The Lockheed Martin/Boeing F-22 Raptor is a fifth-generation jet fighter aircraft that uses stealth technology. F-22 Raptor was designed primarily as an air superiority fighter, but has additional capabilities that include ground attack, electronic warfare, and signals intelligence roles. 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 Raptor. Program partner Boeing Integrated Defense Systems provides the wings, aft fuselage, avionics integration, and all of the pilot and maintenance training systems.The aircraft was variously designated F-22 and F/A-22 during the years prior to formally entering US Air Force service in December 2005 as the F-22A. Despite a protracted and costly development period, 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". In April 2009 the US Department of Defense proposed to cease placing new orders, subject to Congressional approval, for a final procurement tally of 187 Raptors.
F-22 Raptor Specifications
F-22 Raptor General characteristics - Crew: 1
- Length: 62 ft 1 in (18.90 m)
- Wingspan: 44 ft 6 in (13.56 m)
- Height: 16 ft 8 in (5.08 m)
- Wing area: 840 ft² (78.04 m²)
- Airfoil: NACA 64A?05.92 root, NACA 64A?04.29 tip
- Empty weight: 43,430 lb (19,700 kg)
- Loaded weight: 64,460 lb (29,300 kg)
- Max takeoff weight: 83,500 lb (38,000 kg)
- Powerplant: 2× Pratt & Whitney F119-PW-100 Pitch Thrust vectoring turbofans, 35,000+ lb (156+ kN) each
- Fuel capacity: 18,000 lb (8,200 kg) internally, or 26,000 lb (11,900 kg) with two external fuel tanks
F-22 Raptor Performance
- Maximum speed:
- At altitude: Mach 2.25 (1,500 mph, 2,410 km/h)
- Supercruise: Mach 1.82 (1,220 mph, 1,963 km/h)
- Range: 1,600 nmi (1,840 mi, 2,960 km) with 2 external fuel tanks
- Combat radius: 410 nmi (471 mi, 759 km)
- Ferry range: 2,000 mi (1,738 nmi, 3,219 km)
- Service ceiling: 65,000 ft (19,812 m)
- Wing loading: 77 lb/ft² (375 kg/m²)
- Thrust/weight: 1.08 (1.26 with 50% fuel)
- Maximum g-load: -3.0/+9.0 g
F-22 Raptor Armament
- Guns: 1× 20 mm (0.787 in) M61A2 Vulcan gatling gun in starboard wing root, 480 rounds
- Air to air loadout:
- 6× AIM-120 AMRAAM
- 2× AIM-9 Sidewinder
- Air to ground loadout:
- 2× AIM-120 AMRAAM and
- 2× AIM-9 Sidewinder and one of the following:
- 2× 1,000 lb (450 kg) JDAM or
- 2× Wind Corrected Munitions Dispensers (WCMDs) or
- 8× 250 lb (110 kg) GBU-39 Small Diameter Bombs
- Hardpoints: 4× under-wing pylon stations can be fitted to carry 600 US gallon Sargent Fletcher drop tanks or weapons, each with a capacity of about 5,000 lb (2,268 kg).
Avionics
- RWR (Radar warning receiver): 250 nmi (463 km) or more
- Radar: 125-150 miles (200-240 km) against 1 m2 (11 sq ft) targets (estimated range)
| F-22 Raptor | |
|---|---|
| Role | Stealth air superiority fighter |
| National origin | United States |
| Manufacturer | Lockheed Martin Aeronautics Boeing Integrated Defense Systems |
| First flight | 7 September 1997 |
| Introduced | 15 December 2005 |
| Status | In service |
| Primary user | United States Air Force |
| Number built | 168 as of October 2010 (187 planned) |
| Program cost | US$66.7 billion |
| Unit cost | US$150 million (flyaway cost for FY2009) |
| Developed from | Lockheed YF-22 |
| Developed into | Lockheed Martin X-44 MANTA Lockheed Martin FB-22 |
Design
F-22 Raptor Characteristics
The F-22 Raptor is a fifth generation fighter that is considered a fourth-generation stealth aircraft by the USAF. Its dual afterburning Pratt & Whitney F119-PW-100 turbofans incorporate pitch axis thrust vectoring, with a range of ±20 degrees. The maximum thrust is classified, though most sources place it at about 35,000 lbf (156 kN) per engine. F-22 Raptor Maximum speed, without external weapons, is estimated to be Mach 1.82 in supercruise mode; as demonstrated by General John P. Jumper, former US Air Force Chief of Staff, when his Raptor exceeded Mach 1.7 without afterburners on 13 January 2005. With afterburners, it is "greater than Mach 2.0" (1,317 mph, 2,120 km/h), according to Lockheed Martin; however, the F-22 Raptor can easily exceed its design speed limits, particularly at low altitudes, with max-speed alerts to help prevent the pilot from exceeding them. Former Lockheed Raptor chief test pilot Paul Metz stated that the Raptor has a fixed inlet; but while the absence of variable intake ramps may theoretically make speeds greater than Mach 2.0 unreachable, there is no evidence to prove this. Such ramps would be used to prevent engine surge resulting in a compressor stall, but the intake itself may be designed to prevent this. Metz has also stated that the F-22 has a top speed greater than 1,600 mph (Mach 2.42) and its climb rate is faster than the F-15 Eagle due to advances in engine technology, despite the F-15's thrust-to-weight ratio of about 1.2:1, with the F-22 having a ratio closer to 1:1. The US Air Force claims that the F-22A cannot be matched by any known or projected fighter.
The F-22 Raptor is highly maneuverable, at both supersonic and subsonic speeds. It is extremely departure-resistant, enabling it to remain controllable at extreme pilot inputs. The F-22's thrust vectoring nozzles allow the aircraft to turn tightly, and perform extremely high alpha (angle of attack) maneuvers such as the Herbst maneuver (or J-turn), Pugachev's Cobra, and the Kulbit, though the J-Turn is more useful in combat. The F-22 Raptor is also capable of maintaining a constant angle of attack of over 60°, yet still having some control of roll. During June 2006 exercises in Alaska, The F-22 Raptor pilots demonstrated that cruise altitude has a significant effect on combat performance, and routinely attributed their altitude advantage as a major factor in achieving an unblemished kill ratio against other US fighters and 4th/4.5th generation fighters.
F-22 Raptor AvionicsThe F-22's avionics include BAE Systems E&IS radar warning receiver (RWR) AN/ALR-94, AN/AAR 56 Infra-Red and Ultra-Violet MAWS (Missile Approach Warning System) and the Northrop Grumman AN/APG-77 Active Electronically Scanned Array (AESA) radar. The AN/APG-77 has both long-range target acquisition and low probability of interception of its own signals by enemy aircraft.
The AN/ALR-94 is a passive receiver system capable of detecting the radar signals in the environment. Composed of more than 30 antennas smoothly blended into the wings and fuselage, it is described by the former head of the The F-22 Raptor program at Lockheed Martin Tom Burbage as "the most technically complex piece of equipment on the aircraft." With greater range (250+ nmi) than the radar, it enables the The F-22 Raptor to limit its own radar emission which might otherwise compromise its stealth. As the target approaches, AN/ALR-94 can cue the AN/APG-77 radar to keep track of its motion with a narrow beam, which can be as focused as 2° by 2° in azimuth and elevation.
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 aircraft an electronic-attack capability.
The radar's information is processed by two Raytheon 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. The radar 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. In 2007, tests carried out by Northrop Grumman, Lockheed Martin, and L-3 Communications enabled the AESA system of a Raptor to act like a WiFi access point, able to transmit data at 548 Megabit/sec and receive at Gigabit speed; far faster than the current Link 16 system used by US and allied aircraft, which transfers data at just over 1 Megabit/sec.
The F-22 Raptor has several unique functions for an aircraft of its size and role. For instance, it has threat detection and identification capability along the lines of that available on the RC-135 Rivet Joint. While the F-22's equipment isn't as powerful or sophisticated, because of its stealth, it can be typically hundreds of miles closer to the battlefield, which often compensates for the reduced capability.
The F-22 Raptor is capable of functioning as a "mini-AWACS." Though reduced in capability compared to dedicated airframes such as the E-3 Sentry, as with its threat identification capability, the F-22's forward presence is often of benefit. The system allows the F-22 to designate targets for cooperating F-15s and F-16s, and even determine if two friendly aircraft are targeting the same enemy aircraft, thus enabling one of them to choose a different target. It is often able to identify targets "sometimes many times quicker than the AWACS".
The F-22's low probability of intercept radar is being given a high-bandwidth data transmission capability, to allow it to be used in a "broadband" role to permit high-speed relaying of data between friendly transmitters and receivers in the area. The F-22 Raptor can already pass data to other F-22s, resulting in considerably reduced radio "chatter".
The IEEE-1394B data bus, developed for the F-22, was derived from the commercial IEEE-1394 "FireWire" bus system, often used on personal computers. The same data bus is employed by the subsequent F-35 Lightning II fighter.
F-22 Raptor Cockpit
The F-22 Raptor cockpit is a glass cockpit design without any traditional analog flight instruments and represents a marked improvement on the cockpit design of previous advanced aircraft. The leading features of the F-22 cockpit include simple and rapid start-up, highly developed HMI, light helmet, large anthropometric accommodation and highly integrated warning system. Other main features include the large single-piece canopy, side stick and improved life support systems.
F-22 Raptor Airframe
The YF-22A prototype and production F-22A are sometimes confused in pictures, often at angles where it is difficult to see certain features. Several small design changes were made from the YF-22 to the F-22A. The swept-back angle on the wing's leading edge was decreased from 48 degrees to 42 degrees, while the vertical stabilizer area was decreased 20%. To improve pilot visibility, the canopy was moved forward 7 inches (178 mm) and the engine intakes were moved rearward 14 inches (356 mm). The shape of the wing and stabilator trailing edges was refined to improve aerodynamics, strength, and stealth characteristics. Also, the vertical stabilizer was shifted rearward. The airframe also features three internal weapons bays on the bottom and sides of the fuselage.
F-22 Armament
The F-22 Raptor has internal weapons bays that can carry a maximum of six missiles or four bombs in the center bay, and one missile in each side bay. Carrying missiles and bombs internally maintains its stealth capability and maintains lower drag resulting in higher top speeds and longer combat ranges. Launching missiles requires opening the weapons bay doors for less than a second, while the missiles are pushed clear of the airframe by hydraulic arms. This reduces the Raptor's chance of detection by enemy radar systems due to launched ordnance. The aircraft can also carry such air-to-surface weapons as bombs with the Joint Direct Attack Munition (JDAM) guidance system, and the new Small-Diameter Bomb (SDB). The F-22 Raptor carries an M61A2 Vulcan 20 mm rotary cannon, also with a trap door, in the right wing root. The M61A2 is a last ditch weapon, and carries only 480 rounds; enough ammunition for approximately five seconds of sustained fire. The F-22 Raptor has been able to use its gun in dogfighting without being detected, which can be necessary when missiles are depleted.
The F-22 Raptor very high sustained cruise speed and operational altitude add significantly to the effective range of both air-to-air and air-to-surface munitions. These factors may be the rationale behind the USAF's decision not to pursue long-range, high-energy air-to-air missiles such as the MBDA Meteor. However, the USAF plans to procure the AIM-120D AMRAAM, which will have a significant increase in range compared to the AIM-120C. The Raptor launch platform provides additional energy to the missile which helps improve the range of air-to-ground ordnance. 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. In testing, a Raptor dropped a 1,000 lb (450 kg) JDAM from 50,000 feet (15,000 m), while cruising at Mach 1.5, striking a moving target 24 miles (39 km) away. 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. The AIM-120 is the basic missile and the AIM-9 Sidewinder is the short range missile.
While in its air-superiority configurationThe F-22 Raptorcarries its weapons internally, it is not limited to this option. The wings include four hardpoints, each rated to handle 5,000 lb (2,300 kg). Each hardpoint has a pylon that can carry a detachable 600 gallon fuel tank or a rail launcher that holds two air-air missiles. However, use of external stores compromises the F-22's stealth, and has a detrimental effect on maneuverability, speed, and range (unless external fuel is carried). The two inner hardpoints are "plumbed" for external fuel tanks. These hardpoints allow the mounting pylons to be jettisoned in flight so the fighter can regain its stealth after exhausting external stores. Research is currently being conducted to develop stealth ordnance pod and pylon. Such a pod would comprise a low observable shape and carry its weapons internally, then would open when launching a missile or dropping a bomb. The pod and pylon could be detached when no longer needed. This system would allow The F-22 Raptor to carry its maximum ordnance load while remaining stealthy with a loss of maneuverability.
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 Raptor 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. The F-22 Raptor has also been designed to disguise its infrared emissions to make it harder to detect by infrared homing ("heat seeking") surface-to-air or air-to-air missiles. Designers also made the aircraft less visible to the naked eye, and controlled radio and noise emissions. The F-22 Raptor has an under bay carrier made for hiding heat from missile threats, like surface-to-air missiles.
The F-22 Raptor 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 additional maintenance work that decreases their mission capability rate to approximately 62-70%.
The effectiveness of this emphasis on stealth characteristics during the F-22 design process is difficult to measure. While its radar cross-section is almost nonexistent, this is merely a static measurement of the aircraft's frontal or side area and is valid only for a radar source in a stationary location relative to the aircraft. 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. Furthermore, the use of stealth contouring and radar absorbent material are chiefly effective against high-frequency radars, the type usually found on other aircraft. Low-frequency radars, including weather radars and warning stations in areas of the former Soviet Union, are less affected by stealth characteristics and are more capable of detecting some of the aircraft employing them.
F-22 Raptor External lighting
The F-22 Raptor 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.
