A set of four 30,750 lb.s.t. General Electric F101 turbofans were the powerplants of the Rockwell B-1A Lancer long-range strategic bomber. President Jimmy Carter had decided to cancel the B-1A in 1977 after the completion of only four examples. In search of new customers for its F101 turbofan engine, the General Electric company reworked the engine for a fighter aircraft under the Derivative Fighter Engine (DFE) program, a joint USAF/Navy program to explore alternative powerplants to the Pratt & Whitney F100 turbofan in the F-16 and for the TF30 turbofan in the F-14 Tomcat. The new engine was designated F101X, and featured some components derived from the F404 engine used on the F/A-18 Hornet. These included a scaled-up fan and a modified nozzle and afterburner.
The first FSD F-16A (75-0745) was fitted with the new F101X DFE engine and flew for the first time on December 19, 1980. The F101X DFE engine had a pronounced curve to the jet tailpipe, as opposed to the straight-sided Pratt & Whitney F100 engine. The General Electric engine actually performed better than the F100, which was at that time still experiencing teething difficulties. However, the air intake had problems with a high-frequency oscillation at the engine inlet and an instance of a fuel leak occurred which had to be rectified with minor fixes. The F-16/101 made 58 test flights and logged 75 hours in the air before the program was ended in July of 1981. In the event, the J101 engine was not adopted for the F-16, and the F-16 remained powered exclusively by the Pratt & Whitney F100 turbofan for another few years until the advent of the General Electric F110 turbofan, which was a development of the F101X DFE. The F-110 was later adopted as an alternative powerplant for the Fighting Falcon with the appearance of F-16C Block 30.