Delivered to the the USAF as 63-7998 in November 1963. Assigned to the 91st Bombardment (Heavy) Wing (Strategic Air Command), Glasgow AFB (NOV 1963), 310th Strategic Aerospace Wing (SAC), Schilling AFB (JUN 1964), 92nd Strategic Aerospace Wing (SAC), Fairchild AFB (JAN 1966), 22nd Bombardment (H) Wing (SAC), March AFB (APR 1966), 376th Strategic Wing (SAC), Kadena (APR 1989) and 92nd Wing (Air Combat Command), Dyess AFB (1992). Transferred to the MASDC with inventory number CA0100 in May 1994. To NASA in NOV 1994. Used for research regarding weightlessness. To Pima in December 2001.