# Has a Merlin ever been put into a P-39?



## MikeGazdik (Feb 2, 2009)

I have been reading through old posts, and digging up some nice newfound information on the P-39, one of my pet favorites. ( I like underdogs I guess)

Has anyone ever seen or heard about the P-39 having a Merlin installed? For racing or any other reason? That might be quite an airplane!!


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## Colin1 (Feb 3, 2009)

As far as war production goes

I don't think the P-39 was ever even conceptualised with a Merlin but the USAAF placed an order on 27Jun41 for two prototypes of the P-63 powered by the same V-1710-47 engine. The serials were 41-19511 and 41-19512. 
*A third prototype was also ordered, 42-78015, this one fitted with the Packard Merlin.*
The first prototype, 41-19511, flew for the first time on 07Dec42, the first anniversary of Pearl Harbour. It was destroyed on 28Jan43 when its landing gear failed to extend. 
The second prototype, 41-19512, followed 05Feb43. It too was destroyed, this time due to an engine failure. 
The Merlin-engined 42-78015 was later delivered with another Allison instead, as the Merlins were primarily needed for the P-51.

and as far as air racing goes

A P-63C-5 (44-4181/NX73744, race no 53) in natural metal finish was brought to the 1948 air races by Frank Singer. A year later, Singer returned with a P-63C-5 painted dark grey and trimmed in red.
Decades later, it is not clear whether Singer had one Kingcobra or two. Re-registered (B9009/race no 90) this ship was extensively modified and distinguished by a tiny bubble canopy when flown in the 1971 San Diego air races piloted by Larry Havens.
This aircraft had a shortened wing, concave wing tips, and a V-1710-135(G4) engine. 
*Plans existed to convert the craft to a Merlin engine* but before they could materialise, it was lost on a trials flight on 07Sep72 when Havens bailed out.

And that's about as much as I can find concerning Merlin interest for the P-39.

*Sources*
Bell P-39 Airacobra
Robert F Dorr Jerry Scutts
Crowood Aviation Series
ISBN: 1 86126 348 1
Page 130


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## MikeGazdik (Feb 3, 2009)

Wow, very detailed, thanks for the info Colin. I didn't think the Air Corps / Bell had had ever tried. I had figured some racer would have attempted the conversion. With the amount of P-39 /P-63 airframes being found on the increase, I wonder if anyone would try it in the future. 

Which leads me to two more seperate thoughts. 1) Is a P-39 / P-63 lighter than a P-51 and if so, would that translate to more speed around the pylons? 1b) A P-63 does have laminar airfoil wings correct? 2) If the Allisons were orginally better at low altitude, and the Merlins at high altitudes, why are the Merlins THE inline for Unlimited racing? Couldn't the Allison be tuned to equal or greater performance since the racing is on the deck. Or is the Allison still limited by its single stage supercharger even down low when racing?


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## claidemore (Feb 4, 2009)

There are low alt rated Merlins, as well as high alt ones.


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## Colin1 (Feb 4, 2009)

MikeGazdik said:


> 1) Is a P-39 / P-63 lighter than a P-51 and if so, would that translate to more speed around the pylons?
> 
> 1b) A P-63 does have laminar airfoil wings correct?


*P-39*
Empty: 5,600lbs (2540Kgs)
Loaded: 7,780lbs (3530Kgs)
Max speed: 380mph

*P-63*
Empty: 6,375lbs (2892Kgs)
Loaded: 10,500lbs (4763Kgs)
Max speed: 410mph

*P-51 (Allison)*
Empty: 6,300lbs (2858Kgs)
Loaded: 8,600lbs (3901Kgs)
Max speed: 390mph

*P-51D *
Empty: 7,125lbs (3230Kgs)
Loaded: 11,600lbs (5,206Kgs)
Max speed: 437mph

The P-63 was outwardly similar to the P-39, the lineage was obvious and unmistakeable but it was a completely different aircraft. Unfortunately, most of the novel design features were set prior to Pearl Harbour; at the time the design must have looked as good as anything.
The P-63 did indeed employ a laminar-flow wing section but I have my doubts as to the efficacy of the technology as applied to any WWII fighter, not just the P-63.


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## MikeGazdik (Feb 5, 2009)

I guess what I am getting after is this thought. P-51 and P-63 both have laminar wings. The 63 is a little lighter, and I may suspect a little more aerodynamically clean. Put a race Merlin in one with the right prop, you might have a tough racer!


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## Colin1 (Feb 5, 2009)

MikeGazdik said:


> I guess what I am getting after is this thought. P-51 and P-63 both have laminar wings. The 63 is a little lighter, and I may suspect a little more aerodynamically clean. Put a race Merlin in one with the right prop, you might have a tough racer!


Yes
I can see what you're driving at, the fly in the P-63 ointment for me was the retention of the awful, car-door/canopy arrangement that must have dragged at the a/c's aerodynamics.
A few were fitted with a teardop-style canopy a la P-51D, other than that it looked a beautifully clean a/c that has features I'm surprised weren't more extensively emulated throughout the industry. The use of leading-edge radiator cooling, vented at the trailing edge exploiting Meredith Effect and doing away with boxy, under-wing coolers and ventral scoops. This, admittedly, might have proved tricky for a/c using Fowler flap arrangements but then again, maybe not, the vent being blended into the upper wing possibly. 

The other is the mid-engined layout, contentious maybe but like performance cars, it distributes the a/c's weight beautifully, gets it up on tricycle undercarriage for better ground-handling visibility and puts a big, punchy armament in the airscrew. I don't know how comfortable a pilot would feel sitting so close to the airscrew but he could conceivably have been moved much further forward giving him an unparallelled view of his own battlespace, instead of the enemy a/c 'disappearing' behind his engine cowl; it wasn't until planes like the Me163, the Ar234 or the Meteor that this was exploited. I discount the P-38 pilot because he doesn't have airscrews in front of him to worry about.

Fitted with the Packard Merlin, I see no reason why it couldn't have competed with the P-51 in everything but long-range escort - the only viable internal tankage area being occupied by the engine.

As a racer, I agree, it would have made a tough opponent but neither the P-63 nor the P-51 were fast enough in level flight to truly exploit laminar-flow technology - it wouldn't have helped.


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## FLYBOYJ (Feb 5, 2009)

Colin1 said:


> YesA few were fitted with a teardop-style canopy a la P-51D, other than that it looked a beautifully clean a/c that has features I'm surprised weren't more extensively emulated throughout the industry


Agree...


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## drgondog (Feb 5, 2009)

Colin1 said:


> *P-39*
> Empty: 5,600lbs (2540Kgs)
> Loaded: 7,780lbs (3530Kgs)
> Max speed: 380mph
> ...



Hard to pin down. What we do know is that airfoil had a very low Cd0. We debated (on this site) quite extensively Gene Lednicer's VSAERO modelling paper for the P-51B and D, the Fw 190A and D-9 and the Spit IX with excellent graphics demonstrating pressure distribution and drag results very closely approaching the wind tunnel results.

The only limitation that VSAERO had from any theoretical modelling approach I have seen is the inability to introduce surface roughness and any non-steady indicial velocity components to test separation conditions for AoA below critical. 

Interestingly again, from one of the NACA Charts Lednicer presented, the 51 was second only to the P-80 (of US) in total parasite drag - and definitely superior to both the 190s and the Spit and 47 and F4U and P-38 - all of which were in the Spit IX range, above the Fw 190D-9.


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## Colin1 (Feb 5, 2009)

drgondog said:


> Hard to pin down. What we do know is that airfoil had a very low Cd0. We debated (on this site) quite extensively Gene Lednicer's VSAERO modelling paper for the P-51B and D, the Fw 190A and D-9 and the Spit IX with excellent graphics demonstrating pressure distribution and drag results very closely approaching the wind tunnel results.
> 
> The only limitation that VSAERO had from any theoretical modelling approach I have seen is the inability to introduce surface roughness and any non-steady indicial velocity components to test separation conditions for AoA below critical.
> 
> Interestingly again, from one of the NACA Charts Lednicer presented, the 51 was second only to the P-80 (of US) in total parasite drag - and definitely superior to both the 190s and the Spit and 47 and F4U and P-38 - all of which were in the Spit IX range, above the Fw 190D-9.


I've not read that report
it sounds interesting and I'd like to dig it up and go through it.
I'm a big fan of the late Lee Atwood, a US aeronautics and later astronautics engineer; the man was a god and I have huge admiration for him, a genuinely clever guy.
He did some paper on laminar-flow and how it was there on the Mustang, it just didn't do much (what chance of finding that, I wonder?); I seem to remember something about laminar-flow being key to a WWII combat pilot in the dive.


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## Marshall_Stack (Feb 5, 2009)

How about putting a turbosupercharger in the P-39 as originally designed? I know that Bell fought to keep the turbosupercharger on the plane despite the USAAF and NACAs infinite wisdom to delete it (either because of drag or problems with the turbo). If I was Bell, I would have continued testing on that configuration.

I wonder what would have the higher gas consumption; the turbo and Allison or the Merlin 61?


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## Colin1 (Feb 5, 2009)

Marshall_Stack said:


> I wonder what would have the higher gas consumption; the turbo and Allison or the Merlin 61?


Looking at it purely from a mechanical data point of view;

*Allison*
Weight: 1340lbs (608Kgs)
Displacement: 28 litres (1710 cu in)

*Merlin 61*
Weight: 1320lbs (600Kgs)
Displacement: 27 litres (1650 cu in)

the Merlin looks to shade the Allison on fuel; 'ain't no replacement for displacement' holds but it costs fuel. The weight of any supercharger would also need to be added to the all-up weight of the Allison.


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## davebender (Feb 5, 2009)

> 'ain't no replacement for displacement' holds but it costs fuel


I am under the impression that newer versions of the DB605 were more fuel efficient then newer versions of the RR Merlin despite having a greater displacement.


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## Colin1 (Feb 5, 2009)

davebender said:


> I am under the impression that newer versions of the DB605 were more fuel efficient then newer versions of the RR Merlin despite having a greater displacement.


You're probably right
but as a rule of thumb it does hold some water...

my previous post doesn't unequivocally state that the Merlin was better on fuel than the Allison, I used basic, mechanical data to present my assumption that it _probably_ was


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## drgondog (Feb 5, 2009)

Colin1 said:


> I've not read that report
> it sounds interesting and I'd like to dig it up and go through it.
> I'm a big fan of the late Lee Atwood, a US aeronautics and later astronautics engineer; the man was a god and I have huge admiration for him, a genuinely clever guy.
> He did some paper on laminar-flow and how it was there on the Mustang, it just didn't do much (what chance of finding that, I wonder?); I seem to remember something about laminar-flow being key to a WWII combat pilot in the dive.



http://www.ww2aircraft.net/forum/polls/allied-tests-captured-bf-109-s-12456-4.html

Colin - Here is where I posted it last year..last link, bottom page, post 60


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## Colin1 (Feb 5, 2009)

drgondog said:


> Colin - Here is where I posted it last year..


Thanks fella
I'll be taking a look at that


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## MikeGazdik (Feb 6, 2009)

Ok guys, in laymen terms. On Laminar flow, you are saying that at the speeds these fighter used, it did not add speed? Even the Mooney uses this airfoil. I thought that the laminar flow wings of the Mustang and others greatly attributed to the speed these aircraft could obtain.


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## SoD Stitch (Feb 6, 2009)

MikeGazdik said:


> Ok guys, in laymen terms. On Laminar flow, you are saying that at the speeds these fighter used, it did not add speed? Even the Mooney uses this airfoil. I thought that the laminar flow wings of the Mustang and others greatly attributed to the speed these aircraft could obtain.



Laminar flow wings did contribute somewhat to an aircraft's top speed but, IIRC, they were more effective at making the airfoil more efficient, not just faster; the airflow over a laminar-flow wing was "less disturbed" than the airflow over a "normal" wing, making the wing slipperier and, therefore, more efficient, since there was less turbulence over the airfoil. However, laminar-flow wings also had to be kept in much better shape (i.e.: cleaner) than a normal airfoil, since any disturbances in the airflow negated the benefits of the laminar-flow wing. 

This is from Alfred Price's _Combat Development In World War Two: Fighter Aircraft_:

"One important airframe change which was not incorporated in the Spitfire during the Second World War was the so-called 'laminar flow' wing. This was a wing with an exceptionally fine finish; the surface roughness had to be less than .0005 of an inch and the maximum wave allowance was .0001 of an inch in any two inches of surface. The fineness of the finish was combined with a high-speed aerofoil section, with it's thickest point about half way back from the leading edge (rather than a third of the way back, in a conventional aerofoil). The first aircraft operational with the laminar flow wing was the North American P-51 Mustang, which entered service in the RAF in the summer of 1942. Later, re-engined with a Rolls-Royce Merlin with a two-stage supercharger, the Mustang became one of the outstanding fighters of the war. The effect of the laminar-flow wing can be seen if the performance of the P-51B Mustang is compared with that of the Spitfire IX; the comparison is valid, because the two aircraft were powered by almost exactly the same type of Merlin. In terms of wing span and area the Mustang's wing was closely comparable with that of the Spitfire; the latter's wing was 2 inches longer and about 4 per cent greater in area. Yet in spite of the similarity in wing dimensions and engine power, and the considerably greater weight of the Mustang (about a quarter greater), the latter was approximately 20 mph faster than the Spitfire IX for any given cruising power setting of the engine, and about 30 mph faster at maximum speed. The main factors responsible for this were the laminar-flow wing and the high-speed aerofoil."


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## Colin1 (Feb 6, 2009)

SoD Stitch said:


> The effect of the laminar-flow wing can be seen if the performance of the P-51B Mustang is compared with that of the Spitfire IX; the comparison is valid, because the two aircraft were powered by almost exactly the same type of Merlin. In terms of wing span and area the Mustang's wing was closely comparable with that of the Spitfire; the latter's wing was 2 inches longer and about 4 per cent greater in area. Yet in spite of the similarity in wing dimensions and engine power, and the considerably greater weight of the Mustang (about a quarter greater), the latter was approximately 20 mph faster than the Spitfire IX for any given cruising power setting of the engine, and about 30 mph faster at maximum speed. The main factors responsible for this were the laminar-flow wing and the high-speed aerofoil."


I doubt it
the 20 - 30mph difference is more realistically attributed to the outlet for the radiator cooling. North American engineers designed this to allow heated air to exit the a/c under pressure, thus providing the Mustang with, effectively, a rudimentary tail pipe. 

To say that the comparison is valid because both a/c share the same engine is a wee bit shy of good science, the prominent carburettor air intake and boxy under-wing coolers on the Spitfire were not present on the Mustang.

Any advantage of the Mustang over the Spitfire was down to the thrust designed into the radiator cooling by exploiting Meredith Effect.

Laminar-flow would have made its presence more felt if the Mustang had been able to go faster but this wasn't going to happen, the propeller itself was beginning to impose drag and the fact that the wings of a WWII fighter stuck straight out to either side (ie unswept) were the new limiting factors in piston-engined development. 
Sure, there were later versions of the P-51 but they weren't fast enough either, they were just banging up against the limits of what you could do with a piston-engined a/c.

Laminar-flow could overcome the turbulence along the lift surfaces of the wing but it couldn't overcome the frontal, cross-sectional area of a straight-winged, propeller-driven a/c trying to move forwards faster.


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## drgondog (Feb 6, 2009)

Colin1 said:


> I doubt it
> the 20 - 30mph difference is more realistically attributed to the outlet for the radiator cooling. North American engineers designed this to allow heated air to exit the a/c under pressure, thus providing the Mustang with, effectively, a rudimentary tail pipe.
> 
> *While I fundamentally agree your point regarding the outlet (and inlet) design for the radiator, there are analytical studies recently which downplay the thrust effect of the design - reference the Lednicer report as an example for the analytical VSAERO approach on some design details for the racer STREGA..On the other hand the drag of the 51 inlet design was substantially lower than the spit (and 109) designs*
> ...



Not to be too picky - strictly speaking, the introduction of the boundary layer increase in the spanwise direction is the factor which causes laminar flow to transition to turbulent flow. The Laminar flow wing of the P-51 had its max thickness at ~ .4C versus the Spit (and most others at .3-35C). As you know the longer you maintain laminar flow over an airfoil, the later (and farther along the chord) the turbulent flow is created to introdue positive pressure gradient - chordwise - and therfore a profile drag component added to the wing when the airflow separates.

In the Lednicer model, even with his iterative steps to introduce a positive pressure gradient build up at trailing edge, the wing shows lift for what looks like ~ .9C - and that ain't gonna happen in real life.

Having said that his (Lednicer) model yielded very nice results to compare with the NACA wind tunnel and NAA flight tests made without prop (in dives to .75M).

Colin - At this point you may not agree what I said, and I am perfectly fine with leaving it at that rather than take this thread off course. Good to have you on the forum.


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## MikeGazdik (Feb 6, 2009)

So the laminar wing on a Mooney (modern general aviation) does nothing for the speed these aircraft are known?


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## drgondog (Feb 6, 2009)

MikeGazdik said:


> So the laminar wing on a Mooney (modern general aviation) does nothing for the speed these aircraft are known?



????


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## Colin1 (Feb 6, 2009)

drgondog said:


> Colin - At this point you may not agree what I said, and I am perfectly fine with leaving it at that rather than take this thread off course. Good to have you on the forum.


You've definitely got some points to consider
I've not read Lednicer's report yet, though it is downloaded
Mike's enquiry seemed to have two threads to it

did anyone fit a Merlin to a P-39
would the laminar-flow wing of the P-63 have made it a good racer

first one seems done and well, we're thrashing out the pros and cons of laminar-flow design so I'd say we're bang on topic

Good to be here - really.


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## drgondog (Feb 6, 2009)

deleted - something I was about to say based purely on speculation


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## MikeGazdik (Feb 7, 2009)

Sorry if I am dragging this out. But from what I have read from Colin and drgondog, laminar wings don't really add anything to the speed of the Mustang? Thats what Im getting from what has been said, I my be confused.

Yes this started out with my questiong on a Merlin Airacobra, but with the knowledge being posted here I am intrigued.


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## drgondog (Feb 7, 2009)

MikeGazdik said:


> Sorry if I am dragging this out. But from what I have read from Colin and drgondog, laminar wings don't really add anything to the speed of the Mustang? Thats what Im getting from what has been said, I my be confused.
> 
> Yes this started out with my questiong on a Merlin Airacobra, but with the knowledge being posted here I am intrigued.



I did not say that. 

Specifically the Mustang (and P-63) laminar flow wings both had less drag than the conventional wing designs that had max thickness at the 30% Chord range.

So yes, the laminar flow wing contributed to less drag, crucial for increased speed with same Hp. The parasite drag for the airframe is also crucial.

The disadvantage for the laminar flow wings is that, as Colin pointed out, the manufacturing tolerances of the wing surfaces are more important, maintenance in the field to keep dirt/mud off the wings is important, and the CL of the wing is both less (typically) and reaches that point at a lower angle of attack - requiring more design scrutiny for low speed and/or high angle of attack handling charcteristics...

I suspect the fuselage of the Mustang was simply a better design from a parasite drag standpoint - as the primary difference between the P-63 and P-51 B/C/D/K/H top speed.


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## Colin1 (Feb 7, 2009)

Colin1 said:


> You've definitely got some points to consider


Sorry, that didn't read right
You've definitely _given me _some points to consider


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## Watanbe (Feb 7, 2009)

P-63 is a plane I know very little about! How did it perform in combat? I know the US never used it operationally but did the Russians have success with it? Was the poor low level altitude of the P-38 rectified?


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## MikeGazdik (Feb 7, 2009)

drgondog said:


> I did not say that.
> 
> Specifically the Mustang (and P-63) laminar flow wings both had less drag than the conventional wing designs that had max thickness at the 30% Chord range.
> 
> ...



Thankyou, much more clear to me as to what you were saying.

Watanbe; I don't know a whole bunch about the Kingcobra as compared to the Airacobra. The Allison was some 1500hp, and I believe did incorporate a different supercharger than the earllier Allisons which helped it work at higher altitudes, though I don't think as well as the Merlin. It had laminar wings also. I don't know if it was the added power at altitude or the wings but they could do a little over 400mph for speed. Good, but they came out when the P-51 was THE plane, so the U.S. didn't want them. The internal layout of the aircraft limited fuel capacity so they had poor range without droptanks. All that aside, I still like the P-39 and P-63 for the innovation. And arguably Airacobra may be one of the best names for a fighter. Plus I think they look "sexy" sitting up high on its tall gear. Some planes only look right in the air.


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## Watanbe (Feb 8, 2009)

Thanks! How did they compare to something like a FW190 or a Me109? I'm assuming they were inferior? The Kingcobra has always been a mystery to me because as you said the 400mph speed is quite impressive and looking at the plane its hard to see it failing!


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## MikeGazdik (Feb 8, 2009)

The P-39 was used extensively in combat, producing Russian aces that fought against the Bf 109's and Fw 190's. But the P-63 was a late war airplane. The Russians got the vast majority of them, but from what I understand very few went to combat. By then the Russians were able to keep themselves supplied with thier own Yaks and LaGGs.


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## Watanbe (Feb 9, 2009)

I know of the Russians success with the P39, although they did fight at a lower altitude! I always wondered of the operational history of the P-63! I have always highly rated the Yak 9 and LaGG 5/7 and the Russians must of thought highly enough of the cobra series to operate them along with their own fighters!


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## Marshall_Stack (Feb 9, 2009)

The only thing I heard about the P-63 in combat is that the Russians used them in against the Japanese when they invaded Manchuria in 1945. Not much else though....


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## TheMustangRider (Feb 9, 2009)

I read somewhere on the web that after the Russians recieved both the P-39 and the P-40, the found the P-40 to be an inferior fighter and not suitable for the close-support missions they were executing in the Russian front and on the other hand the only disadvantage they found on the P-39 is that it was not available in enough numbers and they even asked the US to stop sending P-40s and send as much P-39s as possible.


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## Colin1 (Feb 9, 2009)

*P-63 Combat Record*

Total P-63 production was 3,303 airframes. 2,421 of these were shipped to the Soviet Union and just over 100 to the Armee d l'Air. The USAAF held on to a few for training.

The USAAF's interest went no further than target practice for bomber gunners after their High Command realised the shortcomings of the bombers' ability to defend itself using gunnery. This was Operation Pinball and entailed a P-63 being shot at with frangible rounds that lit up a light on the a/c when strikes were recorded.

Two P-63s were sent to England, where considerable interest in the merits of laminar-flow led them to take delivery of a P-63A-6 (42-68937) and a P-63A-9 (42-69423) to the RAE at Farnborough. In the course of its study, the A-6 was fitted with the streamlined bubble canopy. This a/c was damaged in a landing accident and was SOC on 18Oct45. The rest of the laminar-flow study was undertaken by the A-9 and it was finally scrapped Sep48.

One Central American country received a batch of P-63s, this being Honduras, taking on charge 5 P-63E-1s and along with 6 P-38Ls made up the mainstay of their airforce for over 5 years. One of these was damaged and provided the surviving 4 with much-needed spares. Two more were damaged and eventually all of them were replaced by F4Us.

P-63s were ferried to the Soviet Union in larger numbers than all other recipients combined, starting with the P-63C, pausing at way-stations in Alaska and Iran (imagine that). It is widely held that the P-63's reputation was short-changed as it never received the local press of the Ilyushin-2 Shturmovik, despite its proven abilities in ground attack and tank-busting.

The Soviets continued military action in the Far East, furthering their acquisition of Manchuria by annexing Sakhalin Island and parts of the Kuriles chain. The Japanese, though exhausted from WWII, fought back and destroyed 62 Soviet aircraft of all types, including 1 P-63, the details of which are unknown.

Just before the end of WWII, the USAAF began transferring P-63s to France for use by the Armee de l'Air. All a/c supplied were the penultimate P-63C-5 model.
The French originally placed an order for 300 a/c though this was later reduced to about one third of that. An initial contract for 40 a/c was signed on 03May45 and a second for 70 a/c on 04Jun45, totalling 112 a/c to which two more were added.
The P-63 was originally intended to directly supplant the existing P-39Q and L fighters but some went straight from the docks into storage. Others were used to equip several Armee de l'Air squadrons; GC9 based in Meknes, Morocco became the first to fully equip on the type.
Trouble brewed for the French in Indo-China, where the locals felt they had earned the right to govern themselves after contributing to the ousting of the Japanese during the previous war. The colonial powers had other ideas and armed conflict was on the cards.
85 P-63s were shipped to Indo-China between July and October 1950 for use by 5 Groupes on a rotational basis.
Most of these were the a/c that had been shipped straight into storage. All were armed with the standard centreline M-10 37mm cannon with 58 rounds plus 4 x .50cal machine guns, 2 in the nose and 2 in underwing gondolas. A 175gal contoured belly tank was usuallly carried and this could be supplemented by 75gal tanks outboard of the underwing guns. This fuel could be swapped for napalm or 2 500lb bombs. The centreline rack was wired for bomb release and provision was made for paired wing launchers for up to 4 HVAR rockets.

*30 August 50:* Ground attack sorties by 5 P-63s against Viet Minh troops.

*04 September:* Strafing missions against guerilla hide-outs and storage dumps; their cannons and machine guns were used to deadly effect.

Further shipments of P-63s were made to Saigon and the French had about 50 a/c in-theatre with about 10 held at an MU, Parc 482.

*10 January:* Less than spectacular debut for napalm

*19 January:* Loss of first P-63 to flak

The Viet Minh, by now being supplied by the Chinese, were getting stronger and French installations were occasionally overrun in the frequent attacks.

*13 February:* Air support for the garrison at Phu Loc failed to prevent it from falling

*3 August:* Having flown 3,703 hours of combat sorties in their P-63s, GCI/5 prepared to return home. II/5 and III/6 maintained the pressure on the guerillas but without appreciably decreasing the Viet Minh's hold on the country. The Armee de l'Air found themselves frustrated by an enemy who rarely went 'toe to toe' with them in pitched battles.

*9 August:* P-63 lost to flak

*4 October:* P-63 damaged by flak in the same area

*6 October:* A detachment of P-63s was sent to Lang Son to provide cover for a supply route favoured by the French.

*17 October:* Lt Perrotte made an emergency landing on Lang Son after being hit by small-arms fire and his a/c started streaming glycol. The French had to abandon Lang Son quickly and another P-63 was sent to destroy Perrotte's machine with a strafing run.

Normandie-Niemen arrive in-theatre, commanded by Capitaine Billoin.

*3 November:* III/6 moved to Cat Bi near Haiphong, where it steadily increased its sortie rate against an increasingly tough enemy who had gained control of the countryside, if not the towns.

*12 February:* III/6 had flown its 1,000th sortie.

*March:* Normandie-Niemen P-63s used for napalm against large-scale attack on Viet Minh infantry at Tra Vinh.

*5 May:* Loss of P-63 to flak

*14 September:* Loss of P-63 to flak

*22 October:* Loss of P-63 to flak

By the time of that last loss, the P-63 was being supplanted by the F8-F

*December:* Enough F8-Fs in-theatre, P-63 sorties began to tail off

*January 51:* 8 P-63s attack ground targets at Cho Phong

*19 January:* 2 P-63s fly armed recce along Thai Nguyen, flak claim one a/c

*20 January:* Loss of P-63 to flak

*28 January:* 2 P-63s failed to return from rocket strike south of Thai Nguyen

In 76 missions, I/9 lost 8 pilots and 9 a/c.

Viet Minh troops were now engaging crack French regiments in pitched battles, the P-63s supported with bombing, strafing and rocket attacks against troops and strongholds wherever they could be found. Eventually, the F8-F and F6-F completely replaced the P-63s and the F8-F in particular proved its superiority over the P-63 in the harsh conditions of Indo-China.

*30 April:* 24 P-63s bombed Quynh Lu, 21 of the 24 bombs hit the target.

At the end of their service 25 P-63s had been lost on ops or in accidents, 20 were SOC as war weary and 40 still in good condition were earmarked for shipment to Africa.

*Sources*
Bell P-39 Airacobra
Robert F Dorr Jerry C Scutts
Crowood Aviation Series
ISBN:1 86126 348 1
Pages 134 - 144
_not typed verbatim_


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## Marshall_Stack (Feb 9, 2009)

Does anyone know how well the external supercharger of the P-63 performed? All I know is that it has a variable speed hydraulic coupling. Being an engineer, it sounds interesting....


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## Colin1 (Feb 9, 2009)

Marshall_Stack said:


> Does anyone know how well the external supercharger of the P-63 performed? All I know is that it has a variable speed hydraulic coupling. Being an engineer, it sounds interesting....


Sorry fella
my source reveals nothing on supercharger specifics, I could dig around and see what else I've got


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## MikeGazdik (Feb 9, 2009)

I can also find very little about the P-63 Allison. I believe it is similar to the P-82 Mustang, so maybe we can dig up some info in that manner. One article I found alluded to the P-82 having the same engine, but I'm not sure of the accuracey of that information. Also the way it described the engine, there was no intregal first stage blower, it was all on this "external" two stage supercharger. Thats all I have been able to find. I have to get off my cheap butt and buy some books on the Airacobra / Kingcobra.


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## drgondog (Feb 9, 2009)

MikeGazdik said:


> I can also find very little about the P-63 Allison. I believe it is similar to the P-82 Mustang, so maybe we can dig up some info in that manner. One article I found alluded to the P-82 having the same engine, but I'm not sure of the accuracey of that information. Also the way it described the engine, there was no intregal first stage blower, it was all on this "external" two stage supercharger. Thats all I have been able to find. I have to get off my cheap butt and buy some books on the Airacobra / Kingcobra.



The P-82 E night fighter version had the 1710-143/145 Allisons which were basically the same as the 1650-9 (P-51H) engine with a Bendix speed density carb used for fuel monitoring.. damn good engine...doubt that it was the P-63 which I think was the -121


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## fly boy (Feb 10, 2009)

one thing about it 
on dec 7 1941 a p-39 pilot from one of the partys the noght before manged to get up in the air and shoot down two zeros ..... in a tux 

the only pilot to get a kill in a tux other then bond


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## Marshall_Stack (Feb 10, 2009)

fly boy said:


> one thing about it
> on dec 7 1941 a p-39 pilot from one of the partys the noght before manged to get up in the air and shoot down two zeros ..... in a tux
> 
> the only pilot to get a kill in a tux other then bond



Where at? I didn't think that there were any P-39s at Pearl Harbor, just P-40s and P-36s.


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