The Tupolev MTB-1 was a patrol flying boat built in the Soviet Union in the mid-1930s. It was a refined version of the unsuccessful Chyetverikov MDR-3. The revised design retained the MDR-3's hull, but added a newly designed, full-cantilever wing, a new tail, and a new engine installation featuring two tractor and one pusher unit. Trials began in March 1934 but the prototype was destroyed during one takeoff.