General Electric YJ93-GE-3 Turbojet Engine

Type: Turbojet, afterburner

Thrust: 142,300 N (32,000 lb)

Compressor: 8-stage axial

Combustor: Annular

Turbine: 2-stage axial

Weight: 2,359 kg (5,200lb)

GE won a contract for the J93 propulsion system of the North American XB-70 Valkyrie supersonic bomber in 1957. The highly-advanced, lightweight single-shaft turbojet engine incorporated variable compressor stator vanes, afterburner, and a fully variable converging-diverging exhaust nozzle; and was the world's first engine designed to operate efficiently up to Mach 3.2. Early flight testing was done with the engine mounted in a pod under a B-58 Hustler testbed aircraft, and the first engines were delivered to the Air Force in 1961.

First flight of the XB-70A powered by YJ93-GE-3 engines occurred in 1964. Because of changes in defense requirements, it was decided to build only two XB-70 aircraft. The second aircraft crashed in 1966, but the first aircraft continued in service until 1969 in a joint Air Force-NASA flight research program primarily for the U.S. Supersonic Transport program. There were no further applications for it when the XB-70 program ended.