Tupolev MTB-2
The Tupolev MTB-2 (Морской Тяжелый Бомбардировщик — Heavy Naval Bomber), also known as the ANT-44, was a Soviet four-engine flying boat built in the late 1930s. Two prototypes were built; performance was satisfactory, but the design was overtaken by the fielding of long-range, land-based bombers by Soviet Naval Aviation and cancelled in 1940.