p 40

A better sport plane might be a Curtiss Wright CW-21 or 22.



At least you can take a friend with you!

Sweet looking ride!

P-40 variants were slower and climbed slower than contemporary P-39s.

Combat ceiling (climb at 1000fpm) was under 20000' for a clean P-40.

Merlin P-40s offered much improved performance, abut the same as contemporary P-39s.

P-40 was just too heavy at 8400lbs, and could not be lightened enough to improve performance substantially.

The two stage Allison was in production by April 1943. This engine would have made the P-40 competitive with contemporary Axis and Allied planes. Not to be.

Yet the P-40 fought all through the war and did WAY better than the P-39 did in the actual war. For the ETO alone:

1) The P-39: flew 30,547 combat sorties (2.5%) of combat sorties; 107 combat losses; had 14 air kills and 18 ground kills; kill-to-loss ratio: 0.3.

2) The P-40: flew 67,059 combat sorties (5.48%) of combat sorties; 553 combat losses; had 481 air kills and 40 ground kills; kill-to-loss ratio: 0.9, or 3 times that of the P-39.

I don't have these numbers for the entire war for all types. They came from Ray Wagoner's American Combat Planes.

Look at the Statistical Digest of World War II, Table 84:
In Dec 41 we had 938 P-40s on hand and 609 P-39s. By Dec 42 we had 2,133 P-40s on hand and 1,116 P-39s. The P-40 had grown to twice as many P-40s as P-39s in one year. By Dec 43 we had 2,245 P-40s on hand and 2,00149 P-39s ... virtual parity that didn't last. By Dec 44 we has 1,716 P-40s and 746 P-39s on hand. By Aug 45 we had 116 P-40s and 22 P-39s on hand. So, the P-4 was ALWAYS better thought of than the P-39 was except when they ordered the P-39s initially.

In total, the P-40 has a solid combat reputation in the U.S.A. and the P-39 doesn't. I'm not making that up; it's history.

Don't leave out what the Soviets did with the P-39 in Europe. They knew the P-39 was better in almost every respect than the P-40. Half of the P-39s manufactured went to the Soviets.

The data on the P-39 in Soviet service are virtually unavailable from primary sources available to me, and I was talking about both airplanes in US service. Foreign service is another subject that is a long and winding road, possibly with little information at the end.

I don't know ANYONE who has complied service of the P-40, A-20, B-24, B-17, etc. in the service of all the counties they served with. Do you? If so, what data did they use? In U.S. service, the P-40 was a good if not stellar performer, especially in lower-priority theaters of operations. The P-39, by contrast, was unloved by almost all of those who operated it outside of the Soviet Union.

GregP said:

The data on the P-39 in Soviet service are virtually unavailable from primary sources available to me, and I was talking about both airplanes in US service. Foreign service is another subject that is a long and winding road, possibly with little information at the end.

I don't know ANYONE who has complied service of the P-40, A-20, B-24, B-17, etc. in the service of all the counties they served with. So you? If so, what data did they use? In U.S. service, the P-40 was a good if not stellar performer, especially in lower-priority theaters of operations. The P-39, by contrast, was unloved by almost all of those who operated it outside of the Soviet Union.

Click to expand...

Chuck Yeager loved the P-39

Yes, it was in his autobiography. I surmise it was the highest-performance aircraft he had flown up to the time when he flew it in training. And, in training, they didn't practice high-altitude dogfighting.

He may have loved it, but I bet he would NOT have chosen it for combat in 1944!

P-39 Expert said:

The two stage Allison was in production by April 1943. This engine would have made the P-40 competitive with contemporary Axis and Allied planes. Not to be.

Click to expand...

Small scale production while they sorted out the WEP problems. large scale production did not start until the fall of 1943.

The tests of the P-40Q say otherwise. It was around 20mph slower than a P-51 using the same power at the same altitude.
And the P-40Q was carrying less ammo and less fuel than a P-51. Granted the P-51 was the Best the US could make at the time but switching priorities or types would have gained very little.
BTW the P-47D with water injection and paddle blade props was faster at the higher altitudes and carried a lot more ammo into the fight.

Hmmm....thread title = p-40.

Current discussion = P-39.

I voluntarily grant this thread a +1 from my own funds so it can return to its rightful subject matter.

Mein Gott, murmeltiertag!

I think 20 mph is relatively unimportant in combat since almost all fights that weren't by ambush started from cruise speed (or speed in an expected-combat zone) and accelerated until combat was joined, which wasn't generally very long from when the throttle was advanced from cruise power. Combat very rarely got to max speed unless in a prolonged dive. For kills made from ambush, speed was unimportant since the victim never saw the attacker until he was hit. I'd argue that the P-40Q was likely a better dogfighter than any P-51 ever was, especially at higher weights such as when loaded for long range escort, but it was never going to supplant the Mustang in long-range escort duty.

Of course, the dogfighting statement above is an opinion, not an established fact. I say it because the production P-40 could always out-turn a P-51. They didn't select the P-40Q for production, but it would NOT have been a bad choice unless the primary mission was long range escort. The P-40s they DID produce fought in all theaters, so its hard to argue it wasn't going to be suitable since, at least historically, it WAS suitable enough to be employed.

Saying that does not nor is intended to detract in any manner from the stellar job the P-51 family did during the war. The post is intended to address the potential P-40Q, not to detract from the P-51.

We have been over this before.

Top speed is an indicator.

Assume that both the P-40 and the P-51 are doing 380mph.
The P-40 has whatever power the extra 40 mph represents to climb, maintain speed in a turn or whatever.
The P-51 has whatever power the extra 60 mph represents to climb, maintain speed in a turn or whatever.

P40Q prototype went 9000lbs and that was with four .50 cal guns and 235 rpg.

Not saying the P-40Q was bad, it simply didn't bring enough to the table (or soon enough).

I have no idea if the P-40Q was going to be worth a hoot or not, but I cannot deny it's a great-looking bird. "If it looks good, it flies good" seems to be something we hear a lot, and by it's looks, it should have been a great aircraft, but it wasn't going to happen. I'd never even heard of it until you posted a picture of it some years ago, but I admit the picture practically took my breath away, it is a wonderful looking bird.

Hi Shortround,

You say we have been over this before, but what really happened is you stated your opinion ... which generally is pretty good. I didn't necessarily agree except that the P-51D was a great airplane.

The prototype XP-40Q-2 came in at 9,000 pounds and the P-51D regularly flew at 12,100 pounds at takeoff for long-range missions. Even for mid-range missions, it flew at about 10,500 lbs.

Let's say we have a P-51D Mustang at 10,500 lbs making 1,490 hp, and it can climb at 3,510 fpm. At 12,000 lbs, it SHOULD climb at 3,070 fpm. The power required for level flight should be about 373 hp against a maximum of 1,490 hp.

Let's say we have an XP-4Q-2. It comes in at 9,000 lbs and can climb at 4,110 fpm (I have seen 4,400 fpm reported at 75" MAP) at 1,425 hp and 75" MAP. The power required for level flight should be about 304 hp against a maximum of 1,425 hp. The engine COULD make 1,800 hp, but the test line I am looking at was run at 3,000 rpm, not 3,200 rpm (yes, there IS a 3,200 rpm line), so the power during the climb test was not 1,800 hp.

Theoretically, they SHOULD be fairly close with the XP-40Q-2 being very slightly slower but climbing better at high power. The tests absolutely did NOT show the XP-40Q to be a bad airplane. It would easily out-turn a P-51D. The climb charts in the test report show very similar climb at 20,000 feet to the P-51D. Regardless, The P-4Q wasn't ever going to be a long-range fighter in the test configurations flown.

I'm not trying to be a P-40Q fanboy, but it seems to me as if it would have been a pretty decent fighter, if not a long-range fighter, and I'm not dismissing it as a failure just because it wasn't selected for production. That's all I'm saying ... that the XP-40Q was pretty good, even if not put into production. I'm not even suggesting is SHOULD have been produced since the P-51 family was doing just fine and came out of the war as a great airplane. But, if the P-40Q HAD been produced, it would most likely have done just fine in combat in ANY theater.

That's my opinion only since any production P-40Qs would be "what if" airplanes. I can't say for sure, of course, but neither can any detractors say for sure either. Let's call it a " might have been" and let it go. I mention it only because the XP-40Q came up above.

Cheers.

At this point in the war the p-40 wasn't being measured against the Mustang. But rather the p-80 and other jets. Extensive development of a prop plane was only going to be done if it addressed a very specific problem.

Shortround6 said:

We have been over this before.

Top speed is an indicator.

Assume that both the P-40 and the P-51 are doing 380mph.
The P-40 has whatever power the extra 40 mph represents to climb, maintain speed in a turn or whatever.
The P-51 has whatever power the extra 60 mph represents to climb, maintain speed in a turn or whatever.

P40Q prototype went 9000lbs and that was with four .50 cal guns and 235 rpg.

Not saying the P-40Q was bad, it simply didn't bring enough to the table (or soon enough).

Click to expand...

Also that 20MPH difference would apply to almost the whole rev range, the Spitfire was 30MPH slower than the P-51 with the same engine. This made little difference in mock combats, but it also went 30MPH faster on cruise settings too, meaning it travelled 30 miles further each hour.

pbehn said:

Also that 20MPH difference would apply to almost the whole rev range, the Spitfire was 30MPH slower than the P-51 with the same engine. This made little difference in mock combats, but it also went 30MPH faster on cruise settings too, meaning it travelled 30 miles further each hour.

Click to expand...

A 30 mph advantage was more worth in real combat than it was in mock combat.

I have heard that a slight speed difference makes a significant difference in combat in here, but not from real fighter pilots who were there, and I've asked more than a few.

They were more concerned about not getting surprised by an unseen enemy airplane while pursuing another one and were always wanting the altitude / position / maneuverability advantage. To them, speed was sort of like money ... it was only important when there wasn't enough of it. About half wished for heavier armament and better climb.

Just a wee interjection about the P-40, holistically speaking. It was the primary fighter of Commonwealth air forces and served them all very well. The P-40E was a hotrod compared to their previous fighters, but improvements made to the design revealed that it was definitely a pre-war design mated to a modern engine in a bid to maintain relevance. Unlike the Spitfire and Bf 109, it had limited growth potential when and where it mattered, without major structural redesign. The war and whatever else was going on at Curtiss affected the fortunes of the P-40 and it never was able to match better types entering service. Later P-40 models, such as the 'M were poorly built and equipped and suffered from lagging performance compared to their contemporaries later in the war but were available in numbers, so the likes of the Commonwealth air forces held on to them, even when they had access to better types.

P-40 still