Talk:P-39 Airacobra

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[edit] P-39 performance

Answering to the 2 previous guys - indeed Spitfire could exceed 450mph, however its wing structure was not able to substain more speed than that with safety.This meant that some high-g would break the wing apast.Instead the P-39 could dive that fast with safety. In recent years what changed people's perconception's about P-39 is the Ubisoft flight simulator IL-2 FB, which as people who flew the P-39 (and several other warbirds) claim that is very close to the real thing as a flight sim can go. I would describe my impressions from the sim, and indeed war vets confirm these impressions.(by the way, I have a pilot lisence, even I have logged hours only in Cessnas 152/182, if that matters). You had to be very able with this plane.For example,with the Spitfire there was not much you could do:Just press 110% power, and try to go to the enemy.Spitfire didn't have even combat flaps.If you were going to make a stupidity, Spit would stall and then just give it a bit of opposite rudder and it would gain some speed and come back to your control. With P-39 you had to play with the throttle, combat flaps to try to get the best of it.P-39 was like a mid-engined car in some ways.It was oversensitive in pitch and this could make difficult for a novice pilot to aim and shoot a target.At least in the flight sim, it felt almost like sliding in the air like a car that slides in its four tires! Roll was fast, even not as fast as P-40 or Fw-190. A P-39 pilot had to be very careful with the rudder too.This was something that was greatly improved in P-63.P-39 didn't like sudden turns of the stick in various directions, something that a novice pilot would often do in his panic to avoid an enemy in its 6 o' clock.This was a certain way to stall.P-39 had a very unusual 30km/h flat spin which was impossible to escape!This was the worst characteristic in this plane. In various maneuvres it was necessary to obtain a certain speed.On the other hand, it could fly in the vertical until almost 30km/h, however this was extremely dangerous for a un-experienced pilot.Only the fantastic Bf-109 was better in this. A Spitfire would just point its nose down, as Yaks would do and other well-mannered planes, however in much higher speed... The P-39 was extremely aerodynamic, actually possibly even better than the P-51 and P-38, two planes that were excellent in this area.Pushing the throttle down, it wouldn't mean an instantaneous fall in speed as it would mean for various aircooled figthers...This would make more difficult to calculate its speed and then been in danger to fly ahead a target. For these reasons the P-39 was from fast to very fast in low altitudes and NOT as bad in medium altitudes, depending on the version and the year-period we are talking about.Don't think that a Spit LF IX was faster in low altitudes...just a bit better in climb speed, due to its more powerful engine. In dive was very fast (again only Bf-109 and the P-38/P-51 were as good). It was, probably to its engine arrangement, more difficult to shoot down than every-other liquid-engined fighter.Its 37mm cannon was really devastating ( I cut in 2 pieces a Ju-88 with just one shell in a mission...), however you needed to approach very close, due to its low muzzle velocity.This again needed an experienced pilot.Instead a novice P-47 pilot could almost spray the sky with bullets of high-velocity muzzles and have a chance to shoot down an enemy plane when the P-39's 2 0.50's were inadequate. Ah, and the car-like canopy was horrible, restricting vision. Conclusion: The P-39 was unpopular because it need an experienced pilot to get the best out of it (something not good at all when thousends of young americans were thrown in battle with absolutely no combat experience).Its canopy would make escape difficult and it didn't fit well to the specific operational needs of the USAAF. In a few words...what a plane! (the flight sim has the versions P-400, P-39D-1, P-39D-2, P-39N, P-39Q-1, P-39Q-10)


One paragraph states P-39 was too heavy compared to its contemporaries which made it inferior to other fighters, then the following parapgraph states it was an air superiority fighter in the hands of VVS. The truth is that while P-39 was somewhat heavier than some of its contemporaries, it was held by many to be one of the best low-altitude fighters of the war in terms of both speed and agility. Soviets liked it so much they worked with Bell on P-63 (least favorite lend-lease aircraft? Hurricane hands down). A remarkable feature of the P-39 was its very clean aerodynamics - I've read pilot accounts of difficulty bleeding off speed. The P-39Q-1 pilot's manual authorizes dives to 523 mph (825 km/h)! Spitfire IX manual says 450 mph (725 km/h) is the limit. - Emt147 Burninate! 17:23, 4 December 2005 (UTC)

I suspect the 450 mph figure for the Spitifre IX is given for a height an Airacobra coudn't even reach. The 450 mph figure you've quoted itself seems strange, as it's not that much faster than a Spitifre IX's top speed in level flight, and the Spitfire had one of the highest Critical Mach numbers ever measured. There should be higher IAS figures given for lower heights, the indicated speed increasing as the air becomes thicker at the lower altitudes. I suspect the highest figure should be around 550 mph for a Sptifire IX, but I don't have the Pilot's Notes myself.
According to Jeffrey Quill's Spitfire - A Test Pilot's Story, the Mark IX's Pilot's Notes gives a table of Vne figures at various heights, one of which works out at M 0.85. Quill's department themselves were diving Spitfire IXs to speeds slightly in excess of Mach 0.86
As mentioned in the article, the Airacobra/P-39s measured performance was considerably down on the figures given to the British Purchasing Commission and on which the 1940 British order was based. The results of an enquiry into this led to the setting up of an evaluation centre, similar to the A&AEE at Martlesham Heath (later Boscombe Down), at Muroc Field in the US. Ian Dunster 12:17, 26 July 2006 (UTC)


Spitfire were FAST also in dives. One of Spit Mk IX reached 960 kmh and more, perhaps over 1100, in a dive. When spit had airframe of the advanced models the structure was reinforced and so, it can reach a real hig mach number. P-39 was strong, no doubt, but its performance at altitude was hampered by rejecting the turbocharger, that was fitted on the same Allison engine in P-38s. This because the 'drag' of the stuff. But this eliminated the possibility to reach high performance with Allison, and none P-39 was fitted with Merlin.--Stefanomencarelli 08:56, 26 July 2007 (UTC)

Seen how P-39s in Italy was badly cutted, i report the whole history written on these aircrafts.

Italy[5] The willing of Cobelligerent Italian Air Force to fight against germans (missions in Italy were generally avoided because fratricide fight weren't well seen by Allied command, so Balkan was the operational zone) sent this airforce to put on first line all Re.2002s and Macchis that it was possible rescue on southern airfields. But these aircrafts were quite worn out and without any industry in the south capable to make them and replacements parts. So these machines dropped quickly in efficency.

When W.Churchill claimed that italians had fought well and needed modern aircraft (24 may 1944, at common's room), british allowed italians to fly on the old ofe, Spitfires. Also americans given some aircrafts: 223th Group leaved P-39s and went on P-47s, so italians were allowed to take these fighters. Totally, atleast 150 were taken on charge, among them, almost all N and Q, but also atleast one L and 5 M. This happened on june 1944. The traing of the 4 Stormo pilots was started and the Airacobra was put in action. N versions were over 200 hours old and dedicated to training, while more modern Q were put on first line. Atleast 19 accidents occurred while italian pilots tryed to take these aircrafts on operational status, among the victims, 25 august, Teresio Martinoli, an 22 victory ace, killed by an allied aircraft after 4 years of air battles.

The 3 groups of 4 Stormo were trained in a small and difficult airfield near Vesuvio, then sent at Galatina airfield in the fall of 1944. 18 sept was the first mission in Albany by a 12 group's P-39. Almost 70 aircraft were operational and until 30-40 at once were sent on balkans. Only november the continous action of strafing of P-39s caused heavy destructions on german side with 1700 hours of flight. Germans almost hadn't aviation, but a fierce flak reaction and accidents caused 10 losses and numerous damaged aircraft. Even if the sturdy and well armed P-39 was almost ideal on ground attacks, these losses weren't few for a single Wing.

After the war in whic almost 3000 flyng hours were made by 4 Stormo, still dozens of P-39s were in charge. 1 april 1946 the remaining 46 P-39s still efficients were sold to Italy at 1% of their cost. Those summer many accidents happened, even mortals. Only n 1947 4 Stormo had P-38s, and P-39s were sent at traing purpuse only, until 1951. By all those italian Airacobra only a T9 gun survive today at Vigna di Valle museum (for all these informations see Marco Gueli's article in the references).

--Stefanomencarelli 14:47, 2 August 2007 (UTC)

[edit] Department of airacorrections

I deleted

"by the Navy in favor of the infamous Brewster Buffalo instead"

as factually wrong (the F2A wasn't named Buffalo by the Navy, & it was to a 1934 program, which even a cursory glance at F2A would have shown...) this

"(which coincidentally also featured a single-speed, single-stage supercharger)."

as irrelevant (especially since single-speed, single-stage superchargers were about as uncommon on period fighters as VW Type 1s on L.A. streets in the '60s (& '70s &...). Also this

"fired with a 900gr ammunition at 610 m."

as hopelessly unclear, & this

"P-39's 1,150hp (at takeoff; 1,014 hp at 6,100 m) V1710 had a single-speed, single-stage supercharger, which brought about a decrease of performance compared to the promising prototype fitted with an exhaust-driven turbo-supercharger"

as wrong or misplaced, & this

"ordered in production but were only capable of 600km/h at 6100 m, with a climb to this altitude in 7.5 minutes."

as extremely questionable. That sounds to me like a rate of climb more like a Spit or 'stang... Oh, & while I was at it, I rewrote. Ta. Trekphiler 15:16, 21 August 2007 (UTC)

[edit] Portugal

This section is way too detailed for inclusion as only 19 a/c are involved. I suggest a sub-article and a brief note on Portugal's use of the aircraft remains. What say you? FWIW Bzuk 23:31, 6 September 2007 (UTC).

Support having a much briefer Portugal section. Binksternet 23:42, 6 September 2007 (UTC)
Support. The present text is too detailed even for Portuguese Air Force and belongs in a separate article. Grant | Talk 01:04, 7 September 2007 (UTC)
Support. Indeed, sorry about that, I was using a book and a website as a reference to create List of aircraft of the Portuguese Air Force, when I found detailed information about the P-39 operational history in Portugal — and I didn't even use all the information :X. Maybe the current content could be moved to an article dedicated to the operators of the Airacobra, like many other aircraft have (i.e. List of C-47 Skytrain operators), or to a dedicated section in the List of aircraft of the Portuguese Air Force article.
Best regards, Get_It 02:10, 7 September 2007 (UTC)
Thank you for this comment. That is exactly the kind of Wikipedia editor that we want. My suggestion is not to cut out this section but to make it a separate article that links back to the main body. FWIW Bzuk 04:23, 7 September 2007 (UTC).
Half a year later and there's been no change to this section. It is still too large, giving undue weight to the very, very minor role of Portugal's few P-39s. Binksternet (talk) 14:47, 16 May 2008 (UTC)

[edit] Bicobra

Anybody got free-use images of the 2-seat RP-39? It'd be a great addition. Trekphiler (talk) 02:25, 22 January 2008 (UTC)

[edit] After Pearl Harbor

The statement "about 200 repossessed by the Army" leaves the reader wondering which army it was... US? UK? It should be made clearer. Binksternet (talk) 14:27, 16 May 2008 (UTC)

I fixed that. It was the USAAF, none went to 8th AF and the Soviets got closer to 200 than 250 planes. Markus Becker02 (talk) 12:20, 11 June 2008 (UTC)