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78-611: [REDACTED] Look up P45 in Wiktionary, the free dictionary. P45 may refer to: Vessels [ edit ] ARA  Robinson  (P-45) , a corvette of the Argentine Navy HMS ; Unrivalled  (P45) , a submarine of the Royal Navy Spanish patrol vessel  Audaz  (P-45) Other uses [ edit ] P45 (tax) ,

156-524: A state regional road in Latvia P45, a digital camera back made by Phase One P45, a hybrid microcar made by Jeremy Clarkson on Top Gear See also [ edit ] Ferrari P4/5 by Pininfarina , an Italian sports car [REDACTED] Topics referred to by the same term This disambiguation page lists articles associated with the same title formed as a letter–number combination. If an internal link led you here, you may wish to change

234-741: A P-39. The last plane shot down by the Luftwaffe was a Soviet P-39, on 8 May by Oblt. Fritz Stehle of 2./JG 7 flying a Me 262 over the Ore Mountains . Also, the last Soviet air victory was in a P-39 on 9 May when Kapitan Vasily Pshenichikov scored against a Focke-Wulf Fw 189 over Prague . Five of the 10 highest scoring Soviet aces logged the majority of their kills in P-39s. Grigoriy Rechkalov scored 44 victories in Airacobras. Pokryshkin scored 47 of his 59 victories in P-39s, making him

312-470: A cannon, a liquid-cooled Allison engine with a General Electric turbo-supercharger , tricycle landing gear , a level airspeed of at least 360 mph (580 km/h) at altitude, and a climb to 20,000 ft (6,100 m) within six minutes. This was the most demanding set of fighter specifications the USAAC had presented to that date. Although Bell's limited fighter design work had previously resulted in

390-471: A characteristic Soviet test pilots demonstrated to the skeptical manufacturer, which had been unable to reproduce the effect. It was determined the spin could only be induced if the aircraft was flown with no ammunition in the nose. The flight manual noted a need to ballast the front ammunition compartment to achieve a reasonable center of gravity . High-speed controls were light, consequently high-speed turns and pull-outs were possible. The P-39 had to be held in

468-615: A computer chipset Mount Pleasant/Scottdale Airport , in Fayette County, Pennsylvania, United States P45 road (Ukraine) Papyrus 45 , a biblical manuscript Pneumonoultramicroscopicsilicovolcanoconiosis , a synonym for the disease known as silicosis P45, a state regional road in Latvia P45, a digital camera back made by Phase One P45, a hybrid microcar made by Jeremy Clarkson on Top Gear See also [ edit ] Ferrari P4/5 by Pininfarina , an Italian sports car [REDACTED] Topics referred to by

546-482: A dive since it tended to level out and the recommended never-exceed dive speed limit ( Vne ) was 475 mph (764 km/h). Soon after entering service, pilots began to report that "during flights of the P-39 in certain maneuvers, it tumbled end over end." Most of these events happened after the aircraft was stalled in a nose high attitude with considerable power applied. Bell pilots made 86 separate efforts to reproduce

624-427: A form designation used as a metonym for termination of employment Bell P-45 , an American fighter aircraft later redesignated P-39C Intel P45 , a computer chipset Mount Pleasant/Scottdale Airport , in Fayette County, Pennsylvania, United States P45 road (Ukraine) Papyrus 45 , a biblical manuscript Pneumonoultramicroscopicsilicovolcanoconiosis , a synonym for the disease known as silicosis P45,

702-399: A low rate of fire, and was prone to jamming. A secondary benefit of the mid-engine arrangement was that it created a smooth and streamlined nose profile. Much was made of the fact that this resulted in a configuration "with as trim and clean a fuselage nose as the snout of a high-velocity bullet". Entry to the cockpit was through side doors (mounted on both sides of the cockpit) rather than

780-518: A regular basis over New Guinea. Compilation of combat reports indicates the Zero was either equal to or close to the P-39 in speed at the altitudes of the various low level encounters. 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

858-399: A relief tube in the shape of a funnel. The armored glass was very strong, extremely thick. The armor on the back was also thick. The oxygen equipment was reliable, although the mask was quite small, only covering the nose and mouth. We wore that mask only at high altitude. The HF radio set was powerful, reliable and clear." Soviet pilot Nikolai G. Golodnikov, recalling his experiences of

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936-721: 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°/s at 235 mph (378 km/h) – better than the A6M2 , F4F , or P-38 up to 265 mph (426 km/h). Above the supercharger's peak altitude of about 12,000 ft (3,700 m), performance dropped off rapidly, limiting usefulness in traditional fighter missions in Europe as well as in

1014-491: A sliding canopy. Its unusual engine location and the long drive shaft caused some concern to pilots 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 propeller shaft failure. The XP-39 made its maiden flight on 6 April 1938. at Wright Field , Ohio, achieving 390 mph (630 km/h) at 20,000 ft (6,100 m), reaching this altitude in only five minutes. However,

1092-494: A speed of 391 mph (629 km/h) at 14,400 ft (4,400 m) in flight test. As this speed was within 1% of the guarantee, the aircraft was declared to have satisfied contractual obligations. Despite the success of these modifications, none were applied to other production P-39s. Later testing of a standard production P-400 by the British Aeroplane and Armament Experimental Establishment (A&AEE) revealed

1170-475: A top speed of 429 mph (690 km/h) could be realized with the aerodynamic improvements they had developed and an uprated V-1710 with only a single-stage, single-speed supercharger. At a pivotal meeting with the USAAC and NACA in August 1939, Larry Bell proposed that the production P-39 aircraft be configured without the turbocharger. Some historians have questioned Bell's true motivation in reconfiguring

1248-406: A top speed of only 359 mph (578 km/h). 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 performance of the non-turbo-supercharged production aircraft differed markedly from what they were expecting. In some areas,

1326-627: Is different from Wikidata All article disambiguation pages All disambiguation pages Bell P-45 The Bell P-39 Airacobra is a fighter produced by Bell Aircraft for the United States Army Air Forces during World War II . It was one of the principal American fighters in service when the United States entered combat. The P-39 was used by the Soviet Air Force , which used it to score

1404-792: The China Burma India Theater by March 1944 and the 350th began transition to the P-47D in August 1944, remaining in Italy with the 12th Air Force. The most successful and numerous use of the P-39 was by the Soviet Air Forces . They received the considerably improved N and Q models via the Alaska-Siberia ferry route . The tactical environment of the Eastern Front did not demand the high-altitude performance

1482-491: The NASA Langley Research Center 20-foot (6 m) Free-Spinning Tunnel during the 1970s. A study of old reports showed that during earlier tests the aircraft never tumbled. However, it was noted that all testing had been done with a simulated full ammunition load, which moved the center of gravity forward. After finding the original spin test model of the P-39 in storage, the new study first duplicated

1560-694: The Airacobra in the VVS was Kobrushka ("little cobra") or Kobrastochka , a blend of Kobra and Lastochka (swallow), "dear little cobra". "I liked the Cobra, especially the Q-5 version. It was the lightest version of all Cobras and was the best fighter I ever flew. The cockpit was very comfortable, and visibility was outstanding. The instrument panel was very ergonomic, with the entire complement of instruments right up to an artificial horizon and radio compass. It even had

1638-591: The Airacobra was inferior to existing aircraft such as the Hawker Hurricane and Supermarine Spitfire and its performance at altitude suffered drastically. Tests by the Royal Aircraft Establishment at Boscombe Down showed the Airacobra reached 355 mph (571 km/h) at 13,000 ft (4,000 m). The cockpit layout was criticized, and it was noted that the pilot would have difficulty in bailing out in an emergency because

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1716-479: The Army Air Corps units and would be the first ones to see action. The P-39 was an all-metal, low-wing, single-engine fighter, with a tricycle undercarriage and an Allison V-1710 liquid-cooled V-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

1794-614: The Bell Model 4) was designed to provide a platform for the 37 mm T9 cannon . This weapon, which was designed in 1934 by the American Armament Corporation, a division of Oldsmobile , fired a 1.3 lb (0.59 kg) projectile capable of piercing .8 in (20 mm) of armor at 500 yd (460 m) with armor-piercing rounds. The 90-inch-long (2.3 m), 200 lb (90 kg) weapon had to be rigidly mounted and fire parallel to and close to

1872-626: The Japanese forces that had invaded Attu and Kiska islands in the Aleutians in June 1942. The factor that claimed the most lives 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, then returned to the United States. While Lieutenant Bill Fiedler

1950-615: The M4 cannon with its powerful rounds and the reliable action but complained about the low rate of fire (three rounds per second) and inadequate ammunition storage (only 30 rounds). The Soviets used the Airacobra primarily for air-to-air combat against a variety of German aircraft, including Bf 109s, Focke-Wulf Fw 190s , Ju 87s, and Ju 88s . During the battle of Kuban River, VVS relied on P-39s much more than Spitfires and P-40s. Aleksandr Pokryshkin , from 16. Gv.IAP ( 16th Guards Fighter Aviation Regiment ), claimed 20 victories in that campaign in

2028-533: The P-39 The first Soviet Cobras had a 20 mm Hispano-Suiza cannon and two heavy Browning machine guns, synchronized and mounted in the nose. Later, Cobras arrived with the M4 37 mm cannon and four machine guns, two synchronized and two wing-mounted. "We immediately removed the wing machine guns, leaving one cannon and two machine guns," Golodnikov recalled later. That modification improved roll rate by reducing rotational inertia . Soviet airmen appreciated

2106-617: The P-40 and were assigned P-39s in February 1944, but only flew the type for a few weeks. The 99th 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. The major MTO P-39 operators included the 81st and 350th Fighter Groups , both flying the maritime patrol mission from North Africa and on through Italy. The 81st transferred to

2184-464: The Pacific, where it was not uncommon for Japanese bombers to attack from above the P-39's ceiling (which in the tropical heat was lower than in cooler climates). The late production N and Q models, which made up 75% of Airacobras built, could maintain a top speed of 375 mph (604 km/h) up to 20,000 ft (6,100 m). Weight distribution could result in it entering a dangerous flat spin ,

2262-564: The RAF and AAF did. The comparatively low-speed, low-altitude nature of most air combat on the Eastern Front suited the P-39's strengths: sturdy construction, reliable radio gear, and good firepower. Soviet pilots appreciated the cannon-armed P-39 primarily for its air-to-air capability. A common Western misconception is that the Bell fighters were used as ground attack aircraft. This is because

2340-694: 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 AH574 , which was passed to the Royal Navy and used for experimental work, including the first carrier landing by a tricycle undercarriage aircraft, on 4 April 1945 on HMS  Pretoria Castle , until it

2418-681: 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. 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

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2496-814: The Soviet Union. Another 200 examples intended for the RAF were taken up by the USAAF after the attack on Pearl Harbor as the P-400 , and were sent to the Fifth Air Force in Australia, for service in the South West Pacific Theatre . By the date of the Pearl Harbor attack, nearly 600 P-39s had been built. When P-39 production ended in August 1944, Bell had built 9,558 Airacobras, of which 4,773 (mostly −39Ns and −39Qs ) were sent to

2574-467: The Soviet term for the mission of the P-39, prikrytiye sukhoputnykh voysk (coverage of ground forces) has been mistaken as meaning close air support . In Soviet usage, it has a broader meaning including protection of the airspace above army operations. Soviet-operated P-39s did make strafing attacks, but it was "never a primary mission or strong suit for this aircraft". To satisfy the strafing requirement,

2652-554: The Soviets built thousands of heavily armored Ilyushin Il-2 aircraft. For the Bell fighters, the Soviets developed successful group aerial fighting tactics, and scored a surprising number of aerial victories over a variety of German aircraft. Soviet P-39s had no trouble dispatching Junkers Ju 87 Stuka s or German twin-engine bombers and matched, and in some areas surpassed, early and mid-war Messerschmitt Bf 109s . The usual nickname for

2730-505: The U.S. 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 British armament was two nose-mounted .50 caliber machine guns and four .303 caliber Browning machine guns in the wings. The 37 mm gun was replaced by a 20 mm Hispano-Suiza cannon . British expectations had been set by performance figures established by

2808-583: The XP-39 through its early engineering teething troubles, but he was ordered to England. The XP-39 project was handed over to others, and in June 1939 the prototype was ordered by General Henry H. Arnold to be evaluated in NACA wind tunnels to find ways of increasing its speed, by reducing parasitic drag. Tests were carried out, and Bell engineers followed the recommendations of NACA and the Army to reduce drag such that

2886-430: The XP-39 was found to be short on performance at altitude. Flight testing had found its top speed at 20,000 ft (6,100 m) to be lower than the 400 mph (640 km/h) of the original proposal. As originally specified by Kelsey and Saville, the XP-39 had a turbo-supercharger to augment its high-altitude performance. Bell cooled the turbo with a scoop on the left side of the fuselage. Kelsey wished to shepherd

2964-455: The XP-39B (P-39C, Model 13, the first 20 delivered) and two .50s and four .30s (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 (230 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,

3042-538: The aircraft. The strongest hypothesis is that Bell's factory did not have an active production program and he was desperate for cash flow. Other historians mention that wind tunnel tests made the designers believe the turbocharger installation was so aerodynamically cluttered that it had more disadvantages than advantages. The Army ordered 12 YP-39s (with only single-stage, single-speed superchargers) for service evaluation and one YP-39A. After these trials were complete, which resulted in detail changes including deletion of

3120-456: The center of the propeller hub for optimum accuracy and stability. This happened because H.M. Poyer, designer for project leader Robert Woods, was impressed by the power of this weapon and pressed for its incorporation. This was unusual, because fighter design had previously been driven by the intended engine, not the weapon. Although the T9 was devastating when it worked, it had very limited ammunition,

3198-471: The centerline of the new fighter. It would have been impossible to mount the weapon in the fuselage, firing through the cylinder banks of the Vee-configured engine and the propeller hub as could be done with smaller 20 mm cannon. Weight, balance and visibility considerations meant that the cockpit could not be placed farther back in the fuselage, behind the engine and cannon. The solution adopted

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3276-473: The cockpit roof could not be jettisoned. The lack of a clear vision panel on the windscreen assembly meant that in the event of heavy rain the pilot's forward view would be obliterated; the pilot's notes advised that in this case the door windows would have to be lowered and the speed reduced to 150 mph (240 km/h) On the other hand, it was considered effective for low level fighter and ground attack work. Problems with gun- and exhaust-flash suppression and

3354-401: The cockpit the fuselage nose was formed from large removable covers. A long nose wheel 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. Because the pilot was above

3432-453: The compass could be fixed. 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 a combination of poor serviceability and deep distrust of this unfamiliar fighter resulted in

3510-628: The derivative P-63 Kingcobra , the P-39 was one of the most successful fixed-wing aircraft manufactured by Bell. In February 1937, Lieutenant Benjamin S. Kelsey , Project Officer for Fighters at the United States Army Air Corps (USAAC), and Captain Gordon P. Saville , fighter tactics instructor at the Air Corps Tactical School , issued a specification for a new fighter via Circular Proposal X-609 . It

3588-411: The earlier tests, with consistent results. Then, the model was re-ballasted to simulate a condition with no ammunition load, which moved the aircraft's center of gravity aft. Under these conditions, the model was found to tumble. The rear-mounted engine was less likely to be hit when attacking ground targets, but was vulnerable to attacks from above and behind. At its upper altitude limits, the Airacobra

3666-404: The elevator and rudder were reduced by 14.2% and 25.2% respectively. Modified fillets were installed in the tail area. The canopy glass was faired to its frame with putty. The gun access doors on the wing had been seen to bulge in flight, so they were replaced with thicker aluminum sheet. Similarly, the landing gear doors deflected open by as much as two inches at maximum speed, so a stronger linkage

3744-589: The end of 1942, the P-39 units of the Fifth Air Force had claimed about 80 Japanese aircraft, with a similar number of P-39s lost. Fifth and Thirteenth air force P-39s did not score more aerial victories in the Solomons due to the aircraft's limited range and poor high altitude performance. Airacobras first fought Japanese Zeros on 30 April 1942 in a low level action near Lae, New Guinea. From May to August 1942 combat between Airacobras and Zeros took place on

3822-426: The extension shaft, he was placed higher in the fuselage than in most contemporary fighters, which, in turn gave the pilot a good field of view. Access to the cockpit was by way of sideways opening "car doors", one on either side. Both had wind-down windows. As only the right-hand door had a handle both inside and outside this was used as the normal means of access and egress. The left-hand door could be opened only from

3900-451: The external radiator, 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 0.30 in (7.62 mm) machine guns to the two existing 0.50 in (12.7 mm) guns. Lacking armor or self-sealing fuel tanks, the prototype was 2,000 lb (910 kg) lighter than

3978-471: The free dictionary. P45 may refer to: Vessels [ edit ] ARA  Robinson  (P-45) , a corvette of the Argentine Navy HMS  Unrivalled  (P45) , a submarine of the Royal Navy Spanish patrol vessel  Audaz  (P-45) Other uses [ edit ] P45 (tax) , a form designation used as a metonym for termination of employment Bell P-45 , an American fighter aircraft later redesignated P-39C Intel P45 ,

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4056-610: The highest number of kills attributed to any U.S. fighter type flown by any air force in any conflict. Other major users of the type included the Free French , the Royal Air Force , and the Italian Co-Belligerent Air Force . The P-39 had an unusual layout, with the engine installed in the center fuselage, behind the pilot, and driving a tractor propeller in the nose with a long shaft. It

4134-493: The highest scoring P-39 fighter pilot of any nation, and the highest scoring Allied fighter pilot using an American fighter. This does not include his 6 shared victories, at least some of which were achieved with the P-39. The United States did not supply M80 armor-piercing rounds for the autocannons of Soviet P-39s—instead, the Soviets received 1,232,991 M54 high-explosive rounds, which they used primarily for air-to-air combat and against soft ground targets. The VVS did not use

4212-418: The lack of a turbo made it nearly impossible to improve upon the Airacobra's performance. The removal of the turbocharger and its drag-inducing inlet cured the drag problem but reduced performance overall. In later years, Kelsey expressed regret at not being present to override the decision to eliminate the turbo. After completing service trials, and originally designated P-45 , a first order for 80 aircraft

4290-462: The link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=P45&oldid=1235080088 " Category : Letter–number combination disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages P45 [REDACTED] Look up P45 in Wiktionary,

4368-405: The main structural attachment point for the main spar of the wing. This arch incorporated a fireproof panel and an armor plate between the engine and 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

4446-401: The nose of the fuselage which, in turn, drove the three- or (later) four-bladed propeller by way of 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 glycol -cooled radiator was fitted in the wing center section, immediately beneath the engine; this

4524-403: The outside and was for emergency use, although both doors could be jettisoned. In operational use, as the roof was fixed, the cockpit design made escape difficult in an emergency. The complete armament fit consisted of the T9 cannon with a pair of Browning M2 .50 in (12.7 mm) machine guns mounted in the nose. This changed to two .50 caliber and two .30 in (7.62 mm) guns in

4602-431: The production fighters. The production P-39 retained a single-stage, single-speed supercharger with a critical altitude (above which performance declined) of about 12,000 ft (3,700 m). As a result, the aircraft was simpler to produce and maintain. However, the removal of the turbo destroyed any chance that the P-39 could serve as a high-altitude front-line fighter. When deficiencies were noticed in 1940 and 1941,

4680-437: The rear canopy. The fuselage structure was unusual and innovative, being based on a strong central keel that 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

4758-412: The reported tumbling characteristics. In no case were they able to tumble it. In his autobiography veteran test and airshow pilot R.A. "Bob" Hoover provides an account of tumbling a P-39. He goes on to say that in hindsight, he was actually performing a Lomcovak , a now-common airshow maneuver, which he was also able to do in a Curtiss P-40 . A study of its spinning characteristics was conducted in

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4836-448: The same term This disambiguation page lists articles associated with the same title formed as a letter–number combination. If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=P45&oldid=1235080088 " Category : Letter–number combination disambiguation pages Hidden categories: Short description

4914-473: The standard fuel load was carried in the wings, with limitations on range. A heavy structure, and around 256 lb (116 kg) of armor, were characteristic of this aircraft as well. The production P-39's heavier weight combined with the Allison engine with only a single-stage, single-speed supercharger, limited high-altitude performance, which was markedly inferior to contemporary European fighters and, as

4992-419: The top speed was increased 16%. NACA wrote, "it is imperative to enclose the supercharger within the airplane with an efficient duct system for cooling the rotor and discharging the cooling air and exhaust gases." In the very tightly planned XP-39, though, there was no internal space left over for the turbo. Using a drag-buildup scheme, a number of potential areas of drag reduction were found. NACA concluded that

5070-452: The unarmed and unarmored XP-39 prototype. The British production contract stated that a maximum speed of 394 mph (634 km/h) +/- 4% was required at rated altitude. In acceptance testing, actual production aircraft were found to be capable of only 371 mph (597 km/h) at 14,090 ft (4,290 m). To enable the aircraft to make the guaranteed speed, a variety of drag-reduction modifications were developed by Bell. The areas of

5148-506: The unusual Bell YFM-1 Airacuda , the Model 12 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 a 37 mm Browning Arms Company T9 cannon , later produced by Oldsmobile , firing through

5226-448: Was a request for a single-engine high-altitude " interceptor " having "the tactical mission of interception and attack of hostile aircraft at high altitude". Despite being called an interceptor, the proposed aircraft's role was simply an extension of the traditional pursuit (fighter) role, using a heavier and more powerful aircraft at higher altitude. Specifications called for at least 1,000 lb (450 kg) of heavy armament including

5304-407: Was added. The airframe was painted with 20 coats of primer, with extensive sanding between coats. Standard camouflage was applied and sanded to remove the edges between the colors. Additionally, about 200 lb (91 kg) of weight was removed, making it lighter than normal (7,466 lb (3,387 kg) gross). After these modifications, the second production aircraft ( serial AH 571 ) reached

5382-480: Was also the first fighter fitted with a tricycle undercarriage . Although its mid-engine placement was innovative, the P-39 design was handicapped by the absence of an efficient turbo-supercharger , preventing it from performing high-altitude work. For this reason it was rejected by the RAF for use over western Europe but adopted by the USSR, where most air combat took place at medium and lower altitudes. Together with

5460-738: Was developed further in the Bell P-63 Kingcobra . A naval version with tailwheel landing gear, the XFL-1 Airabonita , was ordered as a competitor to the Vought F4U Corsair and Grumman XF5F Skyrocket . It first flew 13 May 1940, but after a troublesome and protracted development and testing period, it was rejected. The Airacobra saw combat throughout the world, particularly in the Southwest Pacific, Mediterranean and Soviet theaters. Because its engine

5538-505: Was equipped with only a single-stage, single-speed supercharger, the P-39 performed poorly above 17,000 feet (5,200 m) altitude. In both western Europe and the Pacific, the Airacobra found itself outclassed as an interceptor and the type was gradually relegated to other duties. It often was used at lower altitudes for such missions as ground strafing. In 1940, the British Direct Purchase Commission in

5616-414: Was flanked on either side by a single drum-shaped oil cooler. Air for the radiator and oil coolers was drawn in through intakes 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 carburetor was drawn in through a raised oval intake immediately aft of

5694-425: Was installed to hold them flush. The cooling air exit from the oil and coolant radiators was reduced in area to match the exit velocity to the local flow. New engine exhaust stacks, deflected to match the local flow and with nozzles to increase thrust augmentation, were installed. The machine gun ports were faired over, the antenna mast was removed, a single-piece engine cowling was installed and an exhaust stack fairing

5772-615: Was out-performed by many enemy aircraft. In September 1940, Britain ordered 386 P-39Ds (Model 14), with a 20 mm Hispano-Suiza HS.404 and six .303 in (7.7 mm) instead of a 37 mm cannon and six .30 caliber guns. The RAF eventually ordered 675 P-39s. However, after the first Airacobras arrived at 601 Squadron RAF in September 1941, they were found to have an inadequate rate of climb and performance at altitude for Western European conditions. Only 80 were operated, all by 601 Squadron. Britain transferred about 200 P-39s to

5850-438: Was placed 10 August 1939; the designation reverted to P-39C before deliveries began. After assessing aerial combat conditions in Europe, it was evident that without armor or self-sealing tanks, the 20 production P-39Cs were not suitable for operational use. The remaining 60 machines in the order were built as P-39Ds with armor, self-sealing tanks and enhanced armament. These P-39Ds were the first Airacobras to enter into service with

5928-979: Was scrapped on the recommendation of a visiting Bell test pilot in March 1946. The United States requisitioned 200 of the aircraft being manufactured for the UK, adopting them as P-400s. After the attack on 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 . Though outclassed by Japanese fighter aircraft, it performed well in strafing and bombing runs, often proving 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. Pacific pilots often complained about problems of performance and unreliable armament, but by

6006-557: Was the only American pilot to become an ace in a P-39, many later U.S. aces scored one or two of their victories in the type. The Airacobra's low-altitude performance was good and its firepower was impressive; regardless, it soon became a joke in the Pacific Theatre that a P-400 was a P-40 with a Zero on its tail. In North Africa, the 99th Fighter Squadron (also known as the Tuskegee Airmen ) transitioned quickly from

6084-406: 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 with a 10-foot-long (3.0 m) drive shaft 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

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