K-7, K.A.Kalinin

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

esignation 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.
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.
B/W photo (51k) from the article "Airplane-Giant K-7"
There was an option to carry a 8.4 tons tank (or other equipment to be parachuted) between the main gears and 112 paratroopers.
First test flights were successful, but later the single prototype crushed 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
  • Technical data
    Type K-7
    Function bomber
    Year 1933
    Crew 19
    Engines 7*750hp Mikulin AM-34
    Empty Weight 21,000kg
    Maximum Weight 40,000kg
    Wingspan 53m
    Wing Area 452m2
    Length 28m
    Speed on the ground level 234km/h
    Ceiling 5500m
    Range 2400km with 6,000kg bombs
    5000km in passenger version
    Takeoff/Landing Roll 400m/300m
    Passenger version 128 seats
    Bombs 9,900...16,600kg
    Guns Defence: up to 12 positions
    Modified April 8, 1997
    by Alexandre Savine;
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