|Loaded weight (normal)||13800kg|
|Loaded weight (overload)||18550kg|
|Wing load (normal)||238|
|Wing load (overload)||319|
|Power load (normal)||3.73|
|Power load (overload)||5.0|
|Speed at 0m||445km/h|
|Speed at 5000m||510km/h|
|Landing Roll||570m sec|
|Takeoff Roll||660m sec|
|Rate at 0m||7.1m/sec|
Aircraft was named NB for 'Nochnoj Bombovoz' (night bomb carrier) according to N.N.Polikarpov himself. 'T' was a official project designation. It was a high-wing twin-engine twin-tail monoplane, built with aim to replace the S.V.Ilyushin DB-3F. Polikarpov's bomber had same size as Ilyushin's, but it was better streamlined and carried substantially larger payload.
High wing (equipped with flaps and leading edge slats) allowed to carry large bombs inside (up to 5tons). NB's layout was highly praised by aircraft specialists as a perfect bomber layout. While normal takeoff weight was set at 12640kg, aircraft could be loaded up to 18850kg without risking airframe strength. Fuselage rigidity was provided by (quite sophisticated) internal wielded steel tube frame, surrounding very large bomb bay. Both fuselage and wing included steel, aluminum and wooden elements. This 'composite' approach allowed N.N.Polikarpov to minimize usage of deficit materials without degrading weight and structural strength. Even in overloaded configuration aircraft could withstand loads up to +6g.
Wing, for example, had strong steel main spur with aluminum walls. Center section had aluminum ribs and skin, while outer panels had wooden ribs and variable thickness plywood skin.
Originally designed to fly with air cooled 2000hp M-71 engine, it was actually flown with ASh-82A replaced later with ASh-82FNV. Engine cowling was equipped with electrically controlled adjustable intake and outlet. Electric motors were also used to operate trimmers and landing flaps, as well as main controls while flying with autopilot.
Barrel armament included three heavy UB machineguns: one fixed in the nose, one in each ventral and dorsal rear defence positions.
Aircraft was built at Fall 1943, and a long time was spent on refinement. NB was flown on May 23, 1944 with high altitude ASh-82FNV engines. Factory trials continued in August 1944. Performance was very promising, but with approach of the War end need in such a plane faded. Shortly after N.N.Polikarpov's death NB was abandoned.
|Created January 25, 1996
Modified August 17, 1999