during the korean war, some 45,000 air guardsmen, 80 percent of the force, were mobilized. that callup exposed the weaknesses of the united states' various military reserve programs, including the ang. sixty-six of the air guard's ninety-two flying squadrons, along with numerous support units, were mobilized. once in federal service, they proved to be unprepared for combat. many key air guardsmen were used as fillers elsewhere in the air force. it took three to six months for some ang units to become combat ready. some never did.