Volvo RM8

The Volvo RM8 is a low-bypass afterburning turbofan jet engine developed for the Saab 37 Viggen fighter. An augmented bypass engine was required to give both better fuel consumption at cruise speeds and higher thrust boosting for its short take-off requirement than would be possible using a turbojet. In 1962, the civil Pratt & Whitney JT8D engine, as used for airliners such as the Boeing 727, was chosen as the only engine available which could be modified to meet the Viggen requirements. The RM8 was a licensed-built version of the JT8D, but extensively modified for supersonic speeds, with a Swedish-designed afterburner, and was produced by Svenska Flygmotor (later known as Volvo Aero).