The Fighter Mafia was a controversial group of U.S. Air Force officers and civilian defense analysts who, in the 1970s, advocated the use of John Boyd and Thomas P. Christie's Energy-Maneuverability (E-M) theory as the sole driver in designing fighter aircraft.
The mathematical model they developed enabled quantitative (number-driven) one-to-one comparison of the performance of various aircraft in terms of air combat maneuvering, independent of real world flight testing. The model was used to identify deficiencies in service and proposed designs of the time. The Fighter Mafia influenced the specifications for the F-X, and went on to independently develop specifications for the Light Weight Fighter. The group was also instrumental in a return to air-combat maneuverability being the defining quality of fighter planes, after the Vietnam War showed that long-range missile systems of the time were insufficient as the sole deciding factor in air combat.
The next generation of warplanes combined both maneuverability (which the group advocated) as well as the high-tech electronics and missiles (that they opposed). Aircraft in this generation included the F-14, F-15, F-16 and F/A-18. The Fighter Mafia attracted considerable controversy and the actual extent of their influence and contribution to shaping US fighter design is a matter of debate.
The nickname, a professional jest coined by an Air Force member of Italian heritage, was a rejoinder to the "Bomber Mafia", theorists at the Air Corps Tactical School in the 1930s whose ideas led to the primacy of heavy bomber aircraft performing strategic bombing over that of fighter (the latter at the time being called "pursuit" aircraft in the Army Air Corps and later the Army Air Forces).