Preliminary Flight Test Results of the F100 EMD Engine in an F·15 Airplane

Abstract A flight evalu~tion of the Fl00 engine model derivative (EMD) has recentlybeen conducted at NASA Ames Research Center's Dryden Flight Research Facility.The Fl00 EMD is an advanced version of the F100 engine that powers the F-15 andF-16 airplanes. The Fl00 EMD features a bigger fan, higher temperature turbine,a digital electronic engine control system (DEEC), and a newly designed 16-segmentafterburner, all of which resulted in a 15- to 20-percentincrease in sea-levelthrust. The flight evaluations consisted of investigations of performance (thrust, I fuel flow, and airflow) and operability (transient response and airstart) in theF-15 airplane. The performance of the Fl00EMD has been excellent. Aircraftacceleration time to Mach 2.0 was reduced by 23 percent with two F100 EMD engines.Several anomalies were discovered in the operability evaluations. with theinitial DEEC logic, the throttle response for formation flying was poor andreceived a Cooper-Harper pilot rating of 6 to 8. A software change to the DEECimproved the throttle, and subsequent Cooper-Harper ratings of 3 to 4 wereobtained. The augmentor operation was initially limited by a failure to light athigh-altitudeand low-airspeed conditions; a hardware change was made to elimi-nate the problem. In the extreme upper left-handcorner of the flight envelope,compressor stalls occurred when the throttle was retarded to idle power. Thesestalls were not predicted by aititude facility tests or stability assessments forthe compressor.17.