| B-2 Spirit | |
|---|---|
| A USAF B-2 Spirit in flight | |
| Role | Stealth bomber |
| National origin | United States |
| Manufacturer | Northrop Corporation Northrop Grumman |
| First flight | 17 July 1989 |
| Introduction | April 1997 |
| Status | Active service: 20 aircraft |
| Primary user | United States Air Force |
| Number built | 21[1][2] |
| Program cost | US$44.75 billion (through 2004)[3] |
| Unit cost | $737 million (1997 cost for each aircraft, $1.01 billion today)[3][4] |
The Northrop Grumman B-2 Spirit (also known as the Stealth Bomber) is an American heavy bomber with low observable stealth technology designed to penetrate dense anti-aircraft defenses and deploy both conventional and nuclear weapons. The bomber has a crew of two and can drop up to eighty 500 lb (230 kg)-class JDAM GPS-guided bombs, or sixteen 2,400 lb (1,100 kg) B83 nuclear bombs. The B-2 is the only aircraft that can carry large air to surface standoff weapons in a stealth configuration.
Development originally started under the "Advanced Technology Bomber" (ATB) project during the Carter administration, and its performance was one of the reasons for his cancellation of the B-1 Lancer. ATB continued during the Reagan administration, but worries about delays in its introduction led to the reinstatement of the B-1 program as well. Program costs rose throughout development. Designed and manufactured by Northrop Grumman with assistance from Boeing, 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 includes development, engineering and testing, averaged $2.1 billion per aircraft in 1997.[3]
Because of its considerable capital and operational costs, the project was controversial in the U.S. Congress and among the Joint Chiefs of Staff. The winding-down of the Cold War in the later 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 early 1990s, the Congress slashed initial plans to purchase 132 bombers to 21. In 2008 one bomber crashed just after takeoff and was destroyed as the crew ejected safely.[5] A total of 20 B-2s remain in service with the United States Air Force.
Though originally designed primarily as a nuclear bomber, the B-2 was first used in combat to drop conventional bombs on Serbia during the Kosovo War in 1999, and saw continued use during the wars in Iraq and Afghanistan.[6] B-2s were also used during the 2011 Libyan uprising.[7]
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In the mid-1970s the search for a new US strategic bomber to replace the Boeing B-52 Stratofortress was underway, with nothing to show for it. First the B-70 and then the B-1A were canceled after only small numbers were built. The B-70 was intended to fly above and beyond defensive interceptor aircraft, only to find these same attributes made it especially vulnerable to surface-to-air missiles (SAMs). The B-1 attempted to avoid SAMs by flying close to the ground to use terrain to mask its radar signature, only to face a new generation of interceptors with look-down/shoot-down capabilities that could attack them from above.
However, technology continued to progress throughout. By the mid-1970s it was becoming clear that there was an entirely different way to avoid missiles and intercepts. Known today as "stealth", the idea was to build an aircraft with an airframe that deflected or absorbed radar signals so that too little was reflected back to the radar unit. An aircraft that was stealthy enough would be able to fly wherever it pleased, and could be attacked only by weapons and systems that did not rely on radar. Although such possibilities exist, notably human observers, ranges were so short that most aircraft could fly right by the defence with impunity, especially at night.[8]
In 1974 DARPA requested information from US aviation firms about the largest radar cross section of an aircraft where it would remain effectively invisible to radars.[9] Initially, Northrop and McDonnell Douglas were selected for further work. Lockheed had experience in this field due to their work on the Lockheed 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 finish in radar absorbing paint. A key improvement was the introduction of computer models that could be used to predict the reflections from flat surfaces and could be used to design a "faceted" aircraft. Work on the first such designs had started in 1975 with "the hopeless diamond", a model built at Lockheed to test the concepts.[10] Improvements quickly followed that allowed designs with more traditional layouts and construction techniques.
These plans were well advanced by the summer of 1975, when DARPA started the Experimental Survivability Testbed (XST) project. Northrop and Lockheed won the first round of testing, and Lockheed was the sole winner of the second round in April 1976. This led to the Have Blue program.[11]
By 1976 these programs had advanced to the point where the concept of a long-range strategic stealth bomber appeared to be a safe bet. Whereas the B-1 relied on flying around known defense sites and could only change its mission within a limited selection of pre-selected routes, a stealth bomber would be able to overfly the Soviet Union with impunity, allowing it to loiter and hunt for targets instead of simply running in and out as fast as possible. In a nuclear exchange, this would allow it to wait out the initial attacks and find targets that escaped destruction, eliminating the "overkill" that was built into existing war planning. Better yet, as the need for high speed was reduced or eliminated, and all of the extremely expensive electronic warfare equipment removed, the aircraft would be much simpler and less expensive.
Carter was aware of these developments during 1977, and it appears to have been one of the major reasons the B-1 was canceled.[12] 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 in 1979, Ronald Reagan repeatedly complained that Carter was weak on defence, 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 (DoD) was working to develop stealth aircraft, including a bomber.[13]
The Advanced Technology Bomber (ATB) began in 1979.[14] Full development of the black project followed. The black program was funded under the code name "Aurora".[15] After the evaluations of the companies' proposals, the ATB competition was reduced to the Northrop/Boeing and Lockheed/Rockwell teams with each receiving a study contract for further work.[14] Both teams used flying wing designs.[15] Northrop had previous experience from the development of the YB-35 and YB-49 flying wing aircraft.[16] The Northrop design was larger while the Lockheed design included a small tail.[15]
The Northrop/Boeing team's ATB design was selected over the Lockheed/Rockwell design on 20 October 1981.[14][17] 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.[13] An estimated US$23 billion was secretly spent for research and development on the B-2 by 1989.[18] MIT scientists helped assess the mission effectiveness of the aircraft under a five-year classified contract during the 1980s.[19]
The B-2 was first publicly displayed on 22 November 1988, at Air Force Plant 42, Palmdale, California, where it was assembled. This initial viewing was heavily guarded and guests were not allowed to see the rear of the B-2. However, Aviation Week editors found that there was no ban on overflying the airfield apron/presentation area and, to the chagrin of the USAF, took pictures from above of the aircraft's then-secret planform and suppressed engine exhausts. The B-2's first public flight was on 17 July 1989 from Palmdale.[20] At the program's peak, approximately 13,000 people were employed at a dedicated plant in Pico Rivera, California for the aircraft's engineering and portions of its manufacturing.[21]
In 1984, a Northrop employee, Thomas Cavanaugh, was arrested for attempting to sell classified information to the Soviet Union, which apparently was smuggled out of the Pico Rivera, California factory.[22] Cavanaugh was eventually sentenced to life in prison and released on parole in 2001.
Noshir Gowadia, a design engineer who worked on the B-2's propulsion system, was arrested in October 2005 for selling B-2 related classified information to foreign countries.[23] On 9 August 2010, Gowadia was convicted in the United States District Court for the District of Hawaii on 14 of 17 charges against him.[24] On 24 January 2011, Gowadia was sentenced to 32 years in prison.[25]
A procurement of 132 aircraft was planned in the mid-1980s, but was later reduced to 75.[26] By the early 1990s, the Soviet Union had disintegrated, which effectively eliminated 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.[27] 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.[28]
In 1995, Northrop made a proposal to the USAF to build 20 additional aircraft with a flyaway cost of $566 million each.[29]
The program was the subject of public controversy for its costs to American taxpayers. In 1996, the General Accounting Office 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$9.6 million annually) and over four times as much as the B-52H ($US6.8 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 (52.4 m) wingspan, which are needed to maintain the aircraft's stealthy properties, especially its "low-observable" stealthy skins.[30][31] Maintenance costs are about $3.4 million a month for each aircraft.[32]
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 General Accounting Office (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]
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 kill the bomber. 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 kill the bomber and others in the Senate such as Jim Exon (D-NE) and John McCain (R-AZ) also opposing the project.[33]
The growing cost of the B-2 program, and evidence of flaws in the aircraft's ability to elude detection by radar,[33] were among factors that drove opposition. 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."[34]
In 1990, the Department of Defense accused Northrop of using faulty components in the flight control system. Efforts have also been made to reduce the probability of bird ingestion, which could damage engine fan blades.[35]
In time, a number of prominent members of Congress began to oppose the program's expansion, including former Democratic presidential nominee John Kerry, who cast votes against the B-2 in 1989, 1991 and 1992 while a US 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.[36]
In May 1995, on the basis of its 1995 Heavy Bomber Force Study, the DOD determined that additional B-2 procurements would exacerbate efforts to develop and implement long term recapitalization plans for the U.S. Air Force bomber force.
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 to pay for the new bombers,[37] and because the military had much higher priorities on which to spend its limited procurement dollars.[38]
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 weapons expended by the bomber force by less than US$2 billion in 1995 dollars during the first two weeks of a conflict, which is when the Air Force envisions bombers would make their greatest contribution. This is a small fraction of the US$26.8 billion (in 1995 dollars) life cycle cost that the CBO projected an additional 20 B-2s would cost.[39]
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.[40] Nonetheless, Congress did not approve funding for the purchase of any additional B-2 bombers.
A number of upgrade packages were applied to the B-2 during the 21st century. In 2004, Northrop Grumman tested a new alternate high-frequency material (AHFM) for use as a RAM coating for the B-2.[41] The Air Force Research Laboratory has developed a new material to be used on the part of the wing trailing edge that is subject to engine exhaust to replace the current material that degrades.[42] In 2008, the US Congress funded upgrades to the B-2's weapon control systems for hitting moving targets.[43]
In July 2008, the B-2's computing architecture was redesigned with a new integrated processing unit (IPU) that communicates via a fiber optic network and a smaller, faster single-board processor that runs a new version of the operational flight program (OFP) software converted from JOVIAL to C by automated tools.[44][45]
On 29 December 2008, Air Force officials awarded a production contract to Northrop Grumman to modernize the B-2 fleet's radars. The contract provides advanced radar components, with the aim of sustained operational viability of the B-2 fleet into the future. The contract has a target value of some US$468 million.[46] The award follows successful flight testing with the upgraded equipment. A modification to the radar was needed since the US Department of Commerce required the B-2 to use a different radar frequency.[47] It was reported on 22 July 2009 that the B-2 had passed the second of the two USAF audit milestones associated with this upgraded AESA radar capability.[48]
On 28 April 2009, an Air Force/contractor team verified that the 30,000 lb (14,000 kg) Massive Ordnance Penetrator (MOP) would fit in the B-2's bomb bay.[49]
The Pentagon is currently (as of 2011) evaluating a radically different unmanned stealth bomber, characterized as a "mini-B2", to come into operational service by 2020.[50] During a transition period, US political expert Rebecca Grant has posited when the B-2 is no longer able to penetrate enemy defenses, the Lockheed Martin F-35 Lightning II may take on its strike/interdiction role. The F-35 also carries the B61 nuclear bomb as a tactical bomber and is not covered by strategic arms limitation treaties such as New START.[51]
The B-2's low-observable, or "stealth", characteristics give it the ability to penetrate an enemy's most sophisticated anti-aircraft defenses to attack its most heavily defended targets. The bomber's stealth comes from a combination of reduced acoustic, infrared, visual and radar signatures, making it difficult for opposition defenses to detect, track and engage the aircraft. Many specific aspects of the low-observability process remain classified. The B-2's composite materials, special coatings and flying wing design, which reduces the number of leading edges, contribute to its stealth characteristics.[52] The Spirit has a radar signature of about 0.1 m2.[53] Each B-2 requires a climate-controlled hangar large enough for its 172-foot (52 m) wingspan to protect the operational integrity of its sophisticated radar absorbent material and coatings.[54] The engines are buried within the wing to conceal the engines' fans and hide their exhaust.[55]
The blending of low-observable technologies with high aerodynamic efficiency and large payload gives the B-2 significant advantages over previous bombers. The U.S. Air Force reports its range as approximately 6,000 nautical miles (6,900 mi; 11,000 km).[6][56] Also, its low-observation ability provides the B-2 greater freedom of action at high altitudes, thus increasing its range and providing a better field of view for the aircraft's sensors. It combines GPS Aided Targeting System (GATS) with GPS-aided bombs such as Joint Direct Attack Munition (JDAM). This uses its passive electronically scanned array APQ-181 radar to correct GPS errors of targets and gain much better than laser-guided weapon accuracy when "unguided" gravity bombs are equipped with a GPS-aided "smart" guidance tail kit. It can bomb 16 targets in a single pass when equipped with 1,000 or 2,000-pound (450 kg or 900 kg) bombs, or as many as 80 when carrying 500 lb (230 kg) bombs.
The B-2 has a crew of two: a pilot in the left seat, and mission commander in the right.[6] The B-2 has provisions for a third crew member if needed.[57] For comparison, the B-1B has a crew of four and the B-52 has a crew of five.[6] B-2 crews have been used to pioneer sleep cycle research to improve crew performance on long sorties. The B-2 is highly automated, and, unlike two-seat fighters, one crew member can sleep, use a toilet or prepare a hot meal while the other monitors the aircraft.[58]
As with the Boeing B-52 Stratofortress and Rockwell B-1 Lancer, the B-2 provides the versatility inherent in manned bombers. Like other bombers, its assigned targets can be canceled or changed while in flight, the particular weapon assigned to a target can be changed, and the timing of attack, or the route to the target can be changed while in flight.
The prime contractor, responsible for overall system design, integration and support, is Northrop Grumman. Boeing, Raytheon (formerly Hughes Aircraft), G.E. and Vought Aircraft Industries, are subcontractors.
The original B-2 design had tanks for a contrail-inhibiting chemical, but this was replaced in the final design with a contrail sensor from Ophir that alerts the pilot when he should change altitude.[59] Mission planning also considers altitudes where the probability of contrail formation is minimized.
The first operational aircraft, christened Spirit of Missouri, was delivered to Whiteman Air Force Base, Missouri, where the fleet is based, on 17 December 1993.[60] The B-2 reached initial operational capability (IOC) on 1 January 1997.[61] Depot maintenance for the B-2 is accomplished by U.S. Air Force contractor support and managed at Oklahoma City Air Logistics Center at Tinker Air Force Base.[6] Originally designed to deliver nuclear weapons, modern usage has shifted towards a flexible role with conventional and nuclear capability.
The B-2 has seen service in four campaigns. Its combat debut was during the Kosovo War in 1999. It was responsible for destroying 33% of selected Serbian bombing targets in the first eight weeks of U.S. involvement in the War.[6] During this war, B-2s flew non-stop to Kosovo from their home base in Missouri and back.[6] The B-2 was the first aircraft to deploy GPS satellite guided JDAM "smart bombs" in combat use in Kosovo.[62]
The B-2 has been used to drop bombs on Afghanistan in support of the Operation Enduring Freedom. With the support of aerial refueling, the B-2 flew one of its longest missions to date from Whiteman Air Force Base, Missouri to Afghanistan and back.[6]
The B-2's combat use preceded a U.S. Air Force declaration of "full operational capability" in December 2003.[6] The Pentagon's Operational Test and Evaluation 2003 Annual Report noted that the B-2's serviceability for Fiscal Year 2003 was still inadequate, mainly due to the maintainability of the B-2's low observable coatings. The evaluation also noted that the Defensive Avionics suite also had shortcomings with "pop-up threats".[6]
During the Iraq War (Operation Iraqi Freedom), B-2s operated from Diego Garcia and an undisclosed "forward operating location". Other sorties in Iraq have launched from Whiteman AFB.[6] This resulted in missions lasting over 30 hours and one mission of over 50 hours. "Forward operating locations" have been previously designated as Andersen Air Force Base in Guam and RAF Fairford in the UK, where new climate controlled hangars have been constructed. B-2s have conducted 27 sorties from Whiteman AFB and 22 sorties from a forward operating location, releasing more than 1.5 million pounds of munitions,[6] including 583 JDAM "smart bombs" in 2003.[63]
All B-2s, nuclear-capable B-52s, and nuclear intercontinental ballistic missiles have shifted to the nuclear-focused Air Force Global Strike Command set up in September 2009.[64][65]
In March 2011, B-2s were the first US aircraft into action in Operation Odyssey Dawn, the UN mandated enforcement of the Libyan no-fly zone. Three B-2s dropped 40 bombs on a Libyan airfield in support of the UN no-fly zone.[66]
B-2s are operated exclusively by the United States Air Force active units.
On 23 February 2008, the B-2 Spirit of Kansas, 89-0127 crashed on the runway shortly after takeoff from Andersen Air Force Base in Guam.[68] B-2 89-0127 had been operated by the 393rd Bomb Squadron, 509th Bomb Wing, Whiteman Air Force Base, Missouri, and had logged 5,176 flight hours. It was the first crash of a B-2. The two person crew ejected safely from the aircraft and survived the crash. The aircraft was completely destroyed, a hull loss valued at US$1.4 billion.[69][70] After the accident, the Air Force took the B-2 fleet off operational status until clearing the fleet for flight status 53 days later on 15 April 2008.[71] The cause of the crash was later determined to be moisture in the aircraft's Port Transducer Units during air data calibration, which distorted the information being sent to the bomber's air data system. As a result, the flight control computers calculated an inaccurate airspeed, and a negative angle of attack, causing the aircraft to pitch upward 30 degrees during takeoff.[72]
In February 2010, another serious incident involving a B-2 occurred at Anderson Air Force Base in Guam. The aircraft involved was AV-11 "Spirit of Washington". The aircraft was severely damaged by fire while it was on the ground and underwent 18 months of temporary repairs in order to enable it fly back to the USA for more comprehensive repairs.[73][74]
Because of its high cost, strategic bombing role, and the still-classified aspects of its low observable coatings, no production B-2 has been placed on permanent display. However, B-2s have made periodic appearances on ground display at various air shows.
Data from USAF Fact Sheet,[6] Pace,[81] Spick,[56] Globalsecurity[82]
General characteristics
Performance
Armament
Later avionics and equipment improvements allow B-2A to carry JSOW, GBU-28, and GBU-57A/Bs as well. The Spirit is also designated as a delivery aircraft for the AGM-158 JASSM when the missile enters service.
| Air Vehicle No. | Block No.[83] | USAF s/n | Formal name | Status |
|---|---|---|---|---|
| AV-1 | Test/30 | 82-1066 | Spirit of America | 14 July 2000 – Active[84] |
| AV-2 | Test/30 | 82-1067 | Spirit of Arizona | 4 December 1997 – Active |
| AV-3 | Test/30 | 82-1068 | Spirit of New York | 10 October 1997 – Active, Flight Test |
| AV-4 | Test/30 | 82-1069 | Spirit of Indiana | 22 May 1999 – Active |
| AV-5 | Test/20 | 82-1070 | Spirit of Ohio | 18 July 1997 – Active |
| AV-6 | Test/30 | 82-1071 | Spirit of Mississippi | 23 May 1997 – Active |
| AV-7 | 10 | 88-0328 | Spirit of Texas | 21 August 1994 – Active |
| AV-8 | 10 | 88-0329 | Spirit of Missouri | 31 March 1994 – Active |
| AV-9 | 10 | 88-0330 | Spirit of California | 17 August 1994 – Active |
| AV-10 | 10 | 88-0331 | Spirit of South Carolina | 30 December 1994 – Active |
| AV-11 | 10 | 88-0332 | Spirit of Washington | 29 October 1994 – Nonoperational, severely damaged by fire[73] |
| AV-12 | 10 | 89-0127 | Spirit of Kansas | 17 February 1995 – 23 February 2008, Crashed[68] |
| AV-13 | 10 | 89-0128 | Spirit of Nebraska | 28 June 1995 – Active |
| AV-14 | 10 | 89-0129 | Spirit of Georgia | 14 November 1995 – Active |
| AV-15 | 10 | 90-0040 | Spirit of Alaska | 24 January 1996 – Active |
| AV-16 | 10 | 90-0041 | Spirit of Hawaii | 10 January 1996 – Active |
| AV-17 | 20 | 92-0700 | Spirit of Florida | 3 July 1996 – Active |
| AV-18 | 20 | 93-1085 | Spirit of Oklahoma | 15 May 1996 – Active |
| AV-19 | 20 | 93-1086 | Spirit of Kitty Hawk | 30 August 1996 – Active |
| AV-20 | 30 | 93-1087 | Spirit of Pennsylvania | 5 August 1997 – Active |
| AV-21 | 30 | 93-1088 | Spirit of Louisiana | 10 November 1997 – Active |
| AV-22 through AV-165 | Canceled | |||
Sources: FAS.org,[85] B-2 Spirit (Pace)[86]
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