Kalinin K-7 Giant Transport/Bomber (USRR 1933) 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. http://www.fiddlersgreen.net/models/aircraft/Kalinin-K7.html