Longest-serving USAF warplane in history, the B-52 Stratofortress is known to crews as the 'BUFF', for 'Big Ugly Fat F***er'. Designed for trans-polar nuclear warfare with the now-defunct Soviet Union, it still retains a nuclear capability today, but the 90 or so examples that are still in the first-line inventory are now primarily tasked in the conventional bombing role.

The B-52 was employed in combat as a conventional bomber in Vietnam (1965-73) and in the Persian Gulf (1991). B-52A, B, C, D, E and F models had all been retired by the mid-1980s, but the B-52G and H soldiered on, as the largest part of the manned bomber portion of the American strategic triad. The 'BUFF' continues to have a role in a much-reorganized US Air Force.

XB-52 and YB-52 prototypes (49-0230/0231) were built in secrecy and the YB-52 flew first at Seattle. The B-52 resembled a B-47 Stratojet with its 35 swept wing, podded engines, and 'bicycle' undercarriage.

Fuel capacity was greater than in any previous production aircraft at 38,865 US gal (147,120 liters) with drop-tanks. Powerplants were eight Pratt & Whitney YJ57-P-3 axial-flow turbojets, delivering 8,700 lb (3,946 kg) of thrust each and podded in pairs on four underwing pylons. The gigantic fin, with only its trailing edge hinged to form a rudder, made the bomber's height 48 ft 3 in (14.72 m) and could be folded to permit the bomber to enter standard hangars. The B-52 did not rotate on take-off but, rather, popped aloft, its wing set at an incidence of 8 for a flyaway with the fuselage horizontal. On landing, the B-52 employed a 44-ft (13.41-m) braking parachute, stowed in a compartment in the rear fuselage.

The B-52 changed little during its 10-year production run. Three B-52As (52-0001/0003) were followed by 23 B-52Bs, which entered service with SAC's 93rd Bomb Wing, Castle AFB, California, on 29 June 1955. Twenty-seven RB-52Bs came next. B-52Bs and RB-52Bs were eventually modified to B-52C standard, in addition to 35 new B-52Cs introduced from March 1956. These retained reconnaissance capability but not an R prefix.

The B-52D, of which 170 were built, was first flown on 14 May 1956. One hundred B-52Es followed, and 89 B-52Fs were manufactured, beginning in February 1959.

Boeing produced 193 B-52G aircraft at Wichita. The B-52G introduced a shorter vertical tail and numerous internal changes, including a new integral-tank wing with internal fuel capacity increased to 46,576 US gal (176,309 liters) and with external drop-tanks reduced in volume to 700 US gal (2,650 liters) each. The weight of the aircraft was increased to 488,000 lb (221,357 kg). The B-52G was designed for the GAM-87A Skybolt, an air-launched ballistic missile which underwent extensive Anglo-American design and development work before being cancelled. Its bomb bay was also configured to carry four ADM-20A Quail decoy missiles. B-52Gs also carried two North American GAM-77 (AGM-28) Hound Dog inertial-guidance stand-off weapons. Later, the B-52G was modified to carry 20 AGM-69A SRAMs (short-range attack missile) or ALCMs (air-launched cruise missile).

Where earlier models had a manned tail gun position, the B-52G had its gunner relocated in the main crew compartment and operating his guns via the AN/ASG-15 fire control system. Armament of four .50-caliber (12.7-mm) machine guns in the tail was retained.

The USAF ordered 102 B-52H aircraft in 1960-61, taking first delivery on 30 September 1960. With the short vertical fin of the B-52G, the H model was powered by eight 17,000-lb (7,711-kg) thrust Pratt & Whitney TF33-P-1 or -3 turbofan engines, developed from the familiar J57 but without the latter's water-injection feature. Gross weight of the B-52H went up to 505,000 lb (229,068 kg) for take-off and a maximum of 566,000 lb (256,738 kg) after inflight refueling. Tail armament of the B-52H was again remotely operated but now comprised a single T-171 (later M61A1) 20-mm Vulcan cannon. The B-52H, like the G model, was configured to carry Sky Bolt, Quail, Hound Dog, SRAM and ALCM. The last B-52H was delivered to the USAF on 26 October 1962, ending production of 744 Stratofortresses.

In 1972, a program commenced to reconfigure most B-52s with an electronics suite to assist in low-level terrain following, a suite which includes EVS (electro-optical viewing system), a low-light television, and FLIR. In 1976 came the Rivet Ace program to update ECM equipment aboard the aircraft, enhancing the capability of the B-52 to take on enemy radars while flying in the head-on mode.

Today's B-52H aircraft can carry B61 and B83 nuclear bombs. Standard load is a 'clip' of four B61s, which can accommodate a variety of nuclear warheads—these being 'maximum-drogued' bombs designed to be severely retarded during a low-level drop to enable the 'BUFF' crew to get away. Also retarded by parachute when dropped, the B83 is a one- to two-megaton thermonuclear bomb which is 12 ft (3.65 m) long, 18 in (0.45 m) in diameter, and weighs 2,400 lb (1,089 kg).

The B-52H flies missions today with a crew of five—the pilot or aircraft commander (AC), co-pilot, electronic warfare officer (EWO), navigator and radar navigator (RN). In an economy move, the aerial gunner crew position was eliminated on 1 October 1991.

First successful test-firing of an ALCM from a B-52 was accomplished on 5 March 1976. On 25 March 1980, the USAF chose the Boeing AGM-86B over the competing General Dynamics AGM-109 Tomahawk. The AGM-86, conceived as a second-generation decoy, became a nuclear delivery vehicle and made it possible for a 'BUFF' to attack a target from a distance as great as 1,550 miles (2,494 km). Powered by a 600-lb (272-kg) thrust Williams F107-101 turbojet, eight ALCMs could be carried on an internal rotary launcher in the B-52G and H, with 12 more on underwing pylons. The first operational AGM-86B was placed in service in January 1981. Subsequently, the USAF developed the AGM-129A Advanced ALCM, to be carried by the B-52H.

The AGM-129A, also called ACM (advanced cruise missile), is 21 ft (6.5 m) long, powered by a 900-lb (4.0-kN) thrust Williams F112 turbojet engine, and combines low-observable features with low-altitude maneuvering to evade air defenses en route to its target. The AGM-129A was designed to be effective at a stand-off distance of 2,000 miles (3,218 km). Displayed publicly in June 1991, the AGM-129A was expected to be carried on operational B-52Hs in the same manner as its predecessor.

At the outset of the 1990s, the USAF's position was that the B-52H would continue for a number of years in the stand-off role, while the B-1B remained the US's primary penetrator and the B-2 would begin to join the force in the mid-1990s. The B-2 remains a highly visible target for cost-cutting reductions.

During Operation Desert Storm, B-52G Stratofortresses served in provisional bomb wings and mounted combat missions from Diego Garcia; Jeddah, Saudi Arabia; Moron, Spain; and Fairford, England. B-52Gs flew 1,624 missions, dropped over 72,000 weapons, and delivered over 25,700 tons (23.32 million kg) of munitions on area targets in the Kuwait theater of operations and on airfields, industrial targets, troop concentrations and storage areas in Iraq. Gulf War B-52Gs had a mission-capable rate of over 81 per cent, or two per cent higher than the peacetime rate. B-52Gs also launched conventional-warhead AGM-86C cruise missiles.

Recent changes that have affected the B-52 force included the September 1991 announcement of plans to create a new US Strategic Command and of a cessation of nuclear alert duty by the B-52 and other bomber aircraft. While this may appear to have signposted an intent to place the former SAC heavyweight under alternative command jurisdiction, most of the surviving examples did in fact join the newly-established Air Combat Command, with some being assigned to one of the special composite 'intervention' wings created as part of the process of reorganization.

As it transpired, the small number of B-52G aircraft involved were retired from the inventory not long afterwards, along with other surviving examples of this model and today the only version of the 'BUFF' that remains active with first-line forces is the turbofan-powered B-52H. Attrition has reduced the number of 'Cadillacs' to 94 and these are being consolidated into units at just two air bases, specifically Minot and Barksdale.