Goodbye Stagnation: America's Finest Fighter Engine Outgrows a Childhood Ailment

Abstract

Pratt & Whitney Aircraft's F100 augmented turbofan is the most advanced military engine in service today. It powers two of the U.S. Air Force's front‐line fighters: the twin‐engine McDonnell Douglas F‐15 and the newly introduced single‐engine General Dynamics F‐16. The F100 is a 25,000‐pound‐thrust class engine. Yet it weighs only 3,020 pounds. No other military aircraft engine can match its remarkable 8‐to‐1 thrust‐to‐weight ratio. But the F100's unparalleled performance was marred by an unexpected problem: early production models were susceptible to a curious phenomenon called stagnation. When an F100 stagnates, it won't respond to its throttle. Thrust drops sharply, and the engine's turbine stages may overheat. The only way out of stagnation is to shut down the engine and restart it. Recently, P&WA engineers — working with technical investigators from the U.S. Air Force and McDonnell Douglas — unlocked the mystery of stagnation. Their success represents a significant advance in the technology of high‐performance turbofan engines.

Citation

(1979), "Goodbye Stagnation: America's Finest Fighter Engine Outgrows a Childhood Ailment", Aircraft Engineering and Aerospace Technology, Vol. 51 No. 11, pp. 15-17. https://doi.org/10.1108/eb035573