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

[P-39 Expert]

I doubt very much you've "struck a nerve" here, you've just run across the most knowledgeable group of guys on the subject at hand, namely WWII aviation. Sure is sounds plausible a P-39N could have been manufactured in December '42 and been in action the same month. What you'll learn here is not what is plausible, but what actually happened. Logistics dictates ( to me at least ) the P-39N could not have made it to any combat zone in two weeks time, I've learned that from reading many threads on this forum by posters with far more knowledge and source document resources than I can imagine.

SR6 and others have continually tried to explain 2S/2S superchargers v. 1S/1S etc. not to mention crankshaft differences etc. etc. A person can learn a lot from these guys, you just have to be humble enough to realize that sometimes you may have to pony up with valid references to make your point.

Not to single any one poster out, but for example, when drgondog posts, read carefully and take it to the bank that what he says is based in fact. Not coffee table history book "accepted" versions of events, but dyed in the wool, right from the source documentation and education. And that's just the tip of the ice cube, I could name almost a dozen more posters that have knowledge and source material to back up what they say.

So when you start to rewrite history, you best have source documentation ( and a fair amount of it ) to back up what you're trying to say. Everyone here is always open to new interpretations or new discoveries of data, no one is so hidebound in their beliefs that they close their eyes to new information. But the BS meter is finely tuned and will be used immediately when needed.

I cite the example of your statements about the air war being over by March '44, it may sound like I'm nit picking one point, but it's a very important point. You won't find many here that will agree with that for a reason i.e. it's false. When you attach that type of assertion, it calls into question your entire argument, firmly sticking to such an assertion only lowers your credence going forward. One might posit that it would have been better to ask why many here think that statement is false, and ask them to cite sources.

Pardon the long post, as I said, you seem a well read intelligent bloke and you've come to the right place for information and the exchange of same, I just hope you take this to heart and stick around as I think you could contribute to the group here.

Cheers

Really enjoy talking WWII airplanes with you guys, where else can I find anybody who likes this subject.

All I'm saying is I prefer the facts to heresay. Before late 2012 we all had to take all the heresay as fact. After all the data was put online by wwiiaircraftperformance.org we can compare directly every P-39 model against any other plane (except Russian) and see for ourselves. These are the original source documents, the actual government/military tests. Not some numbers in a coffee table book that seldom match the actual tests. Each of us can then answer the original question, could the P-39 handle the Zero or was it training/performance.

And google N. G. Goludnikov if you want some Russian heresay.

 

[Shortround6]

Let me try and explain this again......................... Hope this helps.

It doesn't because in polite terminology it is so much horse pucky.

Just starting with the US P-36 and P-40 tests we find the P-36 tests described as full fuel and oil, which is a bit disingenuous as on a P-36 "full" fuel did NOT include the tank behind the pilot. That was the overload or ferry tank. Filling it put the aircraft over gross weight and imposed restrictions on flight maneuvers.

Some of the P-40 tests don't describe either fuel state or even the weight of the aircraft. BTW using the date of a test to judge when a plane went into service is dicey at best, one "test" of the XP-40 was dated July 28, 1941 which is about the time the P-40D went into production.
later P-40 tests give test weights but often do not give fuel or ammo state which leaves one guessing, especially when on test of a P-40E gives a weigh of 8011lbs and another test says 8033lbs (propeller test) full fuel and oil, six guns fitted but no ammo and no ballast.
Now this gets weird as the manual for the P-40D/E says the gross weight for the E is 8011lbs with 423lbs of ammo and full internal fuel. Fuel load was given as 720lbs in the manual (design load was only 37 gallons in the rear tank. the extra 25.5 gallons, the belly tank and even an extra 460 rounds of ammo (138lbs) and six 20lb bombs all get listed under alternate max loads. Of course the manual was last revised in Sept of 1941 so weights can differ between planned and actual production aircraft.

A 1944 test of the P-40N-5 was done at 8300lbs and included 157 gallons of fuel and ballast in place of ammunition.

There certainly doesn't seem to be any clear or consistent pattern to the condition of US planes tested let alone planes from other countries.

BTW one P-38G test was done with only 50 rounds for the cannon, only two .50 cal machine guns with 200rpg and 180 gallons of fuel.
They got that sucker up to 25,000ft in 7.36 minutes but I have no idea what it actually proves.

 

[Glider]

Each of us can then answer the original question, could the P-39 handle the Zero or was it training/performance.

.

No it couldn't

 

[Elmas]

View: https://youtu.be/RLT5qbImaJ4


L'Aeronautica Militare festeggia i cento anni del Comandante Galbusera

Com.te Galbusera was born in 1917 and now is more than 100 years old...

"It was a very special airplane, let's say, with the engine in the back, then those Italian maniacs always wanted do aerobatics, when they looped they came in this position and then had to continue, but it was too slow and instead of lowering the head, which it did not have ( for the position of the engine) they went in a flat spin and so they were screwed so a very good Genoese Pilot, Moresi left his skin, another Sergeant left his skin, even though they were saying, ehhhh, do you know what I say, if you loop, do it fast, but for me it was a fabulous plane because it had a tricycle undercarriage, on the ground it was driven like a car, apart from this tricycle undercarriage it had in the axis of the propeller a cannon of 37 and four machine guns on the wings the engine was a 1200 hp Allison a beautiful engine it was a very pretty airplane…"

 

[P-39 Expert]

It doesn't because in polite terminology it is so much horse pucky.

Just starting with the US P-36 and P-40 tests we find the P-36 tests described as full fuel and oil, which is a bit disingenuous as on a P-36 "full" fuel did NOT include the tank behind the pilot. That was the overload or ferry tank. Filling it put the aircraft over gross weight and imposed restrictions on flight maneuvers.

Some of the P-40 tests don't describe either fuel state or even the weight of the aircraft. BTW using the date of a test to judge when a plane went into service is dicey at best, one "test" of the XP-40 was dated July 28, 1941 which is about the time the P-40D went into production.
later P-40 tests give test weights but often do not give fuel or ammo state which leaves one guessing, especially when on test of a P-40E gives a weigh of 8011lbs and another test says 8033lbs (propeller test) full fuel and oil, six guns fitted but no ammo and no ballast.
Now this gets weird as the manual for the P-40D/E says the gross weight for the E is 8011lbs with 423lbs of ammo and full internal fuel. Fuel load was given as 720lbs in the manual (design load was only 37 gallons in the rear tank. the extra 25.5 gallons, the belly tank and even an extra 460 rounds of ammo (138lbs) and six 20lb bombs all get listed under alternate max loads. Of course the manual was last revised in Sept of 1941 so weights can differ between planned and actual production aircraft.

A 1944 test of the P-40N-5 was done at 8300lbs and included 157 gallons of fuel and ballast in place of ammunition.

There certainly doesn't seem to be any clear or consistent pattern to the condition of US planes tested let alone planes from other countries.

BTW one P-38G test was done with only 50 rounds for the cannon, only two .50 cal machine guns with 200rpg and 180 gallons of fuel.
They got that sucker up to 25,000ft in 7.36 minutes but I have no idea what it actually proves.

I was mostly concerned with the P-39, P-38, P-47 and P-51, but I'll stand by my mean/average fuel.

That manual weight of 8011# was for the D, two more machine guns for the E would get it up to 8400#.

I don't think other countries used the mean/average fuel, they mostly just listed takeoff weight.

Glad you noticed that "ultralight" P-38G. A G grossed 15900# and with average fuel it would be 900# lighter at 15000', but that one was a ton lighter and I have never seen a P-38 photo with only 2 MG in my life. That is the only instance that I have found where a test was conducted on a plane clearly too light for operations. And the site shows this performance curve on some comparative curves. Normal time for a G to 25000' was 11 minutes, 7.36 minutes just goes to show how much weight affects climb.

 

[pbehn]

They got that sucker up to 25,000ft in 7.36 minutes but I have no idea what it actually proves.

This is what I find difficult to follow and accept. Removing armour, fuel and guns increases climb rate, well even a child would understand that argument, but it is trending towards a Reno racer not a fighter. When a plane can carry a bomb or a tank the tank may increase range by 100 miles but it doesn't increase the bombing range. Calling a plane "in service" especially a new model plane is a nice idea and the defenders of Malta would have loved it, that loading on carriers etc. was tiresome.

Even the Wiki article on the P 39 discusses stability problems with the P 39 which Bell couldn't replicate, well they couldn't replicate until they removed ballast that simulated ammunition, which seems to show that firing the guns was not recommended by the manufacturer.

 

[drgondog]

Really enjoy talking WWII airplanes with you guys, where else can I find anybody who likes this subject.

All I'm saying is I prefer the facts to heresay. Before late 2012 we all had to take all the heresay as fact. After all the data was put online by wwiiaircraftperformance.org we can compare directly every P-39 model against any other plane (except Russian) and see for ourselves. These are the original source documents, the actual government/military tests. Not some numbers in a coffee table book that seldom match the actual tests. Each of us can then answer the original question, could the P-39 handle the Zero or was it training/performance.

And google N. G. Goludnikov if you want some Russian heresay.

What you consistently evade with your facts is that AAF replaced P-39s of every type as fast as they could - with P-40, P-38, P-51 and shuffled them off to Training Command, The French and Italian and Russian AF in early 1944.

There was a reason for that. Actually many reasons, but the most compelling is that even the later models had too little external load capability for either CAS or medium range escort of AAF bombers, had terrible performance (and range) for high altitude operations, was a poor second to Spit IX and XIV in 1944 for interceptor/air superiority fighter as point interceptor of battlefield air supremacy.

 

[pbehn]

Root: NACA 0015, tip: NACA 23009, no washout (2 deg constant incindence).

I always thought that washout was essential and that without it a plane would stall without warning, does 2 deg constant incidence fulfil the same function in some way or did the P39 have another trick in the box?

 

[tomo pauk]

I always thought that washout was essential and that without it a plane would stall without warning, does 2 deg constant incidence fulfil the same function in some way or did the P39 have another trick in the box?

The AHT bible at pg. 203-204 notes that stall behavoir of the P-39 was not favorable - there was no warning, no tail buffeting prior the stall. High-speed stall was also tricky business.

 

[pbehn]

The AHT bible at pg. 203-204 notes that stall behavoir of the P-39 was not favorable - there was no warning, no tail buffeting prior the stall. High-speed stall was also tricky business.

Bejabers, I remembered something that was correct, it's a miracle

Thanks Tomo

 

[Shortround6]

I was mostly concerned with the P-39, P-38, P-47 and P-51, but I'll stand by my mean/average fuel.

Out of the first 3 P-47 tests on WWII Aircraft Performance 2 have 6 guns installed, ammo and fuel state not given, 3rd has a very similar weight (down 5lbs) but 8 guns.
First test of P-47D on the site says:
" all flights at a gross weight at take-off of 13,200 pounds with c.g. at 27.44% m.a.c., gear up. Total useful load included 300 gallons of fuel, 28 gallons of oil, 525 pounds of ballast in the ammunition boxes, and the pilot. All radio equipment installed; four, 50 cal. M.G. in each wing,"
bolding by me P-47D held 305 gallons in the internal tanks on the early versions. 525 lbs of ammo is just a bit over 1/2 ammo.

another P-47 test
"Airplane ballasted to simulate the following conditions: Six .50 caliber guns; 300 rounds per gun; 305 gallons gasoline; 15 gallons water; 14 pounds pyrotechnics. In this condition the gross weight was 13,234 pounds"

Please link to ANY test on WWII Aircraft Performance
that says mean/average fuel or lists a fuel gallon number that is 1/2 the internal fuel?

That manual weight of 8011# was for the D, two more machine guns for the E would get it up to 8400#.

Actually the wight in the Manual I have access to for P-40D is 7944#, same 120 gallons of internal fuel, the P-40D was designed to hold 1000 rounds for it's for guns (with the ability to hold 2460 rounds in overload condition), The P-40E cut ammo to 235 rounds per gun but had the ability to hold more.

I don't think other countries used the mean/average fuel, they mostly just listed takeoff weight.

Bingo, but not what you said earlier

In wwiiaircraftperformance, the gross weights listed on the test documents show "mean fuel" or average fuel available during the test.

 

[Shortround6]

Even the Wiki article on the P 39 discusses stability problems with the P 39 which Bell couldn't replicate, well they couldn't replicate until they removed ballast that simulated ammunition, which seems to show that firing the guns was not recommended by the manufacturer.

details, details.

 

[Graeme]

Australian Airabonita..... Looks a little under-powered....

 

[buffnut453]

Australian Airabonita..... Looks a little under-powered....

View attachment 486935

Actually, i was thinking it was a little under-undercarriaged!

 

[MIflyer]

Wing washout is for the purpose of enabling the ailerons to remain effective even after the root of the wing stalled. The alternative is differential ailerons, where the ailerons are geared so that as each aileron goes down it hits a limit and then goes back up while the other aileron keeps moving up.

 

[P-39 Expert]

The AHT bible at pg. 203-204 notes that stall behavoir of the P-39 was not favorable - there was no warning, no tail buffeting prior the stall. High-speed stall was also tricky business.

What is AHT please?

 

[b0ned0me]

Ah, the legendary P-39.
From a performance and handling standpoint the P-39 was a tribute to the capabilities of the Bell sales organisation.
Recognizing the desperate need for competitive aircraft, Bell could always be relied upon to miss every performance requirement while citing delivery needs, and to miss every date requirement citing the need to work on performance.
Given adequate engineering support from NACA, Allison and the AF, Bell could have had an improved P-39 as good as any other late ww2 fighter, in front line service, several months before the F-86.
The US was stuck between Lockheed's small production of expensive, complex, difficult-to-use but high-performance aircraft and Curtiss' high production of simple, robust but obsolescent under-performers. They needed something cheap, reliable with competitive performance and Bell was able to give them an aircraft that was expensive, complex, difficult to operate and an under-performer.

Frankly, when it comes to the P-39 the jokes just write themselves. Within the constraints of the USAAFs then doctrine of 'turbo or bust' it was a creditable attempt at rethinking how to build a better interceptor but turned out to be badly flawed in execution, and unfortunately had to be pressed into service for lack of anything better. Once the first panic was over the western allies had far better aircraft to choose from so it went to the USSR who were delighted to supplement their own tactical low-altitude fighters built in tractor factories by farmers with a zero-cost tactical low-altitude fighter built in aviation factories to aviation specs.

It certainly did a lot of good work but it also got people killed who would have survived in better aircraft, and once aircraft like the P-51 were available it was frankly not worth a cup of warm piss.

Should it have been able to handle the Zero? Depends on what is meant. With better training and tactics might the allied P-39 pilots have died slowly enough and bled the Japanese more, enough to make a difference? Quite possibly.
If two identically skilled pilots squared off in P-39 v A6M with no tactical advantages, should the P-39 driver be expected to win the majority of the time? I doubt it very much.

All I'm saying is I prefer the facts to heresay. .

No, you prefer your fanboy obsessions over the experience of the people who actually had dealings with these aircraft in WW2 and everyone who has researched them in the decades since WW2. Just like all the Wehraboos who insist the Germans could have won the war if only they built Napkinwaffe jets in 1941 or got Hugo Boss to make them a sharper-looking uniform.

And there is no such word as heresay. You can have heresy or you can have hearsay, but you cannot combine them into one word. However that is another fact I am sure you will continue to ignore.

 

[tomo pauk]

What is AHT please?

"America's hundred thousand", the book dealing with US fighters mostly of ww2. With 606 pages of tables, analysis, graphs, photos and drawings, it is a must for anyone that has interest in the said US A/C. Like all the bibles, it has a glitch or two, but it is a book that I don't consider lending it to anybody
Link

edit: lending, not borrowing

 

[pbehn]

To me the P-39 had its place in history and was what it was. All aircraft are used until replaced by better performers. In the Late 1930s early 1940s the USA was desperate for aircraft for all roles. The P-39 may not have been a top performer but it did some sort of job until better planes were available. As said earlier, Chuck Jaeger trained on a P39 if there was no P-39 what else was available and better, anything better like a P51 was needed in combat. Just because an aircraft is not the best doesn't mean it is of no use. The Gloster Gladiator was an obsolete bi plane but achieved immortality in Malta when three saved Malta. Well actually that is a legend and the facts are something different, but they were there and did something until replaced by something better.

 

[Stig1207]

Curtiss' high production of simple, robust but obsolescent under-performers.

Y'all might wanna duck down behind the lounge now, buddy.

It's one thing to annoy the P-39.......