The General Electric F118 is a non-afterburning turbofan used in the Northrop B-2A Spirit and Lockheed U-2S. It belongs to the same broad core lineage as the F101 and F110, with a low-pressure system adapted to its specific aircraft applications. The -100 and -101 variants serve different installations and thrust requirements.[1]
B-2 installation
The B-2 uses four F118-GE-100 engines, each rated at 19,000 lbf thrust in GE's technical literature. The aircraft was unveiled in 1988, and engine flight testing began in mid-1989. Omitting an afterburner supported the low-observability requirements of the bomber, while the engine provided the thrust needed for the large flying-wing airframe.[1]
U-2 re-engining
The F118-GE-101 replaced the J75 in the U-2R, producing the re-designated U-2S. Its published thrust is 17,000 lbf. GE offered the F118 when the Air Force sought an engine replacement in the late 1980s, following its qualification for the B-2. The project applied a modern turbofan to an established high-altitude reconnaissance aircraft.[1][2]
Operational effects
GE reports that the U-2 conversion improved thrust and fuel consumption, increased payload capability and extended aircraft range by more than 1,200 miles. Climb time also decreased. These changes illustrate why a re-engining programme can materially change an existing aircraft's mission capability: improved propulsion affects the amount of useful equipment carried, time reaching altitude and endurance available for reconnaissance.[2]
Durability and commonality
The -101 incorporated a lighter engine and improved hot-section design intended to lengthen overhaul intervals. GE also described a service-life extension package for the B-2 engine, designed to increase time on wing and retain parts commonality with the F101 and F110. The family relationship therefore had a maintenance dimension as well as an origin in shared core engineering.[1]