Tupolev MTB-1

The Tupolev MTB-1 was a Soviet patrol flying boat of the mid-1930s, known originally as the MDR-4 and inside the Tupolev bureau as the ANT-27. It was a refined version of the unsuccessful Chyetverikov MDR-3, keeping that aircraft's hull but adding a new full-cantilever wing, a new tail and a new engine installation with two tractor engines and one pusher engine. Trials began in March 1934, but the first prototype was destroyed during a takeoff. A second prototype followed the next year and was renamed MTB-1 to reflect a new torpedo-carrying role. Although its trial performance was poor, the Soviet Navy urgently needed such an aircraft, so it was accepted for production before flight testing finished; 15 were built, they served until 1942, and they were powered by three Mikulin M-34 piston engines of 600 kilowatts each.