Criticism that the U.S. Air Force did not take
close air support (CAS) seriously prompted a few service members to seek a specialized attack aircraft.
[5][6] In 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. In addition, the
UH-1 Iroquois and
AH-1 Cobra helicopters of the day, which USAF commanders had said should handle close air support, were ill-suited for use against armor, carrying only anti-personnel machine guns and unguided rockets meant for
soft targets. Fast jets such as the
F-100 Super Sabre,
F-105 Thunderchief and
F-4 Phantom II proved for the most part to be ineffective for close air support because their high speed did not allow pilots enough time to get an accurate fix on ground targets and they lacked sufficient
loiter time. The effective, but aging, Korean War era,
A-1 Skyraider was the USAF's primary close air support aircraft.
[7][8]