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Revision as of 18:01, 20 June 2006 by 69.236.78.95 (talk)(diff) ← Previous revision | Latest revision (diff) | Newer revision → (diff)Template:Infobox Aircraft The F-22 Raptor is a stealth fighter aircraft built by Lockheed Martin Aeronautics and Boeing Integrated Defense Systems. It was originally envisioned as an air superiority fighter, but is equipped for ground attack, electronic attack, and signals intelligence roles as well. Long in development, the aircraft was also known as the prototype YF-22 and as the F/A-22 for three years before formally entering United States Air Force service in December 2005 as the F-22A.
Development
Intended to be the leading American advanced tactical fighter in the early part of the 21st century, the Raptor is the most expensive fighter to date. As of April 2005 the total development and production cost of the program is at least $70 billion, and the number of planes to be built has dropped to 381, down from the initial requirement of 750. In April 2006, the Government Accountability Office estimated the cost to $361 million per aircraft (Some say the estimate should be somewhat lower because some research and development are transferable to the F-35 Joint Strike Fighter as well.)
The prototype YF-22 Lightning II, named after the Lockheed P-38 Lightning, 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-22A 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 pilot-induced oscillation. The name "Lightning II" persisted until the mid-1990s, and for a short while, the plane was also dubbed "Rapier". The F-22 became the "Raptor" when the first production-representative plane was unveiled on April 9, 1997, at Lockheed-Georgia Co., Marietta, Georgia. First flight occurred on September 7.
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.
The first production F-22 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-22A occurred at Nellis Air Force Base on December 20, 2004, during takeoff. The pilot ejected safely moments before impact. As of April 2005, the accident was still under investigation; investigators are pointing to a software malfunction, rather than pilot error. USAF officials were planning to rebuild the remains into a new jet.
On 12 December 2005 USAF changed the jet's designation again, to F-22A.. Shortly after, on December 15, 2005, the F-22A's entry into initial operational capability was announced.
The dual Pratt & Whitney F119-PW-100 turbofans with afterburners incorporate supercruise and 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 39,000 lbf (173 kN). Maximum speed is estimated to be Mach 1.72 in supercruise mode and without weapons; with afterburners, 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. Gen. John P. Jumper, U.S. Air Force Chief of Staff, September 6, 2001 to September 2, 2005, 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 “flame-out”, which is caused when too much air extinguishes the engine’s “pilot light”, but the intake itself may be designed to prevent such flame-outs. Former Lockheed Raptor chief test pilot Paul Metz says the Raptor has a fixed inlet. Paul 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. This is due to the fact that the F-22 is one of the few western aircraft with a thrust to weight ratio significantly greater than 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 than other modern aircraft due to its lack of drag from external stores.
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.
The first USAF squadron to operate F-22A's was the 43rd Fighter Squadron, at Tyndall AFB, FL. The 43rd was re-established at Tyndall in 2002, and, in 2003, with a corps of 15 Raptor Instructor Pilots, began training student Raptor pilots for the 27th Fighter Squadron at Langley. The 43rd continues to produce new Raptor pilots, and will continually serve as the focal point for all F-22 training of combat USAF Raptor pilots and maintainers. Additionally Raptor units include the 422 Test and Evaluation Squadron, which is responsible for tactics development and evaluation for the F-22, and the 412th Test Squadron, which continues to fly developmental test of F-22 enhancements and modernization. The 27th Fighter Squadron became the first deployable F-22 unit in December of 2005 after receiving sufficient numbers of trained Raptor pilots from the 43rd at Tyndall. The 94th Fighter Squadron, also at Langley, will be the second combat Raptor squadron, with additional squadrons to follow at Elmendorf AFB, Alaska, and Holloman AFB, New Mexico.
General information
Procurement
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, which has yet to receive Congress’ approval, would deliver the final aircraft in 2008 and hold open the possibility for new orders up to that point.
In April 2006 the cost for each F-22A is assessed by the Government Accountability Office to be $361 million per aircraft.
The F-22 is not the most expensive plane aloft; that distinction likely belongs to the $2.2 billion-per-unit B-2 Spirit. The F-22 uses fewer radar absorbent materials than the B-2 or F-117, which is expected to translate into lower maintenance costs.
Unlike past tactical fighters, the opportunity for export is virtually non-existent. Very few allies would even be allowed to import such a high-tech weapon; fewer could afford it. Most current customers for US fighters are either acquiring earlier designs like the F-15 or F-16 or are waiting to acquire the JSF, 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-22A's in its Replacement-Fighter program for its Air Self-Defense Force (ASDF). In such event, it would most likely involve a ‘watered down' version 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.
Variants
Based on the F-22, the swing-wing NATF was proposed for the U.S. Navy to replace the F-14 Tomcat, though the program was subsequently cancelled 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.
Combat systems
The Raptor’s combat computer systems and power are unmatched by any other fighter planned to be developed by 2020. 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 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 .
Although several recent Western fighters have had measures introduced to make them less detectable on radar, such as radar absorbent material coated S shaped intake ducts that shield the compressor fan from reflecting radar waves, the F-22A design has placed a much higher degree of importance on making the plane hard to detect than has previously been seen in fighter designs.
Weapons
The Raptor is designed to carry air-to-air missiles in internal bays to avoid disrupting its stealth capability. Missiles are launched by hydraulic arms that hurl them away from the jet so quickly that the weapons-bay doors pop open for less than one second. The plane can also carry bombs such as the large JDAM and the new Small-Diameter Bomb. It can carry non-stealthy weapons on four external hardpoints, but this vastly increases the plane’s radar signature. The Raptor carries a General Electric M61A2 Vulcan 20 mm Gatling cannon, also with a trap door, in the right wing root.
Testing
F-22 testing has been curtailed to save program costs, but risks hiding flaws until a point at which fixing flaws becomes unaffordable. Raptor 4001 was retired and sent to Wright-Patterson AFB to be fired at for testing the fighters' 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 maintennance trainer at Tyndall AFB.
In March 2003, during a combat training flight called Red Flag, 1 F-22A went against 5 F-15C Eagles. During the exercise, the F-22A "shot down" all F-15's without being hit once.
On May 3, 2006, a report was released detailing a problem with a forward titanium boom on the aircraft that was not properly treated. The flaw can shorten the aircraft's lives. Officials are still investigating the problem.
Current F-22A fleet is undergoing modifications at Hill AFB. There will be 17 modifications before it reservices.
Comparisons
- For a detailed comparison of the Raptor and other fighters, see Comparison of 21st century fighter aircraft.
The F-22 is claimed by many sources to be the world’s most effective air-superiority fighter; however, government secrecy makes comparisons with other aircraft difficult. Among its advantages are its sustained high speed, thrust vectoring, sensors, stealth features, advanced avionics, and ability to exchange data with other U.S. systems.
While making a complete assessment is impossible based on publicly available information, there is a study by the UK's DERA comparing the Eurofighter Typhoon to other contemporary fighters; in it, the F-22 significantly surpassed all other types (including the Typhoon) in combat performance, although it should be noted that the unit cost of the F-22 is several times that of any other modern fighter aircraft.
Maneuverability in real-world combat is hotly debated, with some experts claiming it is inferior to the Typhoon. It is not known whether USAF claims about Raptor's superior maneuverability are accurate; many argue that, in any case, today’s beyond-visual-range air-to-air missiles make maneuverability less important. In fact, it also raises the question of why a stealthy aircraft needs extreme maneuverability, if it is designed not to be seen, thereby avoiding dogfights. In March 2005, USAF Chief of Staff General John P. Jumper, then the only person to have flown both the Typhoon and the Raptor, talked about these 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."
The high cost of the F-22 has forced the USAF to curtail important testing, buy fewer F-22s than planned, and is slowing or curtailing other essential programs. The Air Force continues to prioritize its F-22 buy over less expensive updates and modernization of the rest of its fighter fleet, and over the cheaper, more versatile F-35 Joint Strike Fighter.
In early 2006, after an exercise involving just eight F-22's in Nevada in Nov. 2005, Lieutenant Colonel Jim Hecker, commander of the 27th Fighter Squadron (FS) at Langley AFB in Virginia commented to Jane's Defence Weekly (Jan. 18, 2006) that:
"We killed 33 F-15Cs and didn't suffer a single loss. They didn't see us at all."
Specifications
Data from USAF, F-22 Raptor Team Website
General characteristics
- Crew: 1
- Airfoil: NACA 64A?05.92 root, NACA 64A?04.29 tip
Performance
- Thrust/weight: 1.3~1.41
- Maximum g-load: 9.5 g
Armament
- Guns: 1× M61A2 Vulcan 20 mm Gatling gun with 480 rounds
- Missiles:
- Bombs:
- 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 (907 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 (2,267 kg), albeit at the expense of stealth. The armament is still largely classified.
References
- "Factsheets: F-22A Raptor". Air Force Link. United States Air Force. 2005. Retrieved 2006-04-18.
- "Flight Test Data". F-22 Raptor Team Website. 2006. Retrieved 2006-04-18.
- Presently not published.
External links
- Information and downloads on the F-22
- Pictures and Information on F-22
- Unofficial F-22 Raptor Site
- F-22 News archive
- F-22 Raptor inside out
- F-22 Raptor Congressional Research Service report, 5 January 2005
- History of the F-22 program
- Stealth fighter crashes, a December 2004 article from the Las Vegas Review-Journal
- (PDF). Lengthy critical commentary on the Raptor from a former Air Force Colonel involved in aircraft development projects.
- Pictures: Pilot trapped for 5h in cockpit of USAF's new $135m F-22A Raptor after canopy jams
Related content
Aircraft of comparable role, configuration, and era
- Eurofighter Typhoon
- F-35 Joint Strike Fighter
- Mikoyan Project 1.44
- Shenyang J-XX
- Sukhoi PAK FA
- Medium Combat Aircraft
- YF-23 Black Widow II
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