The Pratt & Whitney F401 was an afterburning turbofan engine developed by Pratt & Whitney in tandem with the company's F100. The F401 was intended to power the Grumman F-14 Tomcat and Rockwell XFV-12, but the engine was canceled due to costs and development issues.
Pratt & Whitney F401
XFV-12A with F401 exhaust nozzle closed
An F401 in 1972, for the planned F-14B
An F401 engine for Rockwell XFV-12 prototype supersonic VTOL fighter
The Pratt & Whitney F100 is an afterburning turbofan engine designed and manufactured by Pratt & Whitney to power the U.S. Air Force's "FX" initiative in 1965, which became the F-15 Eagle. The engine was to be developed in tandem with the F401 which shares a similar core but with the fan upscaled for the U.S. Navy's F-14 Tomcat, although the F401 was later abandoned due to costs and reliability issues. The F100 would also power the F-16 Fighting Falcon for the Air Force's Lightweight Fighter (LWF) program.
Pratt & Whitney F100
Afterburner - concentric ring structure inside the exhaust
Adjustable exhaust nozzle contracted
F100-PW-100 on display at the Virginia Air and Space Center