The development of the R-79 began in the late 1970 under the direction of V.K. Kobchenko with development project designation
Izdeliye 79 ('Product 79'). The design and development of the R-79V-300 was driven by the requirement of designing a power plant for a supersonic V/STOL aircraft working alongside two lift engines (RD-41). Unlike its predecessor, the thrust-vectored non-afterburning turbofan Tumansky R-27 used in the
Yak-38, the R-79 single exhaust design combined with a three-joints ring swivel
nozzle made possible an afterburner turbofan capable of operate in any nozzle position. The R-79V-300 used in the
Yak-141 is a two-shaft axial-flow afterburning turbofan with counter-rotating spools to reduce weight and
gyroscopic forces on the engine. The engine has a three-stage low-pressure compressor (fan) and an eleven-stage high-pressure compressor, with bleed air from after the 6th stage for roll control. Both compressors are driven by a pair of counter-rotating 2-stage
turbines. However the bleed air for roll control, up to 10 kg/s taken from the core will reduce the
thrust. Paired with two RD-41 (4.1 kN, 4,260 kgf) they totals a thrust in hovering mode of at ISA conditions. Ground testing, production and test flights extended from 1983 to 1991 when the Yak-141 was cancelled.
Further developments During the 1990s Soyuz developed an alternative rectangular nozzle for vector control in the pitch axis, replaced the analogue electronic engine controller with a
FADEC and increased thrust. == Variants ==