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Lockheed Martin F-22 Raptor

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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 438, and again to 381, down from the initial requirement of 750[1]. In April 2006, the Government Accountability Office estimated the cost to $361 million per aircraft. [2](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 9 April 1997, at Lockheed-Georgia Co., Marietta, Georgia. First flight occurred on 7 September 1997. (On 7 July 2006, the U.S. Department of Defense announced that the F-35 — called the "Joint Strike Fighter" during most of its development — will be called F-35 Lightning II.[3])

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 14 January 2003. F-22 Dedicated Initial Operational Test and Evaluation occurred on 27 October 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 20 December 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.[4]. Shortly after, on 15 December 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” (2120 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, Florida. 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 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

F-22 Raptors over Utah in their first official deployment, Oct. 2005.

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. The current number for the total amount of aircraft is 381.

In April 2006 the cost for each 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, around $28 billion will have been spent on research and development. An additional $34 billion will have been spent on actually procuring the aircraft. That's about $62 billion for the total program cost. Divided out, that's comes to about $338 million per aircraft. If the Air Force wanted to buy just one more jet, it would cost less than half that amount. The current cost, or "fly away cost" for a single copy of an F-22 stands at about $137 million.[5]

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).[6] 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.

In June of 2006 the House of Representatives voted to lift a 10-year-old ban on foreign sales of the F-22. [7]

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 air-to-air combat power is 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.[8]

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 [9].

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.

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. 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 ordinance. 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 (Air Force Magazine, USAF Almanac, May 2006). 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.

Cruise altitude is a huge factor in performance. The F-22 is the first tactical aircraft to significantly increase sustained cruise altitudes within the last forty years or more. F-22 crews are being equipped with G-suits which are, in effect, partial pressure suits, to sustain life function above 50,000 ft, an altitude at which sudden decompression leads to an almost certain death to improperly equipped aircrew. The F-22 is designed to operate within, and exploit, this high altitude regime.

Testing

F-22 testing has been curtailed to save program costs, but risks hiding flaws until a point at which fixing flaws becomes unaffordable.[10] The US Government Accounting Office cautions, "Moreover, engine and stealthiness problems already disclosed by 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."[11]

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.[12]

Due to the F-15's performance in the first Persian Gulf War, critics of the F-22A claims 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 24, 2006, a presentation from 1st Maintenance Group Langley Airforce Base was released on the SpaceRef Website, reporting a complete failure of the canopy, capturing the pilot for approximately 5 hours. 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 treated. The flaw can shorten the aircraft's life. Officials are still investigating the problem.[13] 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 more ductile than specified shorting the lives of the first 80 or so F-22's. Work is under way to fix these F-22's and bring them back to full life expectancy.

Current F-22A fleet is undergoing modifications at Hill AFB. There will be 17 modifications before it reservices.

Comparisons

An F-22 Raptor observes an F-15 Eagle as it banks left. The F-22 is slated to replace the F-15C/D.
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 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). 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."

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 [non-modernized] F-15Cs and didn't suffer a single loss. They didn't see us at all."

Specifications

F-22 Raptor displaying its F119 engines

Data from USAF[1], F-22 Raptor Team Website[2]

General characteristics

Performance

Armament

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 (2267 kg), albeit at the expense of stealth. The 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 with combat loads typically closer to 4,000-8,000 lbs

References

  1. ^ "Factsheets: F-22A Raptor". Air Force Link. United States Air Force. 2005. Retrieved 2006-04-18.
  2. ^ "Flight Test Data". F-22 Raptor Team Website. 2006. Retrieved 2006-04-18.
  3. ^ Presently not published.

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