Chyetverikov MDR-3

The MDR-3 (a.k.a.11) was a long range flying boat designed and built in the USSR from.

Development
In 1931 Chyetverikov was commissioned to design a new long-range flying boat for MA (Morskaya Aviatsiya - naval aviation), for which Chyetverikov used few new parts borrowing wings, tailplane and engine nacelles (mounted above the wing) from the Grigorovich TB-5 and a scaled up Grigorovich ROM-2 fuselage. The use of ready designed or built components led to quick construction of the prototype which was ready for flight tests in Dec 1931, which commenced in January after the aircraft was transported to Sevastapol in the Crimea. Despite the fast construction and excellent structural qualities, results of the flight tests were disappointing, with a take-off time of 36s, a climb rate of less than a metre per second and a ceiling of only 2,200m, resulting in the whole project being transferred to KOSOS (Konstrooktorskiy Otdel Sektora Opytnovo Stroitel'stva - section of experimental aeroplane construction) due to lack of faith in Chyetverikov's abilities to rectify the poor performance. The MDR-3 became the basis of the ANT-27, MDR-4 and MTB-1.