F22a
It is primarily an air superiority fighter, but has multiple capabilities that include ground attack, electronic warfare, and signals intelligence roles.
The United States Air Force considers the F-22 a critical component of the US strike force, and claims that the F-22 cannot be matched by any known or projected fighter aircraft. Air Chief Marshal Angus Houston, Chief of the Australian Defence Force, said in 2004 that the "F-22 will be the most outstanding fighter plane ever built."
Faced with a protracted and costly development period, the aircraft was variously designated F-22 and F/A-22 during the three years before formally entering US 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.
Program partner Boeing Integrated Defense Systems provides the wings, aft fuselage, avionics integration, and all of the pilot and maintenance training systems.
Development
In 1981 the United States Air Force (USAF) developed a requirement for a new air superiority fighter, the Advanced Tactical Fighter (ATF), to replace the capability of the F-15 Eagle, primarily the F-15A, B, C and D variants. ATF was a demonstration and validation program undertaken by the USAF 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.
It was envisaged that the ATF would incorporate emerging technologies including advanced alloys and composite materials, 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.
On 23 April 1991 the USAF ended the design and test flight competition by announcing Lockheed's YF-22 as the winner. It was anticipated at the time that 650 aircraft would be ordered.
Into production
The first operational F-22 Raptor is painted at the Lockheed Martin assembly plant at Marietta, Georgia
The first production F-22 was delivered to Nellis Air Force Base, Nevada, on 14 January 2003 and "Dedicated Initial Operational Test and Evaluation" commenced on 27 October 2003.
By 2004, 51 Raptors had been delivered.
The first crash of a production F-22 occurred during takeoff at Nellis Air Force Base on 20 December 2004, in which the pilot ejected safely prior to 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; consequently, the aircraft design was corrected to avoid the problem.
In August 2007, the United States Air Force signed a $5 billion, multi-year contract with Lockheed Martin that will extend production to 2011, and as of 2008, F-22 Raptors are being procured at the rate of 20 per year.
In a ceremony on 29 August 2007, Lockheed Martin reached its "100th F-22 Raptor" milestone, delivering AF Serial No. 05-4100.
Procurement
Two F-22s during flight testing, the upper one being the first EMD F-22, "Raptor 01".
The United States Air Force originally planned to order 750 ATFs, with production beginning in 1994; however, the 1990 Major Aircraft Review altered the plan to 648 aircraft beginning in 1996.
The goal changed again in 1994, when it became 442 aircraft entering service in 2003 or 2004, but 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.
By 2006, the Pentagon said it will buy 183 aircraft, which would save $15 billion but raise the cost of each aircraft, and 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. The total cost of the program by 2006 was $62 billion.
In April 2006, the cost of the F-22 was assessed by the Government Accountability Office to be $361 million per aircraft.
This cost reflects the F-22 total program cost, divided by the number of fighters the Air Force is programmed to buy; and which has so far invested $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.
The Unit Procurement Cost was estimated at $177.6 million in 2006 based on a production run of 181 airframes. This unit cost will decrease if total production is higher. This cost includes $3.233 billion already spent on research and development by 2006.
By the time all 183 fighters have been purchased, $34 billion will have been spent on actual procurement, resulting in a total program cost of $62 billion or about $339 million per aircraft.
That distinction likely belongs to the roughly $1.157 billion (1998 USD) per unit B-2 Spirit, whose orders went from 132 to 21 when the Cold War ended thus making the unit cost skyrocket, though the incremental cost was under US$1 billion. 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.
On 31 July 2007, Lockheed Martin received a multiyear contract for 60 F-22s worth a total of US$7.3 billion. The contract brings the number of F-22s on order to 183 and extends production through 2011.
During the two-month grounding of nearly 700 older F-15s in November and December 2007, some US Senators demanded that Deputy Secretary of Defense Gordon England release three government reports that support additional F-22 Raptors beyond the planned 183 jets. The USAF has requested that the F-22 remain in production after the 183 planned fighters.
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.
Stealth
To maintain stealth, the F-22 carries its weapons in internal bays, here shown open.
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-22 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.
Designers also made the aircraft less visible to the naked eye, and controlled radio and noise emissions. The Raptor has an under bay carrier made for hiding heat from missile threats, like surface-to-air missiles.
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.
In early 2009 Lockheed Martin released information on the F-22, showing it to have a radar cross section from certain critical angles of -40 dBsm — the equivalent radar reflection of a "steel marble". However, the stealth features of the F-22 require so much "tape and paste" maintenance work that their readiness rate is approximately 80% of non-stealth USAF fighters.
The effectivenes of this emphasis on stealth characteristics during the F-22 design process is difficult to measure. As soon as the F-22 maneuvers, it exposes a different set of angles and a greater surface area to any radar, increasing its visibility.
Low-frequency radars, including weather radars and warning stations in areas of the former Soviet Union, are unaffected by stealth characteristics and are capable of detecting those aircraft employing them. Also, incorporating stealth features into an aircraft design imposes weight and maneuverability penalties that may not be worthwhile tradeoffs for a fighter aircraft, leading to tactical limitations on that aircraft's use.
External lighting
The aircraft has integral position and anti-collision lighting (including strobes) on the wings, compatible with stealth requirements, supplied by Goodrich Corporation. The low voltage electroluminescent formation lights are located on the aircraft at critical positions for night flight operations (on both sides of the forward fuselage under the chin, on the tip of the upper left and right wings, and on the outside of both vertical stabilizers).
There are similar air refueling lights on the butterfly doors that cover the air refueling receptacle.
Operational history
The 27th Fighter Squadron at Langley Air Force Base was the first squadron to receive the F-22.
Intended to be the leading American advanced tactical fighter in the early part of the 21st century, the Raptor is an expensive fighter 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 technology from the F-22, but at a much more affordable price.
To a large extent the cost of these technologies is lower for the F-35 only because they have already been developed for the F-22.
YF-22 "Lightning II"
The prototype YF-22 won a fly-off competition against the Northrop/McDonnell-Douglas YF-23 for the Advanced Tactical Fighter contract. 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.
The YF-22 was originally given the unofficial name "Lightning II", after the World War II fighter P-38, by Lockheed, which persisted until the mid-1990s when the USAF officially named the aircraft "Raptor". On 15 December 2005, the F-22A entered service.
Testing
An F-22 refuels from a KC-135 during testing; the attachment on the back top is for a spin recovery chute.
Testing of the F-22 began in 1997 and 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. A testing aircraft was converted to a maintenance trainer at Tyndall AFB.
On 3 May 2006, a report was released detailing a problem with a forward titanium boom on the aircraft that was not properly heat treated.
Officials are still investigating the problem which was caused by the boom portion not being subjected to high temperatures in the factory for long enough, causing the boom to be less ductile than specified and potentially shortening the lives of the first 80 or so F-22s. The F-22 is slated to replace the F-15C/D.
In 2006, the Raptor's development team, composed of Lockheed Martin and over 1,000 other companies, plus the United States Air Force, won the Collier Trophy, American aviation's most prestigious award. The U.S.