Bell P-39 Airacobra

Bell P-39 Airacobra was a fighter aircraft 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 at the start of the war, notable for its unconventional design featuring a mid-mounted Allison V-1710 engine located behind the pilot. While its performance at high altitude was limited, the P-39 Airacobra found significant success as a low-altitude fighter and ground-attack aircraft, particularly in the hands of the Soviet Air Forces on the Eastern Front.

Design and development

The design originated from Bell Aircraft's pursuit of United States Army Air Corps Circular Proposal X-609 in 1937, which called for a high-performance interceptor. Chief engineer Robert J. Woods led a team that conceived a radical layout, placing the engine amidships to accommodate a heavy 37 mm M4 cannon firing through the propeller hub, a configuration intended to maximize firepower. This arrangement required a long drive shaft to connect the Allison V-1710 engine to the propeller at the nose, and allowed for a tricycle landing gear, a novel feature for fighters of the era. The aircraft's armament was concentrated in the nose, and the cockpit was positioned forward for good visibility, with the pilot entering through car-style doors. Despite its innovative features, the design omitted a turbocharger, which severely hampered its high-altitude performance against adversaries like the Messerschmitt Bf 109 over Western Europe.

Operational history

Initial service with the United States Army Air Forces revealed the P-39 Airacobra's deficiencies in high-altitude combat during operations in the Pacific Theater and North African Campaign. Its performance led to a mixed reputation among American pilots, though aces like Lt. Col. John R. "Bob" C. scored victories with it. The Royal Air Force briefly operated the type under the name Bell Airacobra I, but found it unsuitable for combat over Europe and relegated most to training. The aircraft's most substantial and successful combat service was with the Soviet Air Forces, which received nearly half of all production via Lend-Lease shipments through Alaska and Iran. Soviet pilots, including top ace Aleksandr Pokryshkin of the 16th Guards Fighter Aviation Regiment, effectively employed the P-39 Airacobra at low to medium altitudes for air superiority and close air support against the Luftwaffe on the Eastern Front. It also saw service with the Free French Air Force and the Italian Co-Belligerent Air Force after the Armistice of Cassibile.

Variants

The primary production model for the USAAF was the P-39D, which introduced self-sealing fuel tanks and increased armor. The P-39F and P-39J featured minor engine improvements, while the P-39L and P-39M had different propellers and engine variants. The definitive and most-produced version was the P-39Q, which replaced the underwing .30 caliber machine guns with underwing pods containing .50 caliber machine guns or, more commonly, deleted them to reduce drag. A two-seat trainer version, the TP-39Q, was also built in limited numbers. The Bell XFL Airabonita was a related design developed for the United States Navy, and the Bell P-63 Kingcobra was a direct, more powerful development.

Operators

The primary military operators were the United States Army Air Forces and the Soviet Air Forces. Other significant operators included the Royal Air Force, the Free French Air Force, the Italian Co-Belligerent Air Force, and the Polish Air Force. Post-war, the Italian Air Force used it until 1949, and it also served with the Portuguese Air Force. Captured examples were evaluated by the Luftwaffe and the Imperial Japanese Army Air Service.

Specifications (P-39Q Airacobra)

* **Crew:** One * **Length:** 30 ft 2 in (9.19 m) * **Wingspan:** 34 ft 0 in (10.36 m) * **Height:** 12 ft 5 in (3.78 m) * **Empty weight:** 5,645 lb (2,560 kg) * **Powerplant:** 1 × Allison V-1710-85 V-12 engine liquid-cooled piston engine, 1,200 hp (890 kW) * **Maximum speed:** 376 mph (605 km/h) at 16,000 ft (4,900 m) * **Range:** 525 mi (845 km) * **Service ceiling:** 35,000 ft (11,000 m) * **Armament:** 1 × 37 mm M4 cannon (30 rounds), 2 × 0.50 in (12.7 mm) M2 Browning machine guns in the nose (200 rpg), 4 × 0.30 in (7.62 mm) M1919 Browning machine guns in the wings (1,000 rpg) or 2 × underwing pods with 0.50 in machine guns

Category:World War II fighter aircraft of the United States Category:Low-wing aircraft Category:Aircraft first flown in 1938