Full Authority Digital Electronic Control
Full Authority Digital Electronic Control (FADEC) refers to a family of computer-assisted control systems for vehicle engines, aircraft flight control, etc. Rather than control the details of ignition and fuel-air mixture, angles of complementary aerodynamic surfaces, etc., FADEC interfaces allow the operator to specify what the aircraft vehicle is to do (e.g., "speed up" or "turn left") without having to manage all the fine-grained tasks of how to do it.
There are cases in which a pilot might want, for specific reasons, to override one of the detailed mechanisms, but FADEC does not allow this. FADEC will also try to prevent what its programming considers to be a hazardous maneuver.
The term "FADEC" applies to a wide range of control techniques, although there are individual cases where the abbreviation is interpreted more specifically. For example, on the F-35 Joint Strike Fighter, FADEC stands for "full authority digital engine control."