Edwards AFB, Calif -- The Northrop YA-9A Cobra specialized ground attack aircraft made its first flight, flown by company test pilot Mr. Lew Nelson. The aircraft subsequently lost the A-X competitive prototype flyoff against the A-10, and never went into production.
Criticism that the U.S. Air Force did not take close air support seriously prompted service senior leadership to seek a specialized attack aircraft. During the Vietnam War, large numbers of ground-attack aircraft were shot down by small arms, surface-to-air missiles, and low-level anti-aircraft gunfire, prompting the development of an aircraft better able to survive such weapons. Fast jets such as the North American F-100 Super Sabre, Republic F-105 Thunderchief and McDonnell Douglas F-4 Phantom II proved, for the most part, to be ineffective for the close air support combat mission..
Members of the National Aeronautics and Space Administration (NASA) took responsibility for the two Cobra prototypes and continued flight testing before retiring the airframes. During retirement, the YA-9As' custom-built engines were removed and later mated to a C-8 Buffalo aircraft as part of the NASA-Boeing joint Quiet Short-haul Research Aircraft study into the development of a quiet short-haul commercial aircraft.