By normal standards long since rendered obsolete due to its great vulnerability to surface-to-air missiles, the mighty Boeing B-52 Stratofortress has seen two would-be successors fall by the wayside. It remains a major element in one of the three US strategic deterrents and will continue to give valuable service well into the 21st century.
The B-52 began life in 1948 as a turboprop successor to the B-50. In 1949, a change to Pratt & Whitney J57 turbojet powerplant was made and the XB-52 prototype made its maiden flight on 15 April 1952. The B-52 evolved through progressively improved B-52A to B-52G models, the latter remaining in service to late 1994.
The ultimate B-52H is characterized by two major changes: introduction of TF33 turbofans that give greater thrust in concert with a considerably reduced specific fuel consumption, and structural changes which permit the B-52 to fly at low altitudes without excessive fatigue problems.
The final B-52H was rolled out in June 1962 and with the B-1B and B-2A entering service in only limited numbers, the B-52H has been constantly upgraded to enable it to remain a credible front-line type. With the B-1B increasingly assuming the free-fall nuclear role of the B-52H, this latter type has been reallocated to the force projection role, with weapons that now include the AGM-86C conventionally-armed variant of the nuclear cruise missile and Have Nap missiles. The importance of the B-52H to the USAF's continued need for warplanes with global reach while carrying very heavy warloads is demonstrated by the fact that comprehensive upgrades for the remaining aircraft, both in terms of avionics and weapons systems, are still planned. And although a re-engining programme has apparently been dropped, the type is still scheduled to remain in service until 2044.