The F-22A Raptor advanced tactical fighter 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 program, the aircraft was designed primarily as an air superiority fighter, but has additional capabilities including ground attack, electronic warfare, and signals intelligence roles.Lockheed Martin is the prime contractor and was responsible for the majority of the airframe, weapon systems, and final assembly of the F-22, while program partner Boeing provided the wings, aft fuselage, avionics integration, and training systems.
The F-22A Raptor advanced tactical fighter entered service with the US Air Force in December 2005. The USAF requirement was for a fighter to replace the F-15, with emphasis on agility, stealth and range.
Developed at Aeronautical Systems Center, Wright-Patterson Air Force Base, Ohio, the F-22A Raptor is a supersonic, dual-engine fighter jet, which has won the 2006 Robert J Collier Trophy from the American National Aeronautic Association (NAA).
Development
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. Code named "Senior Sky", this program 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. The 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 technology demonstrator prototypes, the YF-22 and the YF-23.
By 1990 Lockheed Martin, teamed with Boeing and General Dynamics, had built and flown the demonstration prototype aircraft, designated YF-22. The first F-22 fighter aircraft was unveiled in April 1997 and was given the name Raptor.
In September 2002, the USAF decided to redesignate the aircraft F/A-22 to reflect its multi-mission capability in ground attack as well as air-to-air roles. The aircraft's designation was changed again to F-22A when it achieved initial operating capability (IOC) in December 2005.
The decision to proceed to low-rate initial production (LRIP) was authorised in August 2001 and Lockheed Martin delivered 49 aircraft under LRIP contracts.
The F-22 had several design changes from the YF-22. 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 aerodynamic performance.
The first F-22, an engineering and manufacturing development (EMD) aircraft named Raptor 4001, was unveiled at Marietta, Georgia, on 9 April 1997, and first flew on 7 September 1997.In 2006, the Raptor's development team, composed of over 1,000 contractors and the USAF, won the Collier Trophy, American aviation's most prestigious award.The F-22 was in production for 15 years, at a rate of roughly two per month during peak production.
The USAF originally envisioned ordering 750 ATFs at a cost of $26.2 billion, 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 F-22s by 2003.In 2004, the Department of Defense (DoD) further reduced this to 183 operational aircraft, despite the USAF's preference for 381.In 2006, a multi-year procurement plan was implemented to save $15 billion but raise each aircraft's cost. That year the program's total cost was projected to be $62 billion for 183 F-22s distributed to seven combat squadrons.In 2007, Lockheed Martin received a $7.3 billion contract to increase the order to 183 production F-22s and extend manufacturing through 2011.
In April 2006, the Government Accountability Office (GAO) assessed the F-22's cost to be $361 million per aircraft, with $28 billion invested in development and testing; the Unit Procurement Cost was estimated at $178 million in 2006, based on a production run of 181 aircraft.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 in 2009.The GAO stated the estimated cost was $412 million per aircraft in 2012.
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| The F-22 is powered by two F119-100 engines from Pratt & Whitney. |
Design
Overview
The F-22 Raptor is a fifth-generation fighter that is considered fourth generation in stealth aircraft technology by the USAF.It is the first operational aircraft to combine supercruise, supermaneuverability, stealth, and sensor fusion in a single weapons platform.The Raptor has clipped delta wings with a reverse sweep on the rear, four empennage surfaces, and a retractable tricycle landing gear. Flight control surfaces include leading and trailing-edge flaps, ailerons, rudders on the canted vertical stabilizers, and all-moving horizontal tails; these surfaces also serve as speed brakes.
The aircraft's dual Pratt & Whitney F119-PW-100 afterburning 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.Thrust vectoring is controlled by a Hamilton Standard dual redundant full authority digital engine control (FADEC). The FADEC is integrated with the flight control computers in the BAE Systems flight controls vehicle management system.The F-22's thrust to weight ratio in typical combat configuration is nearly at unity in maximum military power and 1.25 in full afterburner.Maximum speed without external stores is estimated to be Mach 1.82 during supercruise and greater than Mach 2 with afterburners.
The F-22 is among only a few aircraft 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 Raptor's high operating altitude is also a significant tactical advantage over prior fighters.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 F-22's structure contains extensive amounts of high-strength materials to withstand stress and heat of sustained supersonic flight.The F-22 construction is 39% titanium, 24% composite, 16% aluminium and 1% thermoplastic by weight. Titanium is used for its high strength-to-weight ratio in critical stress areas, including some of the bulkheads, and also for its heat-resistant qualities in the hot sections of the aircraft.
Carbon-fibre composites have been used for the fuselage frame, the doors, intermediate spars on the wings, and for the honeycomb sandwich construction skin panels.
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| The AN/APG-77 AESA radar |
The F-22's avionics include BAE Systems E&IS (formerly Sanders Associates) radar warning receiver (RWR) AN/ALR-94, and the Northrop Grumman AN/APG-77 Active Electronically Scanned Array (AESA) radar. The AN/APG-77 is possibly the most capable radar in active service, with both long-range target acquisition and low probability of interception of its own signals by enemy aircraft.
The AN/ALR-94 is a passive receiver system capable of detecting the radar signals in the environment. Composed of more than 30 antennae smoothly blended into the wings and fuselage, it is described by the former head of the F-22 program at Lockheed Martin Tom Burbage as "the most technically complex piece of equipment on the aircraft." With greater range (250+ nmi) than the radar, it enables the F-22 to limit its own radar emission which might otherwise compromise its stealth. As the target approaches, AN/ALR-94 can cue the AN/APG-77 radar to keep track of its motion with a narrow beam, which can be as focused as 2° by 2° in azimuth and elevation.
The AN/APG-77 AESA radar, designed for air-superiority and strike operations, features a low-observable, active-aperture, electronically-scanned array that can track multiple targets in all kinds of weather. The AN/APG-77 changes frequencies more than 1,000 times per second to reduce the chance of being intercepted. The radar can also focus its emissions to overload enemy sensors, giving the aircraft an electronic-attack capability.
A pair on patrol.The radar’s information is processed by two Raytheon Common Integrated Processor (CIP)s. Each CIP operates at 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 Raptor’s software is composed of over 1.7 million lines of code, most of which concerns processing data from the radar. The radar has an estimated range of 125-150 miles, though planned upgrades will allow a range of 250 miles or more in narrow beams.
The F-22 has several unique functions for an aircraft of its size and role. For instance, it has threat detection and identification capability along the lines of that available on the RC-135 Rivet Joint. While the F-22's equipment isn't as powerful or sophisticated, because of its stealth, it can be typically hundreds of miles closer to the battlefield, which often compensates for the reduced capability.
The F-22 is capable of functioning as a "mini-AWACS." Though reduced in capability compared to dedicated airframes such as the E-3 Sentry, as with its threat identification capability, the F-22's forward presence is often of benefit. The system allows the F-22 to designate targets for cooperating F-15s and F-16s, and even determine if two friendly aircraft are targeting the same enemy aircraft, thus enabling one of them to choose a different target. It is often able to identify targets hundreds of times faster than accompanying dedicated AWACS.
The IEEE 1394B bus developed for the F-22 was derived from the commercial IEEE 1394 "FireWire" bus system.In 2007, the F-22's radar was tested as a wireless data transceiver, transmitting data at 548 megabits per second and receiving at gigabit speed, far faster than the Link 16 system.
The F-22's software has some 1.7 million lines of code, the majority involving processing radar data.Former Secretary of the USAF Michael Wynne blamed the use of the DoD's Ada for cost overruns and delays on many military projects, including the F-22.Cyberattacks on subcontractors have reportedly raised doubts about the security of the F-22's systems and combat-effectiveness.In 2009, former Navy Secretary John Lehman considered the F-22 to be safe from cyberattack, citing the age of its IBM software.
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| Scorpion HMCS |
Cockpit
The cockpit is fitted with hands-on throttle and stick control (HOTAS). The cockpit has six color liquid crystal displays. The Kaiser Electronics projection primary multifunction display provides a plan view of the air and ground tactical situation including threat identity, threat priority and tracking information.
Two displays provide communication, navigation, identification and flight information. Three secondary displays show air and ground threats, stores management and air threat information.
A BAE Systems head-up display (HUD) shows target status, weapon status, weapon envelopes and shoot cues. A video camera records data on the HUD for post-mission analysis.
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.The F-22 has a complex life support system, which includes the on-board oxygen generation system (OBOGS), protective pilot garments, and a breathing regulator/anti-g (BRAG) valve controlling flow and pressure to the pilot's mask and garments. The pilot garments were developed under the Advanced Technology Anti-G Suit (ATAGS) project and are to protect against chemical/biological hazards and cold-water immersion, counter g-forces and low pressure at high altitudes, and provide thermal relief.Suspicions regarding the performance of the OBOGS and life support equipment have been raised by several mishaps, including a fatal crash.
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| AIM-120 AMRAAM (right) fitted in a weapons bay of an F-22 |
Armament
An F-22 releases a JDAM from its internal bay while flying at supersonic speed. The Raptor is designed to carry air-to-air missiles in internal bays to avoid disrupting its stealth capability. 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. The aircraft can also carry bombs such as the Joint Direct Attack Munition (JDAM) and the new Small-Diameter Bomb (SDB). The Raptor carries an M61A2 Vulcan 20 mm rotary cannon, also with a trap door, in the right wing root. The M61A2 is a last ditch weapon, and carries only 480 rounds; enough ammunition for approximately five seconds of sustained fire. Despite this, the F-22 has been able to use its gun in dogfighting without being detected, which can be necessary when missiles are depleted.
As other air forces upgrade capabilities in the areas of air-to-air and air-to-ground munitions, one key aspect of the Raptor must be kept in mind. Its very high sustained cruise speeds, and operational altitude (something that is often ignored), add tremendously to the effective range of both air-to-air and air-to-ground munitions. Indeed, these factors could provide a strong rationale as to why the USAF has not pursued long-range, high-energy air-to-air missiles such as the MBDA Meteor. However the USAF plans to procure the AIM-120D AMRAAM, which will have a significant increase in range compared to the AIM-120C. The launch platform, in this case, provides the additional energy to the missile. This speed and altitude characteristic also helps improve the range of air-to-ground ordnance. 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. In testing, a Raptor dropped a 1,000 lb (450 kg) JDAM from 50,000 feet (15,000 m), while cruising at Mach 1.5, striking a moving target 24 miles away. The SDB, as employed from the F-22, should see even greater increases in effective range, due to the improved lift to drag ratio of these weapons.
While in its air-superiority configuration, the F-22 carries its weapons internally, though it is not limited to this option. The wings are capable of supporting four detachable hardpoints. Each hardpoint is theoretically capable of handling 5,000 lb of ordnance. However, use of external stores greatly compromises the F-22's stealth, and has a detrimental effect on maneuverability, speed, and range. As many as two of these hardpoints are "plumbed", allowing the usage of external fuel tanks. The hardpoints are detachable in flight allowing the fighter to regain its stealth once these external stores are exhausted. Currently, there is research being conducted to develop a stealth ordnance pod and hardpoints for it. Such a pod would comprise a stealth shape and carry its weapons internally, then would split open when launching a missile or dropping a bomb. Both the pod and hardpoints could be detached when no longer needed. This system would allow the F-22 to carry its maximum ordnance load while remaining stealthy, albeit at a loss of maneuverability. However, there is concern over this program as external carriage of fuel tanks has shown more stress placed on the wings than originally anticipated.
Countermeasures
The aircraft's electronic warfare system includes a radar warning receiver and a BAE Systems information & electronic warfare systems (IEWS) (formerly Lockheed Martin Sanders) missile launch detector.
Navigation and communications
The TRW CNI communications, navigation and identification system includes an intra-flight datalink, joint tactical information distribution system (JTIDS) link and an identification friend or foe (IFF) system.
Boeing is responsible for mission software and avionics integration. The aircraft has a Northrop Grumman (formerly Litton) LTN-100G laser gyroscope inertial reference, a global positioning system and a microwave landing system.
Stealth
Although several recent Western fighter aircraft are less detectable on radar than previous designs using techniques such as radar absorbent material-coated S-shaped intake ducts that shield the compressor fan from reflecting radar waves, the F-22A design placed a much higher degree of importance on low observance throughout the entire spectrum of sensors including radar signature, visual, infrared, acoustic, and radio frequency.
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. However, reduced radar cross section is only one of five facets that designers addressed to create a stealth design in the F-22. The F-22 has also been designed to disguise its infrared emissions to make it harder to detect by infrared homing ("heat seeking") surface-to-air or air-to-air missiles. Designers also addressed making the aircraft less visible to the naked eye, controlling radio transmissions, and noise abatement.
The F-22 apparently relies less on maintenance-intensive radar absorbent material and coatings than previous stealth designs like the F-117. These materials caused deployment problems due to their susceptibility 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. Furthermore, the F-22 has a warning system (called "Signature Assessment System" or "SAS") which presents warning indicators when routine wear-and-tear have degraded the aircraft's radar signature to the point of requiring more substantial repairs. The exact radar cross section of the F-22 remains classified.
Operational history
The 27th Fighter Squadron at Langley Air Force Base was the first squadron to receive the F-22A Intended to be the leading American advanced tactical fighter in the early part of the 21st century, the Raptor is the world's most expensive fighter to date with an incremental cost of about US$138 million per unit. The number of aircraft to be built has dropped to 183, down from the initial requirement of 750. Part of the reason for the decrease in the requirement is that the F-35 Lightning II uses much of the technology used on the F-22, but at a much more affordable price. To a large extent the cost of these technologies is only lower for the F-35 because they have already been developed for the F-22.
Deployments
F-22 units are frequently deployed to Kadena Air Base in Okinawa, Japan.In February 2007, on the aircraft's first overseas deployment to Kadena Air Base, six F-22s of 27th Fighter Squadron flying from Hickam AFB, Hawaii, experienced multiple software-related system failures while crossing the International Date Line (180th meridian of longitude). The aircraft returned to Hawaii by following tanker aircraft. Within 48 hours, the error was resolved and the journey resumed.In early 2013, F-22s were involved in U.S.-South Korean military drills.
In November 2007, F-22s of 90th Fighter Squadron at Elmendorf AFB, Alaska, performed their first NORAD interception of two Russian Tu-95MS "Bear-H" bombers.Since then, F-22s have also escorted probing Tu-160 "Blackjack" bombers.The first pair of F-22s assigned to the 49th Fighter Wing became operational at Holloman AFB, New Mexico, in June 2008.In 2014, Holloman F-22s and their support personnel were reassigned to the reactivated 95th Fighter Squadron at Tyndall AFB.
Secretary of Defense Gates initially refused to deploy F-22s to the Middle East in 2007.The type made its first deployment in the region at Al Dhafra Air Base in the UAE in 2009. In April 2012, F-22s have been rotating into Al Dhafra Air Base, less than 200 miles from Iran; the Iranian defense minister referred to the deployment as a security threat.In March 2013 the USAF announced that an F-22 had intercepted an Iranian F-4 Phantom II that approached within 16 miles of an MQ-1 Predator flying off the Iranian coastline.
In June 2014, F-22s from the 199th Fighter Squadron of the Hawaii Air National Guard were deployed to Malaysia to participate in the Cope Taufan 2014 exercise conducted by the USAF Pacific Air Forces and Royal Malaysian Air Force.
On 22 September 2014, F-22s performed the type's first combat sorties during the American-led intervention in Syria; a number of aircraft dropped 1,000-pound GPS-guided bombs on Islamic State targets in the vicinity of Tishrin Dam.Combat operations by F-22s are planned to continue into the foreseeable future. While some missions involve striking targets, the F-22's main role is intelligence, surveillance and reconnaissance (ISR) gathering.By January 2015, the F-22 accounted for three percent of Air Force sorties during Operation Inherent Resolve.General Mike Hostage of ACC said the USAF used tactics, techniques, and procedures to overcome the disparity between the F-22's communications abilities and other assets during the deployment, and that it performed "flawlessly", despite combat operations not being the most challenging.Between September 2014 and July 2015, F-22s flew 204 sorties over Syria, dropping 270 bombs at some 60 locations.On 23 June 2015, a pair of F-22s performed the aircraft's first close air support (CAS) mission after receiving a short-notice request for airstrikes in close proximity to friendly forces.
In late 2014, the USAF was testing a rapid deployment concept involving four F-22s and one C-17 for support, first proposed in 2008 by two F-22 pilots. The goal was for the type to be able to set up and engage in combat within 24 hours.Four F-22s were deployed to Spangdahlem Air Base in Germany in August and Lask Air Base in Poland and Amari Air Base in Estonia in September 2015 to train with NATO allies.
Variants
YF-22A – pre-production technology demonstrator for ATF demonstration/validation phase; 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 canceled in 1996 to save development costs.Naval F-22 variant – a carrier-borne variant of the F-22 with variable-sweep wings for the U.S. Navy's Navy Advanced Tactical Fighter (NATF) program to replace the F-14 Tomcat. Program was canceled in 1993.Former SoAF Donald Rice has called the possibility of the naval variant the deciding factor for his choice of the YF-22 over the YF-23.
Derivatives
The FB-22 was a proposed medium-range bomber for the USAF.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.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.
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.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.
General characteristics
Crew: 1
Length: 62 ft 1 in (18.90 m)
Wingspan: 44 ft 6 in (13.56 m)
Height: 16 ft 8 in (5.08 m)
Wing area: 840 ft² (78.04 m²)
Airfoil: NACA 64A?05.92 root, NACA 64A?04.29 tip
Empty weight: 31,700 lb (14,379 kg)
Loaded weight: 55,352 lb (25,107 kg)
Max takeoff weight: 80,000 lb (36,288 kg)
Powerplant: 2× Pratt & Whitney F119-PW-100 Pitch "Thrust" vectoring turbofans, 35,000+ lb (156+ kN) each
Performance
Maximum speed: ˜Mach 2+[28] (1,325+ mph, 2,132+ km/h) ; >Mach 2.42 (Paul Metz)
Cruise speed: Mach 1.72[29] (1,140 mph, 1,825 km/h) supercruise at altitude
Combat radius: 410 nmi[29] (471 mi, 759 km)
Ferry range: 2,000 mi (1,738 nmi, 3,219 km)
Service ceiling: 65,000 ft (19,812 m)
Wing loading: 66 lb/ft² (322 kg/m²)
Thrust/weight: 1.26
Maximum g-load: -3.5/+9.5 g
Guns: 1× 20 mm (0.787 in) M61A2 Vulcan gatling gun in starboard wing root, 480 rounds
Air to air loadout:
6× AIM-120 AMRAAM
2× AIM-9 Sidewinder
Air to ground loadout:
2× AIM-120 AMRAAM and
2× AIM-9 Sidewinder and one of the following:
2× 1,000 lb JDAM or
2× Wind Corrected Munitions Dispensers (WCMDs) or
8× 250 lb GBU-39 Small Diameter Bombs
Note: It is estimated that internal bays can carry about 2,000 lb (910 kg) worth of bombs, and/or missiles. Four external hardpoints can be fitted to carry weapons or fuel tanks, each with a capacity of about 5,000 lb (2268 kg), while compromising, to a certain extent, the aircraft's stealth. Some armament is still largely classified. Aircraft in this size class since the F-105 have historically met a requirement of carrying maximum external payloads in the range of 14,000-15,000 lb with combat loads typically closer to 4,000-8,000 lb.