Couldn't resist sharing this one with you all. At first I thought it was a joke . . .
Designed by World War I aviator Konstantin Kalinin with a wingspan greater than the B-52 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 eleventh flight, during a speed test, the port tail boom vibrated, fractured, jammed the elevator and caused the giant aircraft to plunge to the ground, killing 15.
The K-7 was yet another example of the aviation policy dictated by the infant Soviet regime, which believed that the way to impress the rest of the world was to build aircraft bigger than anyone else's. On its first flight, on August 11, 1933, the pilots reported that they were generally content with the way the huge aircraft handled, except for the instability and vibration, which was found to be caused by the small-diameter propellers and ungeared engines. The aircraft test flights over Kharkov generated huge interest.
http://www.fiddlersgreen.net/models/aircraft/Kalinin-K7.html
