Saturn AL-41

The NPO Saturn AL-41F is a Russian turbofan engine, designed for supercruise flight. Originally developed for the Mikoyan Project 1.44, the engine was built around the geometry of the AL-31F, making it compatible with existing airframes, including the Sukhoi Su-27 series. The engine is reported to have recently entered low rate initial production for use in the Su-34 Fullback.Specifications are not disclosed yet, but it is described by most sources as being in the 40.000 lbf class, 10:1 thrust to weight ratio.

A heavily-upgraded version of the Al-31F is being developed for the Su-35BM prototype and possibly to power the early flights of PAK-FA. This engine has been named the AL-41F1A. It is important to note that the AL-41F1A is not considered a part of the same AL-41 line as was planned for the Mikoyan Project 1.44 because it uses the core of the AL-31F, whereas the AL-41F utilizes an entirely new core. The designation appears to be present because the engine approaches the projected specifications of the new AL-41F class. The engine is specified as being able to provide 14.5 tons of thrust. It is also notable that the engine is capable of mounting 3D Thrust Vectoring Nozzles for extra maneuverability.