B-52 Stratofortress

The Boeing B-52 Stratofortress is an American nuclear-capable, subsonic strategic heavy bomber operated by the United States Air Force since 1955 and flown by NASA from 1959 to 2007. Designed to replace the Convair B-36 Peacemaker, it carries up to 32,000 kg (70,000 lb) of weapons over a combat range of about 14,200 km (8,800 mi) unrefuelled. Boeing built 744 between 1952 and 1962. The type is informally the "BUFF"; the B-52H is the only variant in service, with 76 aircraft as of 2024 and a service life planned into the 2050s.

Development

Air Materiel Command's requirement of 23 November 1945 called for a bomber cruising at 480 km/h (300 mph) at 10,000 m (34,000 ft) with a combat radius of 8,000 km (5,000 mi). Boeing's Model 462, a straight-wing design with six Wright T35 turboprops, beat Consolidated and Martin on 5 June 1946. In October 1948, asked by the USAF's chief of bomber development for a turbojet alternative, Boeing engineers redrew the aircraft over a weekend in a Dayton hotel as the Model 464-49: eight turbojets in four underwing pods, 35-degree swept wings and bicycle landing gear.

A production contract for thirteen B-52As followed on 14 February 1951, the Strategic Air Command commander insisting on side-by-side rather than tandem seating. The YB-52 first flew on 15 April 1952 and the XB-52 on 2 October 1952, and the order rose to 282. The three B-52As were retained for tests; the first production B-52A was rolled out on 18 March 1954, and the last ten aircraft of the order were completed as operational B-52Bs. Production ran at Seattle and Wichita, the latter alone building the B-52G and H from 1957, and closed in 1962 after 742 production aircraft and two prototypes.

The US$1.1 billion CONECT programme, begun in July 2013, modernised communications and added the AN/ARC-210 radio for in-flight retargeting. The Rolls-Royce F130 won the Commercial Engine Replacement Program on 24 September 2021 — 650 engines for US$2.6 billion — and with the AN/APQ-188 AESA radar, new displays and one crew station deleted, the aircraft become B-52Js, due to reach initial operational capability in 2033. A July 2026 GAO report put the engine programme US$3 billion over budget.

Design

The B-52H is 48.5 m (159 ft 4 in) long with a 56.4 m (185 ft) span, an empty weight of 83,900 kg (185,000 lb) and a maximum take-off weight of 221,000 kg (488,000 lb). The flexible wing deflects 9.8 m (32 ft) at the tip between the -1 g and +4 g cases. Roll control comes mainly from six spoilerons per wing — the small ailerons were deleted on late B-52Gs, leaving the G and H prone to Dutch roll — and the main gear pivots 20 degrees either side for crosswind landings. The crew of five (pilot, co-pilot, weapon systems officer, navigator, electronic warfare officer) sits on two decks; the gunner's position was eliminated in 1991.

The eight engines hang in paired pods whose pylons double as wing fences. The F and G used 61.2 kN (13,750 lbf) J57-P-43WB turbojets; from 9 May 1961 the B-52H brought the Pratt & Whitney TF33-P-3 turbofan of 76 kN (17,100 lbf), for a maximum speed of 1,050 km/h (650 mph) and a ceiling of 15,000 m (50,000 ft). The F130 of 75.6 kN (17,000 lbf) keeps the eight-engine layout. Avionics have included the AN/ASQ-38 bombing-navigation system, the IBM AP-101 computer, the AN/ASQ-151 Electro-Optical Viewing System (AN/AVQ-22 low-light television and AN/AAQ-6 FLIR, fitted 1972–1976), the LITENING targeting pod from 2007 and the AN/ASQ-236 Dragon's Eye maritime radar pod.

Armament

The bay and underwing pylons carry 32,000 kg (70,000 lb). Quad 12.7 mm (.50 in) tail guns, replaced by a 20 mm M61 Vulcan on the B-52H, were deactivated from 1 October 1991. For the nuclear mission the G and H received the AGM-28 Hound Dog under the 1959–1963 Big Four programme, then up to twenty AGM-69 SRAMs from 1971. The AGM-86B air-launched cruise missile went on 194 B-52Gs and Hs with twelve under the wings, 82 B-52Hs taking eight more internally; with the B61 and B83 gravity bombs withdrawn by about 2010, it is the B-52H's only nuclear weapon until the Long Range Stand Off missile arrives.

Conventionally, Big Belly B-52Ds carried 108 bombs totalling 27,000 kg (60,000 lb). The Conventional Enhancement Modification qualified 47 B-52Hs by 1996 and 19 more by 1999 for JDAM, the AGM-154 JSOW, AGM-158 JASSM, AGM-84 Harpoon and AGM-142 Have Nap. The MIL-STD-1760 Internal Weapons Bay Upgrade moved precision weapons inside — 24 GBU-38s or 20 GBU-31s, then JASSM-ER and ADM-160 MALD-J. The fleet is certified for Quickstrike mines with JDAM-ER kits at over 64 km (40 mi).

Operational History

The B-52B joined the 93rd Heavy Bombardment Wing at Castle AFB on 29 June 1955. On 21 May 1956 one dropped a Mk-15 over Bikini Atoll in the Cherokee test, the first US air drop of a thermonuclear weapon. SAC held airborne alert under Chrome Dome and similar programmes, shifting to low-level penetration after the 1960 U-2 shoot-down. Vietnam combat opened with Operation Arc Light on 18 June 1965, when 30 B-52Fs of the 9th and 441st Bombardment Squadrons struck near Bến Cát. In Linebacker II, 18–29 December 1972, 729 sorties dropped 15,237 tons on Hanoi and Haiphong for fifteen aircraft shot down; tail gunners were credited with two MiG-21s. Thirty-one B-52s were lost in the war.

Under START, AMARC cut up 365 B-52s, every remaining B-52G among them. Seven B-52Gs from Barksdale opened Desert Storm on 16 January 1991 with 35 AGM-86C CALCMs on a 35-hour round trip; the type flew about 1,620 sorties and delivered 40 percent of the weapons dropped by coalition forces. B-52Hs bombed Yugoslavia from 24 March 1999, fought over Afghanistan from 2001 and launched over 100 CALCMs on 21 March 2003. Transferred to Air Force Global Strike Command in 2010, the fleet has since joined strikes on over 75 Islamic State targets in Syria in December 2024 and, from 3 March 2026, ballistic missile sites and command posts in the 2026 Iran war, overflying Iranian territory from the end of that month. On 15 June 2026 B-52H 60-0061 crashed after take-off from Edwards AFB, killing all eight aboard. As of 2024 the 76 aircraft were split between the 2nd Bomb Wing at Barksdale and 5th Bomb Wing at Minot (58), the Reserve's 307th Bomb Wing (18) and about twelve in storage.

Variants

• XB-52/YB-52: Two prototypes with tandem cockpits and eight YJ57-P-3 turbojets, first flown in 1952.
• B-52A: Three aircraft with side-by-side seating, retained for testing.
• B-52B: First operational model, with the 93rd Bombardment Wing from June 1955; retired by June 1966.
• B-52D: 170 built; Big Belly conversions carried 108 bombs over Vietnam, the last retiring in 1983.
• B-52G: Wet-wing model modified for Harpoon, Have Nap and the AGM-86B; retired in 1994 and destroyed under START.
• B-52H: Final model, delivered from 9 May 1961 with TF33-P-3 turbofans; the only variant in service since the mid-1990s.
• B-52J: B-52Hs re-engined with the Rolls-Royce F130 and fitted with the AN/APQ-188 radar, due to reach IOC in 2033.