General Electric YJ93
|YJ93-GE-3 engine at National Museum of the United States Air Force|
|National origin||United States|
|Manufacturer||General Electric Aircraft Engines|
|Major applications||North American XB-70 Valkyrie|
|Developed into||General Electric GE4|
The General Electric YJ93 turbojet engine was designed as the powerplant for both the North American XB-70 Valkyrie bomber and the North American XF-108 Rapier interceptor. The YJ93 was a single-shaft axial-flow turbojet with a variable-stator compressor and a fully variable convergent/divergent exhaust nozzle. The maximum sea-level thrust was 28,800 lbf (128 kN).
Design and development
The YJ93 started life as the General Electric X275, an enlarged version of the General Electric J79 turbojet. This evolved to the X279 when Mach 3 cruise became a requirement, and ultimately became the YJ93.
The engine used a special high-temperature JP-6 fuel. The six YJ93 engines in the XB-70 Valkyrie were capable of producing a thrust to weight ratio of 5:1 allowing for a speed of 2,000 mph (3,200 km/h) (approximately Mach 3) at an altitude of 70,000 feet (21,000 m).
The XF-108 interceptor was cancelled outright and the B-70 project was reoriented to a research project only.
- Convair NB-58A Hustler (testbed)
- North American XB-70 Valkyrie
- North American XF-108 Rapier (intended)
Data from
- Type: Turbojet
- Length: 6.2 m (237 in)
- Diameter: 1.33 m (52.5 in)
- Dry weight: 3800lb (1,728 kg)
- Maximum thrust: 19,000 lbf (85 kN) (28,800 lbf (128 kN) with afterburner)
- Air mass flow: 275 lb/s (125 kg/s)
- Specific fuel consumption: 0.700 lb/(lbf·h) or 19.8 g/(kN·s) (1.800 lb/(lbf·h) or 51.0 g/(kN·s) with afterburner)
- Thrust-to-weight ratio: 7.58（with afterburner）
- Related development
- Comparable engines
- Related lists
|Wikimedia Commons has media related to General Electric YJ93.|
- Jenkins, Dennis R. and Tony R. Landis. North American XB-70A Valkyrie WarbirdTech Volume 34. North Branch, Minnesota: Specialty Press, 2002. ISBN 1-58007-056-6.
- Jenkins, Dennis R. and Tony R. Landis. Valkyrie: North American's Mach 3 Superbomber. North Branch, Minnesota: Specialty Press, 2005. ISBN 1-58007-072-8.
- National Museum of the USAF Retrieved: December 21, 2016
- NB-58A Testbed for General Electric J93
- Military Turbojet/Turbofan Specifications