010)

billswagger said:


> For the purposes of WW2, it depends on the rounds used. HE rounds explode on impact so armor penetration is not really their intended purpose. AP 20mm was shown to be more consistent and more effective up to 400 yards.



Excellent data, both on this and everything else you've posted in this thread. I'm bookmarking your posts for future reference. 

Obviously, armor-piercing 20mm rounds will outperform .50 cal against armor (I must admit I'm surprised that ball 20mm was inferior to .50 cal, but considering the blunt tips that makes sense.) However, as I understand it, most all 20mm shells employed in WWII were of the HE variety for it's obvious destructive power.

This information changes the dynamics of these two weapons considerably- HE rounds obviously have the ability to blow entire important pieces of the fuselage off completely, but the rather better armor penetration of the .50 cal, plus the greater pattern density (more guns throwing more bullets) means that .50 cals had a better chance of putting a round into something important and protected- the engine, or preferably the pilot.

That's my take on it, at any rate.



> I am not trying to prove that the 20mm was better or equal to the .50 in a purely theoretical case. I am trying to prove that at normal air combat ranges the .50 didn't have enough of an advantage to get all worked up about. Unpleasant as that may be for some .50 cal fans.



Then in that case your own argument is purely semantic as well. 

"Normal combat ranges," for most pilots, consisted of saddling up on a bandit's tail at 100 yards or less, with no deflection, since most pilots were crappy shots (given the difficulty of aerial gunnery.) At 100 yards or less, you could easily down your enemy with rifle-caliber machine guns, much less .50 cals or cannons. (The Germans, naturally, facing planes like the Thunderbolt with aircraft that simply didn't have the room to mount more then two MGs in the cowling were in a different situation, but we're talking Allied armaments.) 

This also negates arguments about "duration of fire," since running out of ammo hosing bullets at ranges the pilot should know he hasn't the skill to hit at is a matter of pilot discipline. Generous ammo supplies matter most in the context of difficult deflection shots at 200 or 300 yards.


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## riacrato (Feb 17, 2010)

Vincenzo said:


> riarcrato what's difference for a 200 meters range?



I calculate ~1.57m. (39.12m for Hispano, 37.55m for 50 cal.).

I would mention though this is all based on that chart provided by bill which says "estimated data". I don't know how good it really is.


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## riacrato (Feb 17, 2010)

Vincenzo said:


> riarcrato what's difference for a 200 meters range?



All else being equal (EA at 563.3 km/h, 90 degree deflection) I calculate ~1.57m at 200m. (lead is 39.12m for Hispano, 37.55m for 50 cal.).

I would mention though this is all based on that chart provided by bill which says "estimated data". I don't know how good it really is.


EDIT: Forget what I wrote, my calculations would only be valid if the attacker is flying at 0 km/h. for an aircraft flying at x km/h the lead for both aircraft would be smaller and the difference between 50cal and Hispano slightly larger. I am too lazy at the moment to try to calculate the values again


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## billswagger (Feb 17, 2010)

Demetrious said:


> Obviously, armor-piercing 20mm rounds will outperform .50 cal against armor (I must admit I'm surprised that ball 20mm was inferior to .50 cal, but considering the blunt tips that makes sense.) However, as I understand it, most all 20mm shells employed in WWII were of the HE variety for it's obvious destructive power.



The belting of the ammo was actually a mixture of a variety of ammo. 

I don't have exact ratios, but typical Spitfire load outs had lower HE ratios than German fighters. 
Don't quote me, but its something like 4 of every 10 rounds mixed with ball and tracer rounds. I think Germans used 7 of 10 HE rounds. 

Its just depends on the given roll of the aircraft, Ground attack missions would carry more AP load outs, while air to air was HE. 

It is rare to see aircraft that use entire beltings of one specific ammunition type, although there are a few cases i can site. 

When you have a multi gun platform of 6 or 8 guns that all have the same exact trajectory and ballistics properties then you only need put tracer rounds in a couple of the guns. 

P-47 pilots would sometimes load 6 guns with 100% AP or API, and have two guns 100 percent incendiary. The 6 guns would work well on hitting vital aircraft parts at long range while the "I" rounds acted as a steady bead of tracers and ignited flammable materials.

http://www.wwiiaircraftperformance.org/p-47/er/56-gabreski-29jan44.jpg
http://www.wwiiaircraftperformance.org/p-47/er/56-gabreski-30jan44.jpg

Bill


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## Vincenzo (Feb 17, 2010)

billswagger said:


> The Putnam Aeronautical Review - Google Books



in the Kuerfurst page there is the RAE report take on base of that article.

as all enemy report i want just noted that the plane was crashed, was not absent to trouble, the pilot and ground crew were not trained on this


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## Vincenzo (Feb 17, 2010)

billswagger said:


> T
> 
> http://www.wwiiaircraftperformance.org/p-47/er/56-gabreski-29jan44.jpg
> 
> ...



as i understand only AP in six guns and only API in two (idk if 50 has HEI)


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## billswagger (Feb 17, 2010)

Vincenzo said:


> as i understand only AP in six guns and only API in two (idk if 50 has HEI)



I'm not sure the US Army ever used HE 50 caliber in WW2 combat. 

The combat report is referring to Incendiary Tracer rounds. 

API is a different kind of ammo. There is no tracer element. It emits a flash on impact which lets the pilot know his shots are hitting, and was later discovered could be used to ignite fires. 

APIT is the same roundf with the added tracer element. 

In the report, he makes note of this. 

"I saw no white flashes.........." ..."but i did observe glycol pouring out of the engines"


There are a dozen more reports that show the range of the ammo. What's interesting about the other example broaches another question that should be looked into. 

"The 109s had the same white tail and wing markings as the Mustang. As a result, fire was withheld til I closed to 250 yards., when black crosses could be plainly seen......"






Bill


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## NZTyphoon (Feb 19, 2010)

billswagger said:


> There are a dozen more reports that show the range of the ammo. What's interesting about the other example broaches another question that should be looked into.
> 
> "The 109s had the same white tail and wing markings as the Mustang. As a result, fire was withheld til I closed to 250 yards., when black crosses could be plainly seen......"
> 
> Bill


I doubt if the Germans would have gone to the trouble of marking 109s to look like Mustangs; for one it would have confused German pilots in the heat of combat and increased the risk of " friendly fire" ; this would have been rather more risky than any potential confusion it may have engendered in enemy pilots. 
Secondly, there were Luftwaffe units using white rudders and wingtips at the time and these could easily have been mistaken for Mustang markings - the report doesn't state the range at which the 109s were first sighted, and it states that the Gabreski and Lt Klibbe closed from dead astern - from such an angle even a flash of white could be mistaken for the Mustang markings.


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## billswagger (Feb 20, 2010)

NZTyphoon said:


> I doubt if the Germans would have gone to the trouble of marking 109s to look like Mustangs; for one it would have confused German pilots in the heat of combat and increased the risk of " friendly fire" ; this would have been rather more risky than any potential confusion it may have engendered in enemy pilots.
> Secondly, there were Luftwaffe units using white rudders and wingtips at the time and these could easily have been mistaken for Mustang markings - the report doesn't state the range at which the 109s were first sighted, and it states that the Gabreski and Lt Klibbe closed from dead astern - from such an angle even a flash of white could be mistaken for the Mustang markings.



From what i've seen it was probably not the intention of the Luftwaffe to look like Mustangs however the vertical surfaces of the tail, including the rudder were sometimes painted white. Also there is a stripe on the tail section used to identify different squadrons, flights, or elements. Usually this was yellow, sometimes it was white. 

If lining up to bounce an aircraft from 5000ft above these markings could be mistaken for Mustangs. 

In Gabreski's other descriptions he shoots from distances over 500 yards, but these aircraft also happen to be the larger Bf110 and Me210, perhaps easier to identify and also hit from longer ranges. In other accounts he does describe hitting smaller aircraft from similar distances using similar ammo load. 

I just raises the point that sometimes hitting the target is not only a matter of range, but also being able to correctly identify the target before you open up on it. 

Bill


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## Milosh (Feb 20, 2010)

billswagger said:


> From what i've seen it was probably not the intention of the Luftwaffe to look like Mustangs however the vertical surfaces of the tail, including the rudder were sometimes painted white. Also there is a stripe on the tail section used to identify different squadrons, flights, or elements. Usually this was yellow, sometimes it was white.
> 
> Bill



The stripes were not unit markings. The P-47 and P-51 had a stripe, white or yellow, on each wing, each stab/elevator and fin/rudder for ID purposes to distinguish them from 190s and 109s.


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## billswagger (Feb 20, 2010)

Milosh said:


> The stripes were not unit markings. The P-47 and P-51 had a stripe, white or yellow, on each wing, each stab/elevator and fin/rudder for ID purposes to distinguish them from 190s and 109s.



agreed.

I think perhaps the white tail used on P-47s as well as Mustangs and P-40s was confused with the vertical tail surfaces of the 109s as well as a white stripe on the tail section. 

Actually the white rudder was a way to distinguish flight leaders of the 109.

I'm not as familiar with markings other than the obvious allied stripes used on the wings and underbelly. 



Bill


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## billswagger (Mar 3, 2010)

Kurfrst - U.S.A.A.F. Material Command - Pilot's Comments on ME 109G[-6/trop], AAF No. EB-102

this is a P-40 pilots assessment of a 109G. Although no specific performance comparisons are made, he makes several remarks that indicate the plane had a poorer turning radius due to heavy elevator forces at 400kph above which these forces only increased. 


Bill


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