During the Korean War, the U.S. Military flew more attack missions than
      any other type of mission.  The U.S. Navy and Marine Corps flew most
      of their attack missions with piston-engined aircraft.
      In 1957 the Navy selected the Grumman  G-128 in a competition for a
      long-range, low-level tactical strike aircraft.  The first flight of
      the prototype was made in 1960 with the type entering service in 1963.
      The  Intruder saw extensive service in the South East Asia.  When
      the last  A-6 variant left the production line in 1990 more than 660 had
      been built.