During the mid-1960s, United States Army initiated the Advanced Aerial Fire Support System (AAFSS) program to develop the Lockheed AH-56 Cheyenne for the anti-tank gunship role.

However the Army's broader concern was the task of protecting Western Europe from the numerous Warsaw Pact tanks to the east.

[2] Bell, Boeing-Vertol (teamed with Grumman), Hughes, Lockheed, and Sikorsky all submitted proposals for the AAH program.

Although it had what had become by then the typical configuration for a helicopter gunship, with a sharklike fuselage, tandem crew seating, and stub wings for armament, the YAH-63 was largely a new machine.

[2] Distinctive features included wheeled tricycle landing gear, flat canopy window plates, an unusual "tee" tail, a large ventral fin, and a three-barreled General Electric XM-188 30 mm (1.18 in) cannon.

This was believed to be more prudent since the YAH-63 was intended to fly "in the treetops" during "nap-of-the-earth" (NoE) operations, and the pilot needed to have a clear view of the aircraft's surroundings.

In addition the service did not like the YAH-63's tricycle landing gear scheme, believing it was less stable than the Apache's "taildragger" configuration.