Lockheed Martin F-22 Raptors park during their inaugural appearance during "Exercise Resilient Typhoon", at the Francisco C. Ada International Airport, Saipan, April 23, 2019. Units from across Pacific Air Forces are practicing rapid re-deployments in new locations as part of a dispersal exercise called Resilient Typhoon. The Raptors are based out of Joint Base Pearl Harbor-Hickam, Hawaii and are comprised of Airmen from the Hawaii Air National Guard’s 154th Wing and their active-duty counterparts from the 15th Wing.
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The Lockheed Martin F-22 Raptor is a fifth-generation, single-seat, twin-engine, all-weather stealth tactical fighter aircraft developed for the United States Air Force (USAF). The result of the USAF's Advanced Tactical Fighter (ATF) program, the aircraft was designed primarily as an air superiority fighter, but also has ground attack, electronic warfare, and signal intelligence capabilities. The prime contractor, Lockheed Martin, built most of the F-22's airframe and weapons systems and conducted final assembly, while Boeing provided the wings, aft fuselage, avionics integration, and training systems.
The aircraft was variously designated F-22 and F/A-22 before it formally entered service in December 2005 as the F-22A. Despite its protracted development and various operational issues, USAF officials consider the F-22 a critical component of the service's tactical air power. Its combination of stealth, aerodynamic performance, and situational awareness enable unprecedented air combat capabilities.
Service officials had originally planned to buy a total of 750 ATFs. In 2009, the program was cut to 187 operational production aircraft due to high costs, a lack of clear air-to-air missions due to delays in Russian and Chinese fighter programs, a ban on exports, and development of the more versatile F-35. The last F-22 was delivered in 2012.
Development
Origins
In 1981, the U.S. Air Force identified a requirement for an Advanced Tactical Fighter (ATF) to replace the F-15 Eagle and F-16 Fighting Falcon. Code named "Senior Sky", this air-superiority fighter program was influenced by emerging worldwide threats, including new developments in Soviet air defense systems and the proliferation of the Su-27 Flanker- and MiG-29 Fulcrum-class of 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 most importantly, stealth technology. In 1983, the ATF concept development team became the System Program Office (SPO) and managed the program at Wright-Patterson Air Force Base. The demonstration and validation (Dem/Val) request for proposals (RFP) was issued in September 1985, with requirements placing strong emphasis on stealth and supercruise. Of the seven bidding companies, Lockheed and Northrop were selected on 31 October 1986. Lockheed teamed with Boeing and General Dynamics while Northrop teamed with McDonnell Douglas, and the two contractor teams undertook a 50-month Dem/Val phase, culminating in the flight test of two technology demonstrator prototypes, the YF-22 and the YF-23, respectively.
Dem/Val was focused on risk reduction and technology development plans over specific aircraft designs. Contractors made extensive use of analytical and empirical methods, including computational fluid dynamics, wind-tunnel testing, and radar cross-section calculations and pole testing; the Lockheed team would conduct nearly 18,000 hours of wind-tunnel testing. Avionics development was marked by extensive testing and prototyping and supported by ground and flying laboratories. During Dem/Val, the SPO used the results of performance and cost trade studies conducted by contractor teams to adjust ATF requirements and delete ones that were significant weight and cost drivers while having marginal value. The short takeoff and landing (STOL) requirement was relaxed in order to delete thrust-reversers, saving substantial weight. As avionics was a major cost driver, side-looking radars were deleted, and the dedicated infra-red search and track (IRST) system was downgraded from multi-color to single color and then deleted as well. However, space and cooling provisions were retained to allow for future addition of these components. The ejection seat requirement was downgraded from a fresh design to the existing McDonnell Douglas ACES II. Despite efforts by the contractor teams to rein in weight, the takeoff gross weight estimate was increased from 50,000 lb (22,700 kg) to 60,000 lb (27,200 kg), resulting in engine thrust requirement increasing from 30,000 lbf (133 kN) to 35,000 lbf (156 kN) class.
Each team produced two prototype air vehicles for Dem/Val, one for each of the two engine options. The YF-22 had its maiden flight on 29 September 1990 and in flight tests achieved up to Mach 1.58 in supercruise. After the Dem/Val flight test of the prototypes, on 23 April 1991, Secretary of the USAF Donald Rice announced the Lockheed team as the winner of the ATF competition. The YF-23 design was considered stealthier and faster, while the YF-22, with its thrust vectoring nozzles, was more maneuverable as well as less expensive and risky. The aviation press speculated that the Lockheed team's design was also more adaptable to the U.S. Navy's Navalized Advanced Tactical Fighter (NATF), but by 1992, the Navy had abandoned NATF.
Production and procurement
As the program moved to full-scale development, or the Engineering & Manufacturing Development (EMD) stage, the production version had notable differences from the YF-22, despite having a broadly similar shape. The swept-back angle of the leading edge was decreased from 48° to 42°, while the vertical stabilizers were shifted rearward and decreased in area by 20%. To improve pilot visibility, the canopy was moved forward 7 inches (18 cm), and the engine intakes moved rearward 14 inches (36 cm). The shapes of the wing and stabilator trailing edges were refined to improve aerodynamics, strength, and stealth characteristics. Increasing weight during development caused slight reductions in range and maneuver performance.
Prime contractor Lockheed Martin Aeronautics manufactured the majority of the airframe and performed final assembly at Dobbins Air Reserve Base in Marietta, Georgia; program partner Boeing Defense, Space & Security provided additional airframe components as well as avionics integration and training systems. The first F-22, an EMD aircraft with tail number 4001, was unveiled at Marietta, Georgia, on 9 April 1997, and first flew on 7 September 1997. Production, with the first lot awarded in September 2000, supported over 1,000 subcontractors and suppliers from 46 states and up to 95,000 jobs, and spanned 15 years at a peak rate of roughly two airplanes per month. In 2006, the F-22 development team won the Collier Trophy, American aviation's most prestigious award. Due to the aircraft's advanced nature, contractors have been targeted by cyberattacks and technology theft.
The USAF originally envisioned ordering 750 ATFs at a total program cost of $44.3 billion and procurement cost of $26.2 billion in fiscal year (FY) 1985 dollars, with production beginning in 1994. The 1990 Major Aircraft Review led by Secretary of Defense Dick Cheney reduced this to 648 aircraft beginning in 1996. By 1997, funding instability had further cut the total to 339, which was again reduced to 277 by 2003. In 2004, the Department of Defense (DoD) further reduced this to 183 operational aircraft, despite the USAF's preference for 381. A multi-year procurement plan was implemented in 2006 to save $15 billion, with total program cost projected to be $62 billion for 183 F-22s distributed to seven combat squadrons. In 2008, Congress passed a defense spending bill that raised the total orders for production aircraft to 187.
The first two F-22s built were EMD aircraft in the Block 1.0 configuration for initial flight testing, while the third was a Block 2.0 aircraft built to represent the internal structure of production airframes and enabled it to test full flight loads. Six more EMD aircraft were built in the Block 10 configuration for development and upgrade testing, with the last two considered essentially production quality jets. Production for operational squadrons consisted of 37 Block 20 training aircraft and 149 Block 30/35 combat aircraft; one of the Block 35 aircraft is dedicated to flight sciences at Edwards Air Force Base.
The numerous new technologies in the F-22 resulted in substantial cost overruns and delays. Many capabilities were deferred to post-service upgrades, reducing the initial cost but increasing total program cost. As production wound down in 2011, the total program cost is estimated to be about $67.3 billion, with $32.4 billion spent on Research, Development, Test and Evaluation (RDT&E) and $34.9 billion on procurement and military construction (MILCON) in then year dollars. The incremental cost for an additional F-22 was estimated at about $138 million in 2009.
Ban on exports
The F-22 cannot be exported under US federal law to protect its stealth technology and other high-tech features. Customers for U.S. fighters are acquiring earlier designs such as the F-15 Eagle and F-16 Fighting Falcon or the newer F-35 Lightning II, which contains technology from the F-22 but was designed to be cheaper, more flexible, and available for export. In September 2006, Congress upheld the ban on foreign F-22 sales. Despite the ban, the 2010 defense authorization bill included provisions requiring the DoD to prepare a report on the costs and feasibility for an F-22 export variant, and another report on the effect of F-22 export sales on U.S. aerospace industry.
Some Australian politicians and defense commentators proposed that Australia should attempt to purchase F-22s instead of the planned F-35s, citing the F-22's known capabilities and F-35's delays and developmental uncertainties. However, the Royal Australian Air Force (RAAF) determined that the F-22 was unable to perform the F-35's strike and close air support roles. The Japanese government also showed interest in the F-22 for its Replacement-Fighter program. The Japan Air Self-Defense Force (JASDF) would reportedly require fewer fighters for its mission if it obtained the F-22, thus reducing engineering and staffing costs. However, in 2009 it was reported that acquiring the F-22 would require increases to the Japanese government's defense budget beyond the historical 1 percent of its GDP. With the end of F-22 production, Japan chose the F-35 in December 2011. Israel also expressed interest, but eventually chose the F-35 because of the F-22's price and unavailability.
Production termination
Throughout the 2000s, the need for F-22s was debated, due to rising costs and the lack of relevant adversaries. In 2006, Comptroller General of the United States David Walker found that "the DoD has not demonstrated the need" for more investment in the F-22, and further opposition to the program was expressed by Secretary of Defense Donald Rumsfeld, Deputy Secretary of Defense Gordon R. England, Senator John McCain, and Chairman of U.S. Senate Committee on Armed Services Senator John Warner. The F-22 program lost influential supporters in 2008 after the forced resignations of Secretary of the Air Force Michael Wynne and the Chief of Staff of the Air Force General T. Michael Moseley.
In November 2008, Secretary of Defense Robert Gates stated that the F-22 was not relevant in post-Cold War conflicts such as irregular warfare operations in Iraq and Afghanistan, and in April 2009, under the new Obama Administration, he called for ending production in FY2011, leaving the USAF with 187 production aircraft. In July, General James Cartwright, Vice Chairman of the Joint Chiefs of Staff, stated to the Senate Committee on Armed Services his reasons for supporting termination of F-22 production. They included shifting resources to the multirole F-35 to allow proliferation of fifth-generation fighters for three service branches and preserving the F/A-18 production line to maintain the military's electronic warfare (EW) capabilities in the Boeing EA-18G Growler. Issues with the F-22's reliability and availability also raised concerns. After President Obama threatened to veto further production, the Senate voted in July 2009 in favor of ending production and the House subsequently agreed to abide by the 187 production aircraft cap. Gates stated that the decision was taken in light of the F-35's capabilities, and in 2010, he set the F-22 requirement to 187 aircraft by lowering the number of major regional conflict preparations from two to one.
In 2010, USAF initiated a study to determine the costs of retaining F-22 tooling for a future Service Life Extension Program (SLEP). A RAND Corporation paper from this study estimated that restarting production and building an additional 75 F-22s would cost $17 billion, resulting in $227 million per aircraft, or $54 million higher than the flyaway cost. Lockheed Martin stated that restarting the production line itself would cost about $200 million. Production tooling and associated documentation were subsequently stored at the Sierra Army Depot, allowing the retained tooling to support the fleet life cycle. There were reports that attempts to retrieve this tooling found empty containers, but a subsequent audit found that the tooling was stored as expected.
Russian and Chinese fighter developments have fueled concern, and in 2009, General John Corley, head of Air Combat Command, stated that a fleet of 187 F-22s would be inadequate, but Secretary Gates dismissed General Corley's concern. In 2011, Gates explained that Chinese fifth-generation fighter developments had been accounted for when the number of F-22s was set, and that the U.S. would have a considerable advantage in stealth aircraft in 2025, even with F-35 delays. In December 2011, the 195th and final F-22 was completed out of 8 test EMD and 187 operational aircraft produced; the aircraft was delivered to the USAF on 2 May 2012.
In April 2016, the House Armed Services Committee (HASC) Tactical Air and Land Forces Subcommittee proposed legislation that would direct the Air Force to conduct a cost study and assessment associated with resuming production of the F-22. Since the production halt directed in 2009 by then Defense Secretary Gates, lawmakers and the Pentagon noted that air warfare systems of Russia and China were catching up to those of the U.S. Lockheed Martin has proposed upgrading the Block 20 training aircraft into combat-coded Block 30/35 versions as a way to increase numbers available for deployment. On 9 June 2017, the Air Force submitted their report to Congress stating they had no plans to restart the F-22 production line due to economic and operational issues; it estimated it would cost approximately $50 billion to procure 194 additional F-22s at a cost of $206–$216 million per aircraft, including approximately $9.9 billion for non-recurring start-up costs and $40.4 billion for aircraft procurement costs.
Upgrades
The first aircraft with combat-capable Block 3.0 software flew in 2001. Increment 2, the first upgrade program, was implemented in 2005 for Block 20 aircraft onward and enabled the employment of Joint Direct Attack Munitions (JDAM). Certification of the improved AN/APG-77(V)1 radar was completed in March 2007, and airframes from production Lot 5 onward are fitted with this radar, which incorporates air-to-ground modes. Increment 3.1 for Block 30 aircraft onward provided improved ground-attack capability through synthetic aperture radar mapping and radio emitter direction finding, electronic attack and Small Diameter Bomb (SDB) integration; testing began in 2009 and the first upgraded aircraft was delivered in 2011. To address oxygen deprivation issues, F-22s were fitted with an automatic backup oxygen system (ABOS) and modified life support system starting in 2012.
Increment 3.2 for Block 35 aircraft is a two-part upgrade process; 3.2A focuses on electronic warfare, communications and identification, while 3.2B includes geolocation improvements and a new stores management system to show the correct symbols for the AIM-9X and AIM-120D. To enable two-way communication with other platforms, the F-22 can use the Battlefield Airborne Communications Node (BACN) as a gateway. The planned Multifunction Advanced Data Link (MADL) integration was cut due to development delays and lack of proliferation among USAF platforms. The F-22 fleet is planned to start receiving Increment 3.2B as well as a software upgrade for cryptography capabilities and avionics stability in May 2019. A Multifunctional Information Distribution System-Joint (MIDS-J) radio that replaces the current Link-16 receive-only box is expected to be operational by 2020. Subsequent upgrades are also focusing on having an open architecture to enable faster future enhancements.
In 2024, funding is projected to begin for the F-22 mid-life upgrade (MLU), which is expected to include new sensors and antennas, hardware refresh, cockpit improvements, and a helmet mounted display and cuing system. Other enhancements being developed include IRST functionality for the AN/AAR-56 Missile Launch Detector (MLD) and more durable stealth coating based on the F-35's.
The F-22 was designed for a service life of 8,000 flight hours, with a $350 million "structures retrofit program". Investigations are being made for upgrades to extend their useful lives further. In the long term, the F-22 is expected to be superseded by a sixth-generation jet fighter to be fielded in the 2030s.
Design
Overview
The F-22 Raptor is a fifth-generation fighter that is considered fourth generation in stealth aircraft technology by the USAF.[91] It is the first operational aircraft to combine supercruise, supermaneuverability, stealth, and sensor fusion in a single weapons platform. The F-22 has four empennage surfaces, retractable tricycle landing gear, and clipped delta wings with reverse trailing edge sweep and leading edge extensions running to the upper outboard corner of the inlets. Flight control surfaces include leading-edge flaps, flaperons, ailerons, rudders on the canted vertical stabilizers, and all-moving horizontal tails (stabilators); for speed brake function, the ailerons deflect up, flaperons down, and rudders outwards to increase drag.
The aircraft's dual Pratt & Whitney F119-PW-100 augmented turbofan engines are closely spaced and incorporate pitch-axis thrust vectoring nozzles with a range of ±20 degrees; each engine has maximum thrust in the 35,000 lbf (156 kN) class. The F-22's thrust-to-weight ratio at typical combat weight is nearly at unity in maximum military power and 1.25 in full afterburner. Maximum speed without external stores is approximately Mach 1.8 at military power and greater than Mach 2 with afterburners.
The F-22's high cruise speed and operating altitude over prior fighters improve the effectiveness of its sensors and weapon systems, and increase survivability against ground defenses such as surface-to-air missiles. The aircraft is among only a few that can supercruise, or sustain supersonic flight without using fuel-inefficient afterburners; it can intercept targets which subsonic aircraft would lack the speed to pursue and an afterburner-dependent aircraft would lack the fuel to reach. The F-22's thrust and aerodynamics enable regular combat speeds of Mach 1.5 at 50,000 feet (15,000 m). The use of internal weapons bays permits the aircraft to maintain comparatively higher performance over most other combat-configured fighters due to a lack of aerodynamic drag from external stores. The aircraft's structure contains a significant amount of high-strength materials to withstand stress and heat of sustained supersonic flight. Respectively, titanium alloys and composites comprise 39% and 24% of the structural weight.
The F-22's aerodynamics, relaxed stability, and powerful thrust-vectoring engines give it excellent maneuverability and energy potential across its flight envelope. The airplane has excellent high alpha (angle of attack) characteristics, capable of flying at trimmed alpha of over 60° while maintaining roll control and performing maneuvers such as the Herbst maneuver (J-turn) and Pugachev's Cobra. The flight control system and full-authority digital engine control (FADEC) make the aircraft highly departure resistant and controllable, thus giving the pilot carefree handling.
Stealth
The F-22 was designed to be highly difficult to detect and track by radar. Measures to reduce radar cross-section (RCS) include airframe shaping such as alignment of edges, fixed-geometry serpentine inlets and curved vanes that prevent line-of-sight of the engine faces and turbines from any exterior view, use of radar-absorbent material (RAM), and attention to detail such as hinges and pilot helmets that could provide a radar return. The F-22 was also designed to have decreased radio emissions, infrared signature and acoustic signature as well as reduced visibility to the naked eye. The aircraft's flat thrust-vectoring nozzles reduce infrared emissions of the exhaust plume to mitigate the threat of infrared homing ("heat seeking") surface-to-air or air-to-air missiles. Additional measures to reduce the infrared signature include special topcoat and active cooling of leading edges to manage the heat buildup from supersonic flight.
Compared to previous stealth designs like the F-117, the F-22 is less reliant on RAM, which are maintenance-intensive and susceptible to adverse weather conditions. Unlike the B-2, which requires climate-controlled hangars, the F-22 can undergo repairs on the flight line or in a normal hangar. The F-22 has a Signature Assessment System which delivers warnings when the radar signature is degraded and necessitates repair. While the F-22's exact RCS is classified, in 2009 Lockheed Martin released information indicating that from certain angles the aircraft has an RCS of 0.0001 m² or −40 dBsm – equivalent to the radar reflection of a "steel marble". Effectively maintaining the stealth features can decrease the F-22's mission capable rate to 62–70%.
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 radar observability. Furthermore, the F-22's stealth contouring and radar absorbent materials are chiefly effective against high-frequency radars, usually found on other aircraft. The effects of Rayleigh scattering and resonance mean that low-frequency radars such as weather radars and early-warning radars are more likely to detect the F-22 due to its physical size. However, such radars are also conspicuous, susceptible to clutter, and have low precision. Additionally, while faint or fleeting radar contacts make defenders aware that a stealth aircraft is present, reliably vectoring interception to attack the aircraft is much more challenging. According to the USAF an F-22 surprised an Iranian F-4 Phantom II that was attempting to intercept an American UAV, despite Iran's assertion of having military VHF radar coverage over the Persian Gulf.
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