Technical data
Type K-7
Function bomber
Year 1933
Crew 19
Powerplant (7)
Type AM-34
Power (each, hp) 750
Size (m)
Wingspan 53
Length 28
Wing Area 452m2
Weights (kg)
Weight 21,000
Maximum 40,000
Speed (km/h)
0m 234
Roll (m)
Takeoff 400
Landing 300
Ceiling (m)
Practical 5500
Range (km)
with 6,000kg bombs 2400
Passenger version 5000
Passenger seats 128
Bombs (kg) 9,900 ~ 16,600
Guns Defence: up to 12 positions

K-7, K.A.Kalinin

B/W photo (35k) from the article "Airplane-Giant K-7"

Designation K-7 was originally assigned to project of 3-engined 22-seat transport (aka the K-Tjazholij, K-Heavy). When this project was abandoned, the K-7 became an experimental heavy bomber.

B/W photo (51k) from the article "Airplane-Giant K-7"

Basically it was an enormous, thick (mechanics were able to walk to engines during the flight), elliptical flying wing design, with twin tail booms, a nacell protruding from the leading edge, and six-wheeled landing gear - each three wheels enclosed in enormous fairings, that contained also 2 gunner positions each and the entrance stair. Defence were arranged so that any direction was covered by at least three gunners.

There was an option to carry a 8.4 tons tank (or other equipment to be parachuted) between the main gears and 112 paratroopers.

Technical project was ready in January 1932 and project entered the blueprint stage. At that time 1:1 wooden mockup of the aircraft central section was built in the KhAZ workshop yard. It had three large passenger cabins.

Official assembly began on November 18 in very pompous atmosphere. Chairman of Ukrainian KPB G.I.Petrovskij himself ignited the gas torch and performed wielding of the first joint. Quality was horrible, and the joint had to be cut away and replaced. Of course when the bosses left...

First test flights were successful, but later the single prototype crashed during maximum speed test. The cause of crash was infamous "flatter"... But it was little known about at the moment.

See an article "Airplane-Giant K-7" from the 'Modelist-Konstructor' magazine;

More Links...
  • K-7, Kalinin
  • K-7 at Virtual Aircraft Museum

  • Modified April 8, 1997 Back to
    Main Gate