Bell P-39 Airacobra

Bell P-39 Airacobra

Première partie sur Wikipedia en version française :

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Le P-39 Airacobra est un chasseur américain de la [Vous devez être inscrit et connecté pour voir ce lien] construit par [Vous devez être inscrit et connecté pour voir ce lien].

Cet avion de conception très moderne (train tricycle) et aux caractéristiques prometteuses sur papier

(verrière panoramique,
armement de gros calibre dans l'axe peu courant aux États-Unis,
moteur au milieu du fuselage très facilement accessible,
entrée dans l'habitacle par une portière d'auto évitant les acrobaties habituelles,
enfin bonnes performances générales)

se révéla particulièrement décevant par son infériorité manifeste contre les chasseurs ennemis sur tous les fronts où il fut engagé (très vite en appui au sol plutôt qu'en chasseur) : Méditerranée, Pacifique, Russie.

Engagements

Il fut utilisé pendant la [Vous devez être inscrit et connecté pour voir ce lien] avec des résultats médiocres par les Américains dans le [Vous devez être inscrit et connecté pour voir ce lien], puis avec une relative efficacité par les Français en Afrique du Nord et Italie (pour l'[Vous devez être inscrit et connecté pour voir ce lien] et non la chasse)
et surtout par les Soviétiques (qui reçurent la majorité de la production) qui appréciaient beaucoup sa puissance de feu en couverture à basse et moyenne altitude (5000 m) où il savait se montrer particulièrement percutant en attaque au sol ou contre des [Vous devez être inscrit et connecté pour voir ce lien].

Les Britanniques en avaient commandé pour la [Vous devez être inscrit et connecté pour voir ce lien] qui, en ayant équipé une escadrille, l'envoya contre la [Vous devez être inscrit et connecté pour voir ce lien].

Les résultats ne furent pas spécialement mauvais mais la maintenance des appareils et les rapports des pilotes britanniques au sujet de son comportement en vol firent que l'escadrille en question fut immédiatement retirée du combat et rééquipée en [Vous devez être inscrit et connecté pour voir ce lien].

Les Américains firent une expérience analogue avec les mêmes résultats.

Ils ne virent dès lors aucun inconvénient à livrer le gros de la production (car l'important plan industriel de fabrication établi pour le P-39 tournait alors à plein régime) à des alliés moins regardants comme l'[Vous devez être inscrit et connecté pour voir ce lien], la France puis l'Italie de [Vous devez être inscrit et connecté pour voir ce lien].

Les Américains ne voulurent même pas engager au combat sous leurs couleurs le [Vous devez être inscrit et connecté pour voir ce lien], successeur très amélioré du P-39 qui ne combattit que sous d'autres couleurs (France, en [Vous devez être inscrit et connecté pour voir ce lien]) malgré le fait que les erreurs de
jeunesse du "cobra" aient été corrigées.


[Vous devez être inscrit et connecté pour voir ce lien]

Deuxième partie plus constante sur Wikipedia, english



The [Vous devez être inscrit et connecté pour voir ce lien] P-39 Airacobra was one of the principal [Vous devez être inscrit et connecté pour voir ce lien] fighter aircraft in service at the start of [Vous devez être inscrit et connecté pour voir ce lien].

Although its mid-engine placement was innovative, the P-39 design was handicapped by the lack of an efficient [Vous devez être inscrit et connecté pour voir ce lien], limiting it to low-altitude work.

The P-39 was used with great success by the [Vous devez être inscrit et connecté pour voir ce lien], who scored the highest number of individual kills attributed to any U.S. fighter type.

Other important users were the Free French and co-belligerent Italian air forces.

Together with the derivative [Vous devez être inscrit et connecté pour voir ce lien], these aircraft would be the most successful mass-produced, fixed-wing aircraft manufactured by Bell.


Design and development

In February 1937, Lieutenant [Vous devez être inscrit et connecté pour voir ce lien], Project Officer for Fighters at the [Vous devez être inscrit et connecté pour voir ce lien] (USAAC), issued a specification for a new fighter via Circular Proposal X-609.

It was a request for a single-engine high-altitude [Vous devez être inscrit et connecté pour voir ce lien] having "the tactical mission of interception and attack of hostile aircraft at high altitude".

Specifications called for at least 1,000 lb of heavy armament including a cannon, a liquid-cooled Allison engine with a [Vous devez être inscrit et connecté pour voir ce lien],
[Vous devez être inscrit et connecté pour voir ce lien],
a level airspeed of at least 360 [Vous devez être inscrit et connecté pour voir ce lien] (580 km/h) at [Vous devez être inscrit et connecté pour voir ce lien], and a climb to 20,000 ft (6,100 m) within 6 minutes;
the toughest set of specifications USAAC had presented to that date.

Although Bell's limited fighter design work had previously resulted in the unusual [Vous devez être inscrit et connecté pour voir ce lien],
the Model 12 proposal adopted an equally original configuration with an [Vous devez être inscrit et connecté pour voir ce lien] engine mounted in the middle of the[Vous devez être inscrit et connecté pour voir ce lien], just behind the cockpit, and a propeller driven by a shaft passing beneath the pilot's feet under the cockpit floor.

The main purpose of this configuration was to free up space for the heavy main armament, a 37 mm (1.46 in) [Vous devez être inscrit et connecté pour voir ce lien] firing through the center of the propeller hub for optimum accuracy and stability when firing.

In fact, the entire design was made to accommodate this gun in the aircraft.

This happened because H.M. Poyer, designer for project leader Robert Woods, was impressed by the power of this
weapon and he pressed for its incorporation though the original concept had been a 20–25 mm (.79–98 in) cannon mounted in a conventional manner in the nose.

This was unusual, because fighters had previously been designed around an engine, not a weapon system.

Although devastating when it worked, the T9 had very limited ammunition, a low rate of fire, and was prone to jamming.

A secondary benefit of the mid-engine arrangement was to create a smooth and streamlined nose profile.

Entry to the cockpit was through side doors (mounted on both sides of the cockpit) rather than a sliding canopy.

Its unusual engine location and the long driveshaft caused some pilot concern at first, but experience showed this was
no more of a hazard in a crash landing than with an engine located forward of the cockpit.

There were no problems with propshaft failure.

As originally designed, the XP-39 had a turbocharger with a scoop on the left side of the fuselage; both were deleted for production.

The production P-39 retained a single-stage, single-speed supercharger with a critical altitude (above which
performance declined) of about 12,000 ft (3,658 m).

The XP-39 made her maiden flight on 6 April 1938 at [Vous devez être inscrit et connecté pour voir ce lien],[Vous devez être inscrit et connecté pour voir ce lien], achieving 390 mph (630 km/h) at 20,000 ft (6,100 m), reaching this altitude in only five minutes.

The Army ordered twelve YP-39s (with only a single-stage, single-speed supercharger) for service evaluation and one YP-39A.

After these trials were complete, which resulted in detail changes including deletion of the external radiator, and on advice from [Vous devez être inscrit et connecté pour voir ce lien], the prototype was modified as the XP-39B; after demonstrating a performance improvement, the 13 YP-39s were completed to this standard, adding two .30 in (7.62 mm) machine guns to the two existing .50 in (12.7 mm) guns.

Lacking armor or self-sealing fuel tanks, the prototype was (900 kg) lighter than the production fighters.

Technical details


The P-39 was an all-metal, low-wing, single-engine fighter, with a tricycle undercarriage and an [Vous devez être inscrit et connecté pour voir ce lien] liquid-cooled Vee-12 engine mounted in the central fuselage, directly behind the cockpit.

The Airacobra was one of the first production fighters to be conceived as a "weapons system";
in this case the aircraft (known originally as the Bell Model 4) was designed around the [Vous devez être inscrit et connecté pour voir ce lien].

This weapon, which was designed in 1934 by the American Armament Corporation, a division of [Vous devez être inscrit et connecté pour voir ce lien],
fired a 1.3 lb (610 g) projectile capable of piercing .8 in (2 cm) of armor at 500 yd (450 m) with [Vous devez être inscrit et connecté pour voir ce lien] rounds.

The 200 lb, 90 inch long weapon had to be rigidly mounted and fire parallel to and close to the centerline of the new fighter; however, it would be impossible to mount the weapon in the fuselage, firing through the propeller shaft as could be done with smaller 20mm cannon.

Weight, balance and visibility problems meant that the cockpit could not be placed farther back in the fuselage, behind the engine and cannon.

The solution adopted was to mount the cannon in the forward fuselage and the engine in the center fuselage, directly behind the pilot's seat.

The tractor propeller was driven via a 10 foot long drive shaft which was made in two sections, incorporating a self-aligning bearing to accommodate fuselage deflection during violent maneuvers.

This shaft ran through a tunnel in the cockpit floor and was connected to a gearbox in the nose of the fuselage which, in turn, drove the three or (later) four bladed propeller via a short central shaft.

The gearbox was provided with its own lubrication system, separate from the engine; in later versions of the
Airacobra the gearbox was provided with some armor protection.

The [Vous devez être inscrit et connecté pour voir ce lien] cooled radiator was fitted in the wing center-section, immediately beneath the engine; this was flanked on either side by a single drum shaped oil cooler.

Air for the radiator and oil coolers was drawn in through intakes formed in both wing-root leading edges and was
directed via four ducts to the radiator faces.

The air was then exhausted through three controllable hinged flaps near the trailing edge of the center section.

Air for the [Vous devez être inscrit et connecté pour voir ce lien] was drawn in via a raised oval intake immediately aft of the rear canopy.

The fuselage structure was unusual and innovative, being based on a strong central keel which incorporated the armament, cockpit and engine.

Two strong fuselage beams to port and starboard formed the basis of the structure.

These angled upwards fore and aft to create mounting points for the T9 cannon and propeller reduction gearbox and
for the engine and accessories respectively.

A strong arched bulkhead provided the main structural point to which the main spar of the wing was attached.

This arch incorporated a fireproof panel and an armor plate separating the engine from the cockpit.

It also incorporated a turnover pylon and a pane of bullet-resistant glass behind the pilot's head.

The arch also formed the basis of the cockpit housing; the pilot's seat was attached to the forward face as was the cockpit floor.

Forward of the cockpit the fuselage nose was formed from large removable covers.
A long nosewheel well was incorporated in the lower nose section.

The engine and accessories were attached to the rear of the arch and the main structural beams; these too were covered using large removable panels.

A conventional semi-monocoque rear fuselage was attached aft of the main structure.^{[Vous devez être inscrit et connecté pour voir ce lien]}

Because the pilot was riding above the extension shaft he was placed higher in the fuselage than most contemporary fighters, which, in turn, allowed Bell to use a raised cockpit enclosure, giving the pilot a good field of view.

Access to the cockpit was via sideways opening "car doors", one on either side.

Both had wind-down windows; because only the right hand door had a handle both inside and outside this was used as the normal means of access.

The left hand door could only be opened from the outside and was only for emergency use, although both doors could be jettisoned. In operational service, however the cockpit was difficult to escape from in an emergency because the roof was fixed.

The complete armament fit consisted of the T9 with a pair of [Vous devez être inscrit et connecté pour voir ce lien] .50 in (12.7 mm) [Vous devez être inscrit et connecté pour voir ce lien] mounted in the nose.

This would change to two .50 in (12.7 mm) and two .30 in (7.62 mm) guns in the XP-39B (P-39C, Model 13, the first 20 delivered) and two 0.50 in/12.7 mm and four 0.30 in/7.62 mm (all four in the wings) in the P-39D (Model 15),
which also introduced self-sealing tanks and shackles (and piping) for a 500 lb (227 kg) bomb or drop tank.

Because of the unconventional layout, there was no space in the fuselage to place a fuel tank.

Although drop tanks were implemented to extend its range, the standard fuel load was carried in the wings, with the result that the P-39 was limited to short range tactical strikes.

In September 1940, Britain ordered 386 P-39Ds (Model 14), with a 20 mm (.79 in) [Vous devez être inscrit et connecté pour voir ce lien] and six [Vous devez être inscrit et connecté pour voir ce lien] (7.7 mm), instead of a 37 mm (1.46 in) cannon and six 0.30 in (7.62 in) guns.

The RAF eventually ordered a total of 675 P-39s. However, after the first Airacobras arrived at [Vous devez être inscrit et connecté pour voir ce lien] in September 1941, they were promptly recognized as having an inadequate rate of climb and performance at altitude
for Western European conditions.

Only 80 were adopted, all of them with 601 Squadron. Britain transferred about 200 P-39s to the Soviet Union.

Another 200 examples intended for the RAF were taken up by the [Vous devez être inscrit et connecté pour voir ce lien] after the [Vous devez être inscrit et connecté pour voir ce lien] as
the P-400, and were sent to the [Vous devez être inscrit et connecté pour voir ce lien] in Australia, for service in the [Vous devez être inscrit et connecté pour voir ce lien].

A heavy structure, and around 265 lb (120 kg) of armor were characteristic of this aircraft as well.

The production P-39's heavier weight combined with the Allison engine having only a single-stage, single-speed supercharger, limited the high-altitude capabilities of the fighter.

The P-39's altitude performance was markedly inferior to the contemporary European fighters and, as a result, the first USAAF fighter units in the [Vous devez être inscrit et connecté pour voir ce lien] were equipped with the [Vous devez être inscrit et connecté pour voir ce lien].

However, the P-39D's roll rate was 75°/s at 235 mph (378 km/h)– better than the A6M2, F4F, F6F, or P-38 up to 265 mph (426 km/h). (see NACA chart).

Above the supercharger's critical altitude of about 12,000 ft (3,658 m), an early P-39's performance dropped off rapidly.
This limited its usefulness in traditional fighter missions in Europe as well as in the Pacific, where it was not uncommon for Japanese bombers to attack at altitudes above the P-39's operational ceiling (which in the tropical hot air inevitably was lower than in moderate climates).

However the late production N and Q models making up 75% of all Aircobras could maintain a top speed of approximately 375 mph (604 km/h) up to 20,000 ft (6,100 m).

The weight distribution of the P-39 was supposedly the reason for its tendency to enter a dangerous [Vous devez être inscrit et connecté pour voir ce lien], a characteristic Soviet test pilots were able to demonstrate to the skeptical manufacturer who had been unable to reproduce the effect.

After extensive tests, it was determined the spin could only be induced if the aircraft was improperly loaded, with no
ammunition in the front compartment.

The flight manual specifically noted a need to ballast the front ammunition compartment with the appropriate weight of shell casings to achieve a reasonable center of gravity.

High speed controls were light, consequently, high speed turns and pull-outs were possible.

However, the P-39 had to be held in a dive since it tended to level out, reminiscent of the Spitfire. Recommended dive speed limit ([Vous devez être inscrit et connecté pour voir ce lien]) was 475 mph (764 km/h) for the P-39.

The rear-mounted engine made the aircraft ideal for ground attack since fire would be coming from the front-bottom quarter and was less likely to hit the engine and its cooling systems.

However, the arrangement proved to be very vulnerable to attacks from above and behind and nearly any hit on the fuselage from an attacking enemy fighter was virtually guaranteed to disable the cooling system and lead to the
prompt demise of the engine and thus the airplane.

Coupled with lack of high-altitude performance, the Airacobra was extremely vulnerable to any enemy fighter with decent high altitude performance.

By the time of the [Vous devez être inscrit et connecté pour voir ce lien] attack, nearly 600 had been built.

When P-39 production ended in August 1944, Bell had built 9,558 Airacobras, of which 4,773 (mostly -39N and -39Q ) were sent to the Soviet Union through the [Vous devez être inscrit et connecté pour voir ce lien].

There were numerous minor variations in engine, propeller, and armament, but no major structural changes in production types, excepting a few two-seat TP-39F and RP-39Q trainers.

In addition, seven went to the [Vous devez être inscrit et connecté pour voir ce lien] as radio-controlled [Vous devez être inscrit et connecté pour voir ce lien].

Trials of a [Vous devez être inscrit et connecté pour voir ce lien] wing (in the XP-39E) and [Vous devez être inscrit et connecté pour voir ce lien] IV-1430 engine (the P-76) were unsuccessful.

The mid-engine, gun-through-hub concept was developed further in the Bell[Vous devez être inscrit et connecté pour voir ce lien].

A naval version with tail-dragger landing gear, the [Vous devez être inscrit et connecté pour voir ce lien], was ordered as a competitor to the[Vous devez être inscrit et connecté pour voir ce lien] and [Vous devez être inscrit et connecté pour voir ce lien]. It first flew 13 May 1940, but after a troublesome and protracted development and testing period, it was rejected.

Operational history


The Airacobra saw combat throughout the world, particularly in the Southwest Pacific, Mediterranean and Russian theaters.
Because its engine was not equipped with a supercharger, the P-39 performed best below 17,000 feet (5,200 m) altitude.
It often was used at lower altitudes for such missions as ground strafing.
Russian pilots appreciated the cannon-armed P-39 primarily for its air-to-air attack capability.

United Kingdom


In 1940, the [Vous devez être inscrit et connecté pour voir ce lien] in the US was looking for combat aircraft; they ordered 675 of the export version Bell Model 14 as the "Caribou" on the strength of the company's representations on 13 April 1940.

The performance of the Bell P-39 prototype and 13 test aircraft which were able to achieve a speed of 390 mph
(630 km/h) at altitude was due to the installation of turbo-[Vous devez être inscrit et connecté pour voir ce lien].

The British armament was 0.50 in (12.7 mm) machine guns in the fuselage, and four 0.30 in (7.62 mm) machine guns in the wings, the 37 mm gun was replaced by a 20 mm (.79 in) [Vous devez être inscrit et connecté pour voir ce lien].

The British export models were renamed "Airacobra" in 1941.
A further 150 were specified for delivery under [Vous devez être inscrit et connecté pour voir ce lien] in 1941 but these were not supplied.

The [Vous devez être inscrit et connecté pour voir ce lien] (RAF) took delivery in mid 1941 and found that actual performance of the non-turbo-supercharged production aircraft differed markedly from what they were expecting.

In some areas, the Airacobra was inferior to existing aircraft such as the [Vous devez être inscrit et connecté pour voir ce lien] and [Vous devez être inscrit et connecté pour voir ce lien] and its performance at altitude suffered drastically.

On the other hand it was considered effective for low level fighter and ground attack work.
Problems with gun and exhaust flash suppression and compass were fixable.

[Vous devez être inscrit et connecté pour voir ce lien] was the only British unit to use the Airacobra operationally, receiving their first two examples on 6 August 1941.

On 9 October, four Airacobras attacked enemy barges near Dunkirk, in the type's only operational action with the RAF.

The squadron continued to train with the Airacobra during the winter, but a combination of poor serviceability and deep distrust of this unfamiliar fighter resulted in the RAF rejecting the type after one combat mission.

In March 1942, the unit re-equipped with Spitfires.

The Airacobras already in the UK, along with the remainder of the first batch being built in the US, were sent to the Soviet Air force, the sole exception being [Vous devez être inscrit et connecté pour voir ce lien],
which was passed to the [Vous devez être inscrit et connecté pour voir ce lien] and used for experimental work, including the first carrier landing by a tricycle undercarriage aircraft on [Vous devez être inscrit et connecté pour voir ce lien], until it was scrapped on the recommendation of a visiting [Vous devez être inscrit et connecté pour voir ce lien] in March 1946.

U.S.


The United States requisitioned 200 of the next part of the order as the P-400.

The P-400 designation came from advertised top speed of 400 mph (644 km/h). After [Vous devez être inscrit et connecté pour voir ce lien], the P-400 was deployed to training units, but some saw combat in the Southwest Pacific including with the [Vous devez être inscrit et connecté pour voir ce lien] in the [Vous devez être inscrit et connecté pour voir ce lien].

Though outclassed by Japanese fighter planes, it performed well in strafing and bombing runs, often proving deadly in ground attacks on Japanese forces trying to retake [Vous devez être inscrit et connecté pour voir ce lien].

Guns salvaged from P-39s were sometimes fitted to Navy PT boats to increase firepower.

From September to November 1942 pilots of the 57th Fighter Squadron flew P-39s and P-38s from an airfield built on land bulldozed into [Vous devez être inscrit et connecté pour voir ce lien] on the barren island of [Vous devez être inscrit et connecté pour voir ce lien] in Alaska's [Vous devez être inscrit et connecté pour voir ce lien].

They attacked the Japanese forces which had invaded Attu and Kiska islands in the Aleutians in June 1942.

The number one foe that claimed the most lives, however, was not the Japanese but the weather.

The low clouds, heavy mist and fog, driving rain, snow and high winds made flying dangerous and lives miserable.

The 57th remained in Alaska until November 1942 and then returned to the United States.

In North Africa, the [Vous devez être inscrit et connecté pour voir ce lien] were assigned P-39s in February 1944.

They successfully transitioned and carried out their duties including supporting [Vous devez être inscrit et connecté pour voir ce lien] over [Vous devez être inscrit et connecté pour voir ce lien] as well as missions over the [Vous devez être inscrit et connecté pour voir ce lien] in the Airacobra but achieved few aerial victories.

By June they had transitioned to [Vous devez être inscrit et connecté pour voir ce lien] and then [Vous devez être inscrit et connecté pour voir ce lien] in July 1944.

While only one U.S. pilot, Lt. Bill Fiedler, became an ace in a P-39, many U.S. aces scored one or two of their victories in the aircraft.

USSR


The most successful use of the P-39 was in the hands of the Soviet Air Force (VVS).

The tactical environment of the [Vous devez être inscrit et connecté pour voir ce lien] did not demand the extreme high-altitude operations that the RAF and [Vous devez être inscrit et connecté pour voir ce lien] employed with their big bombers.

The low-speed, low-altitude turning nature of most air combat on the Russian Front suited the P-39's strengths: sturdy construction, reliable radio gear, and adequate firepower.

The usual nickname for the well-loved Airacobra in the VVS was Kobrushka, "little cobra", or Kobrastochka, a [Vous devez être inscrit et connecté pour voir ce lien] of Kobra and Lastochka (swallow), "dear little cobra".

It was common for the Soviet pilots to remove the wing guns and rely only on the cannon and nose machine guns as armament; a modification that improved roll rate by reducing [Vous devez être inscrit et connecté pour voir ce lien].

The Soviets used the Airacobra primarily for air-to-air combat against a variety of German aircraft, including [Vous devez être inscrit et connecté pour voir ce lien], [Vous devez être inscrit et connecté pour voir ce lien], [Vous devez être inscrit et connecté pour voir ce lien], and [Vous devez être inscrit et connecté pour voir ce lien].

During the battle of [Vous devez être inscrit et connecté pour voir ce lien] river, Soviet air force relied mostly on P-39s, much more appreciated than Spitfires and P-40s. [Vous devez être inscrit et connecté pour voir ce lien], from 16.Gv.IAP, claimed 20 air victories in that campaign.

Aleksandr Ivanovich Pokryshkin, the third-highest scoring Allied ace (with a score of 53 air victories plus six shared) flew the P-39 from late 1942 until the end of the war (though rumours exist that he changed in late 1944 to a [Vous devez être inscrit et connecté pour voir ce lien]);
his unofficial score in the Airacobra stands at nearly 60 Luftwaffe aircraft.

[Vous devez être inscrit et connecté pour voir ce lien], second Soviet top-scoring ace (56 individual air victories plus 5 shared) occasionally his wingman while both in 16.Gv.IAP , scored 44 victories flying Airacobras. The majority of his kills were achieved on P-39N-0 number 42-8747 and P-39Q-15 number 44-2547.

During the Great Patriotic War he was awarded with the Order of Lenin, the Order of the Red Banner (four times), the Order of Alexandr Nievskii, the Order of Patriotic War 1st Class and the Order of the Red Star (twice).

This is the highest score ever gained by any pilot with any U.S.-made aircraft.

The United States did not supply the M80 armor-piercing round for the [Vous devez être inscrit et connecté pour voir ce lien] of Soviet P-39s—instead,
approximately 1,200,000 [Vous devez être inscrit et connecté pour voir ce lien] rounds were supplied, which the Soviets used for air-to-air combat and against soft ground targets.

The VVS did not use the P-39 for tank-busting duties.

A total of 4,719 P-39s were sent to the Soviet Union, accounting for more than one-third of all U.S. and UK-supplied fighter aircraft in the VVS, and nearly half of all P-39 production.

Variants


XP-39


Bell Model 12

• XP-39-BE (1 completed). Prototype. Powered by an Allison V-1710-17 (E2) engine (1,150 hp/858 kW) fitted with a B-5 two-stage turbosupercharger. Provision was made for two .50 in (12.7 mm) machine guns in the forward fuselage and one 25 mm (.98 in) cannon but aircraft remained unarmed.
  

s/n: 38-326

First flight: 6 April 1939

YP-39


Bell Model 12

13 Produced

• YP-39-BE (12 completed): Service test version, V-1710-37 (E5) engine (1,090 hp/813 kW). First two aircraft
  delivered with armament, the remained with a M4 37 mm (1.46 in) autocannon with 15 rounds, 2 × .50 in (12.7 mm) machine guns with 200 rpg, and 2 × .30 in (7.62 in) machine guns with 500 rpg in the nose. wider vertical tail than XP-39B.
  

s/n: 40-027 – 40-038

First flight: 13 September 1940

• YP-39A-BE (1 completed). Intended to have a high-altitude V-1710-31 engine (1,150 hp/858 kW), but delivered as a regular YP-39.
  

s/n: 40-039

XP-39B

• XP-39B-BE (1 conversion). Streamlined XP-39 based on [Vous devez être inscrit et connecté pour voir ce lien] testing resulting in revised
  canopy and wheel door shape, oil and radiator intakes moved from right fuselage to wing roots, fuselage increased length (by 1 ft 1 in, to 29 ft 9 in) and decreased wingspan (by 1 ft 10 in, to 34 ft).
  [Vous devez être inscrit et connecté pour voir ce lien] replaced with single-stage geared [Vous devez être inscrit et connecté pour voir ce lien], Allison V-1710-37 (E5) engine
  (1,090 hp/813 kW), carburetor air intake moved to fuselage behind canopy.
  

s/n: 38-326

First Flight: 25 November 1939.


P-39C


Bell Model 13

80 ordered, 20 produced, remainder redesignated P-39D

• P-39C-BE (20 Produced). First production version, identical to YP-39 except for V-1710-35 engine
  (1,150 hp/858 kW). Armed with 1 × 37 mm (1.46 in) cannon, 2 × .50 in (12.7 mm) & 2 × .30 in (7.62 mm) machine guns in the nose. Aircraft lacked armor and self-sealing fuel tanks.
  

s/n: 40-2971 – 40-2990

First Flight: January 1941.

Airacobra I


Bell Model 13 (P-39C/Airacobra I) – Model 14 (Airacobra Ia)

675 ordered (excluding ex-P-39Cs)

• Airacobra I (3 delivered). Three P-39Cs sent to England for testing.
  

s/n: 40-2981 (DS173) – 40-2983 (DS174)

s/n: 40-2984 (DS175)

• Airacobra Ia. P-400 designation indicates British Contract. Briefly named Caribou. V-1710-E4 (1,150 hp/858 kW) engine, 1 × 20 mm (.79 in) cannon with 60 rounds & 2 × 0.50 in (12.7 mm) machine guns were mounted nose and four 0.303 in (7.7 mm) machine guns were mounted in the wings. IFF set removed from behind pilot. note: the designation Ia indicates direct purchase aircraft.
  

s/n: AH570/AH739 (170 aircraft)

s/n: AP264/AP384 (121 aircraft)

s/n: BW100/BW183 (84 aircraft)

s/n: BX135/BX434 (300 aircraft)

Suite des variantes :


P-39D

Bell Model 13 (P-39D) – Model 14A (D-1) – Model 14A-1 (D-2)

454 ordered

• P-39D-BE (60 Produced). P-39C reordered with 245 lb (111 kg) of additional armor, self-sealing fuel tanks. Armament increased to 1 × 37 mm/1.46 mm cannon (30 rounds), 2 × .50 in/12.7 mm (200 rpg) and 4 × wing mounted .30 in/7.62 mm (1,000 rpg) machine guns.
  

s/n: 40-2991 – 40-3050

• P-39D-1BE (336 produced). M1 20 mm (.79 in) M1 cannon. Specifically ordered for delivery under Lend-Lease.
  

s/n: 41-28257 – 41-28406

s/n: 41-38220 – 41-38404

s/n: 41-38563

• P-39D-2BE (158 produced). V-1710-63 (E6) engine (1,325 hp/988 kW) restored the 37 mm (1.46 in) cannon, provisions for a single 145 gal (549 l) drop tank or maximum 500 lb (227 kg) bomb under the fuselage.
  

s/n: 41-38405 – 41-38562

• P-39D-3BE (26 conversions). P-39D-1s converted to Photo Reconnaissance Configuration; K-24 and K-25 camera in rear fuselage, extra armor for oil coolers
  

• P-39D-4BE (11 conversions). P-39D-2 converted to Photo Reconnaissance Configuration. Same mods as D-3 aircraft.
  

XP-39E

Bell Model: 23

3 Ordered

• XP-39E-BE (three ordered): P-39Ds modified for ground and flight testing. Intended for [Vous devez être inscrit et connecté pour voir ce lien]-1
  engine with (2,100 hp/1,566 kW) actually flown with Allison V-1710-47 (1,325 hp/988 kW) engine. Airframes were used to test various wing and different vertical tail surfaces. Fuselage was lengthened by 1 ft 9 in
  (53 cm).
  Used in the development of the P-63. The production variants, with the Continental engines were to be redesignated as P-76; there was no [Vous devez être inscrit et connecté pour voir ce lien] as such.
  

s/n: 41-19501 – 41-19502 plus an unnumbered airframe for static testing.

s/n 41-19501 replaced by 42-71464 after crash on 26 March 1942.

s/n: 41-71464

First Flight 41-19501: 21 February 1942.

P-39F

Bell Model 15B

254 Ordered, 25 redesignated P-39J

• P-39F-1BE (229 produced). Aeroproducts [Vous devez être inscrit et connecté pour voir ce lien], 12 exhaust stacks.
  

s/n: 41-7116 – 41-7344

• TP-39F-1BE (1 conversion). Two-seat training version with additional cockpit added in nose—no armament.
  

• P-39F-2BE (27 conversions). P-39F-1 with additional belly armor and cameras in rear fuselage.
  

P-39G

Bell Model 26

1800 ordered—redesignated P-39K, L, M and N

• P-39G-BE. Intended to be a P-39D-2 with an Aeroproducts propeller. Due to modifications during production no P-39G were actually delivered. Instead, these aircraft were designated P-39K, L, M and N.
  

s/n: 42-4244 – 42-5043

s/n: 42-8727 – 42-9726

P-39H

Not assigned

P-39J

Bell Model 15B

25 Ordered

• P-39J-BE (25 produced). P-39F with V-1710-59 (1,100 hp/820 kW) engine with automatic boost control.
  

s/n: 41-7053 – 41-7056

s/n: 42-7059 – 42-7079

P-39K


Bell Model 26A

210 Ordered

• P-39K-1 (210 produced). P-39D-2BE with Aeroproducts propeller and V-1710-63 (E6) (1,325 hp/988 kW)
  engine. Vents added to nose
  

s/n: 42-4244 – 42-4453

• P-39K-2BE (6 conversions). P-39K-1 with additional belly armor and cameras in rear fuselage.
  

• P-39K-5BE (1 conversion). V-1710-85 (E19) engine to serve as a P-39N prototype
  

P-39L

Bell Model 26C

250 Ordered

• P-39L-1BE (250 Produced). P-39K with Curtiss Electric propeller, revised nose gear for reduced drag, provision for underwing rockets.
  

s/n: 42-4454 – 42-4703

• P-39L-2BE (11 conversions). P-39L-1 with additional belly armor and cameras in rear fuselage.
  

P-39M

Bell Model 26D

240 Ordered

• P-39M-1BE (240 Produced). 11 ft 1 in Aeroproducts propeller, V-1710-67 (E8) (1,200 hp/895 kW) engine with improved high-altitude performance at the expense of low-altitude performance, 10 mph (16 km/h) faster
  than P-39L at 15,000 ft (4,600 m). Note: some P-39M-1BE were delivered with the V-1710-83 (E18) engine.
  

s/n: 42-4704 – 42-4943

P-39N

Bell Model 26N

2,095 Produced

• P-39N-BE (500 produced). Originally part of the P-39G order. V-1710-85 (E19) (1,200 hp/895 kW) engine. Aeroproducts propeller (10 ft 4 in diameter) & different propeller reduction gear ratio. Starting with the 167th aircraft, propellor increased to 11 ft 7 in & internal fuel reduced from 120 gal (454 l) to 87 gal (329 l).
  

s/n: 42-4944 – 42-5043

s/n: 42-8727 – 42-9126

• P-39N-1BE (900 produced). Internal changes to adjust center of gravity when nose guns were fired.
  

s/n: 42-9127 – 42-9726

s/n: 42-18246 – 42-18545

• P-39N-2BE (128 conversions). P-39N-1 with additional belly armor and cameras in rear fuselage.
  

• P-39N-3BE (35 conversions). P-39N with additional belly armor and cameras in rear fuselage.
  

• P-39N-5BE (695 produced). Armor reduced from 231 lb (105 kg) to 193 lb (88 kg), Armor plate replaced the bulletproof glass behind the pilot, SCR-695 radio was fitted, and a new oxygen system was installed.
  

s/n: 42-18546 – 42-19240

• P-39N-6BE (84 conversions). P-39N-5 with additional belly armor and cameras in rear fuselage.
  

P-39O

Not used

P-39P

Not used

P-39Q

Bell Model 26Q

4,905 Ordered

Final production: August 1944

• P-39Q-1BE (150 produced). Wing-mounted 0.30 in (7.62 mm) machine guns replaced with a single 0.50 in
  (12.7 mm) with 300 rounds of ammunition in a pod under each wing.
  Armor increased to the original 231 lb (105 kg) of armor of the P-39N-1BE.
  

s/n: 42-19446 – 42-19595

• P-39Q-2BE (5 conversions). P-39Q-1s modified to carry cameras for photographic reconnaissance by adding K-24 and K-25 cameras in the aft fuselage.
  

• P-39Q-5BE (950 produced). Reduced armor (193 lb/88 kg), fuel capacity increased (110 gal/l). Type A-1 bombsight adapters added.
  

s/n: 42-19596 – 42-20545

• TP-39Q-5BE (1 conversions). Two-seat training version with additional cockpit added in nose - no armament. Enlarged tail fillet and a shallow ventral fin added.
  

s/n: 42-20024

• P-39Q-6BE (148 conversions). P-39Q-5s modified to carry cameras for photographic reconnaissance by adding K-24 and K-25 cameras in the aft fuselage.
  

• P-39Q-10BE (705 produced). Increased armor (228 lb/103 kg), fuel capacity increased (120 gal/454 l). Automatic Boost controls added and Throttle & RPM controls were coordinated. Winterization of oil systems and
  rubber mounts added to the engines.
  

s/n: 42-20546 – 42-21250

Variantes, fin !

• P-39Q-11BE (8 conversions). P-39Q-10s modified to carry cameras for photographic reconnaissance by adding K-24 and K-25 cameras in the aft fuselage.
  

• P-39Q-15BE (1,000 produced). Reinforced inclined deck to prevent .50 in (12.7 mm) machine gun tripod mounting cracking, bulkhead reinforcements to prevent rudder pedal wall cracking, a reinforced reduction gearbox bulkhead to prevent cowling former cracking, and repositioning of the battery solenoid. Oxygen system reduced from four bottle to only two.
  

s/n: 44-2001 – 44-3000

• P-39Q-20BE (1,000 produced). Minor equipment changes. The underwing 0.50 in (12.7 mm) machine gun pods were sometimes omitted in this version.
  

s/n: 44-3001 – 44-4000

• P-39Q-21BE (109 converted). P-39Q-20 fitted with a four-bladed Aeroproducts propeller.
  

• RP-39Q-22BE (12 conversions). Two seat trainer conversions of the P-39Q-20.
  

• P-39Q-25BE (700 produced). Similar to the Q-21 but with a reinforced aft-fuselage and horizontal stabilizer structure.
  

s/n: 44-32167 – 44-32666

s/n: 44-70905 – 44-71104

• P-39Q-30BE (400 produced). Reverted back to the three-bladed propellor
  

s/n: 44-71105 – 44-71504

• XTDL-1 (two acquired). P-39Qs used by the US Navy for use as target drones. Assigned to NAS Cape May for test work. Later redesignated F2L-1K.
  

s/n: P-39Q-10BE 42-20807 Bu 91102

s/n: P-39Q-5BE 42-19976 Bu 91103

Un coup de chapeau au(x) rédacteur(s) de Wikipedia, EN.
Difficile d'être plus précis, prolixe ! [Vous devez être inscrit et connecté pour voir cette image]

Et, finalement, la bibliographie du P 39

• Bowers, Peter M. "Airborne Cobra Pt.I". Airpower, Vol. 8, No 6, November 1978.
  
• Bowers, Peter M. "Airborne Cobra Pt. II". Airpower, Vol.9, No.1, January 1979.
  
• Brown, Captain Eric. Wings on My Sleeve. London: Weidenfeld & Nicolson, 2006. [Vous devez être inscrit et connecté pour voir ce lien].
  
• Byk, Gary. The Modeller's Guide to the Bell P-39 Airacobra in RAAF Service. Melbourne, Australia: Red Roo Models
  Publication, 1997. [Vous devez être inscrit et connecté pour voir ce lien].
  
• Dean, Francis H. America's Hundred Thousand. Atglen, PA: Schiffer Publishing Ltd, 1997 [Vous devez être inscrit et connecté pour voir ce lien].
  
• Dial, Jay Frank. The Bell P-39 Airacobra, Aircraft in Profile no.165. Windsor, Berkshire, UK: Profile Publications. Ltd., 1966 (reprinted 1971). No ISBN.
  
• "Dimensione Cielo aerei Italiani nella Seconda Guerra Mondiale. (in Italian) Caccia Assalto 3. Roma: Edizioni Bizzarri, 1972.
  
• Donald, David. "Bell P-39 Airacobra." The Encyclopedia of World Aircraft. Leicester, UK: Blitz Editions,
  1997. [Vous devez être inscrit et connecté pour voir ce lien].
  
• Dorr, Robert F. and Jerry C. Scutts. Bell P-39 Airacobra. Ramsbury, Marlborough, Wiltshire: The Crowood Press Ltd., 2000. [Vous devez être inscrit et connecté pour voir ce lien].
  
• Fitzsimons, Bernard. "Airacobra: Bell P-39". The Illustrated Encyclopedia of 20th Century Weapons and Warfare, Volume 1. New York: Columbia House, 1967. [Vous devez être inscrit et connecté pour voir ce lien].
  
• Green, William. War Planes of the Second World War, Volume 4. London: Macdonald & Co., 6th Edition, 1969. [Vous devez être inscrit et connecté pour voir ce lien].
  
• Green, William and Gordon Swanborough. WW2 Aircraft Fact Files: U. S. Army Air Force Fighters, Part 1.
  London: Macdonald and Jane's, 1977. [Vous devez être inscrit et connecté pour voir ce lien].
  
• Gueli, Marco. "Gli Airacobra Italiani" (in Italian). Storia Militare n.132, Sept. 2004.
  
• Gunston, Bill. Aircraft of World War 2. London: Octopus Books Limited, 1980. [Vous devez être inscrit et connecté pour voir ce lien].
  
• Hardesty, Von. Red Phoenix: The Rise of Soviet Air Power 1941–1945. Washington, D.C.: Smithsonian Institution, 1991 (first edition 1982). [Vous devez être inscrit et connecté pour voir ce lien].
  
• Johnsen, Frederick A. Bell P-39/P-63 Airacobra & Kingcobra. St. Paul, Minnesota:
  Voyageur Press, 1998. [Vous devez être inscrit et connecté pour voir ce lien].
  
• Johnson, Brian and Terry Heffernan. A Most Secret Place: Boscombe Down 1939–45. London: Jane's Publishing Company Limited, 1982. [Vous devez être inscrit et connecté pour voir ce lien]
  
• Juszczak, Artur and Robert Pęczkowski. Bell P-39 Airacobra (in Polish). Sandomierz, Poland/Redbourn, UK:
  Mushroom Model Publications, 2003. [Vous devez être inscrit et connecté pour voir ce lien].
  
• Kinzey, Bert. P-39 Airacobra in Detail, D&S Vol. 63. Carrollton, TX: Squadron/Signal Publications,
  Inc., 1999. [Vous devez être inscrit et connecté pour voir ce lien].
  
• Loza, Dmitriy and James F. Gebhardt, editor and translator. Attack of the Airacobras: Soviet Aces, American
  P-39s & the Air War Against Germany. Lawrence, Kansas: University Press of Kansas, 2002. [Vous devez être inscrit et connecté pour voir ce lien].
  
• Mariinskiy, Evgeniy. Red Star Airacobra: Memoirs of a Soviet Fighter Ace 1941–45. Solihull, UK: Helion
  and Company, 2006. [Vous devez être inscrit et connecté pour voir ce lien].
  
• Mason, Francis K. Royal Air Force Fighters of World War Two, Volume One. Garden City, NY:
  Doubleday & Company Inc., 1971. [Vous devez être inscrit et connecté pour voir ce lien].
  
• Mattioli, Marco. Bell P-39 Airacobra in Italian Service, Aviolibri Special 7 (Bilingual Italian/English). Roma, Italia: IBN Editore, 2003. [Vous devez être inscrit et connecté pour voir ce lien].
  
• McDowell, Ernest. P-39 Airacobra in Action, Aircraft No.43. Carrollton, TX: Squadron/Signal Publications, Inc., 1980. [Vous devez être inscrit et connecté pour voir ce lien].
  
• Mellinger, George and John Stanaway. P-39 Airacobra Aces of World War 2. Botley, Oxford, UK: Osprey
  Publishing, 2001. [Vous devez être inscrit et connecté pour voir ce lien].
  
• Mitchell, Rick. Airacobra Advantage: The Flying Cannon. The Complete Story of Bell Aircraft Corporation's P-39
  Pursuit Fighter Plane. Missoula, Montana: Pictorial Histories Publishing Co., 1992 (second printing 1995). ISBN
  0-929521-62-5.
  
• Morgan, Hugh. Gli assi Sovietici della Seconda guerra mondiale. (in Italian) Edizioni del Prado/Osprey
  Aviation, 1999. [Vous devez être inscrit et connecté pour voir ce lien]
  
• Park, Edwards. Nanette, Her Pilot's Love Story. Washington, DC: Smithsonian Institution Press, 1977. (2nd edition 1989). [Vous devez être inscrit et connecté pour voir ce lien].
  
• Pejčoch, Ivo. Bojové Legendy: P-39 Airacobra (in Czech). Prague, Czech Republic:
  Jan Vašut s.r.o., 2008. [Vous devez être inscrit et connecté pour voir ce lien].
  
• Roman, Valerij. Aerokobry vstupayut v boy ('Airacobras enter combat'), Белл P-400,P-39D-1,P-39D-2("Avia-retro" series 1) (in Ukrainian). Kiev, Ukraine: Aero-Hobby, 1993. ISBN 5-7707-5170-03.
  
• Roman, Valerij. Aerokobry nad Kuban'yu (Airacobras over Kuban'), P-39 K, L и M ("Avia-retro" series 2) (in
  Ukrainian). Kiev, Ukraine: Aero-Hobby, 2006. [Vous devez être inscrit et connecté pour voir ce lien].
  
• Tomalik, Jacek. Bell P-39 Airacobra Cz.1, Monografie Lotnicze 58 (in Polish). Gdańsk, Poland: AJ-Press,
  1999. [Vous devez être inscrit et connecté pour voir ce lien].
  
• Tomalik, Jacek. Bell P-63 Kingcobra, XFL-1 Airabonita, P-39 Airacobra Cz.2, Monografie Lotnicze 59 (in Polish). Gdańsk, Poland: AJ-Press, 2001. [Vous devez être inscrit et connecté pour voir ce lien].
  
• United States Air Force Museum Guidebook. Wright-Patterson AFB, Ohio: Air Force Museum Foundation, 1975.
  

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