Designed by World War I aviator Konstantin Kalinin with a wingspan
greater than a B-52's and a much greater wing area, the K-7 was one of
the biggest aircraft built before the jet age. It was only one engine short of
the B-52 as well, having the curious arrangement of six pulling on the wing
leading edge and one pushing at the rear.
The K-7's very brief first flight showed up instability and serious vibration
caused by the airframe resonating with the engine frequency. The solution to
this 'flutter' was thought to be to shorten and strengthen the tail booms, little
being known then about the natural frequencies of structures and their
response to vibration. On the 11th flight, during a speed test, the port
tailboom vibrated, fractured, jammed the elevator and caused the giant
aircraft to plough into the ground, killing 15.
Undaunted by this disaster, Kalinin's team began construction of two
further K-7s in a new factory, but the vicissitudes of Stalin's Russia
saw the project abandoned, and in 1938 the arrest and execution
of Kalinin on trumped up espionage and sabotage charges.
Looks like something out of H.G.Well's "War of the Worlds" or the illustrative aerial creations by Bruce Mccall's "Zany Afternoons". I have no doubts this aircraft could have flown (minus the cannons) eventually with all its faults ironed out. Probably best flown with the pilots and crew wearing brown corduroy trousers. What a sight it would have made at air shows.
If all those guns were fired at the same time the poor old dear would snap into a really spectacular stall, despite the momentum of those 38000-odd kgs. (It could get tricky even on a Spitfire Mk XII and only 8 .303's if you didn't have enough on the ASI.)Mind you, with that very low aspect-ratio wing, she may simply have mushed and wallowed horribly.
It is interesting that in Bill Gunston's book "Back to the Drawing Board", there is aa photo of a full scale mock-up with a different engine arrangement of the completed example. It is photographed with the same background as one of the photos of the completed aircraft.
Hi, Folks !! A fev days ago I got an E-mail from a Norwegian friend,showing a BIG Kalinin K-7.Somewhere later I read something saying;"This aircraft is not the real K-7".Could you tell me if this is right ? Greatings from: Tom in Brazil.....