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F/A-22 Raptor
The F/A-22 Raptor is a highly maneuverable, stealthy fighter aircraft built by
Lockheed Martin Aeronautics and Boeing Integrated Defense Systems. It was
originally envisioned as an air-superiority aircraft but is equipped for ground
attack, electronic attack, and signals-intelligence roles as well.
Intended to be the leading United States advanced tactical fighter in the early
part of the 21st century, the Raptor is certainly the most expensive fighter ever.
The Pentagon concluded in 2004, that the total development and production cost
of the currently planned 279 aircraft will come to $71.7 billion, or $256.9
million per plane. Some say the estimate should be somewhat lower because
some research and development support the F-35 Joint Strike Fighter as well.
The prototype YF-22 Lightning II 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, California. The
test pilot was not injured and the cause of the crash was a software issue. 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 plane was
unveiled on April 9, 1997, at Lockheed-Georgia Co., Marietta, Georgia. First
flight occurred in September. In 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, indicated that the Raptor would have some capability for ground
strikes.
The first production F/A-22 was delivered to Nellis Air Force Base, Nevada, on
January 14, 2003. As of late 2004, 51 Raptors are in service with 22 more ordered
under fiscal year 2004 funding. F/A-22 DIOT&E (Dedicated Initial Operational
Test and Evaluation) occurred on October 27, 2004. The first production F/A-22
crash 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
is still under investigation but investigators are pointing to a software
malfunction, not pilot error. Initial Operational Capability (IOC) is scheduled
to occur around December, 2005.
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; with afterburners 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, flew the Raptor faster than 1.7 Mach 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 solid evidence for 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.
Avionics include Raytheon and Northrop Grumman AN/APG-77 Active Electronically
Scanned Array (AESA) radar.
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 DoD report put the purchase at
339. In 2003, the Air Force said that the existing congressional cost cap limited
the purchase to 277. In 2005, the Pentagon is saying it will buy 180 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.
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.
It's beleived that the Australian Government considered the F/A-22 as a replacement
for Australia's F/A-18 and F-111's. Several independent defence and strategic
policy advisory groups are pressuring the government to procure the plane, hoping
that the government will think along the same lines as the Australian government
in the 1960's did when it was the only country besides the US to order the
similarly high tech and expensive F111. However given that the Government has
already commited financially to the F-35 JSF project it's unlikely that they
would also seek to purchase F/A-22's.
Variants
Based on the F/A-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 a 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 Hughes-built Common Integrated
Processor (CIP)s. Each CIP operates at 10.5 billion instructions per second and
has 300 megabytes of memory. Unprecedented amounts of 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
Weapons
The Raptor is designed to carry its air-to-air missiles in internal bays to
avoid disrupting its stealthiness. The 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.
Comparisons
The F-22 is generally thought to be the world's most effective air-superiority
fighter, but government secrecy makes comparisons with other aircraft difficult.
Among its advantages are its sustained high speed, sensors, low radar signature,
advanced avionics, and ability to exchange data with other U.S. systems.
It is not known whether USAF claims about Raptor's superior maneuverability
are accurate; many argue that, in any case, today's antiair missiles make
maneuverability less important.
Its rising cost has forced the USAF to buy fewer F-22s than planned, and has
likely slowed or curtailed other programs, such as air-superiority unmanned
combat air vehicles.
See comparison of 21st century fighter aircraft for a more extensive discussion.
This article is licensed under the GNU Free Documentation License.
It uses material from the Wikipedia article "F/A-22 Raptor".
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