Delivered to the Air Force in 1963 as a regular Stratotanker, 63-7998, this aircraft served in the aerial refuelling role for thirty years before passing to NASA for use in its Reduced Gravity Research Program. After nearly 35,000 parabolas for 18,000 passengers had been flown from the Johnson Space Center, it made what was reckoned to be the last ever flight by a turbojet KC-135A in October 2004 when it was delivered to Davis Monthan for Pima.

KC-135A N931NA (ex 63-7998), the fifth and final 'Weightless Wonder', at Pima, 1st December 2022. Credited with 34,757 parabolas and inducing 285 gallons of vomit, according to NASA records ... !

Delivered to the US Air Force in 1963 as 63-7998, the aircraft served as a tanker for more than thirty years (1963-1994) before being given to NASA for use in its Reduced Gravity Research Program. Designation: KC-135A "Weightless Wonder V". wfu and stored at DMA 29 Oct 2004. Loaned to the Pima Museum

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.