The General Electric J79 is an afterburning turbojet developed from 1952 as a more powerful successor to the J47. It powered several prominent supersonic military aircraft, including the Lockheed F-104, McDonnell Douglas F-4 and Convair B-58. The design became closely associated with the expansion of operational flight beyond Mach 2.[1]
Variable compressor geometry
The J79 introduced variable-stator compressor technology that allowed rapid acceleration and deceleration without stalling. GE identifies the first variable-stator flight in 1955 as an important milestone in its engine history. Adjusting compressor airflow geometry helped the engine accommodate different operating conditions, a central challenge for a high-performance turbojet expected to work across a broad speed range.[2]
Example configuration
The J79-GE-15 preserved by the US Air Force museum has a seventeen-stage axial compressor and three-stage axial turbine. Its military-power rating is 10,900 lbf, rising to 17,000 lbf with the afterburner operating. The museum gives a weight of 3,850 lb and length of seventeen feet five inches. These figures describe the -15, one member of a family with multiple aircraft-specific versions.[1]
Supersonic aircraft
The B-58 used the J79 for sustained supersonic bomber operation, while the F-104 and F-4 brought the engine into fighter service. Other applications included the RA-5 Vigilante and Kfir. GE's historical account credits J79-powered aircraft with numerous speed, altitude and climb records, reflecting the engine's broad role in the performance gains of its period.[1][3]
Production and support
Nearly 17,000 engines had been built when GE ended production in 1979. Service continued much longer, requiring specialist maintenance knowledge and support for operators in several countries. GE's account of longtime J79 specialist Mike Solon illustrates this later phase: an engine originally associated with new speed records became a mature international fleet supported through accumulated technical experience.[3]