SHOULD the P39 have been able to handle the Zero? Was it training or performance?

[DarrenW]

You and I have a running battle about the weight of the P-39N.



.View attachment 488539

Geez I hope this hasn't turned into something other than just a good natured disagreement? And while I haven't seen EVERY test report on the website (I have a life too), I can say that it would be incorrect to lump all of them in together as having "lightened" test aircraft. The only documents that I have examined in great detail are those of the F6F Hellcat (no surprise). And while there have been testing performed at varying weights, the vast majority of Hellcats tested were in a "fighter overload" condition. This means maximum internal fuel and ammunition load (for machine guns only). This amounts to roughly 12,400lbs (the gross weight of an F6F-3 as given by the manufacturer). I do agree that there is test data where the loaded weight of some Hellcats was less than this standard, but this situation was more of an exception than the rule.

 

[Peter Gunn]

! Uh, Mmmmm? Here we go...I am not saying that the P-39N was God's gift or anything
like that, but since you brought the P-51 in early/mid+ 1943 into the conversation and assumed
IT was all that:
Atitude / MPH / FPM
P-51A vs. P-39N
S.L.......376/3500 vs. 344/4140
1000m.387/3625 vs. 362/4275
2000m.400/3750 vs. 381/4410
3000m.412/3405 vs. 398/4085
4000m.413/2925 vs. 394/3620
5000m.410/2455 vs. 388/3160
6000m.405/2025 vs. 382/2705
The Russians didn't care up higher altitudes.
The P-39N could outturn the P-51A pretty much at any speed.
The P-39N could out roll the P-51A (probably up to 300 mph.) The D-1 could up to 263 mph.
and I believe the Ns acceleration into the turn was improved from the D's.
Power loading of the two fighters at combat weights= 5.405 vs. 5.122 lb./hp.

P-39 blah, blah, blah... those were not my words.

Truth is guys, I agree that the P-39 was not made for the ETO or the PTO. But it was an
excellent addition to the VVS in 1942-1944.

Two things my friend, first, which would you want to take into combat? Don't quote numbers, if you asked an AAF fighter pilot which he'd prefer I doubt it would be the P-39. No RAF pilot with two brain cells to rub together would, of that I would bet the farm... as did the RAF.

Second, you seemed to have missed my point entirely.

 

[Shortround6]

When looking at some of these tests the date and purpose of the test (not always stated) have to be taken into account as these were not all standardized tests with same goal/objective in mind.
And "standards" changed over time.

You also sometimes have to take into account the original specification of the aircraft. AS I pointed out, the P-40E, had a 'design" weight.
This had gone up from the earlier P-40s. The Original P-40 had a design gross weight of 6782lbs. This included two .50 cal guns and 380rpg of 50 cal ammo. NO .30 cal guns, it included 120 gallons of fuel although tankage was provided for 181 gallons (unprotected).

In order to maintain the load standards, especially in peace time, the aircrafts structure has to be beefed up as it gains weight and the P-40 gained an awful lot of weight. Once the shooting started they didn't pay quite as much attention to the load standards on the older planes. But until they get a good idea of what is going to happen they flew first test flights or performance tests at DESIGN weights in order to get baselines.
It took a while for combat experience to sink in too. For example in the summer of 1942 the US has about zero combat experience with land based fighters fighting anybody or what ranges will be needed. It takes until the Fall/winter of 1942for the combat experience of North Africa, New Guinea and Guadalcanal to sink in.

 

[P-39 Expert]

You may want to recheck your figures,
For example the design gross weight for a P-40E was ..............wait..............8011.5 lbs as per the pilots manual.

This included a 180lb pilot instead of the late 200lb pilots but heavier than the 160lb pilots in the P-39
it included only 120 gallons of fuel, tank behind pilot was not full. But the rear fuselage tank on the P-36/40 has a long and somewhat twisted history/use.
IF you fly at over 8011lbs you no longer have the 8 "G" service load/12 "G" ultimate load margins.
BTW a P-40E wvwn with full internal fuel was closer to 8259-8300lbs than to 8400.

I can't be bothered to look up the rest.

That's good because most all the sources out there quote different weights. 8400# was most common in my readings.

But every one of the tested planes was light vs. published weights. Had to be something to do with fuel.

 

[P-39 Expert]

Two things my friend, first, which would you want to take into combat? Don't quote numbers, if you asked an AAF fighter pilot which he'd prefer I doubt it would be the P-39. No RAF pilot with two brain cells to rub together would, of that I would bet the farm... as did the RAF.

Second, you seemed to have missed my point entirely.

There's another P-39 graph a few pages back that shows P-39Q (no wing guns) just about 10mph slower. If it was me flying, I will almost always take the highest climb rate. The N outclimbs the P-51A substantially at all altitudes and 650fpm at 20000'. And only 10-15mph slower.

 

[Shortround6]

That's good because most all the sources out there quote different weights. 8400# was most common in my readings.

But every one of the tested planes was light vs. published weights. Had to be something to do with fuel.

It often was but not because they were testing at 1/2 fuel or average fuel or some other made up condition.

The early (before and part way through 1942) tests were often done at the design weight which is the official contract weight.
Many of the "published" weights are from latter or as used in combat area weights. And some (like for just about every P-51 built) are over the standard load limits. P-51s weren't 8 G aircraft unless running VERY light.

 

[Greg Boeser]

In agreement but you just know it will be dragged and kicked until we all agree that the P-39N was the best aircraft there ever was

Them's fightin' words! Everybody knows that the B-26 Marauder was the finest aircraft ever produced!
It could fly 326 mph with a full load of 5800 lbs of bombs. Says so right in the pilot's manual.

 

[Greg Boeser]

There's another P-39 graph a few pages back that shows P-39Q (no wing guns) just about 10mph slower. If it was me flying, I will almost always take the highest climb rate. The N outclimbs the P-51A substantially at all altitudes and 650fpm at 20000'. And only 10-15mph slower.

I'll take the plane that will get me to where the enemy is and be able to fight there.

 

[buffnut453]

I'll take the plane that will get me to where the enemy is and be able to fight there.

And stands the best chance of bringing me home again.

 

[Shortround6]

Them's fightin' words! Everybody knows that the B-26 Marauder was the finest aircraft ever produced!
It could fly 326 mph with a full load of 5800 lbs of bombs. Says so right in the pilot's manual.

what page?

 

[Greg Boeser]

what page?

32.
Oh, wait. it says at design gross weight of 26,734 lbs. Full fuel and 5800 lbs of bombs puts it a bit above that.

 

[Shortround6]

I always thought the the 5800lb load was a pair of 1600lb AP bombs and a torpedo?
Torpedo hanging on the outside really plays havoc with the speed

 

[CORSNING]

Two things my friend, first, which would you want to take into combat? Don't quote numbers, if you asked an AAF fighter pilot which he'd prefer I doubt it would be the P-39. No RAF pilot with two brain cells to rub together would, of that I would bet the farm... as did the RAF.

I believe the Russians preferred the P-39 to the Allison powered Mustangs. But then again, I would have to look it up to see
if they received any P-51As.

Second, you seemed to have missed my point entirely.

I have been known to go brain dead from time to time.

 

[Peter Gunn]

There's another P-39 graph a few pages back that shows P-39Q (no wing guns) just about 10mph slower. If it was me flying, I will almost always take the highest climb rate. The N outclimbs the P-51A substantially at all altitudes and 650fpm at 20000'. And only 10-15mph slower.

Which MUST by why the RAF couldn't get enough P-39s and used them until the end of the war. /sarc

Second, you seemed to have missed my point entirely.

Seems you have as well.

 

[Peter Gunn]

I have been known to go brain dead from time to time.

You're not the only one my friend.

As I posted waaaaay back earlier in this thread, I agree that the P-39 found its niche as a low altitude fighter with the VVS... yay.

To me that is irrelevant to the needs of the USAAF, RAF, RAAF and RNZAF in the ETO, MTO, PTO and CBI, basically everyone else, everywhere else.

 

[P-39 Expert]

Geez I hope this hasn't turned into something other than just a good natured disagreement? And while I haven't seen EVERY test report on the website (I have a life too), I can say that it would be incorrect to lump all of them in together as having "lightened" test aircraft. The only documents that I have examined in great detail are those of the F6F Hellcat (no surprise). And while there have been testing performed at varying weights, the vast majority of Hellcats tested were in a "fighter overload" condition. This means maximum internal fuel and ammunition load (for machine guns only). This amounts to roughly 12,400lbs (the gross weight of an F6F-3 as given by the manufacturer). I do agree that there is test data where the loaded weight of some Hellcats was less than this standard, but this situation was more of an exception than the rule.

Absolutely just a good natured disagreement, would be better over a couple beers.

Now, data for the original question posed 1155 posts ago: "Should the P-39 have been able to handle the Zero? Was it training or performance?" The attached performance chart for the P-39K with the Zero (Zeke 32 Hamp) superimposed in pencil. Flame away.

 

[Juha2]

You're not the only one my friend.

As I posted waaaaay back earlier in this thread, I agree that the P-39 found its niche as a low altitude fighter with the VVS... yay.

To me that is irrelevant to the needs of the USAAF, RAF, RAAF and RNZAF in the ETO, MTO, PTO and CBI, basically everyone else, everywhere else.

Hello
in fact Soviets saw P-39 as a low- and medium altitude fighter, see my message #197 , according to Soviet tests P-39's good altitude to fought against Bf 109 G-4 was appr. 3 750 – 5 300 m and against Fw 190 A-5 appr. 2 000 – 6 000 m. That was how the Soviets saw it, not necessarily how it was in reality.

 

[Peter Gunn]

Sometimes I doubt people actually READ what I write, or perhaps they do but can't f#cking comprehend it.

Time for me to stop posting here. See ya round.

 

[DarrenW]

Absolutely just a good natured disagreement, would be better over a couple beers.

Now that we are definitely in agreement on!

But to be totally frank, I'm also in agreement with Peter Gunn and others on this forum. IMHO this thread has long outlasted it's usefulness and except for a minor few nobody really changed their opinion about the P-39. Those who think it was unjustly kept from being a bigger player with the AAF still feel that way, while others will always think of it as a second rate fighter that just held the line until more capable fighters came along. I'm just on the side of history, so other then brushing up on my Airacobra facts, this thread offered me very little if any new information. Sorry but that's just how I feel. But by all means keep the good fight going if you must. I'm certain that there will always be those willing to discuss the topic with you because everyone here has a passion for aviation and in that sense we should at least try to be civil and treat each other with the respect that we all want and deserve. Peace.

 

[P-39 Expert]

Now that we are definitely in agreement on!

But to be totally frank, I'm also in agreement with Peter Gunn and others on this forum. IMHO this thread has long outlasted it's usefulness and except for a minor few nobody really changed their opinion about the P-39. Those who think it was unjustly kept from being a bigger player with the AAF still feel that way, while others will always think of it as a second rate fighter that just held the line until more capable fighters came along. I'm just on the side of history, so other then brushing up on my Airacobra facts, this thread offered me very little if any new information. Sorry but that's just how I feel. But by all means keep the good fight going if you must. I'm certain that there will always be those willing to discuss the topic with you because everyone here has a passion for aviation and in that sense we should at least try to be civil and treat each other with the respect that we all want and deserve. Peace.

I hear you. My contention is that the 2012 information in wwiiaircraft put a new light on the P-39 and that it was a match for the FW190 and Me109 (as well as contemporary Hellcats, Corsairs, Lightnings etc, but not Merlin Mustangs or Spitfire IX) , but everybody has read and heard all the old information and changing their minds is impossible. Interesting reading anyway, if anyone will actually go there and look. Oh well.