Northrop Grumman B-2 Spirit

B-2 Spirit
B-2 Spirit (cropped).jpg
A U.S. Air Force B-2 Spirit flying over the Pacific Ocean in May 2006
RoleStealth strategic heavy bomber
National originUnited States
ManufacturerNorthrop Corporation
Northrop Grumman
First flight17 July 1989
Introduction1 January 1997
StatusIn service
Primary userUnited States Air Force
Number built21[1][2]
Program costUS$44.75 billion (through 2004)[3]
Unit cost
$737 million (1997 approx. flyaway cost)[3]

The Northrop (later Northrop Grumman) B-2 Spirit, also known as the Stealth Bomber, is an American heavy penetration strategic bomber, featuring low observable stealth technology designed for penetrating dense anti-aircraft defenses; it is a flying wing design with a crew of two.[1][4] The bomber can deploy both conventional and thermonuclear weapons, such as eighty 500 lb (230 kg)-class (Mk 82) JDAM Global Positioning System-guided bombs, or sixteen 2,400 lb (1,100 kg) B83 nuclear bombs. The B-2 is the only acknowledged aircraft that can carry large air-to-surface standoff weapons in a stealth configuration.

Development started under the "Advanced Technology Bomber" (ATB) project during the Carter administration; its expected performance was one of his reasons for the cancellation of the supersonic B-1A bomber. The ATB project continued during the Reagan administration, but worries about delays in its introduction led to the reinstatement of the B-1 program. Program costs rose throughout development. Designed and manufactured by Northrop, later Northrop Grumman, the cost of each aircraft averaged US$737 million (in 1997 dollars).[3] Total procurement costs averaged $929 million per aircraft, which includes spare parts, equipment, retrofitting, and software support.[3] The total program cost, which included development, engineering and testing, averaged $2.1 billion per aircraft in 1997.[3]

Because of its considerable capital and operating costs, the project was controversial in the U.S. Congress. The winding-down of the Cold War in the latter portion of the 1980s dramatically reduced the need for the aircraft, which was designed with the intention of penetrating Soviet airspace and attacking high-value targets. During the late 1980s and 1990s, Congress slashed plans to purchase 132 bombers to 21. In 2008, a B-2 was destroyed in a crash shortly after takeoff, though the crew ejected safely.[5] Twenty B-2s are in service with the United States Air Force, which plans to operate them until 2032.[6]

The B-2 is capable of all-altitude attack missions up to 50,000 feet (15,000 m), with a range of more than 6,000 nautical miles (6,900 mi; 11,000 km) on internal fuel and over 10,000 nautical miles (12,000 mi; 19,000 km) with one midair refueling. It entered service in 1997 as the second aircraft designed to have advanced stealth technology after the Lockheed F-117 Nighthawk attack aircraft. Though designed originally as primarily a nuclear bomber, the B-2 was first used in combat dropping conventional, non-nuclear ordnance in the Kosovo War in 1999. It later served in Iraq, Afghanistan, and Libya.[7]



By the mid-1970s, military aircraft designers had learned of a new method to avoid missiles and interceptors, known today as "stealth". The concept was to build an aircraft with an airframe that deflected or absorbed radar signals so that little was reflected back to the radar unit. An aircraft having stealth characteristics would be able to fly nearly undetected and could be attacked only by weapons and systems not relying on radar. Although other detection measures existed, such as human observation, their relatively short detection range allowed most aircraft to fly undetected, especially at night.[8]

In 1974, DARPA requested information from U.S. aviation firms about the largest radar cross-section of an aircraft that would remain effectively invisible to radars.[9] Initially, Northrop and McDonnell Douglas were selected for further development. Lockheed had experience in this field due to developing the Lockheed A-12 and SR-71, which included a number of stealthy features, notably its canted vertical stabilizers, the use of composite materials in key locations, and the overall surface finish in radar-absorbing paint. A key improvement was the introduction of computer models used to predict the radar reflections from flat surfaces where collected data drove the design of a "faceted" aircraft. Development of the first such designs started in 1975 with "the hopeless diamond", a model Lockheed built to test the concept.[10]

Plans were well advanced by the summer of 1975, when DARPA started the Experimental Survivability Testbed (XST) project. Northrop and Lockheed were awarded contracts in the first round of testing. Lockheed received the sole award for the second test round in April 1976 leading to the Have Blue program and eventually the F-117 stealth attack aircraft.[11] Northrop also had a classified technology demonstration aircraft, the Tacit Blue in development in 1979 at Area 51. It developed stealth technology, LO (low observables), fly-by-wire, curved surfaces, composite materials, electronic intelligence (ELINT), and Battlefield Surveillance Aircraft Experimental (BSAX). "The stealth technology developed from the program was later incorporated into other operational aircraft designs, including the B-2 stealth bomber".[12]

ATB program

By 1976, these programs had progressed to a position in which a long-range strategic stealth bomber appeared viable. President Carter became aware of these developments during 1977, and it appears to have been one of the major reasons the B-1 was canceled.[13] Further studies were ordered in early 1978, by which point the Have Blue platform had flown and proven the concepts. During the 1980 presidential election campaign in 1979, Ronald Reagan repeatedly stated that Carter was weak on defense, and used the B-1 as a prime example. In return, on 22 August 1980, the Carter administration publicly disclosed that the United States Department of Defense was working to develop stealth aircraft, including a bomber.[14]

Front view of tailless aircraft parked in front of building. On the building face is a blue and red rectangular flag. A star-shaped artwork is on the taxiway in front of aircraft.
The B-2's first public display in 1988 at Palmdale, California: In front of the B-2 is a star shape formed with five B-2 silhouettes.

The Advanced Technology Bomber (ATB) program began in 1979.[15] Full development of the black project followed, and was funded under the code name "Aurora".[16] After the evaluations of the companies' proposals, the ATB competition was narrowed to the Northrop/Boeing and Lockheed/Rockwell teams with each receiving a study contract for further work.[15] Both teams used flying wing designs.[16] The Northrop proposal was code named "Senior Ice" and the Lockheed proposal code named "Senior Peg".[17] Northrop had prior experience developing the YB-35 and YB-49 flying wing aircraft.[18] The Northrop design was larger while the Lockheed design included a small tail.[16] In 1979, designer Hal Markarian produced a sketch of the aircraft, that bore considerable similarities to the final design.[19] The Air Force originally planned to procure 165 of the ATB bomber.[1]

The Northrop team's ATB design was selected over the Lockheed/Rockwell design on 20 October 1981.[15][20] The Northrop design received the designation B-2 and the name "Spirit". The bomber's design was changed in the mid-1980s when the mission profile was changed from high-altitude to low-altitude, terrain-following. The redesign delayed the B-2's first flight by two years and added about US$1 billion to the program's cost.[14] An estimated US$23 billion was secretly spent for research and development on the B-2 by 1989.[21] MIT engineers and scientists helped assess the mission effectiveness of the aircraft under a five-year classified contract during the 1980s.[22]

Secrecy and espionage

Top view of triangular aircraft, with sawtooth trailing edge, in flight over desert
The B-2's first public flight in 1989

During its design and development, the Northrop B-2 program was a gray project before its revelation to the public.[23] Unlike the Lockheed F-117 program, which was a black project, the type of military project of which very few people knew even existed while it was being designed and developed, more people within the United States federal government knew about the B-2 and more information about the project was available. Both during development and in service, considerable effort has been devoted to maintaining the security of the B-2's design and technologies. Staff working on the B-2 in most, if not all, capacities have to achieve a level of special-access clearance, and undergo extensive background checks carried out by a special branch of the Air Force.[24]

For the manufacturing, a former Ford automobile assembly plant in Pico Rivera, California, was acquired and heavily rebuilt; the plant's employees were sworn to complete secrecy regarding their work. To avoid the possibility of suspicion, components were typically purchased through front companies, military officials would visit out of uniform, and staff members were routinely subjected to polygraph examinations. The secrecy extended so far that access to nearly all information on the program by both Government Accountability Office (GAO) and virtually all members of Congress itself was severely limited until the mid-1980s.[25] Northrop (now Northrop Grumman) was the B-2's prime contractor; major subcontractors included Boeing, Hughes Aircraft (now Raytheon), GE, and Vought Aircraft.[7]

In 1984, a Northrop employee, Thomas Cavanaugh was arrested for attempting to sell classified information to the Soviet Union; the information was taken from Northrop's Pico Rivera, California factory.[26] Cavanaugh was eventually sentenced to life in prison and released on parole in 2001.

The B-2 was first publicly displayed on 22 November 1988 at United States Air Force Plant 42 in Palmdale, California, where it was assembled. This viewing was heavily restricted, and guests were not allowed to see the rear of the B-2. However, Aviation Week editors found that there were no airspace restrictions above the presentation area and took aerial photographs of the aircraft's then-secret rear section with suppressed engine exhausts, to the USAF's disappointment. The B-2's (s/n 82-1066 / AV-1) first public flight was on 17 July 1989 from Palmdale to Edwards AFB.[27]

In October 2005, Noshir Gowadia, a design engineer who worked on the B-2's propulsion system, was arrested for selling B-2 related classified information to foreign countries.[28] Gowadia was convicted and sentenced to 32 years in prison for his actions.[29]

Program costs and procurement

A procurement of 132 aircraft was planned in the mid-1980s, but was later reduced to 75.[30] By the early 1990s, the Soviet Union dissolved, effectively eliminating the Spirit's primary Cold War mission. Under budgetary pressures and Congressional opposition, in his 1992 State of the Union Address, President George H.W. Bush announced B-2 production would be limited to 20 aircraft.[31] In 1996, however, the Clinton administration, though originally committed to ending production of the bombers at 20 aircraft, authorized the conversion of a 21st bomber, a prototype test model, to Block 30 fully operational status at a cost of nearly $500 million.[32]

In 1995, Northrop made a proposal to the USAF to build 20 additional aircraft with a flyaway cost of $566 million each.[33]

The program was the subject of public controversy for its cost to American taxpayers. In 1996, the General Accounting Office (GAO) disclosed that the USAF's B-2 bombers "will be, by far, the most costly bombers to operate on a per aircraft basis", costing over three times as much as the B-1B (US$9.6 million annually) and over four times as much as the B-52H (US$6.8 million annually). In September 1997, each hour of B-2 flight necessitated 119 hours of maintenance in turn. Comparable maintenance needs for the B-52 and the B-1B are 53 and 60 hours respectively for each hour of flight. A key reason for this cost is the provision of air-conditioned hangars large enough for the bomber's 172 ft (52 m) wingspan, which are needed to maintain the aircraft's stealthy properties, particularly its "low-observable" stealthy skins.[34][35] Maintenance costs are about $3.4 million a month for each aircraft.[36]

The total "military construction" cost related to the program was projected to be US$553.6 million in 1997 dollars. The cost to procure each B-2 was US$737 million in 1997 dollars, based only on a fleet cost of US$15.48 billion.[3] The procurement cost per aircraft as detailed in GAO reports, which include spare parts and software support, was $929 million per aircraft in 1997 dollars.[3]

The total program cost projected through 2004 was US$44.75 billion in 1997 dollars. This includes development, procurement, facilities, construction, and spare parts. The total program cost averaged US$2.13 billion per aircraft.[3] The B-2 may cost up to $135,000 per flight hour to operate in 2010, which is about twice that of the B-52 and B-1.[37][38]


In its consideration of the fiscal year 1990 defense budget, the House Armed Services Committee trimmed $800 million from the B-2 research and development budget, while at the same time staving off a motion to end the project. Opposition in committee and in Congress was mostly broad and bipartisan, with Congressmen Ron Dellums (D-CA), John Kasich (R-OH), and John G. Rowland (R-CT) authorizing the motion to end the project—as well as others in the Senate, including Jim Exon (D-NE) and John McCain (R-AZ) also opposing the project.[39]

The escalating cost of the B-2 program and evidence of flaws in the aircraft's ability to elude detection by radar[39] were among factors that drove opposition to continue the program. At the peak production period specified in 1989, the schedule called for spending US$7 billion to $8 billion per year in 1989 dollars, something Committee Chair Les Aspin (D-WI) said "won't fly financially."[40] In 1990, the Department of Defense accused Northrop of using faulty components in the flight control system; it was also found that redesign work was required to reduce the risk of damage to engine fan blades by bird ingestion.[41]

In time, a number of prominent members of Congress began to oppose the program's expansion, including later Democratic presidential nominee John Kerry, who cast votes against the B-2 in 1989, 1991 and 1992 while a U.S. Senator, representing Massachusetts. By 1992, Republican President George H.W. Bush called for the cancellation of the B-2 and promised to cut military spending by 30% in the wake of the collapse of the Soviet Union.[42] In October 1995, former Chief of Staff of the United States Air Force, General Mike Ryan, and former Chairman of the Joint Chiefs of Staff, General John Shalikashvili, strongly recommended against Congressional action to fund the purchase of any additional B-2s, arguing that to do so would require unacceptable cuts in existing conventional and nuclear-capable aircraft,[43] and that the military had greater priorities in spending a limited budget.[44]

Some B-2 advocates argued that procuring twenty additional aircraft would save money because B-2s would be able to deeply penetrate anti-aircraft defenses and use low-cost, short-range attack weapons rather than expensive standoff weapons. However, in 1995, the Congressional Budget Office (CBO), and its Director of National Security Analysis, found that additional B-2s would reduce the cost of expended munitions by less than US$2 billion in 1995 dollars during the first two weeks of a conflict, in which the Air Force predicted bombers would make their greatest contribution; a small fraction of the US$26.8 billion (in 1995 dollars) life cycle cost that the CBO projected for an additional 20 B-2s.[45]

In 1997, as Ranking Member of the House Armed Services Committee and National Security Committee, Congressman Ron Dellums (D-CA), a long-time opponent of the bomber, cited five independent studies and offered an amendment to that year's defense authorization bill to cap production of the bombers to the existing 21 aircraft; the amendment was narrowly defeated.[46] Nonetheless, Congress did not approve funding for the purchase of any additional B-2 bombers.

Further developments

A number of upgrade packages have been applied to the B-2. In July 2008, the B-2's onboard computing architecture was extensively redesigned; it now incorporates a new integrated processing unit (IPU) that communicates with systems throughout the aircraft via a newly installed fiber optic network; a new version of the operational flight program software was also developed, with legacy code converted from the JOVIAL programming language to standard C.[47][48] Updates were also made to the weapon control systems to enable strikes upon moving targets, such as ground vehicles.[49]

B-2 from below

On 29 December 2008, Air Force officials awarded a US$468 million contract to Northrop Grumman to modernize the B-2 fleet's radars.[50] Changing the radar's frequency was required as the U.S. Department of Commerce had sold that radio spectrum to another operator.[51] In July 2009, it was reported that the B-2 had successfully passed a major USAF audit.[52] In 2010, it was made public that the Air Force Research Laboratory had developed a new material to be used on the part of the wing trailing edge subject to engine exhaust, replacing existing material that quickly degraded.[53]

In July 2010, political analyst Rebecca Grant speculated that when the B-2 becomes unable to reliably penetrate enemy defenses, the Lockheed Martin F-35 Lightning II may take on its strike/interdiction mission, carrying B61 nuclear bombs as a tactical bomber.[54] However, in March 2012, the Pentagon announced that a $2 billion, 10-year-long modernization of the B-2 fleet was to begin. The main area of improvement would be replacement of outdated avionics and equipment.[55]

It was reported in 2011 that the Pentagon was evaluating an unmanned stealth bomber, characterized as a "mini-B-2", as a potential replacement in the near future.[56] In 2012, Air Force Chief of Staff General Norton Schwartz stated the B-2's 1980s-era stealth would make it less survivable in future contested airspaces, so the USAF is to proceed with the Next-Generation Bomber despite overall budget cuts.[57] In 2012 projections, it was estimated that the Next-Generation Bomber would have an overall cost of $55 billion.[58]

In 2013, the USAF contracted for the Defensive Management System Modernization program to replace the antenna system and other electronics to increase the B-2's frequency awareness.[59] The Common Very Low Frequency Receiver upgrade will allow the B-2s to use the same very low frequency transmissions as the Ohio-class submarines so as to continue in the nuclear mission until the Mobile User Objective System is fielded.[60] In 2014, the USAF outlined a series of upgrades including nuclear war fighting, a new integrated processing unit, the ability to carry cruise missiles, and threat warning improvements.[61]

Although the Air Force previously planned to operate the B-2 to 2058, their FY 2019 budget moved up its retirement to "no later than 2032." It also moved retirement of the B-1 to 2036 while extending the B-52's service life into the 2050s, due to the latter's lower maintenance costs, versatile conventional payload, and ability to carry nuclear cruise missiles (which the B-1 is treaty-prohibited from doing). The decision to retire the B-2 early was made because the small fleet of 20 is considered too expensive per plane to retain, with its position as a stealth bomber being taken over with the introduction of the B-21 Raider starting in the mid-2020s.[6]

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azərbaycanca: Northrop B-2 Spirit
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پنجابی: بی-2 سپرٹ
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اردو: بی-2 سپرٹ