The design that eventually became the NK-12 turboprop was developed after
World War II by a team of Soviet scientists and imprisoned German engineers as part of
Operation Osoaviakhim, led by
Ferdinand Brandner, who had worked for
Junkers previously; the design bureau was headed by chief engineer Nikolai D. Kuznetsov. Thus, the NK-12 design evolved from late-war German turboprop studies. This started with the postwar development of the wartime
Jumo 022 turboprop design that was designed to develop , weighing . The effort continued with a , weighing , completed by 1947. Evolution to the
TV-12 engine required extensive use of new Soviet-developed alloys and was completed in 1951. The NK-12 is the most powerful turboprop engine to enter service, ahead of the
Europrop TP400 (in 2005). Another engine of similar size, the
Pratt & Whitney T57 with and jet thrust, ran 3,100 hours before being cancelled in 1957. The NK-12 powers the
Tupolev Tu-95 bomber and its derivatives such as the
Tu-142 maritime patrol aircraft and the
Tupolev Tu-114 airliner (with NK-12MV), which still holds the title of the world's
fastest propeller-driven aircraft despite being retired from service in 1991. It also powered the
Antonov An-22 Antei (with NK-12MA), the world's largest aircraft at the time, and several types of amphibious assault craft, such as the
A-90 Orlyonok "
Ekranoplan". The engine has a 14-stage axial-flow compressor, producing pressure ratios between 9:1 and 13:1 depending on altitude, with variable inlet guide vanes and blow-off valves for engine operability. The combustion system used is a cannular-type: each flame tube is centrally mounted on a downstream injector that ends in an annular secondary region. The contra-rotating propellers and compressor are driven by the five-stage axial turbine. Mass flow is 65 kg (143 lb) per second. ==Variants==