ADVANCED STEALTH us air force F 22 Stealth Fighter Aircraft
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- Updated: 10 Sep 2014
The F-22 stealth fighter aircraft has served to US Air Force well. The Lockheed Martin F-22 Raptor is a single-seat, twin-engine, all weather stealth tactical fighter aircraft developed for the United States Air Force (USAF). The result of the USAF's Advanced Tactical Fighter program, the aircraft was designed primarily as an air superiority fighter, but has additional capabilities including ground attack, electronic warfare, and signals intelligence roles.[6] Lockheed Martin 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 provides the wings, aft fuselage, avionics integration, and training systems.
Design
Overview
The F-22 Raptor is a fifth generation fighter that is considered fourth-generation in stealth aircraft technology by the USAF.[105] It is the first operational aircraft to combine supercruise, maneuverability, stealth, and sensor fusion into a single platform.[8] The Raptor has large trapezoidal wings, fixed-geometry inlets, and a retractable tricycle landing gear. Flight control surfaces include the rudders on the canted vertical stabilizers and the all-moving horizontal tails; these control surfaces also serve as the speed brake.[106] The aircraft's dual afterburning Pratt & Whitney F119-PW-100 turbofan engines are placed close together and incorporate pitch axis thrust vectoring nozzles with a range of ±20 degrees; each engine has a maximum thrust in the 35,000 lbf (156 kN) class.[107][7] Maximum speed without external stores is estimated to be Mach 1.82 during supercruise and greater than Mach 2 with afterburners.[108][N 2]
The F-22 is among only a few aircraft that can supercruise, or sustained supersonic flight without using fuel-inefficient afterburners; targets can be intercepted which subsonic aircraft would lack the speed to pursue and an afterburner-dependent aircraft would lack the fuel to reach.[7][110] The Raptor's high operating altitude is also a significant tactical advantage over prior fighters.[111] The use of internal weapons bays allows the aircraft to maintain comparatively higher performance over most other aircraft due to a lack of drag from external stores. The F-22's structure contains extensive amounts of high-strength materials to withstand stress and heat of sustained supersonic flight. Respectively, titanium alloys and composites comprise 39 and 24% of the aircraft's structural weight.[112]
The F-22 is highly maneuverable at both supersonic and subsonic speeds. Computerized fly-by-wire control system and full authority digital engine control (FADEC) make the aircraft highly departure resistant and enable it to remain controllable at aggressive pilot inputs.[113][114] The Raptor's relaxed stability and thrust vectoring allow the aircraft to turn tightly, and perform very high alpha (angle of attack) maneuvers such as the Herbst maneuver (J-turn) and Pugachev's Cobra. The F-22 is also capable of maintaining over 60° alpha while having some roll control.[115]
The F-22's aerodynamic performance, sensor fusion, and stealth work together for increased effectiveness. Altitude, speed, and advanced active and passive sensors allow targets to be spotted at considerable ranges and increase weapons range. Altitude and speed also complement stealth's effectiveness by increasing distance between the aircraft and ground defenses and giving defensive systems less time to react.[116][7][117]
Avionics
Key avionics include BAE Systems EI&S; AN/ALR-94 radar warning receiver (RWR),[118] Lockheed Martin AN/AAR-56 Infra-Red and Ultra-Violet missile approach warning system (MAWS) and Northrop Grumman AN/APG-77 Active Electronically Scanned Array (AESA) radar. The RWR is a passive radar detector with more than 30 antennas are blended into the wings and fuselage for all-round coverage. Tom Burbage, former F-22 program head at Lockheed Martin, described it as "the most technically complex piece of equipment on the aircraft." The range of the RWR (250+ nmi) exceeds the radar's, and can cue radar emissions to be confined to a narrow beam (down to 2° by 2° in azimuth and elevation) to increase stealth.[119]
The AN/APG-77 radar features a low-observable, active-aperture, electronically scanned array that can track multiple targets under any weather conditions. Radar emissions can also be focused to overload enemy sensors as an electronic-attack capability.[120][121] The radar changes frequencies more than 1,000 times per second to lower interception probability and has an estimated range of 125–150 miles, though planned upgrades will allow a range of 250 miles (400 km) or more in narrow beams.[111] Radar information is processed by two Raytheon Common Integrated Processor (CIP)s, each capable of processing up to 10.5 billion instructions per second. In a process known as sensor fusion, data from the radar, other sensors,
http://wn.com/ADVANCED_STEALTH_us_air_force_F_22_Stealth_Fighter_Aircraft
The F-22 stealth fighter aircraft has served to US Air Force well. The Lockheed Martin F-22 Raptor is a single-seat, twin-engine, all weather stealth tactical fighter aircraft developed for the United States Air Force (USAF). The result of the USAF's Advanced Tactical Fighter program, the aircraft was designed primarily as an air superiority fighter, but has additional capabilities including ground attack, electronic warfare, and signals intelligence roles.[6] Lockheed Martin 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 provides the wings, aft fuselage, avionics integration, and training systems.
Design
Overview
The F-22 Raptor is a fifth generation fighter that is considered fourth-generation in stealth aircraft technology by the USAF.[105] It is the first operational aircraft to combine supercruise, maneuverability, stealth, and sensor fusion into a single platform.[8] The Raptor has large trapezoidal wings, fixed-geometry inlets, and a retractable tricycle landing gear. Flight control surfaces include the rudders on the canted vertical stabilizers and the all-moving horizontal tails; these control surfaces also serve as the speed brake.[106] The aircraft's dual afterburning Pratt & Whitney F119-PW-100 turbofan engines are placed close together and incorporate pitch axis thrust vectoring nozzles with a range of ±20 degrees; each engine has a maximum thrust in the 35,000 lbf (156 kN) class.[107][7] Maximum speed without external stores is estimated to be Mach 1.82 during supercruise and greater than Mach 2 with afterburners.[108][N 2]
The F-22 is among only a few aircraft that can supercruise, or sustained supersonic flight without using fuel-inefficient afterburners; targets can be intercepted which subsonic aircraft would lack the speed to pursue and an afterburner-dependent aircraft would lack the fuel to reach.[7][110] The Raptor's high operating altitude is also a significant tactical advantage over prior fighters.[111] The use of internal weapons bays allows the aircraft to maintain comparatively higher performance over most other aircraft due to a lack of drag from external stores. The F-22's structure contains extensive amounts of high-strength materials to withstand stress and heat of sustained supersonic flight. Respectively, titanium alloys and composites comprise 39 and 24% of the aircraft's structural weight.[112]
The F-22 is highly maneuverable at both supersonic and subsonic speeds. Computerized fly-by-wire control system and full authority digital engine control (FADEC) make the aircraft highly departure resistant and enable it to remain controllable at aggressive pilot inputs.[113][114] The Raptor's relaxed stability and thrust vectoring allow the aircraft to turn tightly, and perform very high alpha (angle of attack) maneuvers such as the Herbst maneuver (J-turn) and Pugachev's Cobra. The F-22 is also capable of maintaining over 60° alpha while having some roll control.[115]
The F-22's aerodynamic performance, sensor fusion, and stealth work together for increased effectiveness. Altitude, speed, and advanced active and passive sensors allow targets to be spotted at considerable ranges and increase weapons range. Altitude and speed also complement stealth's effectiveness by increasing distance between the aircraft and ground defenses and giving defensive systems less time to react.[116][7][117]
Avionics
Key avionics include BAE Systems EI&S; AN/ALR-94 radar warning receiver (RWR),[118] Lockheed Martin AN/AAR-56 Infra-Red and Ultra-Violet missile approach warning system (MAWS) and Northrop Grumman AN/APG-77 Active Electronically Scanned Array (AESA) radar. The RWR is a passive radar detector with more than 30 antennas are blended into the wings and fuselage for all-round coverage. Tom Burbage, former F-22 program head at Lockheed Martin, described it as "the most technically complex piece of equipment on the aircraft." The range of the RWR (250+ nmi) exceeds the radar's, and can cue radar emissions to be confined to a narrow beam (down to 2° by 2° in azimuth and elevation) to increase stealth.[119]
The AN/APG-77 radar features a low-observable, active-aperture, electronically scanned array that can track multiple targets under any weather conditions. Radar emissions can also be focused to overload enemy sensors as an electronic-attack capability.[120][121] The radar changes frequencies more than 1,000 times per second to lower interception probability and has an estimated range of 125–150 miles, though planned upgrades will allow a range of 250 miles (400 km) or more in narrow beams.[111] Radar information is processed by two Raytheon Common Integrated Processor (CIP)s, each capable of processing up to 10.5 billion instructions per second. In a process known as sensor fusion, data from the radar, other sensors,
- published: 10 Sep 2014
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