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.