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Thursday, 10 January 2013

F-22 Raptor of USA AriForce

"F-22" redirects here. For other uses, see F22 (disambiguation).
F-22 Raptor
F-22 Raptor banking left in-flight, showing the top view of the aircraft. The engines with afterburners emit a pinkish glow. Aircraft mostly gray, apart from the gold cockpit window, with hints of bluish condensation on the wings.
F-22A Raptor at 2008 Andrews AFB airshow
Role Stealth air superiority fighter
National origin United States
Manufacturer Lockheed Martin Aeronautics
Boeing Defense, Space & Security
First flight 7 September 1997[1]
Introduction 15 December 2005
Status In service
Primary user United States Air Force
Produced F-22: 1996–2011[2]
Number built 195 (eight test and 187 operational) aircraft[2]
Program cost US$66.7 billion[3]
Unit cost US$150 million (flyaway cost for FY2009)[4]
Developed from Lockheed YF-22
Developed into Lockheed Martin X-44 MANTA
Lockheed Martin FB-22
The Lockheed Martin/Boeing F-22 Raptor is a single-seat, twin-engine fifth-generation supermaneuverable fighter aircraft that uses stealth technology. It was designed primarily as an air superiority fighter, but has additional capabilities that include ground attack, electronic warfare, and signals intelligence roles.[5] Lockheed Martin Aeronautics is the prime contractor and is responsible for the majority of the airframe, weapon systems and final assembly of the F-22. Program partner Boeing Defense, Space & Security provides the wings, aft fuselage, avionics integration, and training systems.
The aircraft was variously designated F-22 and F/A-22 during the years prior to formally entering USAF service in December 2005 as the F-22A. Despite a protracted and costly development period, the United States Air Force considers the F-22 a critical component of U.S. tactical air power, and claims that the aircraft is unmatched by any known or projected fighter.[6] Lockheed Martin claims that the Raptor's combination of stealth, speed, agility, precision and situational awareness, combined with air-to-air and air-to-ground combat capabilities, makes it the best overall fighter in the world today.[7] Air Chief Marshal Angus Houston, former Chief of the Australian Defence Force, said in 2004 that the "F-22 will be the most outstanding fighter plane ever built."[8]
The high cost of the aircraft, a lack of clear air-to-air combat missions because of delays in the Russian and Chinese fifth-generation fighter programs, a U.S. ban on Raptor exports, and the ongoing development of the planned cheaper and more versatile F-35 resulted in calls to end F-22 production.[N 1] In April 2009, the U.S. Department of Defense proposed to cease placing new orders, subject to Congressional approval, for a final procurement tally of 187 operational aircraft.[10] The National Defense Authorization Act for Fiscal Year 2010 lacked funding for further F-22 production. The final F-22 rolled off the assembly line on 13 December 2011 during a ceremony at Dobbins Air Reserve Base.[11]
Since 2010 the F-22 has been plagued by unresolved problems with its pilot oxygen systems which contributed to one crash and death of a pilot. In 2011 the fleet was grounded for four months before resuming flight operations, but reports of oxygen systems issues have continued.[12] In July 2012, the Air Force announced that the hypoxia-like symptoms experienced were caused by a faulty valve in the pilots' pressure vest; the valve was replaced and changes to the filtration system were also made.

Development

Origins

Main articles: Advanced Tactical Fighter and Lockheed YF-22
An F-22 during takeoff, at Elmendorf AFB, Anchorage, Alaska
In 1981 the U.S. Air Force developed a requirement for an Advanced Tactical Fighter (ATF) as a new air superiority fighter to replace the F-15 Eagle and F-16 Fighting Falcon. This was influenced by the emerging worldwide threats, including development and proliferation of Soviet Su-27 "Flanker"- and MiG-29 "Fulcrum"-class fighter aircraft. It would take advantage of the new technologies in fighter design on the horizon including composite materials, lightweight alloys, advanced flight-control systems, more powerful propulsion systems, and stealth technology. A request for proposals (RFP) was issued in July 1986 and two contractor teams, Lockheed/Boeing/General Dynamics and Northrop/McDonnell Douglas, were selected on 31 October 1986 to undertake a 50-month demonstration phase, culminating in the flight test of two prototypes, the YF-22 and the YF-23.[13][14][15]
Each design team produced two prototypes featuring one of two engine options, one featuring thrust vectoring. The Pratt & Whitney F119 turbofan with vectored thrust permits a tighter turning radius, a valuable capability in dogfights. The ATF's increasing weight and cost drove out some features during development. A dedicated infra-red search and track (IRST) system was downgraded from multi-color to single color and then deleted, the side-looking radars were deleted and the ejection seat requirement was downgraded from a fresh design to the existing McDonnell Douglas ACES II.[16]
On 23 April 1991, the YF-22 was then announced by Secretary of the U.S. Air Force Donald Rice as the winner of the ATF competition.[17] The YF-23 design was more stealthy and faster, but the YF-22 was more agile.[18] The aviation press speculated that the YF-22 was also more adaptable to the Navy's Navalized Advanced Tactical Fighter (NATF), but the U.S. Navy abandoned NATF by 1992.[19] In 1991, the air force planned to buy 650 aircraft.[20]

Production and procurement

F-22 being painted. Workers wearing white apparel standing on the aircraft's top applying a gray and black coat over the F-22. Temporary construction equipment surround its leading edges and nose sections.
The first operational F-22 Raptor is painted at the Lockheed Martin assembly plant at Marietta, Georgia
The production F-22 model was unveiled on 9 April 1997 at Lockheed Georgia Co., Marietta, Georgia. It first flew on 7 September 1997. The first production F-22 was delivered to Nellis Air Force Base, Nevada, on 7 January 2003.[21] In 2006 the Raptor's development team, composed of Lockheed Martin and over 1,000 other companies, plus the United States Air Force, won the Collier Trophy, American aviation's most prestigious award.[22] In 2006, the USAF sought to acquire 381 F-22s, to be divided among seven active duty combat squadrons and three integrated Air Force Reserve Command and Air National Guard squadrons.[23]
Several design changes were made from the YF-22 for production. The swept-back angle on the wing's leading edge was decreased from 48° to 42°, while the vertical stabilizer area was decreased by 20%. To improve pilot visibility, the canopy was moved forward 7 inches (178 mm), and the engine intakes were moved rearward 14 inches (356 mm). The shape of the wing and stabilator trailing edges was refined to improve aerodynamics, strength, and stealth characteristics.[24][25] Also, the vertical stabilizer was shifted rearward.[26]
During the development process the aircraft continued to gain weight at the cost of range and aerodynamic performance, even as capabilities were deleted or delayed in the name of affordability.[27]
F-22 production was split up over many subcontractors across 46 states, in a strategy to increase Congressional support for the program.[28][29] However the production split, along with the implementation of several new technologies were likely responsible for increased costs and delays.[30] Many capabilities were deferred to post-service upgrades, reducing the initial cost but increasing total project cost.[31] Each aircraft required "1,000 subcontractors and suppliers and 95,000 workers" to build.[32] The F-22 was in production for 15 years, at a rate of roughly two per month.[33]
Two F-22s overflying snow-capped mountains.
Two F-22s during flight testing, the upper one being the first EMD F-22, "Raptor 01"
The United States Air Force originally planned to order 750 ATFs at a cost of $26.2 billion,[34] with production beginning in 1994; however, the 1990 Major Aircraft Review led by Defense Secretary Dick Cheney altered the plan to 648 aircraft beginning in 1996. The goal changed again in 1994, when it became 438 aircraft entering service in 2003 or 2004, but a 1997 Department of Defense report put the purchase at 339.[34] In 2003, the Air Force said that the existing congressional cost cap limited the purchase to 277. In December 2004, the Department of Defense reduced procurement funding so only 183 aircraft could be bought.[35] The Pentagon stated the reduction to 183 fighters would save $15 billion but raise the cost of each aircraft; this was implemented in the form of a multi-year procurement plan, which allowed for further orders later. The total cost of the program by 2006 was $62 billion.[23]
In April 2006, the cost of the F-22 was assessed by the Government Accountability Office to be $361 million per aircraft. By April 2006, $28 billion had been invested in F-22 development and testing; while the Unit Procurement Cost was estimated at $177.6 million in 2006, based on a production run of 181 aircraft.[36][37] It was estimated by the end of production, $34 billion will have been spent on procurement, resulting in a total program cost of $62 billion, around $339 million per aircraft. The incremental cost for an additional F-22 was estimated at about $138 million.[23][38] In March 2012, the GAO increased the estimated cost to $412 million per aircraft.[39][40]
Two F-22 Raptors line up for refueling during their first official deployment, October 2005
On 31 July 2007, Lockheed Martin received a multi-year contract for 60 F-22s worth a total of $7.3 billion.[41][42] The contract brought the number of F-22s on order to 183 and extended production through 2011.[41] If production were restarted the cost for another 75 aircraft was estimated in 2009 to be an extra $70 million per unit.[43]

Ban on exports

No opportunity for export currently exists because the export sale of the F-22 is barred by American federal law.[44] Current customers for U.S. fighters are either acquiring earlier designs such as the McDonnell Douglas F-15 Eagle, General Dynamics F-16 Fighting Falcon, and Boeing F/A-18E/F Super Hornet, or are waiting to acquire the Lockheed Martin F-35 Lightning II (Joint Strike Fighter), which contains technology from the F-22 but is designed to be cheaper, more flexible, and available for export.[45] The F-35 will not be as agile as the F-22 or fly as high or as fast, but its radar and avionics will be more advanced.[46] On 27 September 2006, Congress upheld the ban on foreign sales of the F-22;[47] and confirmed this in December 2006.[48]
The Japanese government showed interest in the F-22 for its Replacement-Fighter program.[49] However, a sale would need approval from the Pentagon, State Department and Congress. It was stated that the F-22 would decrease the number of fighters needed by the Japan Air Self-Defense Force (JASDF), reducing engineering and staffing costs. In August 2009, it was reported that the F-22 would require increases to the military budget beyond the historic 1 percent of GDP.[50] In June 2009, Japanese Defense Minister Yasukazu Hamada said Japan still sought the F-22.[51]
Some Australian politicians and defense commentators have proposed that Australia should purchase F-22s instead of the F-35.[52][53] In 2006, Kim Beazley. leader of the Australian Labor Party supported this proposal on the grounds that the F-22 is a proven, highly capable aircraft, while the F-35 is still under development.[54] However, Australia's Howard government ruled out purchase of the F-22, as its release for export is unlikely, and lacks sufficient ground/maritime strike capacity.[55] The following year, the newly-elected Rudd Government ordered a review of plans to procure the F-35 and F/A-18E/F Super Hornet, including an evaluation of the F-22's suitability. The then Defence Minister Joel Fitzgibbon stated: "I intend to pursue American politicians for access to the Raptor".[56] In February 2008, U.S. Defense Secretary Robert Gates said he had no objection to F-22 sales to Australia.[57] However the RAAF found that the "F-22 Raptor cannot perform the strike or close air support roles planned for the JSF."[58]
"The IAF would be happy to equip itself with 24 F-22s, but the problem at this time is the U.S. refusal to sell the aircraft, and its $200 million price tag."
Israeli Air Force (IAF) chief procurement officer Brigadier-General Ze'ev Snir.[59]
Thomas Crimmins of the Washington Institute for Near East Policy speculated in 2009 that the F-22 could be a strong diplomatic tool for Israel, strengthening the capability to strike Iranian nuclear facilities.[60] Crimmins also stated the F-22 may be the only aircraft able to evade Russian S-300 air defense systems, which Russia may sell to Iran.[61] However, Lockheed Martin has stated that the F-35 can handle the S-300, additionally Russia has stated they support and voted for United Nations sanctions on Iran preventing sales of the S-300.[62][63]
The 2010 defense authorization bill included provisions that required the DoD to prepare a report on the costs and feasibility for an F-22 export variant and another report on the impact of F-22 export sales on the U.S. aerospace industry.[64][65]

Production termination

In 2006, David M. Walker, Comptroller General of the United States at the time, found that "the DOD has not demonstrated the need or value for making further investments in the F-22A program."[66] During the two-month grounding of nearly 700 older F-15s in 2007, some U.S. Senators demanded Deputy Secretary of Defense Gordon R. England release three government reports supporting additional F-22s beyond the planned 183 jets.[67] In December 2007, the USAF requested continued production beyond the planned 183 F-22s.[68]
Two F-22A Raptors in close trail formation
In January 2008, the Pentagon announced that it would ask Congress to fund additional F-22s to replace other aircraft lost in combat, and proposed that $497 million that would have been used to shut down the F-22 line be instead used to buy four extra F-22s, leaving the production line open beyond 2011 and allowing the next administration an option to buy more F-22s.[69] Funds earmarked for line shutdown were redirected to repairs upon the F-15 fleet, delaying the end of F-22 production.[70]
On 24 September 2008, Congress passed a defense spending bill funding continued production of the F-22.[71] On 12 November 2008, the Pentagon released $50 million of the $140 million approved by Congress to buy parts for an additional four aircraft, thus leaving the Raptor program in the hands of the incoming Obama Administration.[72] On 6 April 2009, Secretary of Defense Gates called for the phasing out of F-22 production in fiscal year 2011, leaving the USAF with a production run of 187 fighters, minus losses.[10] F-35 acquisition would be accelerated.[73][74] On 17 June 2009 the House Armed Services Committee inserted $368.8 million in the budget towards a further 12 F-22s in FY 2011.[75]
On 9 July 2009, General James Cartwright, Vice Chairman of the Joint Chiefs of Staff, explained to the U.S. Senate Committee on Armed Services his reasons for supporting termination of F-22 production. He stated that fifth-generation fighters need to be proliferated to all three services by shifting resources to the multirole F-35. He noted that commanders had concerns regarding electronic warfare (EW) capabilities, and that keeping the F/A-18 production line "hot" offered a fallback option to the F-35 in the EA-18G Growler.[76]
"The Pentagon cannot continue with business as usual when it comes to the F-22 or any other program in excess of our needs."
Secretary of Defense Robert Gates, speaking on the cancellation.[77][78]
On 21 July 2009, President Obama threatened to veto further F-22 production.[79][80] On 21 July 2009, the Senate voted in favor of ending F-22 production. Secretary Gates said that the decision to end production was taken in light of the F-35's capabilities.[81] On 29 July 2009, the Air National Guard's director asked for "60 to 70" F-22s for air sovereignty missions, noting that these could lack capabilities such as ground attack.[82] On 30 July 2009, the House agreed to remove funds for an additional 12 aircraft and abide by the 187 cap.[83] In mid-2010, Gates reduced the F-22 requirement from 243 to 187 aircraft, by lowering the preparations for two major regional conflicts to one.[84] President Obama signed the National Defense Authorization Act for Fiscal Year 2010 in October 2009, without F-22 funding.[85][86]
RAND estimated the cost of restarting production to build an additional 75 Raptors to be $17 billion or $227 million per aircraft.[87] However Lockheed Martin has said that restarting the production line would only cost $200 million.[88] The RAND paper was produced as part of an USAF study to determine the costs of retaining F-22 tooling for a future Service Life Extension Program (SLEP).[89] The tooling for F-22 production will be documented in illustrated electronic manuals stored at the Sierra Army Depot.[90]
Russian and Chinese fighter developments have fueled concern; General John Corley, head of Air Combat Command, wrote in a 2009 letter to a senator, "In my opinion, a fleet of 187 F-22s puts execution of our current national military strategy at high risk in the near- to mid-term". But Gates replied "Nonsense".[91] On 8 January 2011, Gates clarified that Chinese fifth-generation fighter developments had been accounted when the number of F-22s was set, and that the United States would have a considerable advantage in stealth aircraft in 2025, even with F-35 delays.[92][93] On 11 January 2011, China's J-20 stealth aircraft made its first flight,[94] leading to speculation on the reactivation of F-22 production;[95][96][97] An August 2008 RAND study concluded the F-22 would only play a minor role in a conflict with China over Taiwan as nearby bases would be rapidly shut down by medium-range ballistic missiles (MRBMs); and distant bases would rely upon vulnerable aerial refueling tankers.[98][99]
In December 2011, the 195th and final F-22 was completed (out of 8 test and 187 combat aircraft produced).[100]
Because of the limited production run, there are zero attrition reserve aircraft and extra care is given at the Hill Air Force Base F-22 maintenance center to keep the entire fleet operational. Lockheed's retained tooling will be used to produce additional parts, if needed.[101]

Upgrades

On 5 January 2001, Raptor 4005 flew with the Block 3.0 software, which was the first combat-capable avionics version.[102] In June 2009, Increment 3.1 was tested at Edwards Air Force Base. This provided a basic ground-attack capability through Synthetic Aperture Radar mapping, Electronic attack and the GBU-39 Small Diameter Bomb. The Increment 3.1 Modification Team with the 412th Test Wing received the Chief of Staff Team Excellence Award for upgrading 149 Raptors.[103][104] The fleet upgrade should start at the end of 2011.[105] An additional $808 million will be spent in 2013 to implement the 3.1 upgrade.[106] The first upgraded aircraft were delivered in early 2012.[107]
F-22 Raptor, Andrews Air Force Base
Increment 3.2 was to add an improved SDB capability, an automatic ground collision avoidance system for low level operations (no longer planned) and enable use of the AIM-9X Sidewinder and AIM-120D AMRAAM missiles. However, a helmet mounted cueing system has been deferred by technical issues.[108][109] Increment 3.2 was expected to be fielded in FY15,[110] possibly including the Multifunction Advanced Data Link (MADL).[111][112] In July 2009, the USAF announced the modification of three business jets with the interim Battlefield Airborne Communications Node (BACN) to allow communication between F-22s and other platforms until MADL is installed.[113] In March 2010, the USAF accelerated software portions of the Increment 3.2 upgrades to be completed in FY 2013, other upgrades will be completed later.[114] Upgrading the first 183 aircraft to the 3.2 upgrade is estimated to cost $8 billion.[115] In May 2009, Gen. Norton A. Schwartz and Air Force Secretary Michael B. Donley gave testimony to Congress that this would be paid for through the early retirement of legacy fighters.[116] A total of 249 fourth-generation fighters were retired during Fiscal Year 2010.[117] On 16 September 2009, Gates said "Our commitment to this aircraft is underscored by the 6 and-a half billion dollars... to upgrade the existing F-22 fleet to be fully mission-capable."[118]
The USAF opened the Raptor enhancement, development and integration (REDI) contract to other bidders in January 2011 with a total budget of $16 billion.[119] On 18 November 2011, the upgrade contract with Lockheed Martin was increased by $1.4 billion to a maximum value of $7.4 billion. This increment opens the way for further upgrades in 2012.[120][121][122] The $11.7 billion allocated for the planned upgrades to the 3.2B level (of which $5.5 billion has been spent) includes almost $2 billion for structural repairs and reliability issues, but does not include related infrastructure costs. One of the goals of the reliability costs is to raise the fleet availability rate from its current level of 55.5% to 70.6% by 2015. The 3.2C level upgrades will be bid out as a separate project.[123]
Lockheed Martin has proposed upgrades to add capabilities from the newer F-35.[124] Elements such as MADL are delayed until the F-35 program is completed to reduce risk.[125] One upgrade from the F-35 is new high-durability stealth coatings to lower maintenance.[126] The Ada software language was blamed for slow progress and increased costs on the program, leading to a reorganization in 2011.[127] Increment 3.2A in 2014 focuses on electronic warfare, communications and identification. Increment 3.2B in 2017 will support the AIM-9X and AIM-120D missiles. Increment 3.2C in 2019 may migrate some avionics to an open platform, allowing features to be added by various companies.[128] Lockheed Martin is working on upgrading the AN/AAR-56 Missile Launch Detector (MLD) to provide situational awareness and defensive Infrared Search and Track similar to the F-35's SAIRST.[129]
The current upgrade schedule is:
  • Increment 3.1 now entering service adds capabilities for SDB, SAR, and electronic attack.
  • Update 4 in 2012 will add a rudimentary capability for the AIM-120D.
  • Increment 3.2A will be fielded in 2014 with Link 16 and electronic warfare improvements. (The Link 16 receive capability has been moved up to 2013.)[130]
  • Also by mid-2014 an automatic backup oxygen supply will be installed on all aircraft.[131]
  • Update 5 in 2015 will add an initial capability for the AIM-9X.
  • In 2016 the fleet will be upgraded to 36 Block 20 training aircraft and 149 Block 30/35 operational aircraft.
  • Increment 3.2B in 2018 will add full capability for the air to air missiles, and "significantly improved ground threat geolocation". This schedule has slipped seven years because of "requirements and funding instability".[132] Because of this delay the upgrade will be applied to fielded aircraft that have already consumed a significant fraction of their useful airframe lifespan.[133][134]
  • Increment 3.2C was renamed 3.3 and while it is still being defined,[135] it will include air traffic control updates.[136]
Features not currently planned for addition or upgrades include:
  • The previously planned side-mounted AESA radar arrays
  • Infrared search and track (IRST)
  • Helmet-mounted sight
  • Powered air to surface missiles, the GBU-53 Small Diameter Bomb II, or other systems capable of engaging moving ground targets[137]
Because of these limitations, the Raptor will be unable to use the off-boresite and lock-on after launch features of its missiles.[138]
The Raptor were designed with a lifespan of 30 years and 8000 flight hours, but to achieve this goal required a $100 million "structures retrofit program".[139] Investigations are being made for upgrades to extend their useful lives further.[140][141] The F-22 is expected to eventually be replaced by the fighter from the Next Generation Air Dominance program.[142]
While no definitive, single cause has been found for the frequent oxygen deprivation issues that have killed at least one pilot, the F-22 will be upgraded with a 10 pound backup oxygen system, software upgrades and oxygen sensors to allow the pilots to operate normally in spite of the problem.[143] Due to frequent stand downs during the investigation, the F-22 fleet averaged less than eight flight hours per month over 2011.[144]

Design

Characteristics

Rear view of jet aircraft in-flight at dawn/dusk above mountains. Its engines are in full afterburner, evident through the presence of shock diamonds.
F-22 Raptor flying with its F119-PW-100 engines on full afterburner
The F-22 Raptor is a fifth generation fighter that is considered a fourth-generation stealth aircraft by the USAF.[145] Its dual afterburning Pratt & Whitney F119-PW-100 turbofans incorporate pitch axis thrust vectoring, with a range of ±20 degrees. The maximum thrust is classified, though most sources place it at about 35,000 lbf (156 kN) per engine.[146] Maximum speed, without external weapons, is estimated to be Mach 1.82 in supercruise mode,[147] as demonstrated by General John P. Jumper, former U.S. Air Force Chief of Staff, when his Raptor exceeded Mach 1.7 without afterburners on 13 January 2005.[148] With afterburners, it is "greater than Mach 2.0" (greater than 1,317 mph, 2,120 km/h). Former Lockheed chief test pilot Paul Metz stated that the Raptor has a fixed inlet, as opposed to variable intake ramps, and that the F-22 has a greater climb rate than the F-15, despite the F-15's higher thrust-to-weight ratio of 1.2:1 (the F-22 has a ratio closer to 1:1).[149] The U.S. Air Force claims that the Raptor cannot be matched by any known or projected fighter types,[6] and Lockheed Martin claims: "the F-22 is the only aircraft that blends supercruise speed, super-agility, stealth and sensor fusion into a single air dominance platform."[150]
F-22 Raptor flight demonstration video
The ability of airframes to withstand both stress and heat is a major design factor, thus the F-22 makes use of various materials. The use of internal weapons bays allows the aircraft to maintain a comparatively higher performance while carrying a heavy payload over many other aircraft due to a lack of drag from external stores. It is one of only a few aircraft that can supercruise or sustain supersonic flight without the use of afterburners, which consume vastly more fuel. The F-22 can intercept time-critical or rapidly moving targets that a subsonic aircraft would not have the speed to follow and an afterburner-dependent aircraft would lack fuel to reach.[151]
The F-22 is highly maneuverable, at both supersonic and subsonic speeds. It is extremely departure-resistant,[152] enabling it to remain controllable at extreme pilot inputs. The Raptor's thrust vectoring nozzles allow the aircraft to turn tightly, and perform extremely high alpha (angle of attack) maneuvers such as the Herbst maneuver (or J-turn), Pugachev's Cobra,[149] and the Kulbit.[149] The F-22 is also capable of maintaining a constant angle of attack of over 60°, yet still having some control of roll.[149][153] During June 2006 exercises in Alaska, F-22 pilots demonstrated that cruise altitude has a significant effect on combat performance, and routinely attributed their altitude advantage as a major factor in achieving an unblemished kill ratio against other U.S. fighters and 4th/4.5th generation fighters.[154]
Members of the Fighter Mafia[who?] have criticized the shortcomings of the F-22 as compared to their ideal of the F-16 in pilot visibility, available flight hours for pilot training, a focus on Beyond-visual-range missile combat that ignores air combat history, stealth that does not cover important long range search frequencies, and very limited range.[155] During Red Flag 2012, German pilots flying Typhoons demonstrated the weaknesses of the Raptor in close in combat due to its size, weight, disadvantage in IR sensors, and lack of off-boresite weapons.[156][157] The Eurofighters had a maneuverability advantage because they were flying in a stripped down configuration, but the F-22's equipment is built into the airframe for stealth. So the Raptor always carries the additional size and weight.[158] Also the F-22's BVR advantages are currently blunted because of the delay in reprogramming the onboard computers to properly use the longer ranged 'D' version of the AMRAAM.[159][not in citation given]
The F-22 has a unique combination of speed, altitude, agility, sensor fusion and stealth that all work together to increase its effectiveness. Altitude plus advanced active and passive electronic warfare systems allow the F-22 to spot targets for its own weapons at considerable ranges. Altitude plus speed increases the reach of the F-22's own weapons. Altitude naturally increases the range from ground based defenses, which increases the effectiveness of stealth, and when combined with speed reduces the time defensive systems have to react to the F-22's attacks.[160][161][162][163]

Avionics

The F-22's avionics include BAE Systems E&IS radar warning receiver (RWR) AN/ALR-94,[164] AN/AAR 56 Infra-Red and Ultra-Violet MAWS (Missile Approach Warning System) and the Northrop Grumman AN/APG-77 Active Electronically Scanned Array (AESA) radar. The AN/ALR-94 is a passive receiver system to detect radar signals; composed of more than 30 antennas blended into the wings and fuselage that provide all around coverage. It was described by Tom Burbage, former F-22 program head at Lockheed Martin, as "the most technically complex piece of equipment on the aircraft." It has a greater range (250+ nmi) than the radar, allowing the F-22 to limit its own radar emissions to maximise stealth. As a target approaches, the receiver can cue the AN/APG-77 radar to track the target with a narrow beam, which can be as focused down to 2° by 2° in azimuth and elevation.[165]
Two personnel in white apparel handing a radar
The AN/APG-77 AESA radar
The AN/APG-77 radar, designed for air superiority and strike operations, features a low-observable, active-aperture, electronically-scanned array that can track multiple targets in any weather. The AN/APG-77 changes frequencies more than 1,000 times per second to lower interception probability. Additionally, radar emissions can be focused in an electronic-attack capability to overload enemy sensors.[166][167]
The radar's information is processed by two Raytheon Common Integrated Processor (CIP)s. Each CIP can process 10.5 billion instructions per second and has 300 megabytes of memory. Information can be gathered from the radar and other onboard and offboard systems, filtered by the CIP, and offered in easy-to-digest ways on several cockpit displays, enabling the pilot to remain on top of complicated situations. The F-22's avionics software has some 1.7 million lines of code, the majority involving processing data from the radar.[168] The radar has an estimated range of 125–150 miles, though planned upgrades will allow a range of 250 miles (400 km) or more in narrow beams.[154] In 2007, tests by Northrop Grumman, Lockheed Martin, and L-3 Communications enabled the AESA system of a Raptor to act like a WiFi access point, able to transmit data at 548 megabits per second and receive at gigabit speed; this is far faster than the Link 16 system used by U.S. and allied aircraft, which transfers data at just over 1 Mbit/s.[169]
The F-22 has a threat detection and identification capability comparative with the RC-135 Rivet Joint.[154] The F-22's stealth allows it to safely operate far closer to the battlefield, compensating for the reduced capability.[154] The F-22 is capable of functioning as a "mini-AWACS", however the radar is less powerful than dedicated platforms such as the E-3 Sentry.[149] The F-22 allows its pilot to designate targets for cooperating F-15s and F-16s, and determine whether two friendly aircraft are targeting the same aircraft.[149][154] This radar system can sometimes identify targets "many times quicker than the AWACS".[154] The radar is capable of high-bandwidth data transmission; conventional radio "chatter" can be reduced via these alternative means.[154] The IEEE-1394B data bus developed for the F-22 was derived from the commercial IEEE-1394 "FireWire" bus system.[170] Sensor fusion combines data from all onboard and offboard sensors into a common view to prevent the pilot from being overwhelmed.[171]
In a critical article former Navy Secretary John Lehman wrote "[a]t least [the F-22s] are safe from cyberattack. No one in China knows how to program the '83 vintage IBM software that runs them."[172] Former Secretary of the USAF Michael Wynne blamed the use of the DoD's Ada as a reason for cost overruns and schedule slippages on many major military projects, including the F-22 Raptor.[173] The F-22 uses the INTEGRITY-178B operating system from Green Hills Software, which is also used on the F-35, several commercial airliners and the Orion Crew Exploration Vehicle.[174]
Herbert J. Carlisle has said that the F-22 can datalink with the Tomahawk (missile).[175]

Cockpit

Cockpit of the F-22, showing instruments, head up display and throttle top (lower left)
The F-22 features a glass cockpit with no analog flight instruments.[176] The primary flight controls are a force-sensitive side-stick controller and a pair of throttles. The monochrome head-up display offers a wide field of view and serves as a primary flight instrument for the pilot; information is also displayed upon six color liquid crystal display (LCD) panels.[176] The canopy's dimensions are approximately 140 inches long, 45 inches wide, and 27 inches tall (355 cm x 115 cm x 69 cm) and weights 360 pounds.[177] In August 2006, the Air Force Packaging Technology Engineering Facility (AFPTEF) was tasked with the design of a new shipping and storage container for the fragile F-22 Canopy.[178]
The Raptor has integrated radio functionality for communicating on standard frequencies, the signal processing systems are virtualised rather than a separated hardware module.[179] Radio functions are inactive during the strictest emissions control protocols (EMCON level) to maintain stealth; at lower EMCON levels the pilot may use the radio at will.[citation needed] There has been several media reports on the F-22's inability to communicate with other aircraft and funding cuts on integrating the new datalinking standard, MADL.[180][181] Voice communication is possible, but not data transfer yet.[182] However, the Joint Tactical Radio System (JTRS), the software-defined radio project, was cancelled in October 2011 (before delivery to the F-22).[183]
The integrated control panel (ICP) is a keypad system for entering communications, navigation, and autopilot data. Two 3 in × 4 in (7.6 cm × 10 cm) up-front displays located around the ICP are used to display integrated caution advisory/warning data, communications, navigation and identification (CNI) data[184] and also serve as the stand-by flight instrumentation group and fuel quantity indicator.[185] The stand-by flight group displays an artificial horizon, for basic instrument meteorological conditions. The 8 in × 8 in (20 cm × 20 cm) primary multi-function display (PMFD) is located under the ICP, and is used for navigation and situation assessment.[185] Three 6.25 in × 6.25 in (15.9 cm × 15.9 cm) secondary multi-function displays are located around the PMFD for tactical information and stores management.[185]
The ejection seat is a version of the ACES II (Advanced Concept Ejection Seat) commonly used in USAF aircraft, with a center-mounted ejection control.[186] The F-22 has a complex life support system, components include the on-board oxygen generation system (OBOGS), protective pilot garments and a breathing regulator/anti-g valve controlling flow and pressure to the pilot's mask and garments. The protective garments are designed to protect against chemical/biological hazards and cold-water immersion, to counter g-forces and low pressure at high altitudes, and to provide thermal relief. It was developed under the Advanced Technology Anti-G Suit (ATAGS) project.[187] Suspicions regarding the performance of the OBOGS and life support equipment have been raised by several crashes.[188]
The USAF initially wanted the aircraft to use direct voice input (DVI) controls. This was finally judged too technically risky and was abandoned.[189]

Armament

Jet fighter flying above a streaking missile, which had moments earlier been released by the former.
An F-22 fires an AIM-120 AMRAAM
The Raptor has three internal weapons bays: a large bay on the bottom of the fuselage, and two smaller bays on the sides of the fuselage, aft of the engine intakes.[190] It can carry six compressed-carriage medium range missiles[191] in the center bay and one short range missile in each of the two side bays. Four of the medium range missiles can be replaced with two bomb racks that can each carry one medium-size bomb or four small diameter bombs.[161] Carrying missiles and bombs internally maintains its stealth capability and maintains lower drag resulting in higher top speeds and longer combat ranges. Launching missiles requires opening the weapons bay doors for less than a second, while the missiles are pushed clear of the airframe by hydraulic arms. This reduces the Raptor's chance of detection by enemy radar systems due to launched ordnance and also allows the F-22 to launch long range missiles while maintaining supercruise.[192] The F-22 can also carry air-to-surface weapons such as bombs with Joint Direct Attack Munition (JDAM) guidance and the Small-Diameter Bomb, but cannot self-designate for laser-guided weapons.[193] Air-to-surface ordnance is limited to 2,000 lb (compared to 17,000 lb of F/A-18).[194] The Raptor has an M61A2 Vulcan 20 mm cannon in the right wing root. The M61A2 carries 480 rounds; enough ammunition for approximately five seconds of sustained fire. The opening for the cannon's firing barrel is covered by a door when not in use to maximise stealth.[195] The F-22 has been able to close to gun range in training dogfights while avoiding detection.[149] The cannon fire is tracked by the aircraft's radar and displayed on the pilot's head up display.[196]
For stealth, the F-22 carries weapons in internal bays. The doors for the center bay and smaller side bays are open showing the six LAU-142/A AMRAAM Vertical Ejection Launchers (AVEL).
The Raptor's very high sustained cruise speed and operational altitude add significantly to the effective range of both air-to-air and air-to-surface munitions. This gives it a 40% greater employment range for air to air missiles than the F-35.[197] The USAF plans to procure the AIM-120D AMRAAM, reported to have a 50% increase in range compared to the AIM-120C. While specific figures remain classified, it is expected that JDAMs employed by F-22s will have twice or more the effective range of munitions dropped by legacy platforms.[198] In testing, a Raptor dropped a 1,000 lb (450 kg) unpowered, free-fall JDAM from 50,000 feet (15,000 m), while cruising at Mach 1.5, striking a moving target 24 miles (39 km) away.[199]
While the F-22 typically carries its weapons internally, the wings include four hardpoints, each rated to handle 5,000 lb (2,300 kg). Each hardpoint has a pylon that can carry a detachable 600 gallon fuel tank or a launcher holding two air-air missiles. However, the use of external stores has a detrimental effect on the F-22's stealth, maneuverability and speed. The two inner hardpoints are "plumbed" for external fuel tanks; the hardpoints can be jettisoned in flight so the fighter can maximise its stealth after exhausting external stores.[200] A stealth ordnance pod and pylon is being developed to carry additional weapons internally.[201]

Stealth

The stealth of the F-22 is due to a combination of factors, including the overall shape of the aircraft, the use of radar absorbent material (RAM), and attention to detail such as hinges and pilot helmets that could provide a radar return.[202] However, reduced radar cross section is one of five facets of presence reduction addressed in the designing of the F-22. The F-22 was designed to disguise its infrared emissions, reducing the threat of infrared homing ("heat seeking") surface-to-air or air-to-air missiles, including its flat thrust vectoring nozzles.[203] The aircraft was designed to be less visible to the naked eye; radio, heat and noise emissions are equally controlled.[202]
F-22 with external weapons pylons.
The F-22 reportedly relies less on maintenance-intensive radar absorbent coatings than previous stealth designs like the F-117. These materials are susceptible to adverse weather conditions.[204] Unlike the B-2, which requires climate-controlled hangars, the F-22 can undergo repairs on the flight line or in a normal hangar.[204] The F-22 features a Signature Assessment System which delivers warnings when the radar signature is degraded and has necessitated repair.[204] The exact radar cross section (RCS) remains classified; however, in 2009 Lockheed Martin released information indicating it to have a RCS (from certain angles) of −40 dBsm – the equivalent radar reflection of a "steel marble".[205] Effectively maintaining the stealth features can decrease the F-22's mission capable rate to 62–70%.[N 2]
The effectiveness of the stealth characteristics is difficult to gauge. The RCS value is a restrictive measurement of the aircraft's frontal or side area from the perspective of a static radar. When an aircraft maneuvers it exposes a completely different set of angles and surface area, potentially increasing visibility. Furthermore, stealth contouring and radar absorbent materials are chiefly effective against high-frequency radars, usually found on other aircraft. Low-frequency radars, employed by weather radars and ground warning stations, are alleged to be less affected by stealth technologies and are thus more capable as detection platforms.[207][208] Rebecca Grant states that while faint or fleeting radar contacts make defenders aware that a stealth aircraft is present, interception cannot be reliably vectored to attack the aircraft.[209]
The F-22 also includes measures designed to minimize its detection by infrared, including special paint and active cooling of leading edges to deal with the heat buildup encountered during supercruise flight.[210]

Operational history

Designation and testing

Rear/starboard view of aerial refueling tanker transferring fuel to a jet fighter via a long boom. The two aircraft are slightly banking left.
An F-22 refuels from a KC-135 during testing; the attachment on the back top is for a spin recovery chute
The YF-22 was originally given the unofficial name "Lightning II", after the World War II fighter P-38, by Lockheed, which persisted until the mid-1990s when the USAF officially named the aircraft "Raptor". The aircraft was also briefly dubbed "SuperStar" and "Rapier".[211] The F-35 later received the Lightning II name on 7 July 2006.[212] In September 2002, Air Force leaders changed the Raptor's designation to F/A-22. The new designation, mimicking the Navy's McDonnell Douglas F/A-18 Hornet, was intended to highlight plans for a ground-attack capability amid intense debate over the relevance of expensive air-superiority jets. The F-22 designation was reinstated on 12 December 2005, when the aircraft entered service.[6][213]
Flight testing of the F-22 began in 1997. Raptor 4001 was retired and sent to Wright-Patterson AFB to be fired at for testing the fighter's survivability. Usable parts of 4001 would be used to make a new F-22. Another engineering and manufacturing development (EMD) F-22 was also retired and likely to be sent to be rebuilt. A testing aircraft was converted to a maintenance trainer at Tyndall AFB.[214]
In May 2006, a released report documented a problem with a forward titanium boom on the aircraft. The problem was caused by a manufacturing defect in the heat-treating, making the boom less ductile than specified and potentially shortening the lives of roughly the first 80 F-22s. Modifications were implemented to restore full life expectancy.[215][216]

Entering service

On 15 December 2005 the USAF announced that the Raptor had reached its Initial Operational Capability (IOC).[217] During Exercise Northern Edge in Alaska in June 2006, 12 F-22s of the 94th FS downed 108 adversaries with no losses in simulated combat exercises.[23] In two weeks of exercises, the Raptor-led Blue Force amassed 241 kills against two losses in air-to-air combat; neither Blue Force loss was an F-22. Shortly after was Red Flag 07-1 in February 2007. Fourteen F-22s of the 94th FS supported Blue Force strikes and undertook close air support sorties themselves. Against superior numbers of Red Force Aggressor F-15s and F-16s, 6–8 F-22s maintained air dominance throughout. No sorties were missed because of maintenance or other failures, and only one Raptor was judged lost against the opposing force's defeat.[N 3] F-22s also provided airborne electronic surveillance.[218]
Aerial port view of two aircraft in flight, one on top of the other. The bottom aircraft is a four-engined propeller-driven aircraft, which is escorted by a jet fighter. The Moon is visible as a tiny spot in the sky.
An F-22 from Elmendorf AFB, Alaska, intercepting a Russian Tupolev Tu-95 near American airspace

Deployments

While attempting its first overseas deployment to the Kadena Air Base in Okinawa, Japan, on 11 February 2007, six F-22s flying from Hickam AFB, Hawaii experienced multiple computer failures while crossing the International Date Line (or 180th meridian of longitude dependent on software programming). The failures included navigation and communication.[219] The fighters were able to return to Hawaii by following tanker aircraft. Within 48 hours, the error was resolved and the journey resumed.[220] 90th Fighter Squadron performed the first F-22 NORAD interception of two Russian Tu-95MS 'Bear-H' bombers over Alaska, on 22 November 2007.[221] Since then, F-22s have also escorted probing Tu-160 "Blackjack" strategic bombers.[222]
On 12 December 2007, General John D.W. Corley, USAF, Commander of Air Combat Command, officially declared the F-22s of the integrated active duty 1st Fighter Wing and Virginia Air National Guard 192d Fighter Wing fully operational, three years after the first Raptor arrived at Langley Air Force Base, Virginia.[223] This was followed from 13 to 19 April 2008 by an Operational Readiness Inspection (ORI) of the integrated wing which rated it "excellent" in all categories, with a simulated kill-ratio of 221–0.[224] The first pair of Raptors assigned to the 49th Fighter Wing became operational at Holloman Air Force Base, New Mexico, on 2 June 2008.[225]
In December 2007, Secretary of the Air Force Michael Wynne requested that the F-22 be deployed to the Middle East; Secretary of Defense Gates rejected this option.[226] Time suggested part of the reason for it not being used in the 2011 military intervention in Libya may have been its high unit cost.[227]
An F-22 observes as an F-15 Eagle banks left. The F-22 is intended to replace the F-15C/D
On 28 August 2008, an unmodified F-22 from the 411th Flight Test Squadron performed in the first ever air-to-air refueling of an aircraft using synthetic jet fuel. The test was a part of a wider USAF effort to qualify aircraft to use the fuel, a 50/50 mix of JP-8 and a Fischer-Tropsch process-produced, natural gas-based fuel.[228] Then in 2011 a Raptor made a supersonic flght on a 50% mixture of biofuel derived from camelina.[229]
In April 2012, the U.S. military deployed several F-22s to an allied base less than 200 miles from Iran.[230] The Iranian defense minister called the deployment of stealth fighters to the UAE a security threat.[231]

Maintenance and training

F-22 Raptor U.S. Air Force video
In 2004 the F-22 had a mission ready rate of 62% fleet wide but this was improved to 70% in 2009, with the mission ready rate being predicted to reach 85% as the fleet reached 100,000 flight hours.[232] In the early years of its service, the F-22 required more than 30 hours of maintenance for every flight hour, with the total cost per flight hour of $44,000, however in 2008 this figure had been lowered to 18.1 hours, and 10.5 hours by 2009;[232] this is compared to the original Pentagon requirement of 12 maintenance hours per flight hour.[135] At introduction the F-22 also had a Mean Time Between Maintenance (MTBM) of 1.7 hours, however in the 7 years since this has been improved to 3.2 hours, exceeding the original requirement of 3.0 hours by 2010.[232]
Each Raptor requires a month-long packaged maintenance plan (PMP) after every 300 flight hours.[233] The aircraft's stealth system, including its radar absorbing metallic skin, account for almost one third of all maintenance.[232] Another source of maintenance problems is that many components require custom hand-fitting and are not interchangeable.[45] The canopy of the aircraft was required to have a life of 800 hours, however the original design failed to meet this, averaging at 331 hours.[45] In response to this the canopy was redesigned, and the new canopy has met its requirements of a 800 hour life expectancy.[232]
In January 2007, it was reported that the F-22 maintained a 97% sortie rate (flying 102 out of 105 tasked sorties) while amassing a 144-to-zero kill ratio during "Northern Edge" air-to-air exercises held in Alaska, the first large-scale exercise in which the Raptor participated. Lieutenant Colonel Wade Tolliver, the squadron commander of the 27th Fighter Squadron commented: "the stealth coatings are not as fragile as they were in earlier stealth aircraft. It isn't damaged by a rain storm and it can stand the wear and tear of combat without degradation."[204] However, rain has caused "shorts and failures in sophisticated electrical components" when the Raptors were briefly posted to Guam.[234]
In its 2012 budget request the USAF cut F-22 flight training hours by one-third to reduce the operating costs of flying the aircraft.[235] The F-22 will continue in its role as an airshow demonstration aircraft and will be the only USAF solo aircraft demonstrator in 2012.[236]
The manpower required to maintain each F-22A's stealth coatings has increased as the aircraft have gotten older.[237] Part of this work involves removing and reapplying the stealth coatings in order to maintain a consistent mold line or outside shape of the aircraft.[238]

Operational issues

 This section may be too long and excessively detailed.
Please consider summarizing the material while citing sources as needed. (August 2012)
In 2005 a USAF expert panel called the Raptor Aeromedical Working Group recommended changes to deal with breathing problems on the F-22.[239] These changes were not implemented at the time, but are under consideration in 2012.[240] The changes included the installation of a backup oxygen system that will now be installed. Different reasons have been offered for the omission, including weight and cost.[241] Problems were designed into Raptor by the 1990s USAF, that had shed "much of its scientific, medical and engineering expertise" from the Cold War. These problems only surfaced once F-22 flights became common after 2008.[242]
On 11 February 2007, twelve Raptors flying from Hawaii to Japan were forced to turn back due to a software glitch in the F-22s' on-board navigational computers related to the International Date Line.[243][244] The fleet was briefly grounded in February 2010 due to corroded ejection seat rods.[245]
In May 2011, the Raptor fleet was grounded following the November 2010 crash near Elmendorf Air Force Base, Alaska. The F-22 had been restricted to flying below 25,000 ft while the Honeywell oxygen generating system was inspected. After five incidents of pilots suffering from hypoxia and decompression,[246] General William M. Fraser III of Air Combat Command grounded the F-22 fleet indefinitely on 3 May 2011.[247][248] In June 2011, the investigation broadened across the life support systems,[249] and aircraft deliveries were stopped.[250] During the investigation it was found that F-22 pilots suffered from a "Raptor Cough" and other breathing problems nine times more often than the pilots of other fighters.[251][252]
Some of the polymers used on the F-22 are a significant health risk to personnel; technicians are required to wear protective equipment such as eye protection, respirators and gloves to work on the aircraft.[253] These same materials have been suggested to be behind the "Raptor Cough" and other health problems suffered by F-22 pilots and ground crews.[254] Major General Charles Lyon suggested that the ground crew problems could be from dehydration or hypoglycemia, and that pilots are to be told to improve eating and to stay well hydrated.[255]
In September 2011, the F-22 returned to flight with added pilot safety equipment and careful monitoring of crew and aircraft, while the investigation continued.[256][257] On 21 October 2011, Langley's F-22s were grounded after a suspected oxygen system problem;[258][259] Joint Base Elmendorf-Richardson grounded their aircraft as well.[260] All aircraft were cleared to fly again on 25 October.[261]
In late October 2011, Lockheed Martin was awarded a $24M contract to find the cause of the breathing difficulty, as well as providing other sustainment functions.[262] During the investigation various causes were investigated including poisoning by carbon monoxide from the engines while warming up the aircraft inside the hangars,[263] other chemicals have been inhaled from the on-board oxygen generating system (OBOGS), including oil fumes and propane,[264][265] other toxins that could enter the aircraft environmental control systems such as neurotoxic diisocyanates from the polyurethane adhesive used to glue stealth materials to the aircraft,[266][267] high concentrations of oxygen caused by high-G high altitude maneuvers that other American jet fighters can not duplicate, leading to the collapse of the pilot's pulmonary alveolus,[268] and that the breathing system on board the Raptor might not provide sufficient oxygen in some situations.[269]
In mid-December 2011, the air force said that there had been 14 episodes since September, when the F-22s returned to operation, in which pilots experienced "physiological incidents" that might have been caused by a lack of oxygen.[270] Up to April 2012 seven serious accidents occurred with two pilots killed. Since the redeployment in September 2011, 11 incidents of pilots reporting hypoxia-like symptoms have been recorded.[271]
Air force pilots have reported being pressured to continue flying the aircraft in spite of fearing for their safety because of the still-unresolved problems with the oxygen system.[12] And half of all F-22 pilots have "lost confidence in the aircraft".[272] General Mike Hostage stated that some of the 200 Raptor pilots have asked to transfer to other areas because of the problem.[273] Hostage said that he will start flying the aircraft himself to better understand the relevant issues.[274] Hostage qualified on the Raptor in June 2012.[275] But he soon stepped down from the cockpit after admitting that the flight hours available needed to be reserved for the actual pilots.[276]
In May 2012, it was announced that two pilots, Major Jeremy Gordon and Captain Josh Wilson, who had appeared on the CBS news program 60 Minutes, saying they didn’t feel safe in the jet, were considered whistleblowers protected by the federal whistleblower legislation.[277] Defense Secretary Leon Panetta subsequently ordered that all F-22 flights stay "within the proximity of potential landing locations" as more pilots came forward to report hypoxia-like symptoms.[278][279]
Another cause may be the pressure-garment worn by the pilots, which may interfere with breathing; the fix may be to use the more evolved design built for the F-35.[12][280] In the meantime the pilots have been instructed to not wear the pressure vests during routine flights.[281] The same vests have shown an almost "unanimous failure rate in testing".[282] The two most recent breathing incidents were determined to be the results of mechanical problems unrelated to the general problem.[283]
In July 2012 the Pentagon concluded that a pressure valve on vests worn during high-altitude flights and a carbon air filter were the likely sources of at least some hypoxia-like symptoms, and that long distance flights can resume without the vests and therefore at lower altitudes. The carbon filters were also changed to a different model to reduce shedding of inert, but alarming, black dust into the pilot's lungs.[284][285] The first overseas flight under the new rules was a routine rotation at Kadena Air Base, Okinawa.[286]
On 1 August 2012 it was announced that the connector hoses and valves of the "Combat Edge" upper pressure garment were at fault in many recent hypoxia-like instances, specifically the breathing regulator/anti-G (BRAG) valve that is used to inflate the vest.[287] Later that month the flight duration restrictions were lifted, but without an effective pressure vest the Raptors remained restricted to the same altitudes as other fighters.[288] On 19 September 2012, USAF General Gilmary M. Hostage III stated that the main source of the problems was not the hardware, but the "human physiology" of the pilots. He added that F-22 pilots would undergo training to teach them how to react appropriately to oxygen issues while operating the jet.[289] One of the changes would be to revert to automatic rather than the maximum setting for oxygen as the USAF prepared to open up the Raptors and update the firmware on the OBOGS along with the installation of the backup system.[290] A further investigation found that the OBOGS unexpectedly reduced oxygen levels when the aircraft performed high-G maneuvers.[291]
The same valve had earlier been tried on the F-15 and F-16 aircraft, but found defective and unnecessary. When the higher attitudes of the F-22 then required pressurization of the pilot's vest, the same faulty valve was reintroduced without fixes.[292]
In late 2012, Lockheed was awarded contracts to install an automatic oxygen backup system in addition to the primary system and manual backup.[293]
The USAF is also considering the installation of equipment to determine if the pilots brains are functioning.[294] With a grant from the USAF a pilot helmet sized EEG scanner has been developed by the University of California San Diego together with the Taiwanese National Chiao-Tung University and Taiwanese chipmakers.[295][296][297]

Variants

  • YF-22A – pre-production version used for ATF testing and evaluation. Two were built.
  • F-22A – single-seat production version. Was designated "F/A-22A" in early 2000s.
  • F-22B – planned two-seat variant, but was dropped in 1996 to save development costs.[298]
  • Naval F-22 variant – a carrier-borne variant of the F-22 with swing-wings for the U.S. Navy's Navy Advanced Tactical Fighter (NATF) program to replace the F-14 Tomcat. Program was canceled in 1993.[298]

Derivatives

The FB-22 was a proposed medium-range bomber for the USAF.[299] The FB-22 was projected to carry up to 30 Small Diameter Bombs to about twice the range of the F-22A, while maintaining the F-22's stealth and supersonic speed.[300] However, the FB-22 in its planned form appears to have been canceled with the 2006 Quadrennial Defense Review and subsequent developments, in lieu of a larger subsonic bomber with a much greater range.[301][302]
The X-44 MANTA, or multi-axis, no-tail aircraft, was a planned experimental aircraft based on the F-22 with enhanced thrust vectoring controls and no aerodynamic surface backup.[303] The aircraft was to be solely controlled by thrust vectoring, without featuring any rudders, ailerons, or elevators. Funding for this program was halted in 2000.[304]

Operators

F-22A Raptor from Tyndall AFB, Florida cruising over the Florida Panhandle
An F-22 landing at Holloman AFB, New Mexico
An F-22, based at Elmendorf AFB, Alaska, over mountain terrain
The United States Air Force is the only operator of the F-22. It ordered 187 aircraft with the last received by early Q2 2012.[305][306] By November 2012, crashes had reduced numbers to 182.[307] It is operated by the following commands:

Accidents

In April 1992, the first YF-22 crashed while landing at Edwards Air Force Base, California. The test pilot, Tom Morgenfeld, escaped without injury. The cause of the crash was found to be a flight control software error that failed to prevent a pilot-induced oscillation.[318]
The first crash of a production F-22 occurred during takeoff at Nellis Air Force Base on 20 December 2004, in which the pilot ejected safely before impact.[319][320] The crash investigation revealed that a brief interruption in power during an engine shutdown prior to flight caused a malfunction in the flight-control system;[321] consequently the aircraft design was corrected to avoid the problem. All F-22s were grounded after the crash; operations resumed following a review.[322]
On 25 March 2009, an F-22 crashed 35 miles (56 km) northeast of Edwards Air Force Base during a test flight,[323] resulting in the death of Lockheed test pilot David P. Cooley.[45][324] An Air Force Materiel Command investigation found that Cooley momentarily lost consciousness during a high-G maneuver, then ejected when he found himself too low to recover. Cooley was killed during ejection by blunt-force trauma from the aircraft's speed and the windblast. The investigation found no issues with the F-22's design.[325]
On 16 November 2010, an F-22, based at Elmendorf, Alaska, lost contact with Air Traffic Control.[326] The aircraft was discovered to have crashed; the pilot, Captain Jeffrey Haney, was killed.[327] The F-22 fleet was restricted to flying below 25,000 feet, before being grounded completely, while the accident was investigated.[328] During the summer of 2011, more wreckage from the crash site was recovered; the accident has been attributed to a malfunction in the bleed air system that shut down the aircraft's Environmental Control System (ECS) and On-Board Oxygen Generating System (OBOGS).[329] The OBOGS, which is fed by engine bleed air, was apparently shut down automatically in response to an engine overheat condition detected by the main computer.[330] The accident review board, however, ruled the pilot (wearing bulky cold-weather gear and nightvision goggles) was to blame for the accident, as he did not react properly and did not engage the emergency oxygen system.[331][332] Schwartz has called the Pentagon Office of the Inspector General investigation of the report "routine",[333][334] but did not assign blame to the pilot.[335] The pilot's widow sued, claiming the aircraft has defective equipment.[336][337] In response to the accident investigation results, the engagement handle for the emergency oxygen system was redesigned to improve location and grasping, and the emergency oxygen system should engage automatically when OBOGS is shut down due to an engine failure.[338] The aircraft's manufacturers reached a settlement with the pilot's family.[339]
On 15 November 2012, an F-22 crashed near Tyndall Air Force Base, just south of Panama City, Florida. The pilot ejected safely and no injuries were reported on the ground. The cause of the accident is unknown.[340][341]
On 7 December 2012, an F-22 from the 199th Fighter Squadron sustained $1.8 million in damage to its horizontal stabilizers while landing at Joint Base Pearl Harbor-Hickam. The aircraft was returning from participating in a missing-man formation at a memorial event commemorating the attack on Pearl Harbor.[342][343]

Aircraft on display

In April 2007, the National Museum of the United States Air Force announced it had added EMD F-22A 91-4003 to its collection. It would later be put on display[344] in the space being occupied by a Lockheed YF-22. The museum publicly unveiled its F-22 display on 18 January 2008.[345]

Specifications

Orthographically projected diagram of the F-22A
F-22 with drop tanks in transit to Kadena Air Base, Japan from Langley Air Force Base, Virginia
Data from USAF,[6] F-22 Raptor Team web site,[346] Manufacturers' data,[347][348] Aviation Week,[154] and Journal of Electronic Defense,[165]
General characteristics
Performance
USAF poster overview of key features and armament
Armament
Avionics
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