P-39 Airacobra

infobox Aircraft
name = P-39 Airacobra

---

caption = USAAF P-39F-1-BE
type = Fighter
manufacturer = Bell Aircraft
designer =
first flight = 6 April 1938
introduced = 1941
retired =
status = Retired
primary user = United States Army Air Force
more users = Soviet Air Force Royal Air Force
produced = 1940-May 1944
number built = 9,584
unit cost = 50,666 USD in 1944 [http://www.maxwell.af.mil/au/afhra/aafsd/aafsd_index_table.html Army Air Forces Statistical Digest - World War II ] ]
variants with their own articles = XFL Airabonita P-63 Kingcobra

The Bell P-39 Airacobra was one of the principal American fighter aircraft in service at the start of World War II. Although its mid-engine placement was innovative, the P-39 design was handicapped by the lack of an efficient turbo-supercharger, limiting it to low-altitude work, although the type was used with great success by the Soviet Air Force. In the P-39, Soviet pilots scored the highest number of individual kills attributed to any U.S. fighter type. Together with the derivative P-63 Kingcobra, these aircraft would be the most successful mass-produced, fixed-wing aircraft manufactured by Bell. [Bishop, Chris. "The Encyclopedia of Weapons of World War II". New York: Orbis Publishing Ltd., 1998. ISBN 0-7607-1022-8.]

Design and development

In 1937, the United States Army Air Corps issued a specification for a new fighter via Circular Proposal X-608. It was a request for a high-altitude interceptor aircraft having "the tactical mission of interception and attack of hostile aircraft at high altitude". Specifications called for a maximum airspeed of at least 360 miles per hour (580 km/h) at altitude, and a climb to 20,000 ft (6100m) within 6 minutes" [http://www.daveswarbirds.com/usplanes/aircraft/histp-38.htm Lockheed P-38 Lightning] ". Retrieved: 21 January 2007.] ; the toughest set of specifications USAAC had presented to that date. Other competing designs included the Curtiss P-40, an outgrowth of a previous design, and the Lockheed P-38, which utilized a complex twin-engine twin boom configuration. Although Bell's limited fighter design work had previously resulted in the unusual Bell YFM-1 Airacuda, the Model 12Donald 1997, p. 106.] proposal adopted an equally original configuration with an Allison V-12 engine mounted in the middle of the fuselage, 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 Oldsmobile T9 cannon 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. [Somewhat similar to the Republic A-10 Thunderbolt.] 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 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. [ [http://home.att.net/~C.C.Jordan/XP-39.html XP-39] ]

A secondary benefit of the mid-engine arrangement was to create a smooth and streamlined nose profile. The weight distribution necessitated a tricycle undercarriage, a first among American fighters, concurrent with the Lockheed XP-38. 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 [Johnsen 1998, p. 8.] ; both were deleted for production.Fitzsimons 1978, p. 50.] The production P-39 retained a single-stage, single-speed supercharger with a critical altitude (above which performance declined) of about 12,000 ft. [Dean 1997, p. 191.]

The XP-39 made her maiden flight on 6 April 1938Donald 1997] at Wright Field, Ohio, achieving 390 mph at 20,000 ft. (630 km/h at 6,100 m), reaching this altitude in only five minutes. [Johnsen 1998, p. 7.] 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,Fitzsimons 1978] and on advice from NACA, 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 cal. (7.62 mm) MG to the two existing .50 cals. Lacking armor or self-sealing fuel tanks, the prototype was 900 kg lighter than the production fighters. [Kinzey 1999, pp. 9, 13.]

After completing service trials, and originally designated P-45, a first order for 80 aircraft was placed 10 August 1939; the designation would revert before deliveries began.

Technical details

The P-39 was an all-metal, low-wing, single-engine fighter, with tricycle undercarriage incorporating a very streamlined and aerodynamically efficient design.

The Airacobra was conceived as a "weapons system" design with the T9 cannon in mind. This weapon fired a 1.3 lb. (610 g) projectile capable of piercing .8" (2 cm) of armor at 500 yards (450 m) with armor piercing rounds. The complete armament fit as designed consisted of the T9 with a pair of Browning M2 .50" (12.7 mm) machineguns mounted in the nose. This would change to two .50s and two .30s in the XP-39B (P-39C, Model 13, the first 20 delivered) and 2x0.50 and 4x0.30 (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. The engine was placed behind the cockpit, so pilots often referred to this as "Allison armor." [http://yarchive.net/mil/p39.html C.C. Jordan on rec.aviation.military] A long transmission tunnel passed through the fuselage, under the cockpit, and was linked to the three-bladed propeller. The radiator was located in the fuselage.

In September 1940, Britain ordered 386 P-39Ds (as the Model 14), of 675 in all, differing in the 37 mm being replaced by a 20 mm Hispano and the 6x0.3 by .303 (7.7 mm). These began equipping 601 Squadron in September 1941, and were promptly recognized as having inadequate rate of climb and performance at altitude; only 80 joined the RAF (only 601 Squadron being outfitted), about 200 being transferred to the Soviets, another 200 repossessed by the USAAF after Pearl Harbor, and sent to Australia (the models being designated P-400). [Dean 1997, p. 194.]

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. [Dean 1997, pp. 191–192.]

A heavy structure, and around 265 lbs. (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 European Theater were equipped with the Spitfire V. However, the P-39D's roll rate was 75 degrees per second at convert|235|mi/h|km/h|0|abbr=on– better than the A6M2, F4F, F6F, or P-38 up to convert|265|mi/h|km/h|0|abbr=on. (see NACA chart). [Dean 1997, pp. 192, 602.]

Above the supercharger's critical altitude of about 12,000 ft, the 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).

The weight distribution of the P-39 supposedly is the reason for its tendency to enter a dangerous flat spin — 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 plane 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 thus high speed turns and pull-outs were possible although the P-39 had to be held in a dive since it tended to level out, reminiscent of the Spitfire. Recommended dive speed limit (Vne) was convert|475|mi/h|km/h|0|abbr=on for the P-39. [Dean 1997, p. 200.]

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. [Dean 1997, pp. 206–207.]

By the time of the Pearl Harbor 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 Lend-Lease program. 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. [Donald 1997, p.107. Trainers were a rarity for fighter types outside the Soviet Union in the 1940s.] In addition, seven went to the U.S. Navy as radio-controlled drones.

Trials of a laminar flow wing (in the XP-39E) and Continental IV-1430 engine (the P-76) were unsuccessful. The mid-engine, gun-through-hub concept was developed further in the Bell P-63 Kingcobra.

A naval version with tail-dragger landing gear, the XFL-1 Airabonita, was ordered as a competitor to the F4U Corsair and XF5F Skyrocket. 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 convert|17000|ft|m|-2 altitude. It often was used at lower altitudes for such missions as ground strafing. Russian pilots appreciated the cannon-armed P-39 for its ground attack capability.

United Kingdom

In 1940, the British Direct Purchase Commission 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 convert|390|mi/h|km/h|-1|abbr=on at altitude was due to the installation of turbo-supercharging. The British armament was 0.50-inch machine guns in the fuselage, and four 0.30-inch machine guns in the wings, the 37 mm gun was replaced by a 20 mm Hispano-Suiza.

The British export models were renamed "Airacobra" in 1941. A further 150 were specified for delivery under Lend-lease in 1941 but these were not supplied. The Royal Air Force (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. [Mason 1969, pp. 5–6.] In some areas, the Airacobra was inferior to existing aircraft such as the Hawker Hurricane and Supermarine Spitfire 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.

No. 601 Squadron RAF 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 in March 1942, it 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 "AH574", which was passed to the Royal Navy and used for experimental work, including the first carrier landing by a tricycle undercarriage aircraft on HMS "Pretoria Castle" [Brown 2006, p. 93.] , until it was scrapped on the recommendation of a visiting Bell test pilot in March 1946. [Brown 2006, p. 145.]

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 convert|400|mi/h|km/h|0|abbr=on. After Pearl Harbor, the P-400 was deployed to training units, but some saw combat in the Southwest Pacific including with the Cactus Air Force in the Battle of Guadalcanal. [ [http://home.att.net/~jbaugher1/p39_5.html Airacobra I for RAF, P-400] ] It often proved deadly in ground attacks on Japanese forces trying to retake Henderson Field. Guns salvaged from P-39s were sometimes fitted to Navy PT boats to increase firepower. [A PT boat restored in Portland, Oregon has been fitted with a replica of such a gun.]

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 Kuluk Bay on the barren island of Adak in Alaska's Aleutian Islands. 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 Tuskegee Airmen were assigned P-39s in February 1944. They successfully transitioned and carried out their duties including supporting Operation Shingle over Anzio as well as missions over the Gulf of Naples in the Airacobra but achieved few aerial victories. [ [http://www.tuskegeeairmen.org/uploads/stats.pdf The combat record of the Tuskegee Airmen speaks for itself] ] By June they were scoring with P-47 Thunderbolts and then in P-51 Mustangs in July 1944.

Only one U.S. pilot, Lt. Bill Fiedler, became an ace in a P-39; however, many U.S. aces scored one or two of their kills using the P-39. [Pejčoch 2008, p. 86.]

USSR

The most successful use of the P-39 was in the hands of the Soviet Air Force (VVS). The tactical environment of the Eastern Front did not demand the extreme high-altitude operations that the RAF and USAAF 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. 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. The Soviets used the Airacobra extensively for air-to-air combat against a variety of German aircraft, including Bf 109s, Fw 190s, Ju 87s, and Ju 88s. The second-highest scoring Allied ace, Aleksandr Pokryshkin, flew the P-39 from late 1942 until the end of the war (though rumours exist that he changed in late 1944 to a P-63 Kingcobra); his unofficial score in the Airacobra stands at nearly 60 Luftwaffe aircraft. His wingman, Grigori Rechkalov, scored 57 victories with the P-39. This is the highest score ever gained by any pilot with any U.S.-made aircraft. The usual nickname for the well-loved Airacobra in the VVS was "Kobrushka", "little cobra", or "Kobrastochka", "dear little cobra".Loza] [Mitchell 1992, p. 34.] A total of 4719 P-39s were sent to the Soviet Union, accounting for more than one-third of all U.S. and U.K.-supplied fighter aircraft in the VVS, and nearly half of all P-39 production. [Hardesty 1991, p. 253.]

Australia

In early 1942, the Royal Australian Air Force (RAAF), experiencing Japanese air raids on towns in northern Australia, found itself unable to obtain British-designed interceptors or sufficient numbers of P-40s. US Fifth Air Force squadrons in Australia were already receiving the brand new P-39D-1. [ [http://www.adf-serials.com/research/Airacobra.pdf Gordon R. Birkett, 2005, "RAAF Bell Airacobras Part 1" (adf-serials.com)] Retrieved: 20 June 2007.] Consequently, in July 1942, older USAAF P-39s, which had been repaired at Australian workshops, were adopted by the RAAF as a stop-gap interceptor.

Seven P-39Ds were sent to No. 23 Squadron RAAF at Lowood, Queensland. Later, seven P-39Fs were operated by No. 24 Squadron RAAF at Townsville. In the absence of adequate supplies of P-39s, both squadrons also operated Wirraway armed trainers. However, neither squadron received a full complement of Airacobras, or saw combat with them. The home air defence role was filled first by P-40s, followed by Spitfires. Plans to equip two more squadrons with P-39s were also abandoned. No.s 23 and 24 Squadrons converted to the Vultee Vengeance in 1943.

France

In 1940, France ordered numerous P-39s to Bell, but because of the armistice with Germany they were not delivered. However, after Operation Torch, French forces in North Africa sided with the Allies, and were re-equipped with Allied equipment including P-39Ns. From mid-1943 on, three fighter squadrons, the GC 3/6 "Roussillon", GC 1/4 "Navarre" and GC 1/5 "Champagne", flew these P-39s in combat over the Mediterranean, Italy and Southern France. A batch of P-39Qs was delivered later, but Airacobras, which were never popular with French pilots, had been replaced by P-47 Thunderbolts in front line units by late 1944.

Italy

In June 1944, the Italian Co-Belligerent Air Force (ICAF) 223° Group received approximately 150 P-39s, almost all -Ns and -Qs, but also at least one -L and five -Ms. The training of 4° Stormo pilots began on P-39Ns (with over 200 hours on them), while more modern Qs were used in the front line. The three groups of 4° Stormo trained at a small and poorly-maintained airfield near Vesuvio, then were sent to Galatina airfield in fall 1944. At least 19 training accidents occurred; among the victims on 25 August 1944 was Teresio Martinoli, a 22-victory ace with four years of combat experience.

Almost 70 aircraft were operational, and on 18 September 1944, 12° Group's P-39s flew their first mission over Albania. Concentrating on ground attack, the Italian P-39s proved to be suitable in this role, losing 10 aircraft to German flak in over 3,000 hours of combat.Gueli 2004]

Portugal

Between December 1942 and February 1943, the "Aeronáutica Militar" (Army Military Aviation) obtained aircraft operated by the 81st and the 350th Fighter Groups originally dispatched to North Africa as part of Operation Torch. Due to several problems en route, some of the aircraft were forced to land in Portugal and Spain. Of the 19 fighter aircraft that landed in Portugal, all were interned and entered service that year with the Portuguese Army Military Aviation. [ [http://www.geocities.com/CapeCanaveral/Hangar/9376/airacobra.htm Portuguese Airacobra service history] ]

Though unnecessary, the Portuguese Government paid the United States US$20,000 for each of these interned aircraft as well as for one interned P-38 Lightning.Public Record Office entry of 18 March 1943, quoted by "Wreckovery" in Aviation News 10-23 August 1984.] The US accepted the payment, and gave as a gift four additional crates of aircraft, two of which were not badly damaged, without supplying spares, flight manuals or service manuals. Lacking proper training, incorporation of the aircraft into service was plagued with problems, and the last six Portuguese Airacobras that remained in 1950 were sold for scrap.

Postwar

In 1945, Italy purchased the 46 surviving P-39s at 1% of their cost but in summer 1946 many accidents occurred, even fatal ones. By 1947, 4 Stormo re-equipped with P-38s, and P-39s were sent to training units until retirement in 1951. Only a T9 cannon survives today at Vigna di Valle Museum.Gueli 2004]

The Airacobra was raced at the National Air Races in the United States after World War II. Famous versions used for racing included the twin aircraft known as "Cobra I" and "Cobra II," owned jointly between three Bell Aircraft test pilots, Chalmers "Slick" Goodlin, Alvin M. "Tex" Johnston, and Jack Woolams. These craft were extensively modified to use the more powerful P-63 Kingcobra engine and had prototype propeller blades from the Bell factory. "Cobra I" with its pilot, Jack Woolams, was lost in 1946, over the Great Lakes while he was flying from the National Air Races in Cleveland, Ohio back to the factory to get a fresh engine.

The "Cobra II" (Race #84) flown by famed test pilot "Tex" Johnston, beat out P-51 Mustangs and other P-39 racers, which were the favorites, to win the 1946 Thompson Trophy race. Cobra II raced again in the 1947 Thompson Trophy race, finishing 3rd. It raced yet again in the 1948 Thompson trophy race, but was unable to finish owing to engine difficulties. Cobra II did not race again and was destroyed on 10 August 1968 during a test flight prior to a run on the world piston-engine speed record, when owner-pilot Mike Carroll lost control and crashed. Carroll perished and the highly-modified P-39 was wrecked.

Mira Slovak's "Mr. Mennen" (Race #21) P-39Q Airacobra was a very fast unlimited racer - a late arrival in 1972 kept this little 2000+ hp racer out of the Reno races, and it was never entered again. Its color scheme was all white with "Mennen" green and bronze trim. It is now owned and displayed by the Kalamazoo Air Zoo. The P-39Q (former USAAC serial no. 44-3908/NX40A), is painted as a P-400, "Whistlin' Britches."

In 1942, an P-39 Airacobra crashed in Fiji, but was not found until a local pig farmer discovered the wreck in 2004. The pilot's body was also found and sent to Hawaii for identification. Personal items were recovered at the site. [ [http://www.taipeitimes.com/News/world/archives/2006/07/14/2003318738 P-239 recovery] ]

A number of P-39s are still in existence of which three are still flying. The Commemorative Air Force flies a Bell P-39 Airacobra painted in the markings and colors of the 350th Fighter Group, which consisted of the 345th, 346th and 347th Fighter Squadrons operating P-39s in North Africa and Italy. At one time, the Airacobra was painted in Russian colors and markings. Bell P-39Q-6-BE USAAF, serial no. 42-19993, "Brooklyn Bum– 2nd" is now at the Fighter Collection in Duxford, UK. The Smithsonian's National Air and Space Museum has P-39Q-15BE, serial no. 44-2433 on display.

, has one restored P-39Q Airacobra, "White 26", on static display. The aircraft is originally a Soviet lend-lease plane which landed to Finnish held territory after getting lost and running out of fuel and was captured by Finnish troops in World War II. It has been restored in the original wartime camouflage and markings.

Variants

;XP-39: first prototype, unarmed;YP-39: service test version, V-1710-37 (E5) 1,090 hp engine, 12 built;YP-39A: intended to have a high-altitude V-1710-31 engine (1,150 hp) but delivered as a regular YP-39, one built.;XP-39B: streamlined XP-39 based on NACA wind tunnel testing resulting in revised canopy and wheel door shape, oil and radiator intakes moved from right fuselage to wing roots, increased length (by 1 ft 1 in to 29 ft 9 in) and decreased wingspan (by 1 ft 10 in to 34 ft). Turbosupercharger replaced with single-stage geared supercharger, Allison V-1710-37 (E5) engine rated to convert|13300|ft|m|-1|abbr=on.;P-39C: first production version, identical to YP-39 except for V-1710-35 1,150 hp engine. Armed with 1x 37 mm cannon, 2x .50 cal and 2x .30 cal machine guns. First aircraft lacked armor and self-sealing fuel tanks.;P-39D: 245 lb of additional armor, self-sealing fuel tanks. Armament increased to 1x 37 mm cannon (30 rounds), 2x .50 cal (200 rounds/gun) and 4x .30 cal (1,000 rounds/gun) machine guns. Provisions for a single 250-lb, 325-lb, or 500-lb bomb under the fuselage.;P-39D-1: Lend-Lease version, Hispano 20 mm cannon instead of the 37 mm cannon;P-39D-2: Lend-Lease version, upgraded V-1710-63 (E6) engine with 1,325 hp; restored the 37 mm cannon; provisions for a single 145 US gallon drop tank under the fuselage.;Bell Model 14: export version, ordered by France but not delivered.;P-400 Airacobra I: P-39D for Royal Air Force, briefly called :Caribou:; Hispano 20 mm cannon (60 rounds) instead of the 37 mm cannon. A total of 200 were requisitioned by USAAF after Pearl Harbor; most were used for training, but some saw service in the Southwest Pacific.;XP-39E: intended for Continental I-1430-1 engine with 2,100 hp; see Bell XP-76;P-39F-1: Aeroproducts constant speed propeller;P-39F-2: field conversion of P-39F-1 with additional belly armor and cameras in rear fuselage;TP-39F: Two-seat training version, built in small numbers.;P-39G: 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.;P-39J: P-39F with V-1710-59 1,100 hp engine with automatic boost control;P-39K: P-39D-2 with Aeroproducts propeller and V-1710-63 (E6) 1,325 hp engine; one aircraft designated P-39K-5 and fitted with a V-1710-85 (E19) engine to serve as a P-39N prototype;P-39L: P-39K with Curtiss Electric propeller, revised nose gear for reduced drag, provision for underwing rockets.;P-39M: 11 ft 1 in Aeroproducts propeller, V-1710-67 (E8) 1,200 hp engine with improved high-altitude performance at the expense of low-altitude performance, 10 mph faster than P-39L at convert|15000|ft|m|-2|abbr=on.;P-39N: V-1710-85 (E19) 1,200 hp engine; Aeroproducts propeller enlarged from 10 ft 4 in to 11 ft 7 in starting with 167th aircraft. The P-39N-5 had reduced armor.;P-39Q: wing-mounted 0.30 cal machine guns replaced with a single 0.50 cal with 300 rounds of ammunition in a pod under each wing. These wing guns were often removed on Soviet aircraft. P-39Q-21 had a four-bladed Aeroproducts propeller. The P-39Q-30 reverted to a three-bladed propeller because the four-bladed unit worsened directional stability.;RP-39Q: Two-seat training version, built in small numbers.;P-45: The P-45 was the initial designation of the P-39C or Model 13.;F2L: Seven P-39s were supplied to the U.S. Navy to be used as target drones.;XFL-1 Airabonita: One prototype for the U.S. Navy.;A-7: Proposed radio-controlled target drone, never built.;TDL: Radio-controlled target drone for the U.S. Navy

Operators

;AUS
* RAAF;FRA
* Armée de l'Air;flag|Italy|1861-state
* Italian Co-Belligerent Air Force;ITA
* Aeronautica Militare;POL
* "Lotnictwo Wojska Polskiego" (two aircraft only);POR
* "Esquadrilha Airacobra" (Airacobra Squadron), later renamed "Esquadrilha 4" (Squadron No. 4) — "Aeronáutica Militar" (Army Military Aviation);USSR
* Soviet Air Forces;UK
* Royal Air Force;USA
* United States Army Air Corps / United States Army Air Force

pecifications (P-39Q)

aircraft specification

plane or copter?=plane
jet or prop?=prop
crew=One
length main=30 ft 2 in
length alt=9.2 m
span main=34 ft 0 in
span alt=10.4 m
height main=12 ft 5 in
height alt=3.8 m
area main=213 ft²
area alt=19.8 m²
empty weight main=5,347 lb
empty weight alt=2,425 kg
loaded weight main=7,379 lb
loaded weight alt=3,347 kg
max takeoff weight main= 8,400 lb
max takeoff weight alt= 3,800 kg
engine (prop)=Allison V-1710-85
type of prop=liquid-cooled V-12
number of props=1
power main=1,200 hp
power alt=895 kW
max speed main=376 mph;
max speed alt=605 km/h; Redline dive speed=525 mph.
range main=1,098 miles
range alt=1,770 km
ceiling main=35,000 ft
ceiling alt=10,700 m
climb rate main=3,750 ft/min
climb rate alt=19 m/s; 15,000'/ 4.5 min at convert|160|mi/h|km/h|-1|abbr=on.
loading main=34.6 lb/ft²
loading alt=169 kg/m²
power/mass main=0.16 hp/lb
power/mass alt=0.27 kW/kg
armament=
* 1x 37 mm M4 cannon firing through the propeller hub at the rate of 140 rpm with 30 rounds of HE ammo.
* 4 x .50 cal (12.7 mm) machine guns. Rate of fire was 750 rpm x 1 gun in each wing, only 300 rpm each x 2 guns synchronized in the cowl. Ammo: 200 rounds per nose-gun, 300 per wing-pod.
* Up to 500 lb (230 kg) of bombs externally

Popular culture

* "Introduction to the P-39" (1942) Bell wartime training film (38 min) intended for military pilots examining flight techniques, cockpit layout and armament. [ [http://www.imdb.com/title/tt0034900/ "Introduction to the P-39"] ]
* "Flying the P-39" (1943) Bell Training Film No. A.F. - 110 (23 min) demonstrating techniques for piloting the P-39 including aerobatics and strafing. [ [http://www.imdb.com/title/tt0035892/ "Flying the P-39"] ]
* The P-39 Airacobra is featured in the Russian movie "Peregon" (Transit) (2006) dealing with Lend Lease aircraft in transit to Russia. [ [http://www.imdb.com/title/tt0416111/ IMDb. "Peregon" (2006)] ]

ee also

aircontent
related=
* XFL Airabonita
* P-63 Kingcobra

similar aircraft=
* Curtiss P-40
* Messerschmitt Bf 109
* Supermarine Spitfire
* Yakovlev Yak-1
* Yakovlev Yak-9

lists=
* List of military aircraft of the United States
* List of fighter aircraft

see also=

References

Notes

Bibliography

* Brown, Captain Eric. "Wings On My Sleeve". London: Weidenfeld & Nicolson, 2006. ISBN 0-29784-565-9.
* Byk, Gary. "The Modeller's Guide to the Bell P-39 Airacobra in RAAF Service". Melbourne, Australia: Red Roo Models Publication, 1997. ISBN 0-646-32869-7.
* Dean, Francis H. "America's Hundred Thousand". Atglen, PA: Schiffer Publishing Ltd., 1997. ISBN 0-7643-0072-5.
* Dial, Jay Frank. "The Bell P-39 Airacobra, Aircraft in Profile no.165". Windsor, Berkshire, UK: Profile Publications. Ltd., 1966 (reprinted 1971). No ISBN.
* Donald, David, ed. "Bell P-39 Airacobra." "Encyclopedia of World Aircraft". Etobicoke, ON: Prospero Books, 1997. ISBN 1-85605-375-X.
* Dorr, Robert F. and Jerry C. Scutts. "Bell P-39 Airacobra". Ramsbury, Marlborough, Wiltshire: The Crowood Press Ltd., 2000. ISBN 1-86126-348-1.
* FitzSimons, Bernard, ed. "Airacobra Bell P-39." "The Illustrated Encyclopedia of 20th Century Weapons and Warfare Volume 1". London: Phoebus, 1978. ISBN 0-83936-175-0.
* Green, William. "War Planes of the Second World War, Fighters, Volume Four". London: Macdonald & Co. (Publishers), 1961 (sixth impression 1969). ISBN 0-356-01448-7.
* Green, William and Gordon Swanborough. "WW2 Aircraft Fact Files: US Army Air Force Fighters, Part 1". London: Macdonald and Jane's Publishers Ltd., 1977. ISBN 0-356-08218-0.
* Gueli, Marco. "Gli Airacobra Italiani" (in Italian). "Storia Militare n.132", Sept. 2004.
* Hardesty, Von. "Red Phoenix: The Rise of Soviet Air Power 1941-1945". Washington, D.C.: Smithsonian Institution, 1991 (first edition 1982). ISBN 0-87474-510-1.
* Johnsen, Frederick A. "Bell P-39/P-63 Airacobra & Kingcobra". St. Paul, Minnesota: Voyageur Press, 1998. ISBN 1-58007-010-8.
* Juszczak, Artur and Robert Pęczkowski. "Bell P-39 Airacobra" (in Polish). Sandomierz, Poland/Redbourn, UK: Mushroom Model Publications, 2003. ISBN 83-916327-9-2.
* Kinzey, Bert. "P-39 Airacobra in Detail, D&S Vol.63". Carrollton, TX: Squadron/Signal Publications, Inc., 1999. ISBN 1-88897-416-4.
* Loza, Dmitriy. "Attack of the Airacobras: Soviet Aces, American P-39s & the Air War Against Germany". Lawrence, Kansas: University Press of Kansas, 2002. ISBN 0-7006-1140-1.
* Mariinskiy, Evgeniy. "Red Star Airacobra: Memoirs of a Soviet Fighter Ace 1941-45". Solihull, UK: Helion and Company, 2006. ISBN 1-87462-278-7.
* Mason, Francis K. "Royal Air Force Fighters of World War Two, Volume One". Garden City, NY: Doubleday & Company Inc., 1971.
* Mattioli, Marco. "Bell P-39 Airacobra in Italian Service, Aviolibri Special 7" (Bilingual Italian/English). Roma, Italia: IBN Editore, 2003. ISBN 88-86815-85-9.
* McDowell, Ernest. "P-39 Aircobra in Action, Aircraft No.43". Carrollton, TX: Squadron/Signal Publications, Inc., 1980. ISBN 0-89747-102-4.
* Mellinger, George and John Stanaway. "P-39 Airacobra Aces of World War 2". Botley, Oxford: Osprey Publishing, 2001. ISBN 1-84176-204-0.
* 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.
* Park, Edwards. "Nanette, her Pilot's Love Story". Washington, DC: Smithsonian Institution Press, 1977. (2nd edition 1989). ISBN 0-87474-737-6.
* Pejčoch, Ivo. "Bojové Legendy: P-39 Airacobra" (in Czech). Prague, Czech Republic: Jan Vašut s.r.o., 2008. ISBN 80-7236-573-9.
* 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. ISBN 0-9780696-0-9.
* Tomalik, Jacek. "Bell P-39 Airacobra Cz.1, Monografie Lotnicze 58" (in Polish). Gdańsk, Poland: AJ-Press, 1999. ISBN 83-7237-032-X.
* Tomalik, Jacek. "Bell P-63 Kingcobra, XFL-1 Airabonita, P-39 Airacobra Cz.2, Monografie Lotnicze 59" (in Polish). Gdańsk, Poland: AJ-Press, 2001. ISBN 83-7237-034-6.

External links

* [http://home.att.net/~jbaugher1/p39.html P-39 Airacobra]
* [http://www.microworks.net/pacific/aviation/fl_airabonita.htm XFL-1 Airabonita]
* [http://www.acepilots.com/planes/p39_airacobra.html Bell P-39 Airacobra]
* [http://www.acepilots.com/planes/soviet_p39_airacobra.html Web site with more description of the Loza reference and use of P-39 for air superiority]
* [http://www.quarry.nildram.co.uk/WW2guneffect.htm Article on aircraft guns of WWII]
* [http://home.att.net/~C.C.Jordan/XP-39.html article on technical and operational faults of P-39]