The Kalinin K-7 (Russian: Калинин К-7; Ukrainian: Калінін К-7) was a heavy experimental aircraft designed and tested in the Soviet Union in the early 1930s. It was of unusual configuration with twin booms and large underwing pods housing fixed landing gear and machine gun turrets. In the passenger version, seats were arranged inside the 2.3-meter thick (7 ft 7 in) wings. The airframe was welded from KhMA chrome-molybdenum steel.
General characteristics
Crew: minimum 11
Capacity: 120 passengers in civilian configuration
Length: 28 m (91 ft 10 in)
Wingspan: 53 m (173 ft 11 in)
Height: 12.4m (estimated to top of engine shell)
Wing area: 454 m² (4,886.8 ft²)
Empty weight: 24,400 kg (53,793 lb)
Loaded weight: 38,000 kg (83,776 lb)
Powerplant: 7 × Mikulin AM-34F V-12 piston engines, 560 kW (750 hp) each
Performance
Maximum speed: 225 km/h (121 knots, 140 mph)
Service ceiling: 4,000 m (13,123 ft)
Wing loading: 84 kg/m² (17 lb/ft²)
Power/mass: 103 W/kg (0.06 hp/lb)
