Kalinin K-7

The Kalinin K-7 was a heavy experimental aircraft designed and tested in the Soviet Union in the early 1930s.

The K-7 was built in two years in Kharkiv, starting in 1931.

The aircraft completed seven test flights before a crash due to structural failure of one of the tail booms on 21 November 1933.

Specifications

Crew

11 

Capacity

(120 passengers / 7,000 kg (15,432 lb) cargo, in civilian configuration)

Length

28 m (91 ft 10 in)

Wingspan

53 m (173 ft 11 in)

Height

12.4 m (40 ft 8 in) (estimated to top of engine nacelle)

Wing area

454 m2 (4,890 sq ft)

Aspect ratio

6.2

Airfoil

Root

TsAGI R-II (22%)

Tip

TsAGI R-II (19%)

Empty weight

24,400 kg (53,793 lb)

Gross weight

38,000 kg (83,776 lb) normal

42,400 kg (93,500 lb) maximum bomb load

Max take-off weight

46,500 kg (102,515 lb)

Fuel capacity

9,130 l (2,410 US gal; 2,010 imp gal) in wing tanks

Powerplant

7 × Mikulin AM-34F V-12 liquid-cooled piston engines,

560 kW (750 hp) each

Propellers

2-bladed fixed-pitch propellers

Performance

Maximum speed

225 km/h (140 mph, 121 kn)

Cruise speed

180 km/h (110 mph, 97 kn)

Range

1,600 km (990 mi, 860 nmi)

Service ceiling

4,000 m (13,000 ft)

Wing loading

84 kg/m2 (17 lb/sq ft)

Power/mass

0.084 kW/kg (0.051 hp/lb)

Armament

Guns

3x 20 mm (0.79 in) cannon (at least)

8 x 7.62 mm (0.30 in) machine guns (at least)

Bombs

Maximum 19,000 kg (42,000 lb) of bombs.