Message posted by Andre' M. Dall'au on July 18, 2004 at 13:01:03 PST:
For a slow Sunday, here is a good F/A-22 write up from Military.com. It was directed to me by a good friend from Boeing. The U.S. has long been king of the skies, and Lockheed Martin intends to keep it that way with the F/A-22 Raptor fighter. Pure performance, the latest systems, the best in avionics -- the F/A-22 has it all. Air dominance personified: The F/A-22 fighter. The Raptor: Killer Features Related Links: F-15 Eagle The F/A-22 is driven by two Pratt & Whitney F119-PW-100 advanced technology afterburning engines. Each engine is rated at 39,000 pounds of thrust wet (full afterburner.) Each engine has three fan stages, six compressor stages, and one high and low pressure fans each. While the F/A-22's top speed (mach 1.8, or 1,368 mph at sea level) isn't as fast as other aircraft currently in production, this is by design. The F/A-22 uses fixed geometry air intakes for ease of maintenance and stealth constraints. Furthermore, the F119 engines produce proportionately more thrust at supersonic speeds and is able to accelerate the aircraft to mach 1.5 (half again the speed of sound) without the use of the fuel guzzling afterburner (this effect is referred to as supercruising). Finally, the F/A-22, with full fuel and weapons load out (i.e. in full combat configuration) is, in fact, the fastest fighter in production. This means that while the F/A-22 may not be the speediest at the Reno Air Races, it is the fastest, most efficient combat aircraft ever. Cornering on a Dime: Vectored Thrust Augmenting the F199 engines is the first ever production-vectored thrust exhaust system. This two dimensional system is capable of vectoring the exhaust up to 20 degrees above and below the horizontal in a fraction of a second, enabling the Raptor to execute sustainable out of plane maneuvers (achieving angles of attack (AoA) as high as 60 degrees.) In comparison, other high AoA aircraft, such as the MiG-29 Fulcrum and the Su-27 Flanker (which is capable of AoAs as high as 180 degrees) achieve their maneuverability through extreme control surface manipulation -- in effect, using wing lift to haul the nose out of plane. This method not only places enormous structural stresses on the airframe, but also causes a rapid bleed off of airspeed and energy, which could leave the fighter suspended helpless in the air following the pitch over. The F/A-22, on the other hand, is able to maintain it's high AoA maneuvers because it uses engine thrust to bring the nose around. In addition, the nozzles can be vectored in opposite directions that increase the roll rate of the Raptor by 50 percent. The integrated avionics package is the most sophisticated ever to be built. While some of the Raptor's subsystems are currently in use by other aircraft, what sets the F/A-22 apart from the rest is how these systems, from the radar to the weapons management system to the communications, navigation, and the electronic defense systems all collect and share information, rather than functioning as separate and individual automated systems. Must-Have Gear At the heart of the Raptors integrated avionics package is the Common Integrated Processor, which has been specially built with both the present and future in mind. Roughly the size of a large toaster, the CIP handles and processes all sensor and pre-programmed mission data. Data processing functions are handled by one of seven different processing modules, and each of the CIPs (there are two aboard each Raptor) can accommodate up to 66 individual modules. What's more, by design, the CIPs are under utilized. Each processing module is built at only 70 percent capacity (to allow for a 30 percent increase in module performance without changing the dimensions of the processor module), so there are currently 19 unused slots in CIP #1 and 22 unused slots in CIP#2 which provides for additional growth in information management. Lastly, there is room in the F/A-22 for yet a third CIP box, which would increase the information processing potential of the Raptor by 200 percent. X-Ray Vision: The AN/APG-77 Radar Speed and a highly developed processor are pluses, but what about attack radar? The short answer: the Raptor's AN/APG-77 radar is the most advanced tactical radar ever manufactured. Guns, Bombs and Missiles, Oh My… But let's not forget that the Raptor has been labeled as an "air superiority fighter," its primary function to hunt down and destroy enemy aircraft. Just like the rest of the Raptor's systems, the weapons do not disappoint. At the heart of the Raptor's weapons suite is the venerable M61A2 20mm Vulcan rotary cannon. Armed with 480 rounds of explosive ammunition, the cannon remains concealed behind a stealth-enhancing door until the pilot pulls the trigger. The ammunition feed system is hydraulically driven, linkless, and spent brass is recycled back into the ammunition storage drum. On the missile side of the house, the F/A-22 is capable of firing all existing air-to-air missiles (specifically the medium range AIM-120 and the short ranged AIM-9) and provides sufficient space for future missile designs. To preserve in-flight stealth characteristics, the Raptor's weapons are housed in a series of four weapons bays (two located on the air intake walls, and two located on the fuselage itself). F-22 Weapons Carriage Capability The F/A-22 is also equipped with four wing hardpoints that can be used for fuel tanks or additional ordnance, but at a loss of stealthy performance (the F/A-22 is currently rated to carry either two GBU-32 500 lb or two GBU-30 1,000 lb Joint Direct Attack Munitions (JDAM)). To launch weapons from the internal bays the weapon management system (which is CIP controlled) selects a missile and when the pilot "fires" the system automatically opens the bay and extends the selected missile out of the bay on an ejection rack. Once the missile acquires the target and is clear of the aircraft, the ejection rack retracts and the bay door automatically closes. For its primary air-to-air role, the F-22 will carry six AIM-120C and two AIM-9 missiles. For its air-to-ground role, the F-22 can internally carry two 1,000 pound-class JDAM, two AIM-120C, and two AIM-9 missiles. With the Global Positioning System-guided JDAM, the F-22 will have an adverse weather capability to supplement the F-117 (and later the Joint Strike Fighter) for air-to-ground missions after achieving air dominance. Builder: The F-22 is a legacy of the Cold War, when constant improvement was needed for the United States to remain competitive with the Soviet Union. With the Cold War over, however, the need to upgrade is no longer as paramount as it once was. This isn't to say that the F-15, which is now over 30 years old, won't need to refurbished or replaced eventually. The question is, do we need such an advanced fighter as the F-22 when the F-15 is still capable of meeting our current air defense and air superiority requirements? On the one hand, the answer is a resounding no. Air superiority hasn't been a challenge for the United States since the Korean War. Since 1952 the U.S. has pretty much owned the air in any armed conflict it has been involved in, and, barring a war with China or one of the Western European powers, this condition is unlikely to change. On the other hand, however, military planning and readiness are based on threat capabilities, not possibilities, and so it would seem prudent and reasonable to develop and field a suitable replacement for the F-15. Another point to consider: Over the years, the U.S. has come to fully embrace the idea of stealth technology as a means of surviving in the modern aerial battlefield, and has been a leader in developing this technology. Unfortunately, the benefits of stealth technology have not come without sacrifices. To achieve meaningful levels of "stealth," radar reflective surfaces as ordnance, fuel tanks, and electronics pods and jammers must be mounted internally (as is the case with the F-117, F/A-22, and the proposed F-35 JSF.) While this makes the aircraft harder to detect by enemy sensors, it dramatically reduces the payload that the aircraft can carry. With this has come a corresponding shift in ordnance use; where precision guided munitions were once the exception, they have now become the rule, and as is the case with the F/A-22, precision-guided munitions are sometimes the only choice. This has had a serious impact on ground support operations; while a 500 pound laser guided bomb might be capable of landing within 10 feet of its aim point, at the end of the day it is still just one 500 pound bomb, and the F/A-22 can only carry two of them (in comparison, the Republic P-47 Thunderbolt, at a cost of $85,000 dollars in 1944, was armed with 8 .50 caliber machine guns and could carry 2,500 pounds of ordnance, and the Douglas AD-1 Skyraider, at $285,000 in 1957, was armed with 4 20mm cannons and could carry 8,000 pounds of bombs). The McDonnell-Douglas F-4 Phantom II (a.k.a. the Rhino and the Double Ugly) is a good example of a pre-stealth tactical multi-role fighter. While it had the radar cross-section of a bus, the Phantom II was capable of performing not only air superiority missions, but also delivering a very large payload of both conventional and precision-guided munitions to support ground operations. In addition, purpose built variants of the F-4, such as the RC-4 tactical reconnaissance aircraft, and the F-4G Wild Weasel SAM suppression aircraft, filled a specialized roles which have gone unfilled since the Phantom was retired. Given the types of combat missions that the Air Force is actually performing right now, the U.S. need may be for a new Rhino, rather than a new Eagle -- a true multi-role (not multi-service) aircraft that combines the payload and ordnance delivery capabilities of the F-4 with the advanced avionic and flight characteristics of the F/A-22. In addition to air superiority and air to ground missions, such an aircraft could also be fully capable of filling the vacancies left by the RC-4 and F-4G. While the F-16 Falcon is currently serving in these roles, it is decidedly less capable than aircraft it has replaced. None of the aircraft in America's inventory are getting any younger, and the processes of developing new technologies and fielding new aircraft should always be ongoing. What should be given some thought, however, are what capabilities and priorities we assign those aircraft to ensure that they are fully mission capable. The question remains: should we design aircraft capable of surviving on the "real" battlefields of today (i.e., Afghanistan and Iraq), as opposed to designing them based on the "theoretical" battlefields of the Cold War?
Andre'
It's hard to believe that it was over two decades ago -- 1981, to be exact -- when the United States, fearing an advance in Soviet fighter technology that would challenge the supremacy of the McDonnell Douglas F-15 Eagle, began work on the next generation of air superiority fighter. Twenty years later, that vision has finally become a reality in the form of the Lockheed Martin F-22 Raptor. They say that money can't buy you love, but 15 billion dollars in development costs and 91 million dollars per airframe can sure buy you one loaded air superiority fighter. Dubbed an "air dominance platform," the F-22 (now the F/A-22) Raptor redefines the concept of pure performance. Everything, from the fighter's vectored thrust exhaust, to its multitasking attack radar to its "supercrusing" aerial performance makes the F/A-22 the most capable fighter to ever take to the skies.
The F/A-22 is the world’s first fighter to introduce all-aspect stealth, as well as supercruise – supersonic flight without afterburners.
Sophisticated mission suite provides first-look, first-shot, first-kill capability. Pilots can concentrate on the mission, rather than on managing the sensors as in current fighters.
Life-cycle costs 40 percent lower than the F-15, the fighter it is replacing.
Design goal for all areas is a 100 percent improvement in capability over the F-15 weapons system.
More Aircraft
Equipment Guide
Flying at the Speed of Heat
The F/A-22 Raptor in flight.
Integrated Avionics: All for One and One for All
The F/A-22 Raptor's radar processes (graphic by f-22raptor.com).
The AN/APG-77 is an active aperture, electronically scanned, low observable array that is capable of performing search, track, and attack functions simultaneously. The radar itself is actually made up of 2000 individual radar transmitter-receiver modules. The modules can be steered electronically (the entire array is fixed and does not move) to perform individually assigned tasks (the CIP determines how many modules are required to perform each function.) Since the radar is CIP-driven, it is capable of very rapid changes in pulse energy and direction, which allows the Raptor to quickly acquire targets while maintaining a stealthy flight profile. To provide the F/A-22 with the widest possible field of view (design requirements called for 120 degrees of FOV in each direction off of the nose) the APG-77 is made up of three separate arrays; one pointed forward and one each off to either side. To provide the Raptor with a truly stealthy target acquisition capability, two Infrared Search and track systems are incorporated into the wings (one in each leading edge root) which allows the F/A-22 to look for the IR signatures of threat aircraft or ground targets without revealing it's position.
F-22 Raptor Specifications
Lockheed Martin
Function:
Air Superiority Fighter
Propulsion:
Two Pratt & Whitney F119-PW-100 engines
Thrust:
35,000 lbst
Length:
62.08 feet (18.90 meters)
Height:
16.67 feet (5.08 meters)
Wingspan:
44.5 feet (13.56 meters)
Wing Area:
840 square feet
Horizontal Tailspan:
29 feet (8.84 meters)
Speed:
Mach 1.8 (supercruise: Mach 1.5)
Crew:
One
Armament:
- Internally, six radar-guided AIM-120C advanced medium-range air-to-air missiles (or two 1,000-pound class GBU-32 joint direct attack munitions in place of four of the AIM-120Cs) in main weapons bay; two heat-seeking AIM-9 Sidewinder short-range air-to-air missiles in side weapons bays (one in each bay
- One M61A2 20 mm multi-barrel cannon
- Four external stations can carry additional stores (weapons or fuel tanks)
Planned Production:
339 aircraft
The F/A-22 Raptor is a state-of-the-art air superiority fighter -- this is obvious. But setting aside its unparalleled performance, the question that will be most often asked about it is, "Do we need it?"
-- Eric Daniel, Military.com
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