B-2 Spirit

The Northrop Grumman B-2 Spirit is an American nuclear-capable, subsonic stealth strategic bomber operated solely by the United States Air Force. A four-engined flying wing with a crew of two, it was designed to penetrate dense air defences with conventional or thermonuclear weapons. It first flew on 17 July 1989, reached initial operational capability on 1 January 1997, and remains the only acknowledged in-service aircraft able to carry large air-to-surface standoff weapons in a stealth configuration. Twenty-one were built for a programme cost of US$44.7 billion, or US$2.13 billion per aircraft; nineteen were in service as of 2024, based at Whiteman AFB, Missouri.

Development

DARPA's stealth studies of the mid-1970s produced Lockheed's Have Blue, which led to the F-117, and Northrop's Tacit Blue, in development from 1979, which proved curved low-observable surfaces, fly-by-wire and composite construction. The Advanced Technology Bomber (ATB) programme began in 1979 as a black project under the Carter administration, the promise of stealth having already contributed to the 1977 cancellation of the B-1A. Two teams were funded: Northrop/Boeing with the curved-surface "Senior Ice" and Lockheed/Rockwell with the faceted "Senior Peg", which kept a small tail. The USAF, then planning 165 aircraft, selected the Northrop team on 20 October 1981.

A mid-1980s switch from high-altitude to low-altitude terrain-following delayed first flight by two years and added about US$1 billion. The aircraft was rolled out at USAF Plant 42, Palmdale, on 22 November 1988, and AV-1 (82-1066) flew to Edwards AFB on 17 July 1989. The planned buy fell from 132 to 75, then to 20 under President George H. W. Bush's 1992 State of the Union address; in 1996 a 21st airframe, a test aircraft, was converted to Block 30 standard for nearly US$500 million. A 1996 GAO report put its per-aircraft operating cost at over three times that of the B-1B and over four times that of the B-52H; maintenance took 119 hours per flight hour in September 1997.

Modernisation came in steps: a July 2008 computing redesign with flight software converted from JOVIAL to C; a US$468 million contract on 29 December 2008 to shift the radar's operating frequency; and the Defensive Management System Modernization, awarded in 2013 and cancelled by 2020. The FY2019 budget brought retirement forward from 2058 to "no later than 2032", as the B-21 Raider replaces the type.

Design

The B-2 has neither fuselage nor vertical tail. It is 21.0 m (69 ft) long with a span of 52.4 m (172 ft), an empty weight of 71,700 kg (158,000 lb) and a maximum take-off weight of 170,600 kg (376,000 lb) including 75,750 kg (167,000 lb) of fuel. Four General Electric F118-GE-100 non-afterburning turbofans of 77 kN (17,300 lbf) each are buried in the wing; cold boundary-layer air drawn in below the inlets is mixed with the exhaust, which then spreads over carbon-fibre and titanium surfaces to cut the infrared signature. Maximum speed is 1,010 km/h (630 mph) at 12,000 m (40,000 ft), ceiling 15,200 m (50,000 ft), unrefuelled range 11,000 km (6,900 mi) and over 19,000 km (12,000 mi) with one refuelling. The pilot sits left and the mission commander right, with provision for a third crew member.

Because a flying wing is unstable, a quadruplex fly-by-wire system works four pairs of trailing-edge surfaces; yaw comes from split brake-rudders and differential thrust, and air data from flush pitot-static plates. The structure is mostly carbon-graphite composite with radar-absorbent materials and the continuous-curvature shaping first tested on Tacit Blue; radar cross-section is reported at about 0.1 m² (1.1 sq ft). Each aircraft lives in a climate-controlled hangar; the deployable B-2 Shelter System costs about US$5 million. Avionics centre on the low-probability-of-intercept AN/APQ-181 multimode radar, since refitted with active electronically scanned arrays, the NAS-26 astro-inertial navigator, GPS, Link 16 and the Defensive Management System.

Armament

Two internal bays carry ordnance on rotary launcher assemblies or bomb rack assemblies, with an official limit of 18,000 kg (40,000 lb); 27,000 kg (60,000 lb) has been carried operationally. The nuclear load is sixteen B61 or B83 bombs on the rotary launchers. Conventional precision came after the Cold War through the GPS-Aided Targeting System, which uses the APQ-181's synthetic aperture mode to fix targets for GPS-aided bombs — sixteen originally, eighty JDAMs after a 2004 upgrade.

Documented loadouts are eighty 230 kg (500 lb) Mk 82 or GBU-38 bombs, 36 CBU-class weapons of 340 kg (750 lb), sixteen 910 kg (2,000 lb) Mk 84 or GBU-31 bombs, and sixteen standoff weapons — AGM-154 JSOW, AGM-158 JASSM, AGM-158B JASSM-ER or AGM-158C LRASM. Compatibility with the 14,000 kg (30,000 lb) GBU-57 Massive Ordnance Penetrator, one per bay, was reported in July 2009; as of 2012 the B-2 was the only aircraft cleared to carry it.

Operational History

The first operational aircraft, Spirit of Missouri, reached Whiteman AFB on 17 December 1993, and the type achieved initial operational capability on 1 January 1997. The combat debut came in the 1999 Kosovo War: six B-2s flew 30-hour round trips from Missouri, accounting for 50 of NATO's 34,000 sorties yet 11 percent of the bombs dropped, and were the first aircraft to use JDAM in combat. On 7 May 1999 one dropped five JDAMs on the Chinese embassy, killing three. The type bombed Afghanistan at the opening of Enduring Freedom in 2001 and in the 2003 Iraq War released more than 680,000 kg (1,500,000 lb) of munitions, including 583 JDAMs, from Whiteman, Diego Garcia and an undisclosed forward location. The fleet passed to Air Force Global Strike Command on 1 February 2010.

Three B-2s opened Operation Odyssey Dawn over Libya in March 2011, dropping 40 bombs on an airfield, and on 18 January 2017 two dropped 108 GBU-38s on an ISIS camp near Sirte, Libya, on a 33-hour mission. RAAF Tindal in Australia staged the 16 October 2024 strike on five underground Houthi weapons stores in Yemen. On 22 June 2025 six B-2s dropped twelve GBU-57s on the Fordow enrichment plant while a seventh put two on Natanz, and from 1 March 2026 the fleet struck missile and underground facilities in the 2026 Iran war. Forward hangars exist at Diego Garcia, Andersen AFB on Guam and RAF Fairford.

Spirit of Kansas (AV-12) crashed on take-off from Andersen on 23 February 2008 after moisture in its port transducer units corrupted the air data, a US$1.4 billion loss that grounded the fleet for 53 days; the crew ejected. Spirit of Hawaii (AV-16) made an emergency landing at Whiteman on 10 December 2022 that grounded the fleet until 18 May 2023; the USAF said in May 2024 it would be divested as uneconomical to repair. The nineteen survivors fly with the 509th Bomb Wing and the Air National Guard's associate 131st Bomb Wing at Whiteman, one being assigned to the 412th Test Wing at Edwards AFB, pending retirement by 2032.