Bell P-39 Airacobra
The radical Bell P-39 Airacobra singleseat fighter was designed around the hub-firing 37-mm T-9 cannon which had given impressive demonstrations in 1935. The Allison V-12 engine was located amidships behind the cockpit, driving the propeller by an extension shaft, and nosewheel landing gear was adopted. The prototype XP-39 was first flown in April 1939; production P-39D aircraft entered service with the USAAC in 1941 and first saw combat in the Pacific theatre in April 1942. P39Ds also served with US forces in Europe but suffered heavily in action; they also flew with one RAF squadron (No. 601) but persistent problems caused them to be withdrawn after scarcely a single action.
The Airacobra flew with much better results with three USAAF groups based in North Africa from the end of 1942. The P-39D was followed by the P-39F, which introduced an Aeroproducts propeller in place of the former Curtiss type, the P-39J with V-1710-59 engine, the P-39K with -63 engine and Aeroproducts propeller, and the P-39L with -63 engine and Curtiss propeller. The P-39M introduced the -83 engine with largediameter propeller. Final and mostbuilt versions were the P-39N and P39Q with -85 engine; production amounted to 2,095, bringing the total of all P-39s to 9,558. Of these, no fewer than 4,773 were shipped to the Soviet Union in response to Stalin's desperate appeals for military assistance.
Type: single-seat fighter bomber
Powerplant: one 895-kW (1,200-hp) Allison V-1710-85 V-12 piston engine
Performance: maximum speed 642 km/h (399 mph) at 2955 m (9,700 ft); climb to 4570 m (15,000 ft) in 3.8 minutes; service ceiling 11735 m (38,500 ft); range 1207 km (750 miles)
Weights: empty 2566 kg (5,657 lb); maximum take-off 3720 kg (8,200 lb)
Dimensions: span 10.36 m (34 ft 0 in); length 9.19 m (30 ft 2 in); height 3.78 m (12 ft 5 in); wing area 19.79 m2 (213.0 sq ft)
Armament: one hub-firing 37-mm gun, two 12,7-mm (0.5-in) machine-guns in nose decking, and four 7.62-mm (0.3 in) guns in the wings, plus provision for one 227-kg (500-lb) bomb under the fuselage