Tupolev TB-6

The Tupolev TB-6, internal designation ANT-26, was a proposal by the Tupolev Design Bureau in the 1930s for a super-heavy bomber. Had it been built, it would have been the biggest Soviet bomber ever and the largest aircraft by wingspan of its time. Work began in 1931, alongside the ANT-16 and ANT-20, on a bomber with twelve engines and a takeoff weight of 70,000 kg; the design called for twelve Mikulin M-34FRN engines, eight on the leading edge of the wing and four in two tandem pairs above it, with three vertical stabilizers. An alternative TB-6 design used six Mikulin M-44 engines. A sub-scale aircraft flew in 1935 to test the flight behaviour. By the mid-1930s military aviation had shifted towards smaller and faster aircraft, and the TB-6 was cancelled when the airframe was 75 percent complete and the entire aircraft 16 percent complete.