XP-39 II - The Groundhog Day Thread

[P-39 Expert]

ACTUALLY...

It's been a fair amount of those 66 pages of qualified guys from the aviation industry saying that what you have been proposing (over and over and over ad infinitum ad nauseam) isn't that simple of an equation. That you would quibble about "3mph" when the real issue is the 25 horsepower it takes to get that 3mph and what that means in combat, even though THAT was explained to you (more than once). 3mph.

Even then I could probably take your arguments seriously except then you come off with:


Are you seriously contending that the P-39 was a match for the FW-190 or Bf-109 in the skies over Western Europe? Man Eaker, Spaatz and Arnold must have been either dullards or totally in cahoots with Republic, Lockheed and North American to make sure Bell got screwed over.

Russians say yes. Tests in wwiiaircraftperformance.org say yes.

Sorry, but the proof is in the pudding, how many missions did the P-39 fly for the 8th AF? Or the 9th? What does this prove again?

I believe the RAF flew one (1) mission and said "Nyet" and shipped them to the Soviets, ah but that's right, the Brits were in on the conspiracy to add weight to it and make it a dog. They certainly added a lot of weight that certainly wasn't needed, and that certainly affected its performance.

Tell me again of it's stunning record in the SWP as it handily brought down Zero's by the fistful.

All said and done, don't take this as a dislike for you, hell, you posts have kept me in stitches for while now but obviously there's no way to enlighten you, so the best I got is a shoulder shrug and a "whatever dude". I don't think you dislike me, you don't even know me. I certainly don't dislike you. Just read the tests in wwiiaircraftperformance.org and tell me how 836lbs won't affect climb rate in the same plane, while a couple of inches in length, a tail fillet, a different model number of the same diameter propeller and phantom CG issues will?

Please expand above.

 

[pbehn]

I never said to remove any cannons, only the wing .30cal MGs. Only armor I recommend removing is the nose armor.

And I didn't say remove all guns just the cannons, the Spitfire didn't need nose armour it had an engine there, it needed armour behind the pilot and that was specified standard equipment.

 

[P-39 Expert]

And I didn't say remove all guns just the cannons, the Spitfire didn't need nose armour it had an engine there, it needed armour behind the pilot and that was specified standard equipment.

Your point being?

 

[pbehn]

Your point being?

The P-39 needed nose armour as a military machine, the Spitfire would certainly have been better in every way without cannon, speed climb and roll would have all been improved, but they were mainly concerned with those few seconds when the pilot presses the fire button, the reason it is called a fighter and not a Reno racer.

Quote"I believe the RAF flew one (1) mission and said "Nyet" and shipped them to the Soviets, ah but that's right, the Brits were in on the conspiracy to add weight to it and make it a dog. They certainly added a lot of weight that certainly wasn't needed, and that certainly affected its performance."
This (your bold), as I said, has been the issue from the start, you contend that the weight was not needed, but the RAF disagreed and the pilots who were relieved to switch to Spitfires that had that equipment on them did also.

 

[jmcalli2]

What's the book? Some operational history and pilot's accounts of the P-39 would be most welcome here instead of the endless drama over trivial matters and ongoing personal smears.

P-39: "P-39/P-400 vs A6M2/3 ZERO-SEN New Guinea 1942" by Michael John Claringbould

P-38: " 'Twelve to One' V Fighter Command Aces of the pacific" by Tony Holmes

 

[Stig1207]

Weight was actually only reduced by 600+lbs which allowed the P-39K to fight at 27000'. Best Japanese bombers G4M came in at 18000'-22000'.

Yes, but it was suggested, (I can't make out exactly what the abbreviation given in the text is, due to the poor quality) that 1500 pounds could be stripped.

 

[GregP]

P-39 Expert,

There is not a 1,000 fpm climb difference between a P-39C and D, despite the test. For more than the 3rd time, there is something wrong with the P-39D test climb data. And the difference, whatever it is, is due to several factors, not just weight.

If you remove just nose armor, you move the CG aft. We already covered that. You could take off that way, sure. But, if you expended your ammunition, you might be a fatal danger, maybe not. Depends on what gets removed and the weight and balance of that partcular airplane.

Regardless of a sentence in a report, you can't remove 1,500 pounds from a P-39 and still have a fighter aircraft that flies, regardless of what the memo says. There isn't 1,500 pounds of stuff to be removed. There is only 193 pounds of armor including the windscreen glass. There is only 331 pounds of 30-cal guns and ammo. Where are you going to get the rest of your 1,500 pounds, huh?

You showed us a memo report on removing the wing 30's, but that was NOT a common practice, even in the South Pacific. While it might have worked for some specific missons at specific bases, it was not adopted widely. Let it go guy. The P-39, in these specific cases, didn't score a significant number of victories to get the practice noticed and emulated by anyone else.

 

[P-39 Expert]

The P-39 needed nose armour as a military machine, the Spitfire would certainly have been better in every way without cannon, speed climb and roll would have all been improved, but they were mainly concerned with those few seconds when the pilot presses the fire button, the reason it is called a fighter and not a Reno racer.

Quote"I believe the RAF flew one (1) mission and said "Nyet" and shipped them to the Soviets, ah but that's right, the Brits were in on the conspiracy to add weight to it and make it a dog. They certainly added a lot of weight that certainly wasn't needed, and that certainly affected its performance."
This (your bold), as I said, has been the issue from the start, you contend that the weight was not needed, but the RAF disagreed and the pilots who were relieved to switch to Spitfires that had that equipment on them did also.

P-39 did not need nose armor, Spitfire did not have armor for it's nose reduction gear, no other plane had armor for it's reduction gear. Bell theater tech reps never saw one instance where the nose armor was struck by an an enemy shell.

 

[fubar57]

Did the Bell tech reps check the P-39s that were shot down to see if the nose armour was struck by enemy shells? Aircraft that survive rarely have damage to vital parts

 

[P-39 Expert]

P-39 Expert,

There is not a 1,000 fpm climb difference between a P-39C and D, despite the test. For more than the 3rd time, there is something wrong with the P-39D test climb data. And the difference, whatever it is, is due to several factors, not just weight.

The test disagrees with you. What was wrong with the P-39D test? Conducted by the AAF at Wright Field jut like all the other tests. Didn't climb as well as the C because it was 836lbs heavier.

If you remove just nose armor, you move the CG aft. We already covered that. You could take off that way, sure. But, if you expended your ammunition, you might be a fatal danger, maybe not. Depends on what gets removed and the weight and balance of that partcular airplane.

Remove the nose armor and move the radio in the tail up to behind the engine. Proved this on the excel CG matrix that I believe you provided. C didn't have the nose armor, did it fall out of the sky? Radio was moved to the tail in the D model to counter the nose armor.

Regardless of a sentence in a report, you can't remove 1,500 pounds from a P-39 and still have a fighter aircraft that flies, regardless of what the memo says. There isn't 1,500 pounds of stuff to be removed. There is only 193 pounds of armor including the windscreen glass. There is only 331 pounds of 30-cal guns and ammo. Where are you going to get the rest of your 1,500 pounds, huh?

I have never said that 1500lbs could be removed from the P-39. That was a suggestion in an AAF document. They eventually did remove 650lbs and the plane could operate at 27000', plenty high enough to counter Japanese bombers.

You showed us a memo report on removing the wing 30's, but that was NOT a common practice, even in the South Pacific. While it might have worked for some specific missons at specific bases, it was not adopted widely. Let it go guy. The P-39, in these specific cases, didn't score a significant number of victories to get the practice noticed and emulated by anyone else. P-39 scored significant victories by the Russians against the Luftwaffe, toughest opponent of WWII. They removed the wing guns and IFF radio equipment, not the voice radios. They removed the .30s and beat the Luftwaffe, but the AAF never did remove the .30s. Plenty of armament left with a 37mm canon and two .50s. Same thing I have been saying for 67 pages. You please let it go, or prove me wrong.

Expand above.

 

[fubar57]

Not all VVS squadrons removed the wing guns

 

[pbehn]

P-39 did not need nose armor, Spitfire did not have armor for it's nose reduction gear, no other plane had armor for it's reduction gear. Bell theater tech reps never saw one instance where the nose armor was struck by an an enemy shell.

Did the Bell tech reps check the P-39s that were shot down to see if the nose armour was struck by enemy shells? Aircraft that survive rarely have damage to vital parts

Beat me too it Fubar, in fact that was a branch of military statistical research. There is a "sampling error" here in that those who didn't return are not included causing "survivorship bias", it is actually a fairly convincing argument for more armour. Bullet Holes in Bombers: Operations Research and Management Science Applied to Marketing

 

[GregP]

The gearbox armor was 71 pounds out of 172 pounds of armor exculding the windscreen glass. If you add in the wing guns and wing gun ammuntion, that is only 503 pounds, not 1,500 pounds. Is there something you are missing here?

The empty weight of the P-39Q was 5,684 pounds. Then you add windscreen glass, armor, guns and ammunition, oil, fuel, pilot, and parachute. The total useful load was 1,886 pounds, guy, and the pilot was 200 pounds of the 1,886. Remove the pilot and you have 1,686 pounds of armor, guns, ammo, oil, and fuel. We need the oil. We need the fuel. If we don;t have guns and ammo, we might as well not take off. If we ditch ALL the armo, we only save 172 pounds.

Either you are not reading the weight and balance, not reading the posts, or are just being a troll.

Which is it? Help us out here. If you want to remove anything, identify it specifically. Please don't suggest leaving out the oil or fuel or pilot.

If I remove ALL the armor, I can take off just fine. But if I shoot all the ammunition, then I am out of CG aft, not good. Are you understanding this?

 

[Mike Williams]

P-39: "P-39/P-400 vs A6M2/3 ZERO-SEN New Guinea 1942" by Michael John Claringbould

P-38: " 'Twelve to One' V Fighter Command Aces of the pacific" by Tony Holmes

Thanks jmcalli2!

 

[Stig1207]

The gearbox armor was 71 pounds out of 172 pounds of armor exculding the windscreen glass. If you add in the wing guns and wing gun ammuntion, that is only 503 pounds, not 1,500 pounds. Is there something you are missing here?

The empty weight of the P-39Q was 5,684 pounds. Then you add windscreen glass, armor, guns and ammunition, oil, fuel, pilot, and parachute. The total useful load was 1,886 pounds, guy, and the pilot was 200 pounds of the 1,886. Remove the pilot and you have 1,686 pounds of armor, guns, ammo, oil, and fuel. We need the oil. We need the fuel. If we don;t have guns and ammo, we might as well not take off. If we ditch ALL the armo, we only save 172 pounds.

Either you are not reaading the weight and balance, not reading the posts, or are just being a troll.

Which is it? Help us out here. If you want to remove anything, identify it specifically. Please don't suggest leaving out the oil or fuel or pilot.

If I remove ALL the armor, I can take off just fine. But if I shoot all the ammunition, then I am out of CG aft, not good. Are you understanding this?

Post #1346 Greg; it's not P-39Expert advocating removing 1500 pounds, it's from the USAF Historical Study no. 101 and is suggested by some presumably official organisation or command to Gen. Harmon.
As you point out, and why I brought up, is that it doesn't seem at all possible , from what I have read in this thread.

 

[GregP]

My mistake, P-39 Expert.

Slap me. More than one in here likely wants to do just that ...

 

[Stig1207]

P-39: "P-39/P-400 vs A6M2/3 ZERO-SEN New Guinea 1942" by Michael John Claringbould

Somewhere in the depths of this thread FLYBOYJ posted a report by Lt. Col. Boyd Wagner, wherein he reported on the April 30 combat, and from his (and probably his pilots) perspective 4 Zeros were shot down (3 by Boyd, 1 by Greene), one Zero was actually lost. Boyd wrote that 3 P-39's were hit by Zero's and forcelamded due to cooling leaks, but all 3 pilots survived. Four P-39's were lost, Boyd makes no mention of Durand, who didn't return and remains MIA.
I reponded to the post here #261 with links to the fate of the respective planes and pilots on Pacific Wrecks.

To summarize, Pacific Wrecks has 1 forcelanded damaged by AAA (Andres), 1 sustained damage during combat and forcelanded (Brown); 1 short of fuel and likely lost, forcelanded (Bevlock); Durand last seen bailing out, MIA.

Claringbould has on p. 38, Andres as a focus, and writes that Andres (his own words) was chased by a Zero which he outran, but also ran short of fuel and bellied in18 miles SE of Buna.

On p.42-43, describing the combat, Claringbould has Andres forced to land due to damaged coolant system and both Brown and Bevlock forcelanding low on fuel. Andres was one of the few to witness Durands demise, but no mention of him bailing out.

So four differing versions, two from the same book.

 

[Stig1207]

My mistake, P-39 Expert.

Slap me. More than one in here likely wants to do just that ...

Not me, I'm tired of standing in queues.

 

[GregP]

Tough to be precise when your sources disagree with themselves, isn't it?

 

[P-39 Expert]

Did the Bell tech reps check the P-39s that were shot down to see if the nose armour was struck by enemy shells? Aircraft that survive rarely have damage to vital parts

The only planes that they could check would be the ones that returned to base, right? They did not say that no nose armor had ever been struck, just that they had not seen one that had been struck.