The Boeing B-52 Stratofortress has been operational with the United States Air Force since 5 June, 1955. This list is of the units it was assigned to, and the bases it was stationed. In addition to the USAF, A single RB-52B (52-008) was flown by the National Aeronautics and Space Administration (NASA) until it was retired on 17 December 2004. It now is on static display at the west gate of Edwards AFB, California. One other B-52H (61-0025) was flown for many years by the Air Force Flight Test Center at Edwards, and was transferred to NASA on 30 July 2001 as a replacement for the RB-52B. On 9 May 2008, that aircraft was flown for the last time to Sheppard AFB, Texas where it became a GB-52H maintenance trainer, never to fly again. Current USAF B-52 units The only active operational model of the B-52 is the B-52H. It is currently stationed at three USAF bases, flown by three wings: 2nd Bomb Wing – Barksdale AFB, Louisiana 11th Bomb Squadron (B-52H, Tail Code: LA, Gold Tail Stripe) 20th Bomb Squadron (B-52H, Tail Code: LA, Blue Tail Stripe) 96th Bomb Squadron (B-52H, Tail Code: LA, Red Tail Stripe) 5th Bomb Wing – Minot AFB, North Dakota 23nd Bomb Squadron (B-52H, Tail Code: MT, Red Tail Stripe) 69th Bomb Squadron (B-52H, Tail Code: MT, Yellow Tail Stripe) 307th Bomb Wing (AFRC) – Barksdale AFB, Louisiana 93rd Bomb Squadron (B-52H, Tail Code: BD, Blue/Gold Chex Tail Stripe) 343rd Bomb Squadron Historical USAF B-52 units 2nd Bombardment Wing (Heavy), Barksdale AFB, Louisiana Activated by re-designation of: 4238th Strategic Wing B-52F, 1963–1965; B-52G, 1965–1992; B-52H, 1992–present 11th Bombardment Squadron (B-52H) 20th Bombardment Squadron (B-52F/H) (to 7th BW 6/65 – from 7th BW 12/92) 62nd Bombardment Squadron (B-52G) (from 39th BW 6/65, inactivated 12/92) 96th Bombardment Squadron (B-52H) 596th Bombardment Squadron (B-52G) (from 397th BW 4/68) Currently flying B-52Hs at Barksdale AFB 5th Bombardment Wing (Heavy) Travis AFB, California (1959–1968) Minot AFB, North Dakota, (1968–Current) B-52B, 1959; B-52G, 1959–1968; B-52H, 1968–Current 23rd Bombardment Squadron 31st Bombardment Squadron (to 4126th SW 1/60) 72nd Bombardment Squadron (B-52H) Currently flying B-52Hs at Minot AFB. 6th Bombardment (later Strategic Aerospace) Wing, Walker AFB, New Mexico B-52E, 1957–1967 24th Bombardment Squadron 39th Bombardment Squadron 40th Bombardment Squadron 4129th Combat Crew Training Squadron (1959–1963) Moved to Eielson AFB, AK after closure of Walker AFB in 1967; 24th BS began flying RC-135s.