Nickname for the U.S. Army's 53rd Aviation Detachment, later the 1st Aviation Detachment (Provisional) of the 1st Cavalry's 228th Assault Support Helicopter Battalion, this unit was only recently acknowledged by the US Army after nearly 30 years of being classified. This unit was the only group to fly the ACH-47A "Go-Go Bird" attack helicopter. Despite an excellent service record in the Vietnam War, the unit was disbanded in mid-1968 following the loss of one of its last two helicopters in the assault on Hue during the Tet Offensive. The unit insignia was a skull bearing rotors fore and aft (mirroring the twin rotor configuration of the Chinook airframe) and firing guns protruding from the mouth and both eyes, the whole oriented toward the lower left.