In the 1950s, the Soviet Union's Kuznetsov Design Bureau developed the NK-12 turboprop. It drives an 8-blade contra-rotating propeller and, at , it is the most powerful turboprop in service. Four NK-12 engines power the Tupolev Tu-95 "Bear", the only turboprop bomber to enter service, as well as one of the fastest propeller-driven aircraft. The Tu-114, an airliner derivative of the Tu-95, holds the world speed record for propeller aircraft. The Tu-95 was also the first Soviet bomber to have intercontinental range. The Tu-126 AEW aircraft and Tu-142 maritime patrol aircraft are two more NK-12 powered designs derived from the Tu-95.