Why did the P-40 lag behind?

[Shuckins]

Hello guys, it's been a few years since I logged in on these boards.  Hope some of you still remember me.   

I'm kind of surprised that nobody has mentioned the fact that the P-40 wasn't designed from scratch to be an inline engine fighter.  It's a direct offshoot of the P-36, which was a radial-engined fighter.  When the Army Air Corps realized that the P-36, which had outstanding handling qualities and maneuverability, could not stand up to the new high-performance inline engine fighters emerging in Europe, they pressured Curtiss to produce a fighter that could compete with these more modern designs.

Curtiss' answer to this request was to cobble together the P-36's fuselage with an Allison inline engine.  Sometimes such a mating of disparate factors can yield a superior aircraft, but such was not the case with the P-40.  As some have said, the chin scoop was not properly designed for drag reduction and the lack of a two-stage two-speed supercharger made the P-40 a dog at altitudes above 15,000 feet.

Some have suggested that the only reason it was kept in production throughout the war was because of the pull that Curtiss had with those in charge of procurement, and because it filled a "niche" in our wartime needs.  The first of these reasons is entirely probable, but the second I find hard to accept, for there were more than enough superior aircraft being produced by other manufacturers to fill the P-40's "niche".

Regards, Shuckins

[Pongo]

Surprising that it didn't occur to CW and the airforce to really make a world class P36 decedent. They might have eventually come up with some interesting aircraft.

[33Vortex]

Wasn't there a radial powered Mustang somewhere in between all testbeds too?

[Krusty]

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..I just threw up in my mouth a little....

[BaDkaRmA158Th]

Surprising that it didn't occur to CW and the airforce to really make a world class P36 decedent. They might have eventually come up with some interesting aircraft.
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"The Floppy Fish." 

[Widewing]

Surprising that it didn't occur to CW and the airforce to really make a world class P36 decedent. They might have eventually come up with some interesting aircraft.
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There were so many issues with the XP-60 series that the USAAF had no interest when the YP-60E was delivered. Curtiss demonstrated little interest as well, having flown the aircraft only twice. There was no need for this fighter, and its limited range made it unsuitable for escort work. Performance was good, however. The single prototype was powered by the same R2800-18 that was installed in the Vought F4U-4. During its second and last test flight, the YP-60E managed a climb rate of over 4,100 fpm in MIL power. WEP was never used during either of the two test flights. Curtiss estimated a maximum speed of 434 mph @ 27,500 feet, and 424 mph at 22,000 feet, both using combat power. 406 mph @ 24,500 feet at MIL power. No estimate is known for climb using combat power, but some experts have stated that 4,500 fpm was within reason.

[Pongo]

just answering the OPs question, since no one else seemed to know.

[Daubie]

Now, there's an old saying that "if it looks right, it'll fly right", and to my eyes the P-40 always looked right. Not just the shark mouth, but the sleek lines and the pointy prop spinner, although I admit the undercarriage could have done with some work. Nonetheless it looked like a modern, high-performance monoplane fighter, but all the way throughout the war its performance lagged behind its contemporaries, less so as time went on but still enough to tarnish its historical reputation. I understand that earlier versions had a limited supercharger that neutralised its high-altitude performance, but even when fitted with Merlin engines and lightened the aircraft always seemed to be a few dozen MPH slower than the competion, a thousand feet per minute less sprightly. Having said that, it's impressive that a design dating back to the days of the Hawker Hurricane was still getting kills in 1945,* and it seems to have defenders, not least because it has always been kicked around like Richard Nixon.

So, was the P-40 doomed by a fundamental, insurmountable design problem - perhaps an aerodynamic deficiency - or was it just limited by a combination of things that individually might have been debugged, but collectively held it back? Was there enough horsepower in Christendom to make it a worldbeater, or could it have been tidied up aerodynamically, a la the Bf-109F? I surmise that the scoop didn't help, but other, faster aircraft also had large chin-mounted scoops (the Typhoon springs to mind, although the Tiffie had considerably more horsepower). The P-40Q turned it into something almost but not quite as good as a contemporary P-51, by essentially replacing everything except the cockpit seat, but by that time the P-51 existed, and so the P-40Q was abandoned.

This intrigues me because, in most other cases, I can see why other early war fighters couldn't keep pace with technological developments. The Zero relied too much on light weight and a big wing for its performance, and when the aircraft was fitted with armour and self-sealing tanks it was no longer lightweight, and the big wing held back its top speed; the Hurricane's frame construction meant that it was just too heavy, with a thick wing; the 109 was too small to contain the equipment it needed to perform a relevant role as the war progressed without modifying the structure to such an extent that it was no longer sleek, which necessitated a larger, heavier, more powerful, torquier engine that taxed the landing gear and the wings, thus creating a kind of negative feedback loop, etc. In contrast the P-40 was at least capable of great speed in 1940, in a dive, and the basic design looked good.

Reading up on its history I get the impression that the earlier YP-37 - a long-nosed P-36 mod based on a turbo-supercharged Allison V-1710 - would have been a wiser long-term choice, but I'm sure they had their reasons for cancelling it, not just the awful cockpit view.

* Which seems to be about a year longer than the Hurricane itself (the last confirmed Hurricane kills I have read about were in 1944).

I've seen this before here, to Aces High.

In reality, real life, most aircraft involved, is what is the application?  What is the enemy aircraft it is fighting against?  And then the engineering mods to that end.

Chenault's pilots did very well with the P-40 at the time of what and who they were fighting against in the early war time period.  That was before Pearl Harbor?

The military usually does it about right.  Like sending the winter time, mountaineering, ski troops of the 10th Mountaineering Division to Italy in the summer time and as to my own experience, lots of other examples exist.  Wonder if it has changed much in later wars?

[Widewing]

Chenault's pilots did very well with the P-40 at the time of what and who they were fighting against in the early war time period.  That was before Pearl Harbor?

The AVG didn't see any combat before Pearl Harbor. I believe their first combat was on December 20, 1941.

[Daubie]

The AVG didn't see any combat before Pearl Harbor. I believe their first combat was on December 20, 1941.

(Personal thanks to Widewing for teaching me CV landings, way back when.)  It is funny watching how most guys here try to land on a CV.

Eastern Long Island---Gruman?

[vafiii]

For me the P-40 does not look like a modern fighter compared to other planes of it's era. Remove the shark mouth paint job and it's down right ugly. I've been to air shows where they have operational P-40's and it looks like a poorly designed early war fighter. In fact, most of the American planes, other than the P-51D, are down right ugly when compared to a Spitfire, 109 or 190. It reminds me of the old muscle car days of the late 60's & early 70's when American cars were big & bulky and designed to go straight and fast, whereas European cars were sleek and maneuverable. I liken the P-51D to the American Corvette. They were both fast and looked great but neither one could do much more than go straight. 

[Brooke]

In terms of beauty, I think that the P-51, Spitfire, FW 190, Typhoon, and the P-38 are nice looking.  I don't think that the 109 is all that attractive (canopy detracts until later versions, and then the later versions have too many odd-looking bumps and protrusions).  I like the plane, but I don't think it's pretty.  The P-40, to me, is not at all ugly but a decent-looking plane.

Assuming that HTC got the modelling of the P-40 right (which is what I always assume, since they do a lot of research on planes and use lots of actual flight-test data), the P-40 is quite a good plane against Japanese aircraft.  It is better in scenario situations than Hurricanes, Brewsters, and Zeros in my opinion.