This paper describes the design, demonstration and evaluation of a Full Authority Digital Electronic Control (FADEC) capable of controlling an advanced variable cycle gas turbine engine in an advanced supersonic Navy fighter aircraft application.The FADEC design incorporates many advanced technology features including the latest microelectronics, extensive fault tolerance capability, and high-speed digital communication using a fiber optic data link. The advanced technology FADEC system was successfully demonstrated in a comprehensive test program, which included open loop environmental bench testing, closed loop bench testing, and testing on an F401 afterburning turbofan engine at sea level and at nine altitude conditions from 7000 to 50,000 ft, and at Mach numbers from 0.3 to 1.6. This testing was a major milestone in a program to design, develop, and demonstrate an engine-mounted full authority digital electronic control for advanced military aircraft engine application in the 1980's and beyond.Over 7000 hr of electronic control operation were achieved during this program. Over 1100 hr of testing were achieved with the engine-mounted control unit, which included over 68 hr of engine testing without a hardware malfunction. In addition to the advanced electronic circuitry employed in the FADEC, the first demonstration of optic communication with engine-mounted equipment was achieved.The success of the FADEC program to date has led to plans to flight test the FADEC in either an F-15 or F-14 aircraft in the early 1980's.