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The F-22 Raptor is a high-tech strike fighter aircraft of the United States Air Force.
The F-22 Raptor is a fifth generation stealth fighter aircraft. F-22 Raptor was originally envisioned as an air superiority fighter for use against the Soviet Air Force. The F-22 Raptor is also equipped for ground attack, electronic warfare and signals intelligence roles as well. Faced with a protracted development period, the prototype aircraft was designated YF-22 and, as F/A-22 during the three years before formally entering United States Air Force service in December 2005 as the F-22A. 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 Raptor. Along with Lockheed Martin, partner Boeing Integrated Defense Systems provides the wings, aft fuselage, avionics integration, and 100% of the pilot and maintenance training systems.
Background of the F-22 Raptor.
The Advanced Tactical Fighter (ATF) contract was a demonstration and validation program undertaken by the United States Air Force to develop a next-generation air superiority fighter to counter emerging worldwide threats, including development and proliferation of Soviet-era Su-27 'Flanker'-class fighter aircraft.
In 1981, USAF developed a requirement for a new air superiority fighter intended to replace the capability of the F-15 Eagle. It was envisaged that the ATF would incorporate emerging technologies including advanced alloys and composite material, advanced fly-by-wire flight control systems, higher power propulsion systems, and low-observable/stealth technology.
A request for proposal (RFP) was issued in July 1986, and two contractor teams, Lockheed/Boeing/General Dynamics and Northrop/McDonnell Douglas were selected in October 1986 to undertake a 50 month demonstration/validation phase, culminating in the flight test of two prototypes, the YF-22 and the YF-23.
Following a hard-fought fly-off competition, in August 1991 the YF-22 was declared the winner and Lockheed was awarded the contract to develop and build the Advanced Tactical Fighter.
History of the F-22 Raptor.
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 a cost of about US$120 million per unit, or US$361 million per unit when development costs are added. As of April 2005 the total development and production cost of the program is at least US$70 billion, and the number of planes to be built has dropped to 438, then 381, and now to 180, 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. Had the F-22 not been developed, the costs of these technologies for the F-35 would have been significantly higher.
YF-22 'Lightning II'.
The YF-22 was a developmental aircraft that led to the to F-22; however, there are significant differences between the YF-22 and the F-22. Relocation of cockpit, structural changes, and many other smaller changes exist between the two types. The two are sometimes confused in pictures, often at angles where it is difficult to see certain features. For example, there are some F-22 with pitot booms which some think are only found on the YF-22 (such as pictured at end of article). The YF-22 was originally given the unofficial name "Lightning II" by Lockheed, which persisted until the mid-1990s. For a short while, the plane was also dubbed "SuperStar" and "Rapier". The F-35 later received the Lightning II name on July 7, 2006.
The prototype YF-22 won a fly-off competition against the Northrop/McDonnell-Douglas YF-23 for the Advanced Tactical Fighter contract. In April 1992, during flight testing after contract award, the first YF-22 prototype crashed while landing at Edwards Air Force Base in California. The test pilot, Tom Morgenfeld, was not injured and the cause of the crash was found to be a flight control software error that allowed and created a pilot-induced oscillation.
F-22 Raptor to F/A-22 and back again.
The production model was formally named F-22 "Raptor" when the first production-representative plane was unveiled on 9 April, 1997 at Lockheed-Georgia Co., Marietta, Georgia. First flight occurred on September 7, 1997.
In September 2002, Air Force leaders changed the Raptor’s designation to F/A-22. The new designation, which mimicked that of the Navy’s F/A-18 Hornet, was intended to highlight plans to give the Raptor a ground-attack capability amid intense debate over the relevance of the expensive air-superiority jet. This was later changed back to simply F-22 on December 12, 2005. On December 15, 2005, the F-22A entered service.
Production of the F-22 Raptor.
The first production F-22 Raptor was delivered to Nellis Air Force Base, Nevada, on January 14, 2003. F-22 Dedicated Initial Operational Test and Evaluation occurred on October 27, 2004. As of late 2004, 51 Raptors were in service, with 22 more ordered under fiscal year 2004 funding. The first crash of a production F-22 occurred at Nellis Air Force Base on December 20, 2004, during takeoff. The pilot ejected safely moments before impact. 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. The technical data for the aircraft has been amended to avoid this problem in the future. USAF officials were planning to reuse the remains into a new airframe.
Procurement of the F-22 Raptor.
The United States Air Force originally planned to order 750 ATFs, with production beginning in 1994. The 1990 Major Aircraft Review altered the plan to 648 aircraft beginning in 1996. The goal changed again in 1994, when it became 442 planes entering service in 2003 or 2004. A 1997 Department of Defense report put the purchase at 339. In 2003, the Air Force said that the existing congressional cost cap limited the purchase to 277. In 2006, the Pentagon is saying it will buy 183 aircraft, which would save $15 billion but raise the cost of each plane. This plan has been de facto approved by Congress in the form of a multi-year procurement plan, which still holds open the possibility for new orders past that point. Lockheed Martin has stated that it would need to know by FY 2009 whether more planes would be bought, to place orders for long-lead items.
In April 2006 the cost of the F-22A is assessed by the Government Accountability Office to be $361 million per aircraft. This cost reflects the F-22A total program cost, divided by the number of jets the Air Force is programmed to buy. So far, the Air Force has invested as much as $28 billion in the Raptor's research, development and testing. That money, referred to as a "sunk cost," is already spent and is separate from money used for future decision-making, including procuring a copy of the jet.
By the time all 183 jets have been purchased, $34 billion will be spent on actually procuring the aircraft. This will result in a cost of about $339 million per aircraft based on total program costs. The incremental cost for one additional F-22 is around $120 million. If the Air Force were to buy 100 more F-22s today, each plane would be less than $117 million and would continue to drop with additional aircraft purchases.
The F-22 is not the most expensive plane aloft; that distinction likely belongs to the roughly $2.2 billion-per-unit B-2 Spirit; though the incremental cost was under 1 billion USD. In fairness, orders for the B-2 went from hundreds to a few dozen when the Cold War ended thus making the unit-cost skyrocket. The F-22 uses fewer radar absorbent materials than the B-2 or F-117 Nighthawk, which is expected to translate into lower maintenance costs.
Proposed foreign sales of the F-22 Raptor.
Like many past tactical fighters for a long period, the opportunity for export is currently non-existent because the export sale of the F-22 is barred by federal law. There was a time in the 1970s when the then-new F-16 had many restrictions also. However, regardless of restrictions, very few allies would even be considered for export sale because it is such a sensitive and expensive system. Most current customers for US fighters are either acquiring earlier designs like the F-15 or F-16 or are waiting to acquire the F-35, which contains much of the F-22's technology but is designed to be cheaper and more flexible.
More recently Japan reportedly showed some interest in buying F-22As in its Replacement-Fighter program for its Air Self-Defense Force (JASDF). In such an event, it would most likely involve a "watered-down" export variant while still retaining most of its advanced avionics and stealth characteristics. However, such a proposal would still need approval from the Pentagon, State Department and Congress.
Some Australian defense commentators have proposed that Australia purchase F-22 aircraft instead of the F-35. This proposal is supported by the Australian Labor Party, which is Australia's main opposition party, on the grounds that the F-22 is a proven and highly capable aircraft while the F-35 is still under development. The Australian Government, however, has ruled out seeking the purchase of F-22s on the grounds that it is unlikely to be released for export and does not meet Australia's requirements for a strike aircraft. This assessment is supported by the Australian Strategic Policy Institute, which is a non-partisan government-funded think-tank, which argues that the F-22 "has insufficient multi-role capability at too high a price" for Australia.
In a joint conference between the US House of Representatives and the Senate on September 27, 2006, the ban on F-22 Raptor foreign sales was upheld. The US Executive have also ruled out foreign sales of the aircraft with a letter from United States Deputy Secretary of Defense Gordon R. England to Australian Defence Minister Brendan Nelson saying the US will not export the F-22 after discussions between Dr Nelson and senior Bush administration officials during the annual Ausmin defence talks in Washington in December.
Recent developments of the F-22 Raptor.
In 2006, the Raptor's development team, comprised of Lockheed Martin and over 1,000 other companies, plus the United States Air Force, won the Collier Trophy, aviation's most prestigious award.
While attempting its first overseas deployment to the Kadena Air Base in Okinawa, Japan, on February 11, 2007, a group of six Raptors flying from Hickam AFB experienced multiple computer crashes coincident with their crossing of the 180th meridian of longitude (the International Date Line). The computer failures included at least navigation (completely lost) and communication. The planes were able to return to Hawaii by following their tankers in good weather. The error was fixed within 48 hours and the F-22s continued their journey to Kadena.
Description of the F-22 Raptor.
The dual afterburning Pratt & Whitney F119-PW-100 turbofans incorporate thrust vectoring. Thrust vectoring is in the pitch axis only, 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. Maximum speed is estimated to be Mach 1.72 in supercruise mode and without external weapons; with afterburners, it is "greater than Mach 2.0" (2,120 km/h), according to Lockheed Martin. The Raptor can easily exceed its design speed limits, particularly at low altitudes; max-speed alerts help prevent the pilot from exceeding the limits. General John P. Jumper, former U.S. Air Force Chief of Staff, flew the Raptor faster than Mach 1.7 without afterburners on January 13, 2005. The absence of variable intake ramps may make speeds greater than Mach 2.0 unreachable, but there is no evidence to prove this. Such ramps would be used to prevent engine surge, but the intake itself may be designed to prevent this. Former Lockheed Raptor chief test pilot Paul Metz stated that the Raptor has a fixed inlet. Metz has also stated that the F-22 has a top speed greater than 1600 mph (Mach 2.42) and its climb rate is faster than the F-15 Eagle due to advances in engine technology, despite the F-15's thrust-to-weight ratio of about 1.2:1, with the F-22 having a ratio closer to 1:1.
The true top-speed of the F-22 is largely unknown, as engine power is only one factor. The ability of the airframe to withstand the stress and heat from friction is a key factor, especially in an aircraft using as many polymers as the F-22. However, while some aircraft are faster on paper, the internal carriage of its standard combat load allows the aircraft to reach comparatively higher performance with a heavy load over other modern aircraft due to its lack of drag from external stores. It is one of a handful of aircraft that can sustain supersonic flight without the use of afterburner augmented thrust. The fuel usage from using afterburner greatly reduces flight time.
The F-22 is highly maneuverable, at both supersonic and subsonic speeds. The usage of the F-22's thrust vectoring nozzles allows the aircraft to turn tightly, and perform extremely high alpha (angle of attack) maneuvers such as the J-Turn (or Herbst maneuver), Pugachev's Cobra, and the Kulbit, though the J-Turn is more useful in combat. The F-22 is also capable of maintaining a constant angle of attack of over 60º. Cruise altitude is a huge factor in performance. During June, 2006 exercises in Alaska, F-22 pilots routinely attributed their altitude advantage as major factor in an unblemished kill ratio.
Avionics include Raytheon and Northrop Grumman AN/APG-77 Active Electronically Scanned Array (AESA) radar, 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.
F-22 Raptor avionics.
The AN/APG-77 AESA (active electronically scanned array) 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 plane an electronic-attack capability.
The radar’s information is processed by the two Raytheon-built 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 Raptor 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 Raptor's equipment isn't as powerful or sophisticated, because of its stealth, it is typically hundreds of miles closer to the battlefield, which often compensates for the reduced capability.
The F-22 Raptor 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 aircraft, thus enabling one of them to choose a different aircraft. It is often able to identify targets hundreds of times faster than accompanying dedicated AWACS.
The F-22's low probability of intercept radar is being given a high-bandwidth data transmission capability, to allow it to be used in a "broadband" role to permit high-speed relaying of data between friendly transmitters and receivers in the area. The F-22 can already pass data to other F-22s, resulting in considerably reduced radio "chatter."
The MIL-STD-1394B data bus, developed for the F-22 Raptor, was derived from the commercial FireWire (IEEE-1394) bus system, often used on Apple Macintosh computers. The bus was subsequently deployed on the derivative F-35 Lightning II fighter.
Armament of the F-22 Raptor.
The F-22 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, as the missiles are pushed clear of the airframe by hydraulic arms. The plane can also carry bombs such as the Joint Direct Attack Munition (JDAM) and the new Small-Diameter Bomb (SDB). It can carry weapons on four external hardpoints, but this vastly decreases the plane’s stealthiness, maneuverability, speed and range. 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 Raptor has been able to use its gun in dogfighting without being detected, which can be necessary when missiles are depleted.
There have been some design studies of the possibility of placing a laser weapon, possibly derived from the THEL program, inside the weapons bay.
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 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 specific impulse 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-22 Raptors 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 Raptor, 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 detachable hardpoints. Each hardpoint is theoretically capable of handling 5,000 lb of ordnance. However, usage of external stores greatly compromises the F-22 Raptor stealth, and has a detrimental effect on maneuverability. 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.
Stealth capabilities of the F-22 Raptor.
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 a low radar signature, i.e. making it more difficult to see with radar.
The stealth of the F-22 Raptor is due to a combination of factors, including 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. The F-22 Raptor has also been designed to disguise its infra-red emissions to make it harder to detect by Infrared homing ("heat seeking") surface-to-air or air-to-air missiles.
The F-22 Raptor 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 Raptor 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 secret.
Use of afterburners may apparently lead to jet emissions being quite detectable on radar, which may be a further reason for the emphasis on supercruise performance.
Testing of the F-22 Raptor.
F-22 Raptor testing has been curtailed to save program costs, but risks hiding flaws until a point at which fixing flaws becomes unaffordable. The U.S. General Accounting Office cautioned, "Moreover, engine and stealthiness problems already disclosed by the DoD, and the potential for avionics and software problems, underscore the need to demonstrate the weapon system’s performance through flight testing before significant commitments are made to production."
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 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.
Due to the F-15's performance in the first Persian Gulf War, critics of the F-22A claim that the F-15 is already the best fighter in the skies and the F-22A wouldn't be necessary. This view, however, was dismissed by the USAF.
On April 10, 2006, an F-22 Raptor pilot became trapped in his aircraft due to the canopy being stuck. With no other options left, the canopy was cut by fire department personnel leaving $182,205 canopy replacement costs, not considering the further damage to the aircraft.
On May 3, 2006, a report was released detailing a problem with a forward titanium boom on the aircraft that was not properly heat treated. The flaw can shorten the aircraft's life. Officials are still investigating the problem. The problem was caused by the boom portion not being subjected to high temperatures in the factory for long enough. This caused the boom to be less ductile than specified, shortening the lives of the first 80 or so F-22s. Work is underway to fix these F-22s and restore them to full life expectancy.
The current F-22A fleet is undergoing modifications at Hill AFB and at Palmdale, California. There will be 17 modifications before it re-enters service.
Comparisons with the F-22 Raptor.
The F-22 Raptor is claimed by several sources to be the world’s most effective air-superiority fighter. One such source is Air Marshal Angus Houston, chief of the Australian Defence Force, and former head of the Royal Australian Air Force, who said in 2004 that the "F-22 Raptor will be the most outstanding fighter plane ever built." US government secrecy makes comparisons with other aircraft difficult. Among its advantages are its sustained high speed and altitude capabilities, thrust vectoring, sensors, stealth features, advanced avionics, and ability to receive data from other U.S. systems.
Though exceptional maneuverability for a stealth aircraft seems unneeded, Lockheed Martin and USAF decided that the Raptor should prepare against all threats. Notably, in the past, similar assumptions about the unimportance of maneuverability for the F-4 Phantom II turned out to be incorrect; the more so for anti-aircraft systems like SA-21 'Growler', which may be capable of detecting stealth planes since there is information exchange with neighbor radars, which observes the appropriate zone via different angles and form of signal.
In March 2005, United States Air Force Chief of Staff General John P. Jumper, then the only person to have flown both the Eurofighter Typhoon and the F-22 Raptor, gave a verbal comparison on the two aircraft. He said that "the Eurofighter is both agile and sophisticated, but is still difficult to compare to the F-22 Raptor." "They are different kinds of airplanes to start with," the general said. "It's like asking us to compare a NASCAR car with a Formula 1 car. They are both exciting in different ways, but they are designed for different levels of performance."
In early 2006, after an exercise involving just eight F-22s in Nevada in Nov. 2005, Lieutenant Colonel Jim Hecker, commander of the 27th Fighter Squadron (FS) at Langley AFB, Virginia, commented "We killed 33 F-15Cs and didn't suffer a single loss. They didn't see us at all."
In June 2006 during Exercise Northern Edge (Alaska's largest joint military training exercise), the F-22A achieved a 144-to-zero kill-to-loss ratio against F-15s, F-16s and F/A-18s simulating MiG-29 'Fulcrums', Su-30 'Flankers', and other current front line Russian aircraft, which outnumbered the F-22A 4 to 1 at times. The small F-22 force of 12 aircraft generated 49% of the total kills for the exercise, and operated with an unprecedented reliability rate of 97%.
Variants of the F-22 Raptor.
Based on the F-22, the swing-wing Navalized Advanced Tactical Fighter (NATF) was proposed for the U.S. Navy as a carrier-borne variant of the F-22 to replace the F-14 Tomcat, though the program was subsequently canceled in 1993. Another more recent proposal is the FB-22, which would be used as a deep strike bomber for the USAF. There has yet to be any word on whether the USAF plans further development of the program. Also, the X-44 MANTA, short for Multi-Axis, No-Tail Aircraft, is an experimental aircraft which itself is an F-22 with enhanced thrust vectoring controls and no aerodynamic backup (i.e. the aircraft is controlled solely by thrust vectoring, without rudders, ailerons, or elevators). It is scheduled to be tested some time in 2007.
Operators of the F-22 Raptor.
F-22 Raptor future squadrons will include:
Specifications of the F-22 Raptor.
Data from USAF, F-22 Raptor Team web site, and Aviation Week & Space Technology
General characteristics of the F-22 Raptor.
Performance of the F-22 Raptor.
Armament of the F-22 Raptor.
Related content and development of the F-22 Raptor.
Comparable aircraft to the F-22 Raptor.
Designation sequence of the F-22 Raptor.
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