Development of TB-3 heavy bomber with doubled takeoff weight and doubled wing area. Four of six engines were installed in the thick (2m!) wing, two - in a tandem above the fuselage. Project started even before the TB-3 was ready.

TB-4 was built following dominating theory stating that efficiency of bomber increases with its payload. Low speed had to be compensated by strong defensive weapons and capability of huge aircraft to withstand serious punishment from enemy fighters. Even heavier aircraft were considered (to emerge later as ANT-26 and ANT-28 projects), with wingspan approaching 100m and payload of 25tons.

The aircraft novelties included two enormous 5x1.8x1.8m bomb bays in the fuselage (designed by K.P.Sveshnikov and V.M.Myasichev). Such a bomb bays made a 'World Record' - none other contemporary bomber was even close.

First flight was performed by M.M.Gromov on July 3, 1933. Flight test program (pilots Riazanov, Stefanovsky, Nukhtikov) was fulfilled in a short time - on September 29, 1933. Performance of TB-4 was found poor. In-wing engines wasted too much power to blow 2m thick wing, tandem installation was inefficient (typical for tandems), and as a result aircraft was badly underpowered.

Installation of more powerful 1250hp M-35 engine was suggested, but never done.

TB-4 was not accepted for production, but gained experience helped to finish even larger ANT-20 "Maksim Gorky" in record short time.

Specifications