[1] During the mid-1960s, the United States Army initiated the Advanced Aerial Fire Support System (AAFSS) program, which led to the development of the Lockheed AH-56 Cheyenne for use in the anti-tank gunship role.

However, the Army's broader concern was the task of protecting Western Europe from the legions of Warsaw Pact armor to the east.

[2][3] The main scenario used by NATO throughout the Cold War was that, if the Soviet Union and Warsaw Pact forces were to conduct a massive tank offensive attack on Western Europe, they would probably cross either the Fulda Gap (capturing Frankfurt first and then aiming for the westward bend of the Rhine south of Wiesbaden: a total distance of just 85 miles), or cross the North German Plain (see map).

[5] The Department of Defense (DOD) conducted a study which concluded that the Air Force's A-X program, the Navy's proposed Harrier, and the Cheyenne were significantly different and that they did not constitute a duplication of capabilities.

[6] The Army convened a special task force under General Marks in January 1972, to reevaluate the requirements for an attack helicopter.

[6] The task force conducted flight evaluations of the AH-56, along with two industry alternatives for comparison; the Bell 309 KingCobra and Sikorsky S-67 Blackhawk.

The report recommended funding of the Air Force's A-X program, which would become the A-10 Thunderbolt II, and limited procurement of the Harrier for the Navy.

The report never referred to the Cheyenne by name and only offered a lukewarm recommendation for the Army to continue to seek to procure attack helicopters, so long as their survivability could be improved.

[11] AAH sought an attack helicopter based on combat experience in Vietnam, with a lower top speed of 145 knots (269 km/h) and twin engines for improved survivability.

[1] Bell's Model 409/YAH-63A prototype featured a three-wheel landing gear in a tricycle arrangement, and placed the pilot in the cockpit front instead of the usual rear seat, to help with nap of earth flying.

[18][19] A separate competition was conducted for the sensor and targeting suite for the AAH, with Martin Marietta and Northrop submitting proposals in November 1976.

[17] Reasons for selecting the YAH-64A included its more damage-tolerant four-blade main rotor and reduced stability of the YAH-63's tricycle landing gear arrangement.