Groundhog Thread Part Deux - P-39 Fantasy and Fetish - The Never Ending Story (Mods take no responsibility for head against wall injuries sustained)

special ed said:

If I may chime in, Saburo Sakai in his book describes just such a combat and reports how well flown the American and his P-39 were. The P-39 jock may have survived against a lesser experienced Japanese pilot.

Click to expand...

Hello Special Ed,
If the combat you are referring to is the same one I am thinking of, then the problem was that the P-39 simply ran out of room at ground level and had to pull up. According to the test we have been discussing, the P-39 should have had a huge advantage in speed and climb at sea level. Its speed advantage from sea level to 5,000 feet according to these tests was around 35 MPH and yet the practical difference seems to have been much less than that.

- Ivan

However, all of these tests are akin to "lab tests" rather than real world with worn engines, frequently overboosted ( savings one's life doesn't limit the boost to 5 min. or 15 min.) and repaired in the field.

You also have a big variable in that the "tests" are started with both planes at the same speed or close to it.
In combat one plane or the other may have 10-30mph advantage over the 'test' plane.

Lets face it a 10% advantage in speed can mean a difference but is unlikely to be noted in a combat report (assuming one is made)

You also need a a certain amount of altitude for certain tactics to work, diving away when you are only 3-4000 ft above the ground/sea is unlikely to get you enough distance to get out of the fight.

I just went to look for my Allison book, which once again is mislaid, to verify an example discovered when reading Dwane Schultz's book on the AVG. In the real world, the long nose Allisons seemed to have gearbox failure more often than expected. Reading the story of the Allison, In order to fill the emergency requirement for the AVG, Supervisors were called to work weekends and overtime to hand assemble engines from the reject pile of parts and assemblies, if I remember right. My assumption is that these engines put together by the most experienced, and knowing where they were going, probably put out another 50hp which contributed to gear failure at full throttle in combat.

Kevin J said:

This is simply not true. The Bell fighter had a list of issues to sort out and it simply lacked the range of the Allison Mustang. The Soviets took them, sorted out the problems and unlike the Americans operated it successfully until the end of the war. They didn't need it as a fighter with high altitude capability or range. Over half the Soviet top scoring aces flew it. As for the Americans, it simply lacked the range to be useful.

Click to expand...

Shortround was correct, just a little snarky humor injected into a looooong discussion on the Iron Dog.

Peter Gunn said:

Wait, from what I've read here, the P-39 could out climb the Allison powered Mustangs, was only ~10MPH slower and had almost the same range and if outfitted properly, could intercept bombers at 31,000 feet.

Yet somehow North American hoodwinked the Brits into buying as many Allison Mustangs as they could build (and would have kept buying them as long as NAA was building them) meanwhile, these same Brits conspired to add weight and put the kibosh on this wonderful little Bell fighter because... reasons.

Either the Brits have some serious 'splainin to do or Bell was just totally incompetent at politicking and greasing the correct palms while NAA was apparently a past master at same...

Click to expand...

If they have the same engine (either the 8.8 gears or the 9.6 gears) the P-39 would outclimb the P-51 since it was 800# lighter and was only 10-15mph slower since the P-51 was cleaner aerodynamically.

P-39 never had near the same range since the P-51 carried 50% more internal fuel. The modification to substitute fuel tanks for the .30 caliber wing guns would have greatly increased the P-39's internal fuel, but that modification was never implemented. Except on the post war racing planes.

The reasons for the Brits love of the Mustang and hate of the Airacobra have been beaten to death on this board. Their reasons for disliking the P-39 were largely financial. The Russians loved the P-39 and didn't care for the P-51. Their reasons were largely survival.

Was the Allison P-51 better than the P-39? In speed and range, yes. In climb and ceiling, no.

P-39 Expert said:

If they have the same engine (either the 8.8 gears or the 9.6 gears) the P-39 would outclimb the P-51 since it was 800# lighter and was only 10-15mph slower since the P-51 was cleaner aerodynamically.

P-39 never had near the same range since the P-51 carried 50% more internal fuel. The modification to substitute fuel tanks for the .30 caliber wing guns would have greatly increased the P-39's internal fuel, but that modification was never implemented. Except on the post war racing planes.

The reasons for the Brits love of the Mustang and hate of the Airacobra have been beaten to death on this board. Their reasons for disliking the P-39 were largely financial. The Russians loved the P-39 and didn't care for the P-51. Their reasons were largely survival.

Was the Allison P-51 better than the P-39? In speed and range, yes. In climb and ceiling, no.

Click to expand...

The Mustang was often more than 10-15 faster.
Climb is the power to weight ratio at best climb speed. If lower drag plane is using less power simply to fly at climb speed then it has more power to climb. I am not saying the Allison Mustang out climbed the P-39, just that the difference might not be as great as a comparison of the weight would suggest.

You also keep wanting it both ways, the speed and climb of a light weight P-39 but the range/endurance of one carrying 420-500lbs of extra fuel and tanks.

You have also never shown any proof what so ever that the British disliked the P-39 on finicial grounds. Show us the proof or shut up about it.
The British certainly showed no tendency to try to get out of other contracts including Vultee Vengence or Brewster Burmuda contracts.

Agree about Vengeance and Burmuda.

P-39 Expert said:

The reasons for the Brits love of the Mustang and hate of the Airacobra have been beaten to death on this board. Their reasons for disliking the P-39 were largely financial. .

Click to expand...

Actually no, the comment that has been beaten to death on this board is your repeated statement that the British were trying to get out of their commitments for financial reasons. An often repeated comment, that has never, and almost certainly will never, be substantiated. If you had firm evidence, (make that any evidence) I am very confident that you would have supplied it

The P39 as supplied to the RAF wasn't combat worthy, wasn't up to scratch, missed all its performance targets by a substantial margin and the RAF had better aircraft namely the Spit V, coming on stream

Shortround6 said:

The Mustang was often more than 10-15 faster. And often less.
Climb is the power to weight ratio at best climb speed. If lower drag plane is using less power simply to fly at climb speed then it has more power to climb. I am not saying the Allison Mustang out climbed the P-39, just that the difference might not be as great as a comparison of the weight would suggest.

You also keep wanting it both ways, the speed and climb of a light weight P-39 but the range/endurance of one carrying 420-500lbs of extra fuel and tanks. I have it both ways. The extra fuel would have added negligible extra weight since it was in place of the .30 cal MGs.

You have also never shown any proof what so ever that the British disliked the P-39 on finicial grounds. Show us the proof or shut up about it. PLEASE DON'T TELL ME TO SHUT UP. I have never told you to shut up. This is a message board where members are entitled to post their views, whether they agree with yours or not. How would you like for me to prove that the Brits were broke (or near broke). It's common historical knowledge.
The British certainly showed no tendency to try to get out of other contracts including Vultee Vengence or Brewster Burmuda contracts.What about the
lightning?

Click to expand...

See above.

Everyone remain calm, breath and relax, or we shall put this thread to bed for a while.

I have a back ache from putting these fuel tanks in and taking them out again.

P-39 Expert said:

The reasons for the Brits love of the Mustang and hate of the Airacobra have been beaten to death on this board. Their reasons for disliking the P-39 were largely financial. The Russians loved the P-39 and didn't care for the P-51. Their reasons were largely survival.

Click to expand...

As the British government was able to print its own money, purchasing items in an emergency situation was no issue.

Lend-Lease simply pushed the debt further down the road. The British government still owed the money for the items supplied.

As the issue was survival, any aircraft that the British could lay their hands on that could help with that goal would be gleefully accepted. The P-39 was clearly not up to scratch.

P-39 Expert said:

Was the Allison P-51 better than the P-39? In speed and range, yes. In climb and ceiling, no.

Click to expand...

For the earlier engines with the 8.8 gears the P-51 was faster to 10,000ft, line ball to 25,000ft and had a ceiling about 250ft higher.
http://www.wwiiaircraftperformance.org/P-39/P-39D_41-6722_PHQ-M-19-1325-A.pdf
http://www.wwiiaircraftperformance.org/mustang/P-51_41-37320_PHQ-M-19-1415-A.pdf

The top speed was nearly 30mph faster at a thousand feet lower than for the P-39 - 396mph @ 12,650ft vs 368mph @ 13,800ft.

The P-51 appears to have been fitted with 4 cannon.

With the higher rated altitude V-1710, the P-51A was a bit slower than the P-39N to 15,000ft, by about 36s. And by 2 minutes to 25,000ft.
The P-51A was about 18mph faster at ~10,000ft, around where both had their maximum speed.

The ceiling was about 3,000ft lower for the P-51A.

http://www.wwiiaircraftperformance.org/mustang/P-51-A_43-6007_Flight_Tests.pdf
http://www.wwiiaircraftperformance.org/P-39/P-39N_FS-M-19-1487-A.pdf

Compared to the P-39M, the P-51A was faster to 15,000ft, just, and they were line ball to 25,000ft. Ceiling was 800ft higher for the P-39M. The P-39M was about 30mph slower than the P-51A at a similar altitude for top speed.

http://www.wwiiaircraftperformance.org/P-39/P-39M-3_42-4706_FS-M-19-1511-A.pdf

P-39 Expert said:

The Mustang was often more than 10-15 faster. And often less.

Click to expand...

And often a lot more. You would have to plot the curves against each other to find where the maximum and minimum differences were.

P-39 Expert said:

You also keep wanting it both ways, the speed and climb of a light weight P-39 but the range/endurance of one carrying 420-500lbs of extra fuel and tanks. I have it both ways. The extra fuel would have added negligible extra weight since it was in place of the .30 cal MGs.

Click to expand...

That depends how much fuel you would be storing. And you may be forgetting the weight of the tanks themselves.

Surely the .30mgs don't weigh 420-500lbs?

P-39 Expert said:

The British certainly showed no tendency to try to get out of other contracts including Vultee Vengence or Brewster Burmuda contracts.What about the
lightning?

Click to expand...

As supplied, the P-38 was a turd.

The Lightning I didn't have turbos and had both engines turning the same direction.

The bulk of the British order was to be the Lightning II, which had handed engines and turbochargers. But only one was built. Not sure why - maybe the USAF pulled rank on that one?

Hey Wuzak,

I don't know if this answers your question, but the primary reason the UK cancelled the Lightning II and P-38F orders is that the Spitfire Mk IX came along. With the advent of the Mk IX in early- to mid-1942 the need for a high altitude interceptor could be met by a single engine fighter built in the UK. Since the Lightning Mk II with turbos and the
P-38F would not be available until mid- to late-1942 there was no longer a point to the purchase.

The P-38 may be the ONLY aircraft the British got out of a cash deal for.
Without knowing the exact financial details, instead of guesses or accusations of nefarious activity most of us are just speculating.

At least Lockheed may have warned the British (and the French who originated the both engines turning in the same direction thing) that performance would not be up to the "normal" version/s.

Most accounts of these aircraft skip over the financial details and such terms as requisitioned as in "......nearly 200 of the British direct-purchase Airacobras still in the USA were promptly requisitioned by the USAAC. " doesn't tell us if the British got their money back directly or were given credits to offset some lend lease orders or if any compensation was paid or credited in any way. Some more sensational accounts claim the British "dumped" the unwanted Airacobras on the US.

As far as the P-38 story goes, that too has some confusing details or dates. One account says the the French (and British ) skipped the turbo because of doubts that the US would allow it to be exported and they wanted the planes as soon as possible, perhaps starting delivery in one year, Lockheed missed this by a good 9 months. Planes ordered before France fell were not delivered to England until March of 1942. Accounts differ as when the contract was amended so that only the first 143 would be built without turbos and the last 524 would be delivered with turbos as Lightning IIs. Some accounts say the change was in July of 1940 and other accounts say July of 1941. In any case the 140 unwanted P-38s were also taken over by the US army and used as trainers. of the other 524 aircraft. "Twenty-eight other British-ordered aircraft were completed as P-38F-13-LO for the USAAF, 121 as P-38F-15-LO, 174 as P-38G-13-LO, and 200 as P-38G-15-LO. "

Now considering that Lockheed had only built 207 P-38s in 1941 and 1479 in 1942 the picking up of 664 British airframes provided a considerable boost to the USAAF.
BTW one Lightning II was completed as a P-38F-13-LO and became much photographed.

AF221 is a British serial number.

Now most accounts say the British refused delivery of the model 322s, not one account that I have seen says the British got their money back or who (the US Army?)paid Lockheed what. Now perhaps Lockheed, with orders for hundreds of Hudsons and hundreds of Ventura's and ready customer for 322s as they were, didn't kick up a fuss, I don't know.

The US forces certainly "obtained" hundreds if not well over 1000 aircraft that were ordered by the British, either cash or lend-lease.
Again, without specific contracts and/or amendments we are only speculating as to what the financial arrangements were and/or the motives.

Peter Gunn said:

somehow North American hoodwinked the Brits into buying as many Allison Mustangs as they could build (and would have kept buying them as long as NAA was building them) meanwhile, these same Brits conspired to add weight and put the kibosh on this wonderful little Bell fighter because... reasons.

Click to expand...

Peter, you'd look rather funny with a tongue-sized hole in your cheek! You're stretching it near the failure point. And Xpurt's nose is starting to resemble Pinocchio's. Trying to make a plane a full aeronautical generation (if only three short years) more advanced, look inferior to a Larry Bell imaginary figment by making best-case, worst-case comparisons, stretches even my gullible credulity to the breaking point. If planes in actual combat historically can't duplicate these optimistic performance numbers, then they're little better than flim-flam and fodder for armchair aviators and historical revisionists.
The Allison Mustang had:
1) MORE RANGE
2) Better aerodynamics (less cooling drag and better L/D with its near laminar flow wing.
3) More room for growth (it could take on armament/armor/fuel protection weight with less loss of performance.
4) It was upgradable in the propulsion department without serious penalties in handling or structure.
All in all, a WAY better investment.
My dad (4F, not draft fodder) worked at Bell Niagara as a DCAS agent the last two years of the war, and had very little good to say for the place.
"Bunch of money-grubbing crooks!" His job wiih DCAS(Defense Contract Assurance Service) was to catch Bell employees artificially jacking up the costs of production to make more profit on their cost-plus contract. He said the rank and file workers were disgusted with management's shenanigans and were quick to tip off DCAS when schemes were afoot. The schemes got rather creative at times.
This is getting old. Color me gone.
Cheers,
Wes

XBe02Drvr said:

Peter, you'd look rather funny with a tongue-sized hole in your cheek! You're stretching it near the failure point.

*SNIP*

Cheers,
Wes

Click to expand...

Wes,

I must admit, my cheek was hurting pretty bad after that post, in fact, I think I have a temporary speech impediment from it now...

Pete

The conversation is a slipping ratchet, it appears to be making progress then it hits the "The British didn't want to pay tooth" and slips back to the start again.

This is very much like an occasion years ago (the late 60s) at my office. A big sales meeting was called in Atlanta and the sales manager and the top salesman were to go. When they were to make ticket reservations, the salesman said he would go by train because he didn't fly and has never flown. When asked about his Army time he said he always traveled by train. The manager pointed out how it would look if he went by plane and his top salesman went by train. So the manager began to show him newspaper stories of how safe air travel was, how many air miles flown without incident and every time an agreement was made, the manager would come out of his office and say "Look, another one went down in Spain" or wherever. Then. the build up of confidence would begin again. The salesman finally agreed he would fly, but he needed booze before boarding. A bet was made if the salesman could fly sober, the manager would pay his bar tab the entire week in Atlanta. We found out they went to the counter and the manager told the agent "Give us two chances to Atlanta" and the salesman did a 180 straight to the bar. That's why the manager was the manager.

How early could the Army have reasonably pulled the plug on the P-39 and called it quits, or at least keep it in a developmental stage?
And what might have the ramifications been?
Perhaps have Bell build something else under license?
Build more P-40's to fill the void? Perhaps NAA would have stepped up and said, hey, we can build a better P-40?