Dust Off
n.— «The 57th had worked without a tactical call sign, simply using “Army” and the tail number of the aircraft.…Major [Lloyd E.] Spencer decided that this slapdash system had to go. In Saigon he visited Navy Support Activity, which controlled all the call words in South Vietnam. He received a Signal Operations Instructions book that listed all the unused call words. Most, like “Bandit,” were more suitable for assault units than for medical evacuation units. But one entry, “Dust Off,” epitomized the 57th’s medical evacuation missions. Since the countryside then was dry and dusty, helicopter pickups in the fields often blew dust, dirt, blankets, and shelter halves all over the men on the ground. By adopting “Dust Off,” Spencer found for Army aeromedical evacuation in Vietnam a name that lasted the rest of the war.» —“Dust Off: Army Aeromedical Evacuation In Vietnam” by Peter Dorland, James Nanney in Office of the Surgeon General Office of Medical History , 1982. (source: Double-Tongued Dictionary)