Favorite fighter/interceptor?

[renrich]

According to Dean P51D with full max internal fuel GW is 10208 lbs. Fuselage tank is 55 lbs and fuel is 1590 lbs. The number of 9611 lbs gross weight is without the fuselage tank and the internal fuel weight is 1080 lbs. I don't know where 10176 GW came from but that was the weight quoted in the table. F4U 4 w/GW of 12420 lbs is with 1404 lbs of internal fuel. I do believe there are a lot of exciting stories about the MU2 but my memory does not serve as well as it once did. The lady I mentioned is about 70 years young and when they had the MU2 would probably be in the time frame mentioned.

 

[FLYBOYJ]

Ever see the fuel control/ power lever rigging in an MU2? It looks like a drunk spider's web.

 

[drgondog]

According to Dean P51D with full max internal fuel GW is 10208 lbs. Fuselage tank is 55 lbs and fuel is 1590 lbs. The number of 9611 lbs gross weight is without the fuselage tank and the internal fuel weight is 1080 lbs. I don't know where 10176 GW came from but that was the weight quoted in the table. F4U 4 w/GW of 12420 lbs is with 1404 lbs of internal fuel. I do believe there are a lot of exciting stories about the MU2 but my memory does not serve as well as it once did. The lady I mentioned is about 70 years young and when they had the MU2 would probably be in the time frame mentioned.

P 51D Performance Test

The 9760 Gross weight in the report is the weight with full ammo, full oil, Gentile in the cockpit, wing racks, full wing tanks (184 Gallons) plus 25 of the 85 possible gallons in the fuse tank - another 60 gallons would add 396 pounds if topped off.

That would take Gross to 10156 for complete internal fuel. Having said that, the test really represented a normally max (internally) loaded P-51D which rarely carried more than 55-60 gallons in fuselage tank because of aft cg problems.

So, your number of 10,208 is closer to above calculated 10,156 max TO total (for complete internal fuel, but no external load) and is closer than my recollection of 9600 (P-51B level - full internal load) gross.

 

[drgondog]

Ever see the fuel control/ power lever rigging in an MU2? It looks like a drunk spider's web.

There is a reason that such a high performance ship like this is pretty cheap..

I had all I wanted of it in three flights. The first time I shot a landing in it you would have been switching between laughing and cryin' - I'm glad (just this once) that He wasn't there to critique it.

 

[renrich]

My table for Typical P51D in Fighter configuration is as follows: empty wgt=7205, trp fluid=61, 6 50 cal=401, pyrotech=6, basic weight=7673, pilot=200,use. oil=94, cal. 50 ammo=564, int. fuel =1080. total =9611 Fighter max fuel configuration is same except: fus. tank=55, bomb racks=32, internal fuel=1590, for total of 10208.

 

[FLYBOYJ]

There is a reason that such a high performance ship like this is pretty cheap..

I had all I wanted of it in three flights. The first time I shot a landing in it you would have been switching between laughing and cryin' - I'm glad (just this once) that He wasn't there to critique it.

There's a trash hauler operating out of Centennial airport that has MU2s - they plant one about 2x a year.

 

[Soren]

Bill,

The FW-190 Dora-9 performance figures are all at fully loaded weight, which is 4,300 kg.

As for the maneuverability, well I can't really stress this hard enough, the Dora-9 turns better than ANY of the Antons. Also there's no difference in performance or maneuverability between the A-7 A-8, and the A-9 was a rather rare bird so they couldn't have been refering to this. All comparative tests were done with a cleanly loaded A-8 D-9.

Didn't notice the P-51B in question had wing racks, thanks for pointing that out. However in terms of climb it doesn't change much other than 10 km is reach 0.05 to 0.1 min faster. Speed is most affected.

A clean model running at +25 lbs/sq.in. boost with a British Merlin engine reached 6km in 5.25 min.

As for diving, well the lighter FW-190A-5 out-accelerated the P-47D initially as-well.

Regarding take off roll, well according to the POH which lists minimum figures the P-51D at 10,000 lbs takes off after 1600 ft (487m) and will clear a 50 ft (15m) object after 2400 ft (731m).

Compared to other LW a/c:

P-51D: 487m, 731m to clear 15m object.
FW-190 A-8: 430m, 715m to clear 20m object.
FW-190 A-9: 390m, 600m to clear 20m object.
FW-190 D-9: 365m, 570m to clear 20m object.
Ta-152H-0: 295m, 495m to clear 20m object.

German data for fully loaded weight and take off power.

 

[drgondog]

Bill,

As for the maneuverability, well I can't really stress this hard enough, the Dora-9 turns better than ANY of the Antons. Also there's no difference in performance or maneuverability between the A-7 A-8, and the A-9 was a rather rare bird so they couldn't have been refering to this. All comparative tests were done with a cleanly loaded A-8 D-9.

Soren - I did get a reply back from Don. He did not get disagreement from the JG26 pilots regarding either the diary comments in his JG26 War Diaries or his JG26 Top Gun book comments regarding anecdotes on the 109K-4.

He did say that the JG26 vet comparisons were largely not about high altitude performance as the Geschwader was largely tactical at that time in the war and most of the reflections were at low to medium altitude.

He was very emphatic that the Dora pilots felt they had an edge overall on the P-47 and Tempests - their main opponents but were disappointed that the Mustang still seemed to have an edge. He also emphasized that the pilots were getting aircraft of varying quality so performance figures had to be taken with a grain of salt.

He finished by saying that the Anton did have an edge in manueverability but what could you expect in comparison with a heavier, longer ship against the best fighter roll rate in the ETO


As for diving, well the lighter FW-190A-5 out-accelerated the P-47D initially as-well.

But not the 51B

Regarding take off roll, well according to the POH which lists minimum figures the P-51D at 10,000 lbs takes off after 1600 ft (487m) and will clear a 50 ft (15m) object after 2400 ft (731m).

Compared to other LW a/c:

P-51D: 487m, 731m to clear 15m object.
FW-190 A-8: 430m, 715m to clear 20m object.
FW-190 A-9: 390m, 600m to clear 20m object.
FW-190 D-9: 365m, 570m to clear 20m object.
Ta-152H-0: 295m, 495m to clear 20m object.

German data for fully loaded weight and take off power.

Soren - I will look when I get home. The number that sticks in my head for P-51D the max gross - internal- takeoff roll, at STP, was 1080-1100+ ft. 1600 is way too far.

I know from personal experience in one that was loaded with full wing tanks, me in back seat, no 85 gallon tank.. was between a Long Par 3 and Short Par 4" - or about 1000 feet plus or minus.

I'll send you an email with more detail from Don's observations in his interviews.

 

[SoD Stitch]

Btw, drgondog, I think the methanol in MW50 was only used as an anti-freeze, while the evaporating water sinks the engine temp to allow a higher power output. So pure water will be more effective but it will freeze and cause corrosion. So the Power output will be similar.

Greetings

Thrawn

You are quite correct in your assessment of MW50; yes, the methanol was there simply to prevent freezing at high altitude. The number "50" in the designation meant it was 50% water 50% methanol; there was another formula used during the War, also, which was MW30, meaning it only had a 30% methanol ratio (to 70% water). I can only assume MW30 was used in aircraft that weren't planning on flying at high-altitudes (tactical bombers?), since it would've been more susceptible to freezing.

In any case, it was the water that did the trick; injecting water into the incoming compressed air stream cooled the air charge down, making it denser and, therefore, more volatile for combustion, especially at high altitude.

 

[Kurfürst]

Indeed, in fact even pure water could be used without any additive in emergency.

As for Caldwell, where did you contact him ? Personally, I found his book a great read (it was translated here, too) and an extremely well written unit history that is both very readable and yet informative. OTOH I don't think Caldwell did much research into aircraft, thing I read in his book about various aircraft types merely seem to repeat old topos taken from old books like Green, and in cases uncorrect. In short I wouldn`t rely on at all how he rates different aircraft, opinions of veterans he gives is an entirely different matter of course, but I realize how subjective those are, and how much based on perception/feel/personal preference.

But that`s fine, it`s a unit history after all, not a danged type catalouge...!

As for anecdotes about the 109K in Caldwell`s book, I can only recall two, summerized by Caldwell; one being that the K-4s JG 26 received were at first equipped with gondolas, while G-10s were not, and this made the G-10 more popular for high altitude work - no big surprise here - so later the gondies were removed. The other being the story of a German pilot who dived sometime in the winter in his 109K and his canopy glass misted/freeze up in the dive. Again, no big surprise. Neither accounts tell too much about the type`s qualities, the only tactical experience report I own is from units on different types (Bf 110, but mainly 262), which has a couple of paragraph devoted to the experiences with the K model. Not much there either, though. I don`t want to dig up the details, but the story was something about a higher ranking pilot shooting down three Thunderbolts in his K-4, then forced landed because of a radiator hit he received during combat.

 

[drgondog]

Indeed, in fact even pure water could be used without any additive in emergency.

As for Caldwell, where did you contact him ? Personally, I found his book a great read (it was translated here, too) and an extremely well written unit history that is both very readable and yet informative. OTOH I don't think Caldwell did much research into aircraft, thing I read in his book about various aircraft types merely seem to repeat old topos taken from old books like Green, and in cases uncorrect. In short I wouldn`t rely on at all how he rates different aircraft, opinions of veterans he gives is an entirely different matter of course, but I realize how subjective those are, and how much based on perception/feel/personal preference.

Yes I did Kurfurst. The comments I just made were very close paraphrase of what he told me from the email I received last night. Soren raised a question about Caldwell's 'accuracy' and I was interested not so much in validating Don's opinion or refuting Soren's as I was in various reactions from many fine fighter pilots that helped Don compile his various books.

But that`s fine, it`s a unit history after all, not a danged type catalouge...!

As for anecdotes about the 109K in Caldwell`s book, I can only recall two, summerized by Caldwell; one being that the K-4s JG 26 received were at first equipped with gondolas, while G-10s were not, and this made the G-10 more popular for high altitude work - no big surprise here - so later the gondies were removed.

The one I asked him about some time agao came from the December timeframe in his Top Gun book. I do not remember the exact words but in effect the pilot describing the high altitude formation flying efforts as difficult to maintain in contrast to the G-10 or G-6. Conversely, the P-51H was described in Flight test as having a tendency to 'hunt' which I interpreted as a little Dutch Roll... so maybe the 109K pilot was describing one annoying characteristic and failed to mention all the good one?

The other being the story of a German pilot who dived sometime in the winter in his 109K and his canopy glass misted/freeze up in the dive. Again, no big surprise. Neither accounts tell too much about the type`s qualities, the only tactical experience report I own is from units on different types (Bf 110, but mainly 262), which has a couple of paragraph devoted to the experiences with the K model. Not much there either, though. I don`t want to dig up the details, but the story was something about a higher ranking pilot shooting down three Thunderbolts in his K-4, then forced landed because of a radiator hit he received during combat.

The question of subjectivity is always a difficult perspective to separate from objective evaluations. I don't exclude myself from this curse but I try to hold a balance (the engineer in me won't go away).

Don also made the comment that at that stage of the war and the early introduction of the Dora into JG 26 made for a range of reactions to this powerful new fighter - some expecting invincibility were disappointed, others expecting parity against the best the Allies had weren't disappointed.

But your point on tactical observations is a strong key point. They are largely written by survivors of air combat. It is rare that you see "Despite this pig of an airplane" my skill overcame great odds and I emerged victorious".. on both sides.

I talk to Mustang veterans all the time that seriously believe no Me 109 could ever out turn a 51. We know that statement is false - just that none he engaged with escaped in a turn, or continued, closed and shot him (MUstang pilot) down. That makes for one sided evaluations - both sides

Having said that there were very very few Mustang aces shot down in aerial combat in ETO. That is a reflection of the superb performance, the tactics of the Luftwaffe to AVOID fighter-fighter combat by orders, and the decline in pilot standards over time from 1943 on.

So, to summarize. He stood by his words, said he was not 'chastised' for mis hearing what was discussed regarding such anecdotal reflections by the pilots, is NOT a 8th AF/US bigot on this subject and IS a great admirer of the Luftwaffe and its battle skills and aircraft. He describes his role as a trusted 'scribe', not a serious evaluator of aerodynamics and performance.

At any rate I respect your POV, as well as Soren's. I depend on my own capacity to sort facts from opinion and sometimes fail - but I do a lot of cross checking on interesting topics - this is one of them

Regards,

Bill

 

[drgondog]

Bill,

Regarding take off roll, well according to the POH which lists minimum figures the P-51D at 10,000 lbs takes off after 1600 ft (487m) and will clear a 50 ft (15m) object after 2400 ft (731m).

P-51D Performance

Use this as one reference for 51D flight test at 9600 pound (no fuel in fuse, full internal wing fuel, full ammo and oil and 200 pound pilot - equipped for 1100 mile range fighter config

Summary @9600pounds on STP calibration
to = 1040ft, then 1720ft to clear 50'

with 1/2 fuel @ 9071pounds on STP
landing roll = 1520 at 110mph
to clear 50ft = 2250ft

I wonder if your source confused the landing roll with Take Off stats? Or was using flaps 'neutral' instead of short field 15-20 degrees. If so, their figures make sense but doesn't tell the whole story

the extra 560 pounds fro full fuse tank would mean perhaps another 100-120 ft to generate the airspeed to lift the extra weight.

These numbers closely approximate my own experience, which for the one I was flying in - would have been around 9300+ (me in back, no fuse fuel, full wing tanks, no guns/ammo, extra radio/nav/flight controls) and routine take offs in 1000 feet with flaps at 20 degrees


Compared to other LW a/c:

P-51D: 487m, 731m to clear 15m object.
FW-190 A-8: 430m, 715m to clear 20m object.
FW-190 A-9: 390m, 600m to clear 20m object.
FW-190 D-9: 365m, 570m to clear 20m object.
Ta-152H-0: 295m, 495m to clear 20m object.

German data for fully loaded weight and take off power.

I'm a little suprised that the 190D took 10% less take off run than the A-8. What were the differences in weight between the two?

 

[Soren]

Bill,

The figures you have presented are calculated and VERY optimistic IMO, just take a look at the Spitfires take off roll which was renowned for being very short, it's longer than that calculation. The POH lists the true minimum 1600 ft take off roll at 10,000 lbs and 1400 ft at 9,000 lbs. Don't you have the P-51D's POH ?

Interestingly though the better aerodynamics of B version made for a 200 ft shorter take off run at 1400 ft, compared to the 1600 ft of the P-51D.

Also why are you surprised about the difference between the A-8 D-9 ? While weighing roughly the same the D-9 is less draggy and it's prop produces slightly more thrust.

 

[Soren]

Btw, also remember that down low and at slow speeds the FW-190 A-8 has a better sustained turn rate than the P-51D, hence the shorter take off roll.

The excellent charts by Crumpp:
FW_190 A-8

P-51D

 

[Soren]

He was very emphatic that the Dora pilots felt they had an edge overall on the P-47 and Tempests - their main opponents but were disappointed that the Mustang still seemed to have an edge.

According to German comparisons the Dora was slightly better than the P-51 down low and about the same at high altitude.

He finished by saying that the Anton did have an edge in manueverability but what could you expect in comparison with a heavier, longer ship against the best fighter roll rate in the ETO

Roll rate isn't turn rate

However in short I wouldn't trust Caldwell when it comes to a/c performance, and that's not that he's untrustworthy, he just isn't much into this area.

Please also bare in mind that most Dora-9's flown by JG-26 weren't equipped with the MW-50 system, so that would explain the remarks Caldwell has recieved.

 

[drgondog]

Bill,

The figures you have presented are calculated and VERY optimistic IMO, just take a look at the Spitfires take off roll which was renowned for being very short, it's longer than that calculation. The POH lists the true minimum 1600 ft take off roll at 10,000 lbs and 1400 ft at 9,000 lbs. Don't you have the P-51D's POH ?

What I presented you was Flight Test Report, May 1944 test results at Wright Pat taking a random P-51D-15 and running it through its paces.

What it (Report) presented you was average observed take off roll in fully loaded combat condition except for fuselage fuel. for short field conditions using 20 degrees of flaps


Interestingly though the better aerodynamics of B version made for a 200 ft shorter take off run at 1400 ft, compared to the 1600 ft of the P-51D.

That wasn't our discussion but I knew that. The P-51B in similar load, short field, hard runway, 20degrees flaps is probably less than 1000 feet.

Also why are you surprised about the difference between the A-8 D-9 ? While weighing roughly the same the D-9 is less draggy and it's prop produces slightly more thrust.

Because you didn't present the Report stating each condition, and elements of test, including either corrections for STP or the actual temperatures or the field conditions for take off, definitions for what constituted the load. You present no context.

Even Combat Load has different connotations depending on the mission. I was careful to highlight the specific meaning and demonstrate the difference the internal fuselage tank load meant to Max Gross TO 'Clean External -except for racks'

Your source is already suspect because the data you give is for clean (no flaps) take off for a P-51D. If that is what it states, the 1540-1600 ft is correct, or close enough depending on pilot skill, altitude of the airfield, hard or soft, hot or cold day.

What is your source?

 

[drgondog]

According to German comparisons the Dora was slightly better than the P-51 down low and about the same at high altitude.

Please post the German comparisons you are alluding to. I have done so fro anecdotal reference, have never found a written comparison performed by test pilots except for the ones performed by RAF and USAAF - which you refute. Post the tests and comparisons that meet your standard for fairness.

Absent that, you waste both our time covering the same ground.

Roll rate isn't turn rate

Soren -When did you come to that realization? Having said that how would you prove that D-9 out turned an A8 or A9? The anecdotal evidence that came from Caldwell's book indicated the Anton out turned and out rolled it. You say no. What is the German Report making these comparisons that I should look at? The D-9 is heavier, I suppose the W/L is higher for exactly the same comparison combat load? - but tell me other wise if you have the facts. What difference in wing parameters would favor the Dora and overcome the weight and possible length influence?

Additionally, unless you have flight test comparisons between Fw 190D-9 and P-51B/C/D for turn or acceleration or roll, what factual base are you arguing from. The P-51D and B could turn with a Fw 190A. Altitude and speed would dictate which one had an advantage however slight.

If the Anton indeed out turned the Dora, as related, it is logical to conclude that the Dora DID NOT out turn a Mustang - unless you have evidence to the contrary.

However in short I wouldn't trust Caldwell when it comes to a/c performance, and that's not that he's untrustworthy, he just isn't much into this area.

Soren, unless you have the data, the Reports and the Comparisons to state unequivocally your point, neither do you (or me).

Please also bare in mind that most Dora-9's flown by JG-26 weren't equipped with the MW-50 system, so that would explain the remarks Caldwell has recieved.

That would not explain any remarks regarding comparisons between the Anton and Dora. Nor have I seen evidence that JG26 was punished by witholding MW50 systems. Where would you direct me for evidence of this?

 

[Soren]

From the P-51D P-51B POH:

Those are the official average take off distances, so obviously they're with flaps Bill. The figures you presented were calculated, the doc says so itself in the beginning.

Here are the Official German figures, the same Leistung Daten chart, and ALL the take off landing distance figures are at std. atmosphere and zero wind:

Moving on to turn rate;

First Crumpp's comparison:
FW-190 D-9

FW-190 A-8

This is real physics, and they don't change.

I'll post the German comparative remarks tommorrow.

 

[drgondog]

From the P-51D P-51B POH:

Those are the official average take off distances, so obviously they're with flaps Bill. The figures you presented were calculated, the doc says so itself in the beginning.

Two points Soren - first look to the note on the lower right side of the 51 chart you presented - highlighting that "20 degrees flaps -80% of Chart" - Obviously the table values on the left do Not represent flaps used in TO - and for what it is worth the tables you found seem accurate otherwise

Second Point. The Flight tests in June 45 by Gentile yielded Better results than the Calulated results for 2-46.

Here are the Official German figures, the same Leistung Daten chart, and ALL the take off landing distance figures are at std. atmosphere and zero wind:

Moving on to turn rate;

First Crumpp's comparison:
FW-190 D-9

FW-190 A-8

This is real physics, and they don't change.

I'll post the German comparative remarks tommorrow.

I have a lot of respect for Crump's charts and his math. I would also point out that the models presented are subject to the engine performance at different altitudes, depending on where the blowers kick in so even the models must be carefully used with all caveats discussed

They do not, however, represent anything more than a mathmatical model. Aerodynamics and flight mechanics are math models to arrive at estimates of predicted performance.

The reason flight tests are performed, other than for better understanding of the limits of aircraft, are to demonstrate the REAL physics and characteristics.

An aircraft is a complicated model. Extrapolations on lift are influenced by Wing-Body interaction, laminar flow separation, unexpected wash out, complications introduced by aeroelastic effects due to wing loads when angle of attack is changed by those loads, etc, etc.

That is why we will always be talking past each other. If you make an statement that a Fw 190D-9 out turns an Anton or a P-51D and I ask you for the Test data - and you present Gene's performance calculations - I'm interested but unconvinced for all the reasons I mentioned above.

Gene would tell you the same thing about calculations versus flight tests. The calcs lead to design, tests lead to adjustment of calcs/models to fit real life, modified models lead to next design, etc. I lived in that world, but mostly airframe structures after my first two years.

Circle back to key points.

Caldwell reproduces comments and diary from JG26 during December, 1944.

Diary expresses disappointment that the Anton out turns and out rolls the Dora, and worse does not out perform the Mustang.

You say Caldwell 'full of it' and every LW pilot knows that none of that is true.

And the debate rolled on from there. I found flight tests as late as March 1945 that refuted your top numbers, you found performance charts that substantiated yours. In all candor, I don't read German so I don't know if the charts you presented on the D were Flight Test or Theoretical calculations based on wind tunnel drag results.

and so on.

So, what do you believe substantiates your claim that the Dora was faster and out turned the Mustang? Do you have anything in the way of Flight tests or other one on one comparative tests that substantiate your claim? An anecdotal comment is interesting as part of the equation, but not the conclusive fact

You just dismissed the Calculated values from USAAF Flight Test Reports (even though the calculated figures for speed and climb were less than actual test results), but posed Gene's very nice performance charts as gospel. Why the selective embrace of one while dismissing the other?

At any rate I KNOW that the take off roll for a loaded 51 as I described it above, on a hard runway with 20 degrees of flaps is in the 1000-1100 foot range from personal experience so I had to really look at the tables you presented to try to figure the discrepancy. But by my own rules, anecdotal is interesting but not conclusive fact - I buy that.

 

[Soren]

It says "Optimum take off" which means the setting which yields the quickest take off, it doesn't say flaps werent used.

80% of 1600 ft (487 m) is 1280 ft (390m), which sounds reasonable at take off power. I'll happily believe that (1600 ft did sound a little high).

As to your personal experience with a restored P-51, well the P-51's in service were heavier as they were stacked with ammo and also different electrical systems I'd presume?

Moving on....

Regarding the calculations made by Crumpp, well I've talked to him over PM and his calculations are based on actual flight data on the a/c, stall speed, thrust etc etc.. So they are in the right ballpark, and are good for comparing a/c.

The elastic deformation of the wings is something which needs be considered yes, and it has been. Infact this very effect actually gave the FW-190's wings elliptical lift distribution in tight turns, hence the violent stall. (Elliptical lift distribution makes for violent stalls)

By looking at the power available to the Dora-9 and the lower drag it's quite obvious it was a better turn fighter than the A-8, and the German comparative reports and the opinions of the vets who flew the a/c agree with this. Actually I have a very nice original aerodynamics chart on the FW190 Ta-152 series I'll post here tommorrow when I get home, then you can see the difference between the a/c for yourself.

As for Caldwell, I never said he was full of it, I infact said otherwise. What I did say is that he has little insight into technical aspect of these fighters, where'as Dietmarr has covered this area extensively.

Finally like I said, I'll provide the German comparative report tommorrow.

PS: I really don't appreciate your accusations of bias Bill, I haven't been biased or selective I have just looked at and compared the data I have and have been made available. So I hope for the sake of this debate that you don't continue with these blind accusations, either that or I will cease to participate.