If no P-51, how would the P-40 have evolved?

I have no intention of competing in a "Urinary Olympics" it just that I dislike "caparisons" that say "plane A was as good as plane B if Plane A used XX power level" while leaving out that plane B is at XX minus 20/30%.

No need to play with airfoils or prop efficiency or adjust weights to equalize things, they were different aircraft. But if one gets to use WEP (or beyond and 70" is beyond any book WEP for an Allison in a P-40) then the other should be compared using WEP.

There is a reason the P-40 was being phased out in 1943 and it has nothing to do with politics or anything other than aerodynamics. It was a higher drag, older airframe.

Shortround6 said:

There is a reason the P-40 was being phased out in 1943 and it has nothing to do with politics or anything other than aerodynamics. It was a higher drag, older airframe.

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Didn't the Truman Committee investigate this?

I believe the Truman Committee did investigate the continued production of the P-40 but I believe it was from the point of view of why did the Army continue to buy such an obsolete aircraft for so long. Production ended November 30, 1944. A pilots manual printed in 1943 (month not given) says that no new P-40 units will be formed to go overseas and that the P-40 is basically an advanced trainer. New P-40s may have gone overseas as replacements for units already equipped or as equipment for "allied" nations but apparently the US planners at some point in 1943 had decided the P-40 had no future as a US first line combat aircraft.
Again. please remember that it could take 3-4 months for a US aircraft to make it from the factory door to a combat theater. The vast majority of US fighters went overseas by ship.

krieghund said:

And don't forget the airfoil differences between the them as well as prop efficiencies, etc. This could wind down into an Urinary Olympics.

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It could, with the Mustang pissing till St. Paddy's day!

I very strongly disagree with yout assertions above, Shortround, but then again, maybe you never flew in both a P-40 and P-51. They aren't that far apart below 15,000 feet, and I might even prefer the P-40 below 10,000 feet.

Add an altitude-rated engine and it could very easily be the other way. Don't dismiss it until you have flown both. The P-40 is every inch a good fighter when flown below its critical altitude.

I have flown neither. Have you flown either at Military power or WEP levels?

Unless somebody has been lying about the test results the P-40 was a lot slower than a Mustang, at any level, however nice the P-40 maybe to fly.

" The P-40 is every inch a good fighter when flown below its critical altitude".

I am not saying it wasn't. But "good" is not "best". And "good" in 1943 could mean less than second best in 1944/45.

Comparison saying the P-40 was as fast or faster using 70" of MAP than a Mustang using an unknown amount of MAP doesn't tell us anything except the P-40 pilot was very, very low and beating the crap out of his engine. Unless I am mistaken the "book' figure figure for WEP for a later Allison (9.60 supercharger gear) used in a P-40 N was 57". Book figure for a P-40K with a V-1710-73 (8.80 supercharger gears) was 60" which it could hold to 2500ft. Allisons could stand a lot of abuse and were, without a doubt, flown at times beyond book figures. That does not mean the airframe they were in was as good or better than another airframe being flown at the time with an engine that was NOT being thrashed. Please note that the engines/planes with 8.80 gears might not be able to even pull 70" at ANY altitude without over revving the engine.

I am not talking about aileron response or turning circle, both of which are very important. Granted the Merlin powered Mustangs have a bit more drag than the Allison powered ones and need a bit more power down low to get the same speeds but the Allison Mustang is 40-50mph faster than a P-40 with the same engine. That should say something about the drag of the P-40 airframe. Sticking an altitude-rated engine into a P-40 airframe isn't going to lower the drag, if anything it will increase it unless it is a simple change in supercharger gear ratio

Shortround.

Except in the Pacific, WWII was a mostly a high-altitude war. In Europe, most combat happened at 20,000+ feet because that is wheere the bombers were flying and the fighters were there to either attack or defend the bombers. To me, in Europe, "Down Low" means 10,000 - 15,000 feet. The P-40 was a great diver, one of the best rollers on the Allied side, and could take punishment. It also had a 9-g airframe.

People tend to remember the Zero as "the best of the early war," and fail to rememebr that the P-40 beat the Zero at almost every turn. The kill-to-loss ratio of the AVG was about 70:1 versus the Japanese. Yet the P-40 is denigrated. It held the line in North Africa and did not have a bad racord against the Me 109. It was, in fact, a winning record.

You mentioned the XP-40Q had four guns ... correct, as usual. Production version were to have either six 50-cal (12.7 mm) MG or four 20mm cannons. It wasn't selected for production solely due to the fact that the P-47 and P-51 were already in production and doing the job quite well.

As I said earlier, I think the P-40 had great potential for development. You disagree and we can leave it at that. In the real world, Curtiss never did get the development past the XP-40Q, which was a pretty darned good fighter in my book. Since it wasn't acquired by the USAAC, we'll never really have an opportinity to compare it with the deployed fighters in a WWII combat situation. The same can be said of quite a few really good prototypes. The Boeing F8B comes to mind, as does the Chance-Vought XF5U-1, which was built but never flown! With a pair of R-2800's, it wasn't short on power. The CAC-15 also never got a chance, and there are many more, so I suppose the XP-40Q is in good company as a plane that could have been a good one but never got the chance.

Of course, there were also some turkeys, such as the Curtiss XF14C, which flew but was disappointing even wghen fitted with the eventually mighty R-3350.

Again, we'll have to agree to disagree. I like the P-40 and you obviously do not. So be it. I get to see one operated regularly alongside P-51D's, a P-47, a P-38, an A6M5 Model 52 Zero etc at the museum and I must say, it has been robust and reliable, if only a P-40.

Regarding Trebor's post # 28, he must not have a grasp of the P-40 at all. It was one of the most maneuverable Allied fighters at 250 - 350 mph below 15,000 feet and definitely among to top two rollers. It could not match the Zero at low airspeed in pitch (and nothing else could, either), but if the fight got to 300 mph, the P-40 was definitely at an advantage. It might have been not too fast, and the rate of climb might have been a bit low, but unmaneuverable? I don't think so, and neither did most of its pilots or most of Me 109's the P-40 happened to have gotten into a turning fight with.

GregP said:

People tend to remember the Zero as "the best of the early war," and fail to rememebr that the P-40 beat the Zero at almost every turn. The kill-to-loss ratio of the AVG was about 70:1 versus the Japanese. Yet the P-40 is denigrated. It held the line in North Africa and did not have a bad racord against the Me 109. It was, in fact, a winning record.

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No one can dispute the AVG's record even in the most conservative terms, but let's not forget the AVG never fought the Zero.

the avg P-40 get very good results vs type 1 army fighters but others P-40 USAAF units not get superiour result v/s Type 1 or Zero.
in NA the P-40 not winning the comparison with 109

GregP,
"Except in the Pacific, WWII was a mostly a high-altitude war. In Europe, most combat happened at 20,000+ feet because that is where the bombers were flying and the fighters were there to either attack or defend the bombers. To me, in Europe, "Down Low" means 10,000 - 15,000 feet. The P-40 was a great diver, one of the best rollers on the Allied side, and could take punishment. It also had a 9-g airframe."

Don't forget the Eastern Front, I've read the Soviet pilots thought well of the P-40 in air to air combat - more so then the Hurricane or the P-39 or even their own MiG-3.

"People tend to remember the Zero as "the best of the early war," and fail to remember that the P-40 beat the Zero at almost every turn. The kill-to-loss ratio of the AVG was about 70:1 versus the Japanese. Yet the P-40 is denigrated. It held the line in North Africa and did not have a bad record against the Me 109. It was, in fact, a winning record."

I agree with you, I don't think the AVG flew, as is the common belief, an obsolete aircraft. The P-40 was in most ways superior to the JAAF aircraft it faced in 1941-42. Recent research has questioned the AVG's kill claims, by a lot. I don't believe this detracts from their reputation.

"You mentioned the XP-40Q had four guns ... correct, as usual. Production version were to have either six 50-cal (12.7 mm) MG or four 20mm cannons. It wasn't selected for production solely due to the fact that the P-47 and P-51 were already in production and doing the job quite well."

And it was common for the P-51 to have 4 guns on long missions.

Vincenzo said:

the avg P-40 get very good results vs type 1 army fighters but others P-40 USAAF units not get superiour result v/s Type 1 or Zero.
in NA the P-40 not winning the comparison with 109

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According to Girbigs book JG27 the German pilots rated even the Hurricane higher than the P-40 not talking about the Spitfire which was rather rare in NA.
cimmex

FLYBOYJ said:

No one can dispute the AVG's record even in the most conservative terms, but let's not forget the AVG never fought the Zero.

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It annoys me that even in more recent books pilots of the CATF and the 14th AF still refer to the "Zero's" they encountered.
According to another thread Daniel Ford extensively researched his 2007 edition of "Flying Tigers, Claire Chennault and His American Volunteers, 1941-42". His conclusion is that the Tigers actually shot down just over 1/3 of the planes they are credited with but goes to lengths to say this in no way detracts from their acheivements.

Greg - do you have any factual sources in the form of a complete Test report on the P-40Q? Details like Gross weight at Take Off, fully combat loaded/not loaded, Critcal altitude of the Allison 1710-121(?) as tested, Hp at speed run altitudes, etc?

Neither the P-40F with the 1650-1 or the P-40N w/1710 @ 57" were remotely close to P-51B (or the heavier D) in any comparison except roll rate and turn (at or below critical altitude). There was nearly a 50mph differential at SL for Allison P-40 at 57" and P-51B at 67" and much worse above Critical altitude of the Allison.

Nobody in the PTO/CBI were wildly enthusiastic about dogfighting a Zero, even though a good pilot could Yo-Yo at high(er) speeds to get parity with the Zero. Nobody was recommending dogfighting the Zero - universally the recommendations were to make high speed pass and keep your speed up in the fight. As soon as you sustain a turn airspeed bleeds off rapidly into the Zero's stike zone for both turn and climb, where even roll is near parity.

John Landers couldn't get away in his P-40F over Rabaul and he was a pretty damn good pilot.. I know several aces who were confident in beating Zero's in meduim speed manuevering but the IJN in general, almost universally held the P-40 in contempt for dogfighting. Ditto LW pilots in 109F and 109G but the P-40K and above scored reasonably near parity in North Africa early 1943... as contrast to P-51B vs Me 109G series.

P-40 get bad result v/s 109 in NA, Nikademus posted from Shore's books: P-40 (US&allies) losses vs 109: 522, 109 losses vs P-40 (US&allies): 206

The XP-40Q's were made from P-40K airframes. They had revised cooling systems, two-stage superchargers, had the turtledeck removed, were fitted with bubble canopies, and a 4-bladed prop. The first XP-40Q was S/N 42-9987. The other two were 42-45722 and 43-24571.

Later, the wingtips were clipped. The engine was the Allison V-1710 fitted with water injection. 20,000 feet could be reached in 4.8 minutes in the XP-40Q-3. Service ceiling was 39,000 feet. The XP-40Q-1 had the V-1710-81 and was later fitted with a -101, 2-stage supercharger unit. Data from Dan Whitney's Vees for Victory. The XP-4Q-2 could climb at 3,800 feet per minute at 13,000 feet and reached 20,000 feet in 6 minutes. The XP-40Q-3 had a V-1710-121 engine of 1,425 HP. War Emergency power was 1,700 HP at 26,000 feet at 3,200 RPM and this was the aircraft that could make 20,000 feet in 4.8 minutes

As for the German opinion of the P-40 in the desert, Tomahawks claimed 77 aircraft destroyed between June 1941 and May 1943. Kittyhawks claimed 206. Total P-40 claims in the desert for that timeframe were 283 against a loss of 100 aircraft.

Was it a great fighter? Not particularly, but it had enough good qualities to render it a dangerous opponent for any other opponent it encountered and I believe it DID have good potential for development.

WW II covered almost 6 years. The P-40 was built is about 4 major sub variations and lots more minor sub-variations. It was in production for 4 years and 7 months. It was not the most advance fighter when it went into production but was the best fighter the US could into production in a hurry. The P-40 was not wanted by the British as a fighter in Europe in the "B" or "C" versions. It may have done well against the Italians in NA and this is the Version the Flying Tigers used to establish their record against the Japanese. These early Versions did good work in holding the line and perhaps did more than was expected of them. The D/E version starts to show up in Aug of 1941 and is a worthwhile improvement. The "F"s that start to show up in Jan 1942 are another improvement but the world standard is moving. The "E" "F" ( and the K L) also help hold the line and do much good work in North Africa and the Pacific and the Russian front. But in many cases they are already being used as short range strike aircraft and not air superiority fighters. They can often hold their own after bombs are dropped but are also often given top cover and/or escorted which should tel us something. The late "L"s and early "N"s resort to stripping out operational equipment ( guns, ammo, fuel tanks, electric starting motors, etc)) in an effort to improve performance. These "Stripper" models start coming of the production lines in Jan-mar of 1943 which should also tell us something about how the performance of the regular P-40 was viewed in the fall/winter of 1942. The P-40s continue to give good service but not in the air superiority role ( which does not mean they did not engage in air to air combat, only that it was not usually it's primary role).
I have no Problem with the P-40 or it's war record from 1940-43. I do have a problem with the 1715 or so P-40s built in 1944. I also have a problem with some people trying to make the P-40 into something it was not. It was a stop gap fighter from day one and while it was a good stop gap fighter (perhaps one of the best stop gaps in any force) the gap had been stopped by Jan of 1944.
I will freely admit that trying account for the P-40s combat performance vs it's "book" performance is one of the hardest allied fighters to work with. The USAAC didn't officially sanction WEP or WER ratings until Dec of 1942 While many British and more than a few US units did use 55-60in of MAP instead of the "book" 44-45" during this time. This coupled with (until now?) a scarcity of official tests results leaves a lot of guess work as to actual performance or comparisons.

As far as the P-40 vs Mustang thing goes, the British never used the P-40 as a fighter ( or for much of anything else) from England or North West Europe. They were still using 5 squadrons of Allison powered Mustangs on D-day and still had 2 squadrons of Allison powered Mustangs at VE day. Photo recon planes or not that seems to indicate a level of performance not achievable by the P-40.

GregP said:

T
As for the German opinion of the P-40 in the desert, Tomahawks claimed 77 aircraft destroyed between June 1941 and May 1943. Kittyhawks claimed 206. Total P-40 claims in the desert for that timeframe were 283 against a loss of 100 aircraft.
.

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this numbers are very strange too far from Shore's book data (obviously i'm talking of P-40 losses, their claims have not value).

The XP-40Q's were made from P-40K airframes. They had revised cooling systems, two-stage superchargers, had the turtledeck removed, were fitted with bubble canopies, and a 4-bladed prop. The first XP-40Q was S/N 42-9987. The other two were 42-45722 and 43-24571.

Later, the wingtips were clipped. The engine was the Allison V-1710 fitted with water injection. 20,000 feet could be reached in 4.8 minutes in the XP-40Q-3. Service ceiling was 39,000 feet. The XP-40Q-1 had the V-1710-81 and was later fitted with a -101, 2-stage supercharger unit. Data from Dan Whitney's Vees for Victory. The XP-4Q-2 could climb at 3,800 feet per minute at 13,000 feet and reached 20,000 feet in 6 minutes. The XP-40Q-3 had a V-1710-121 engine of 1,425 HP. War Emergency power was 1,700 HP at 26,000 feet at 3,200 RPM and this was the aircraft that could make 20,000 feet in 4.8 minutes

So, what was the weight during these speed trails, any armament/ammo installed, new wing span/area? Runs made at WEP? was critical altitude 26K? if not, what? as and FYI this airframe should immediateky be compared to XP-51J, XP-51H and XP-72.

As for the German opinion of the P-40 in the desert, Tomahawks claimed 77 aircraft destroyed between June 1941 and May 1943. Kittyhawks claimed 206. Total P-40 claims in the desert for that timeframe were 283 against a loss of 100 aircraft.

Our claim to credit process in NA not as good as ETO. German loss records were pretty good and their records show far fewer losses to all causes than we claim for air to air combat. It really has nothing to do in comparing performance but a lot regarding 'opinions held' by German pilots. The DAF claim to LW loss reporting seems to be closer, and LW claims to credits were also way overblown.

Drgondog, I am not the world's foremost authority on the XP-40Q. I have what I have found that has been written, and all of them give the test results only. If I find it, I'll post it. I do know that the V-1710-121 engine had the auxilliary supercharger unit installed and made good power at high altitude. At our Allison shop in Rialto, CA, we have TWO aux stages ready for a customer's aircraft. They are very neat units, but I still would prefer an iintegral 2-stage, multi-speed supercharger. Unfortunately, they never made one for the Allison.

But I would not hold my breath if I were you. People may spend yesrs documenting a favorite aircraft, but hardly anyone researches a plane that didn't make production and of which they only made three ... unles it is German. If si, then we find new flight test data 70 years after the fact.

Vicenzo, if the claims are worthless, then the repoarted losses are worthless, too. Both come from the same Air Force. You're saying one number is good but the other is junk? You can't choose only the data you want to believe, Vicenzo. You have to look at the aggregate data, whether or not it supports your theories. I don't see anyone in here saying the Italian Air Force claims should be disregarded, so why are you arguing about reported P-40 claims? Are you saying all claims are worthless or just Allied claims?

We've had these claim wars before and most everyone overclaimed a bit, but not horribly so. Regardless of the arguments, I recognize the numbers that are accepted by the respective Air Forces on both sides. You, of course, can do as you see fit, but you can't dismiss Allied claims and then turn around and accept Axis claims or you will lose your credibility in here. If you reject some, then you just started an enormous research project for yourself, Good luck.

The fact of the matter is the P-40, while not a first-rate, front-line fighter, held its own in battle with Axis aircraft all over the world until better types came into service. That is not in dispute by anyone who is based in fact.

Greg - losses reported by both sides are far more relaiable than claims/credits simply because your aircraft returns or it doesn't - or it returns bady damaged and is salvaged, or it returns damaged and repaired.

If the Command authority asks the Group for a maximum effort count there is no escaping lost or damged aircraft and crews -