Cobra 318, a 1966 AH-1G/S/F helicopter purchased by the US Army in November 1967, arrived in Vietnam in early February 1968, was damaged in a mortar attack on February 12, 1968, and sent back to the United States for repairs. After repairs were completed in May 1969, it returned to Vietnam, sustained extensive combat damage on August 24, 1969, was repaired there in early September and reassigned to another combat unit, was hit by ground fire on September 11, and was forced to land from ground fire damage on October 19, 1969. Returned to the United States for repairs in November 1969, it was repaired and upgraded by January 1972 and assigned to Fort Hood, Texas. From May 1979 to December 1980 it was modified at the Bell Helicopter factory into an S model Cobra, and in July 1981 it received an instructor's flight control boost system. Assigned to Fort Rucker, Alabama, in August 1981, it served in training Army aviators to fly Cobras, was assigned to the Arizona National Guard in Marana, Arizona, in 1994, and was moth-balled at Fort Drum, New York, in May 2001.