Kalinin K-7

Kalinin K-7 ( _ru. Калинин К-7) was a heavy experimental aircraft designed and tested in the Soviet Union in the early 1930s. K-7 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. The original design called for six engines in the wing leading edge but when the projected loaded weight was exceeded, the seventh engine was added in the trailing edge of the central pod.

K-7 first flew on 11 August 1933. Then on 21 November 1933 the aircraft crashed due to structural failure of one of the tail booms, killing 14 people aboard and one on the ground. Although two more prototypes were ordered in 1933, the project was canceled in 1935 before they could be completed.

pecifications (K-7)

aircraft specifications
plane or copter?=plane
jet or prop?=prop
ref=Shavrov 1985cite book|author=Shavrov V.B.|year=1985|title=Istoriia konstruktskii samoletov v SSSR do 1938 g. (3 izd.)|language=Russian|publisher=Mashinostroenie|id=ISBN 5-217-03112-3]
crew=
capacity=120 passengers in civilian configuration
payload main=
payload alt=
payload more=
length main=28 m
length alt=91 ft 10 in
span main=53 m
span alt=173 ft 11 in
height main=
height alt=
area main=454 m²
area alt=4886.8 ft²
airfoil=
empty weight main=24,400 kg
empty weight alt=53,793 lb
loaded weight main=38,000 kg
loaded weight alt=83,776 lb
max takeoff weight main=
max takeoff weight alt=
more general=
engine (prop)=Mikulin AM-34F
type of prop=V-12 piston engines
number of props=7
power main=560 kW
power alt=750 hp
max speed main=225 km/h
max speed alt=121 knots, 140 mph
max speed more=
cruise speed main=
cruise speed alt=
cruise speed more=
range main=
range alt=
range more=
ferry range main=
ferry range alt=
ferry range more=
ceiling main=4,000 m
ceiling alt=13,123 ft
celing more=
climb rate main=
climb rate alt=
climb rate more=
loading main=84 kg/m²
loading alt=17 lb/ft²
thrust/weight=
power/mass main=103 W/kg
power/mass alt=0.06 hp/lb
more performance=
armament=
avionics=

References