SHOULD the P39 have been able to handle the Zero? Was it training or performance? (3 Viewers)

[BiffF15]

Since the Hellcat was considered the unquestioned master of the Japanese planes, the P-39N should have been able to handle Zeros like the Hellcat. Zeros were 330-340mph planes, Hellcats and P-39Ns were 40-50mph faster at all altitudes.

The simple problem with this is airfields. The USN planes had movable ones and the AAF did not. Next problem is range. The 51, 47, and 38 all had the legs so they could cover the distances required and still have station time to fight before bingo (RTB fuel state).

Cheers,
Biff

 

[Shortround6]

P-39 was not superior to the Spitfire IX or Merlin P-51, I have never stated this. Those had two STAGE engines for high altitude performance.

The F4U and Hellcat had two stage mechanical R-2800s. The P-39N substantially outclimbed both the Corsair and Hellcat. Those planes and the P-47 (those operational in 1943) climbed about the same as the FW190, a little under 3000fpm initially and around 1800fpm at 20000' with a service ceiling of 37000'. The N climbed at near 4000fpm initially and 2650fpm at 20000' with a service ceiling of 38500'. The N was faster under 15000' and a little slower at 25000', 375mph vs about 390mph for the Corsair which was faster than the Hellcat. Hard to believe the N had a higher ceiling than Corsairs and Hellcats.

Since the Hellcat was considered the unquestioned master of the Japanese planes, the P-39N should have been able to handle Zeros like the Hellcat. Zeros were 330-340mph planes, Hellcats and P-39Ns were 40-50mph faster at all altitudes.

You are relying on that stripper N (or at the least low fuel) using WEP power for your performance figures. OK I will concede that this N, which shows up sometime in the middle of 1943 in combat theaters, could handle a Zero, IF the Zeros were delivered to the close vicinity of the P-39s airbase.
SEE:http://zenoswarbirdvideos.com/Images/P-39/P39FOIC.pdf
P-39Q FLight operation chart for P-39Q with 87 gallons of fuel and weight between 7200-7600lbs using the same engine as the N (?)
The Small tank P-39s couldn't go anywhere and get back. Even with a drop tank you are restricted to around 100 miles or less over Europe.
In the Pacific you can go a bit further (lower cruising speeds work) but base protection interceptor is a rather limited role for plane thousands of miles from home.
More general purpose planes were wanted for the investment in logistics and ground crew.

 

[drgondog]

In order to spin a plane must first stall. According to the training films and other sources the P-39 had excellent stall characteristics with plenty of warning and no wing drop. I wouldn't recommend spinning one, but you had to get into substantial trouble before that happened.

Regarding the fuselage tank, I read a pilot's comments that it was a court martial offense to use the fuselage tank before exhausting the drop tanks. Any usage of the fuselage tank prior to exhausting the drop tanks meant a loss of range if the drop tanks had to be dropped before they were empty. Use your fuselage tank before your drop tanks and you have one third less internal fuel after they are dropped.

Both the FW190 and the P-47 wings were too small. Both were known as sleds and the FW190 had real stall problems and the resulting spin was quite an experience with control reversal.

There were a lot of propeller comparisons in wwiiaircraftperformance for the P-47, but again did any of these props actually get used before 1944? The P-47D-10 test on Oct 11 1943 said it used the STANDARD Curtiss 12'2" propeller that had been used on all the production P-47s to date. One thing that I don't like about wwiiaircraft is all the experimental testing with different propellers and exotic fuels that never got into use before the Luftwaffe was defeated in March 1944. So a lot of information is on that site about planes that never saw the light of day, or if they did it was too late to have a meaningful impact on the war. Oh well.

You bring so much criticism from others because you wander astray with value judgments about other aircraft that simply aren't based on facts.

The FW 190 was regarded by most that flew it, including post war luminaries like Wing Captain Winkle Brown to be one of the most responsive and good handling fighters of the war. Second point about 190 stall - yes it had a vicious stall response - due largely to no washout for outer 20% of semi span. That said, many LW pilots PUT the 190 into a spin because it was easy to recover from. A favorite trick was full throttle showing exhaust smoke and a spin to fool a pursuing pilot into thinking he had shot the 190 down.

Second, The P-47 (highest) , Bf 109G, P-51B, FW 190A (about the same) had a wing loading within ~ 5% of each other at full internal combat load. There were no 'lead sleds' in comparison until the escort altitudes were reached and the HP available for the P-51B and P-47D compared to HP required began to heavily favor both US fighters. The P-47D easily out turned the FW 190 above 25,000 feet - and conversely was out turned by the Bf 109 and FW 190A under 20,000 feet (Ditto climb and acceleration). Nothing out rolled an FW 190, including a P-39/63 on its very best day.

March 1944 marked the point in time when the P-51B eliminated safe sanctuary for the LW T/E day and night fighter as bomber destroyers, as well as introduced the heavy attrition of LF Reich over central and deep Germany/Poland/CZ. The operative word is 'Introduced'. It was the beginning of the end of the LW ability to resist the Invasion on June 6, but a lot of aircrews (day and night) were lost between March 1 and June 5, 1944. The bleeding continued throughout the summer and finally ended with Bodenplatte in the West.

As to 'stability'? Yes the P-51B/D was limited in high G maneuvers until approximately 20-25 gallons of fuel had been burned down in the 85 gallon fuselage tank. Easily solved. SOP for mid Germany escort was to fill the fuse tank to 65 gallons. For long range (Stettin/Posnan), burn 25 gallons climbing to 25,000 feet from UK, then switch to externals. There were no other factors affecting aft CG for the Mustang, but shooting most ammo from nose was a factor for the P-39. According to pilot notes, the pitch controls were extremely sensitive (AHT pg 200) resulting in comments like "If you moved the stick 1" the resulting change in level flight CL of 0.20 to 'new stall CL' of 1.4 with normal CG location - resulting into stall/spin". With aft CG/Ammo expended, the flight stability deteriorated - "After the CG moved back, the airplane would do strange things' including snap rolls, spins, pure tumbles' as the stick forces per G of maneuver were below all other operational US fighters and below AAF standards.

At normal landing speeds per flight test report (AHT, pg 203) "Stalls always developed with no warning of approach, no buffeting of the aircraft or controls". One G and accelerated stalls were similar - "The P-39 would do the most wicked stall of any airplane I flew. That is why there were so many stall-spin accidents."

I suspect from an aero standpoint that the lack of wash-out for the P-39 was the major contributor to lack of aileron warning or authority in near stall conditions. It is clear that stick force per G and particularly for both roll and elevator response were primary factors for entering accelerated stall conditions leading to departures.

Most of the comments presented by Dean were extracted from both AAF Flight tests at Eglin as well as the many pilots that flew it as anecdotal summaries. The P-63 allegedly solved some of the stick force issues but Stab/Control remained the gating factor preventing AAF acceptance as operationally suitable..

 

[MIflyer]

For those who have not read it, this is an interesting account of the 67th Ftr Squadron and its P-400's on Guadalcanal:

https://ia902205.us.archive.org/17/items/PacificCounterblow/PacificCounterblow.pdf

It says they looked into reducing the weight of the P-39 and by the end of September 1942 were able to strip a P-39K of 650 lb of its original equipment. It also says that Gen Harmon asked DC for the P-38, P-47, or the P-40 with the Merlin engine. I guess that explains why those P-40F's got to Guadalcanal.

 

[Shortround6]

In order to spin a plane must first stall. According to the training films and other sources the P-39 had excellent stall characteristics with plenty of warning and no wing drop. I wouldn't recommend spinning one, but you had to get into substantial trouble before that happened.

Regarding the fuselage tank, I read a pilot's comments that it was a court martial offense to use the fuselage tank before exhausting the drop tanks. Any usage of the fuselage tank prior to exhausting the drop tanks meant a loss of range if the drop tanks had to be dropped before they were empty. Use your fuselage tank before your drop tanks and you have one third less internal fuel after they are dropped.

Both the FW190 and the P-47 wings were too small. Both were known as sleds and the FW190 had real stall problems and the resulting spin was quite an experience with control reversal.

There were a lot of propeller comparisons in wwiiaircraftperformance for the P-47, but again did any of these props actually get used before 1944? The P-47D-10 test on Oct 11 1943 said it used the STANDARD Curtiss 12'2" propeller that had been used on all the production P-47s to date. One thing that I don't like about wwiiaircraft is all the experimental testing with different propellers and exotic fuels that never got into use before the Luftwaffe was defeated in March 1944. So a lot of information is on that site about planes that never saw the light of day, or if they did it was too late to have a meaningful impact on the war. Oh well.

Many evaluations of the P-39 contradict that statement about stalls. and speaking about control reversal. On the P-39 with wing guns and full ammo loads the proper spin recovery use of ailerons was opposite the proper use of ailerons without or with light load of ammo.

You keep claiming one thing and then back tracking. It is true the P-47 couldn't turn with a 109 but the against the 190 it was not so clear cut. And an Aircobra trying to turn against a 109 may not be happy with the result so why pick on the P-47 to begin with?

A Mustang was supposed to be able to get home from the point where it dropped it's tanks and fought for 20 minutes over a distance of 460 miles. The rear tank extended the planning radius to 700 miles. Obviously there were a bunch of missions where the rear tank didn't need to be used or would work perfectly well if some fuel was burned off. A P-51D could do about 5 miles per gallon at 370mph true at 25,000ft. even 25 gallons was good for 125 miles.

You keep getting called on the March 1944 date. That may be the date at which point somebody/s decided the outcome was no longer in doubt, the timing of the outcome was not anywhere near certain and thousands of airmen (on both sides) died in the next year. The air war was hardly over.

 

[pbehn]

www.taphilo.com/history/WWII/Loss-Figures-Aircraft-USA-Training.shtml
The accident rate per 100,000 hrs training/no of fatalities
P38 = 139/379
P39 = 245/395
P40 = 188/350
P47 = 127/455
P51 = 105/137

Looking at the table which is difficult to copy here, the P 39 was not only more likely to have an accident than the other types, if it had an accident it was more likely to be fatal.

 

[DarrenW]

The P-39N substantially outclimbed both the Corsair and Hellcat. Those planes and the P-47 (those operational in 1943) climbed about the same as the FW190, a little under 3000fpm initially and around 1800fpm at 20000' with a service ceiling of 37000'.

Hi P-39 Expert,
While I agree that the P-39N had an excellent rate of climb, I would add that the P-47 didn't climb nearly as well as the Corsair or Hellcat until the advent of 100/150 fuels and the paddle blade propeller. The F4U-1 and F6F-3/5 easily had initial climb rates ranging between 3,000 - 3,600fpm (depending on power settings and use of water injection), while a P-47 wouldn't normally touch 3,000fpm unless it was running at the highest combat boost levels and sporting a paddle prop.

 

[Dimlee]

I am afraid this statement doesn't pass the smell test ... ... the Soviets had a shopping list of things they wanted from the USA and their commissionaires roamed the country ... inspecting factories and mostly getting what they wanted.
What didn't they get? 4-engined bombers ... the USA, GB and Commonwealth needed all such bombers for their 2-Front war ... which the Soviets were NOT fighting.
They received P-47s. They received state-of-the-art radar and communications equipment. They received machine tools. They received trucks, tanks, DUCKs. Food. Food. And more Food. Everything they received was what was being used by the Americans themselves.
And what the Soviets didn't received honorably .. they took by subterfuge ... aka Los Alamos project.
http://lend-lease.airforce.ru/english/documents/index.htm

Well, the Soviets just did not get ALL what they wanted. Request lists included B-17, B-24, B-29, Mosquitto, late Spitfire, P-61, etc. They wanted to have H2S radars, Nordon sights and much more. Hence the keynote of Soviet (and much of Russian language post-Soviet) historical literature: "they gave us left-overs, they kept the best for themselves, it was not fair!".

 

[P-39 Expert]

You are relying on that stripper N (or at the least low fuel) using WEP power for your performance figures. OK I will concede that this N, which shows up sometime in the middle of 1943 in combat theaters, could handle a Zero, IF the Zeros were delivered to the close vicinity of the P-39s airbase.
SEE:http://zenoswarbirdvideos.com/Images/P-39/P39FOIC.pdf
P-39Q FLight operation chart for P-39Q with 87 gallons of fuel and weight between 7200-7600lbs using the same engine as the N (?)
The Small tank P-39s couldn't go anywhere and get back. Even with a drop tank you are restricted to around 100 miles or less over Europe.
In the Pacific you can go a bit further (lower cruising speeds work) but base protection interceptor is a rather limited role for plane thousands of miles from home.
More general purpose planes were wanted for the investment in logistics and ground crew.

Wasn't a "stripper" N. Test was at combat weight with AVERAGE fuel. Add 360# back (60 gals, half fuel) and you get 7634# Gross weight of P-39N was 7650#. This was done to get the average weight for this flight. WEP only used below 16000', above the critical altitude WEP not available, by definition. The climb figures on the Oct 17, '42 test were at military power, no WEP. These were faster climb rates up to 25000' than any P-38F/G, P-40, P-47, P-51, Corsair, Hellcat, Wildcat, FW190, Me109, Zero, Oscar in combat in 1943. Not faster than the Spitfire IX or P-51B (December).

Your P-39Q operations chart clearly shows internal capacity of 86 gallons. The Russians requested the reduction since that's apparently all they needed since they seldom flew with drop tanks. N (and all older P-39s) originally had the full 120 gallon internal capacity. Normal combat P-39N carried a 110gallon drop tank. That's 120 internal plus 110 drop=230gals and drop tanks of 156 gallons and 175 gallons were also available.

 

[pbehn]

Well, the Soviets just did not get ALL what they wanted. Request lists included B-17, B-24, B-29, Mosquitto, late Spitfire, P-61, etc. They wanted to have H2S radars, Nordon sights and much more. Hence the keynote of Soviet (and much of Russian language post-Soviet) historical literature: "they gave us left-overs, they kept the best for themselves, it was not fair!".

You can put a spin on anything, the B 29 was the most expensive military project ever done at the time, who gives such things away, by the hundred? The USA wanted more mosquitos themselves but the fact is everyone wanted mosquitos at one stage. When you look at all that Russia actually was given completely free of charge their complaints are a bit OTT.

 

[P-39 Expert]

Hi P-39 Expert,
While I agree that the P-39N had an excellent rate of climb, I would add that the P-47 didn't climb nearly as well as the Corsair or Hellcat until the advent of 100/150 fuels and the paddle blade propeller. The F4U-1 and F6F-3/5 easily had initial climb rates ranging between 3,000 - 3,600fpm (depending on power settings and use of water injection), while a P-47 wouldn't normally touch 3,000fpm unless it was running at the highest combat boost levels and sporting a paddle prop.

I'm trying to limit the planes to those that were fighting in 1943.

 

[Dimlee]

You can put a spin on anything, the B 29 was the most expensive military project ever done at the time, who gives such things away, by the hundred? The USA wanted more mosquitos themselves but the fact is everyone wanted mosquitos at one stage. When you look at all that Russia actually was given completely free of charge their complaints are a bit OTT.

I was ironic. Let me put one more smiley to emphasize that..

 

[pbehn]

I was ironic. Let me put one more smiley to emphasize that..

I worked briefly in Russia and got the complaints first hand.

 

[Shortround6]

Wasn't a "stripper" N. Test was at combat weight with AVERAGE fuel. Add 360# back (60 gals, half fuel) and you get 7634# Gross weight of P-39N was 7650#. This was done to get the average weight for this flight. WEP only used below 16000', above the critical altitude WEP not available, by definition. The climb figures on the Oct 17, '42 test were at military power, no WEP. These were faster climb rates up to 25000' than any P-38F/G, P-40, P-47, P-51, Corsair, Hellcat, Wildcat, FW190, Me109, Zero, Oscar in combat in 1943. Not faster than the Spitfire IX or P-51B (December).

Your P-39Q operations chart clearly shows internal capacity of 86 gallons. The Russians requested the reduction since that's apparently all they needed since they seldom flew with drop tanks. N (and all older P-39s) originally had the full 120 gallon internal capacity. Normal combat P-39N carried a 110gallon drop tank. That's 120 internal plus 110 drop=230gals and drop tanks of 156 gallons and 175 gallons were also available.

DO you have ANY evidence that combat weight was at half fuel? You keep repeating but give no proof.

IN fact we may both be wrong.
http://www.wwiiaircraftperformance.org/P-39/P-39_Aircraft_Performance_Characteristics.jpg
Gross weights of Ns at 7393.7 and 7395.? I am not going to argue over a few pounds but both Ns are shown with 87 gallons of fuel.
Many books say that the "N"s were produced with 87 gallon capacity. Kits were supplied to bring them back to 120 gallons that could be installed in the field.
Military power was 44.5in of MAP, full WEP was 57in. this test was done at 50.5in (take-off power) until the supercharger could no longer supply that pressure.
Not WEP but not military power either. and then we have.
http://zenoswarbirdvideos.com/Images/P-39/P39TOCLC.pdf

P-39 Q at 7200lbs needs 9.3 minutes to get to 25,000ft using take off power for the first 5 minutes, and uses 33 gallons of it's 87 gallons just to get there.
P-39Q at 7600lbs needs 10.1 minutes to get to 25,000ft using take off power for the first 5 minutes and uses 34 gallons to get there.
the under wing pods created that much drag?????
Elapsed time to altitude was at 0 degrees C or 32 degrees F.

we also have the penciled in chart saying 4.1 minutes to 14,600ft?

and

about 300lbs heavier (120 gals fuel?) but even using MIlitary power for the first few minutes ( and NO drag from wing guns) needs over 9 minutes to get to 25,000ft.

We also have the basic Bf 109G climbing to 7000 meters ( 22,966ft) in 8 minutes so your p-39 had better be on watch. which climbed faster where I don't know.
I would also note that a plain Spitfire MK V using 16lbs boost (below 8,800ft) can make it to 24,000ft in 8.15 mins using a single speed single stage supercharger.

Now just for balancing things out a bit, the super P-39N is climbing at 1940fp at 25,000ft, the Spitfire V is climbing at 1740fps at 24,000ft and the 109G (basic?) is climbing at at least 2066 at 22,966.
A P-39Q at 7871lbs was climbing at 1570fpm at 25,000.

The P-39 has to be very careful about weights and altitude or it can get into big trouble.
Falling into the ocean because you don't have enough fuel can also ruin a pilots day

 

[tomo pauk]

I'm trying to limit the planes to those that were fighting in 1943.

In the Allied camp, the Spitfire IX, VIII, XII and Typhoon offer overall better performance and payload, that includes bigger drop tank volume. A P-39N/Q qith 87 US gals (72.5 imp glas) of fuel + 75 US gals (that is maximum, not 110 US gals) in drop tanks is next to useless for ETO, MTO and Asia/Pacific. Even the Spitfire V is better in some categories.
The P-40F and N are a bit slower, the N with less fuel and less guns can compete vs. Axis stuff, but it is again useless in ETO, MTO and Asia/Pacific. It can carry more fuel, though, and with 'normal' internal fuel it is can be useful. P-51A offers greater speed and far better range, the P-51 not so much.
P-47 (1943 - toothpick prop, 130 grade fuel, no ADI) can hold it's own vs. Axis best above 20000 ft, and dominates most of them above 25000 ft, with proper drop tanks ot was escorting bombers 375 miles away from East Anglia in Autumn of 1943. P-38 has it's own host of porblems, buat also it's crucial abilities - US commanders asked for more of those, they dont clamor for more P-39s.

I'll happily conceede that P-39N was either better or equal to the best Soviet, Japanese or Italian fighters, apart the range vs. Japanese gear. Unfortunately, it's advantage vs. Fw 190A-3/A-4 and Bf 109G-2/G-6 are limited to low to mid altitude, and climb performance depends on how much fuel tankage is installed and somehow getting the pilot on Fw 190 not to use 2700 rpm for climb. Ironically, both German A/C are longer ranged than P-39N with reduced fuel.

All of the mentioned Western A/C (bar Bf 109, maybe) have far better capability to carry external ordnance than the P-39. I'll repeat once again - the P-39N was not solving any real problem the Anglo-American (including Commonwealth) air forces had in 1943.

 

[XBe02Drvr]

However with the P39 the reports of tumbling and flat spins were actually not believed by Bell, only when they did tests with no ammunition were they believed. Now this means that the plane had not been fully tested before entering service, having no ammunition is a normal condition on a combat plane.

Whoa! Bell had to have been playing "Disingenuous" here. The idea that the possibility of aft CG stability issues never entered their minds, considering the unconventional layout of their bird begs credibility. And then to build a wing with no washout, thus guaranteeing a buffetless, violent stall? And whoever thought of not including the entire range of CG scenarios in flight testing?
IIUC, the purpose of the midships engine was to minimize polar moment of inertia and enhance agility. Any kindergartner can forsee that this will likely result in very light stick force gradients and a "twitchy" machine prone to over controlling and PIOs unless compensated for in the flight control linkages. Add that to the wobbly aft CG and the sharp stall characteristics, and you've got a tailor made "lieutenant loser". (The unintended Lomcevak is a free of charge fringe benefit! People pay good money at amusement parks across the land to experience thrills like that.)
It's hard to believe Bell would not have been aware of this, or that they would knowingly foist such a deathtrap on the government.
I've read here and there in dark ages of prehistory that USAAC Wright Pat forced a number of changes on Bell Aircraft to comply with some high ranking infantry officer in Procurement's concept of "improvements". IIRC, this included reducing the wing area to "go faster, like a GeeBee", adding a heavy radio behind the cockpit to talk to ground troops, and removing some bobweights from the elevator linkage and some other (don't remember) weight from the nose section.
Since we seem to have a P-39 expert in our midst, maybe he can enlighten us on this. Fact or fiction? And if fiction, any idea where that story came from?
Cheers,
Wes

 

[Shortround6]

I don't know about any of that but a reasonable explanation of the "tumbling" (at least reasonable to me, a non pilot) is on Page 256 of "Cobra" by Birch Mathews.

" The attitude from which a maneuver most resembling tumbling occured was that resulting from a stall with the airplane in a vertical position, following which the stick was pushed violently forward and held there for a prolonged period with high power still applied. From it's vertical attitude the nose of the airplane was pushed over as a result of the forward stick motion. The airplane performed a portion of an inverted snap roll, faltered momentarily and then did one or two turns of an oscillatory inverted spin. It then moved suddenly into a normal left hand spin of high rotational velocity. After one to three turns the spin became normal when the the engine was throttled.
In no case did the airplane do one complete tumble although its spen and snap roll were done so rapidly that at first glance, the manuever could be misinterpreted as an end-over-end motion. IN all cases, recovery form the the left spin was entirely normal when proper spin recovery technique was employed"

Later on the page is says
" With an extreme aft center of gravity, the airplane could be made to enter a snap roll and inverted oscillatory spin where the nose passed through the horizon two times during each 360 degree rotation."

I can agree that the P-39 never tumbled (or did so only under the rarest of circumstances) but that does not mean the plane was vice less or couldn't catch out an unwary pilot.
Stalls at low speed in landing configuration are often not the same as stalls in clean condition in high speed turns.

 

[DarrenW]

I'm trying to limit the planes to those that were fighting in 1943.

I understand that is what you were doing, but to lump all R-2800 engined fighters flying in 1943 as having similar initial climb rates is simply incorrect. Both Navy fighters could comfortably reach 3,000 fpm, but this was not the case with Thunderbolt as it struggled in the climb before the paddle prop was introduced and even then it still couldn't match the Corsair or Hellcat.

 

[pbehn]

Whoa! Bell had to have been playing "Disingenuous" here. The idea that the possibility of aft CG stability issues never entered their minds, considering the unconventional layout of their bird begs credibility. And then to build a wing with no washout, thus guaranteeing a buffetless, violent stall? And whoever thought of not including the entire range of CG scenarios in flight testing?
IIUC, the purpose of the midships engine was to minimize polar moment of inertia and enhance agility. Any kindergartner can forsee that this will likely result in very light stick force gradients and a "twitchy" machine prone to over controlling and PIOs unless compensated for in the flight control linkages. Add that to the wobbly aft CG and the sharp stall characteristics, and you've got a tailor made "lieutenant loser". (The unintended Lomcevak is a free of charge fringe benefit! People pay good money at amusement parks across the land to experience thrills like that.)
It's hard to believe Bell would not have been aware of this, or that they would knowingly foist such a deathtrap on the government.
I've read here and there in dark ages of prehistory that USAAC Wright Pat forced a number of changes on Bell Aircraft to comply with some high ranking infantry officer in Procurement's concept of "improvements". IIRC, this included reducing the wing area to "go faster, like a GeeBee", adding a heavy radio behind the cockpit to talk to ground troops, and removing some bobweights from the elevator linkage and some other (don't remember) weight from the nose section.
Since we seem to have a P-39 expert in our midst, maybe he can enlighten us on this. Fact or fiction? And if fiction, any idea where that story came from?
Cheers,
Wes

I agree, I am by no means well read on the subject, but I am much better read than I was a week ago. There are documented statements of poor stall performance. Handling or stability problems with ammunition expended are also documented which had to be brought to Bells attention. The one mission flown by the RAF was straffing barges near Dunkerque, the pilots I would suspect returned with no ammunition in a completely different plane to the one they took off in. I have no access to any flight reports but I strongly suspect the British tested the P 39 without ammunition/ballast and said "you must be joking" Additionally, wing washout causes drag, and is a price worth paying in the compromises made. All the P39s rivals would have gone faster with no washout.

Much is made of the P39 having a tricycle undercarriage landing gear, I would suggest it would be a very dangerous beast as a tail dragger.

 

[XBe02Drvr]

I would suggest it would be a very dangerous beast as a tail dragger.

AMEN!!