Saturday, October 8, 2011

Deadly F-22 Raptor : The King on The Air

Army and Weapons | Deadly F-22 Raptor : The King on The Air | The Lockheed Martin / Boeing F-22 Raptor is a single-seat, twin engine of the fifth generation super-maneuverable fighter that uses stealth technology. It was designed primarily as an air superiority fighter, but has additional features that fall to the ground, electronic warfare and signals intelligence roles to take. Lockheed Martin Aeronautics is the prime contractor and is responsible for most of the airframe, weapon systems and final assembly of the F-22. Program partner Boeing Defense & Space Security provides the wings, rear fuselage, avionics integration and training systems.

The plane was different designated F-22 and F/A-22 in the years prior to formally entering USAF service in December 2005 as the F-22A. Despite a lengthy and costly development period, the United States Air Force considers the F-22 is an essential element of U.S. tactical air force, and claims that the aircraft is unmatched by any known or projected fighter, while Lockheed Martin claims that the Raptor combination of stealth, speed, agility, precision and situational awareness combined with air-air and air-ground combat capabilities makes it the best overall fighter in the world today. Air Chief Marshal Angus Houston, former head of the Australian Defence Force, said in 2004 that the "F-22 will be the most outstanding fighter ever built."
The high cost of the aircraft, a lack of clear air-to-air combat missions because of delays in the Russian and Chinese fifth-generation fighter program, a U.S. ban on exports Raptor, and the continued development of the planned cost and versatile F-35 led to calls to F-22 production ended. In April 2009 the U.S. Department of Defense proposed to cease placing new orders, subject to congressional approval, for a final purchase strips of 187 Raptors. The National Defense Authorization Act for fiscal year 2010 lacked the funding for the further F-22 production.
The F-22 Raptor is a fifth generation fighter that is fourth-generation stealth aircraft in the opinion of the USAF. Its dual afterburning Pratt & Whitney F119-PW-100 turbofans incorporate thrust vectoring pitch axis, 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. Maximum speed, without external weapons, is estimated to be Mach 1.82 in super cruise mode, as demonstrated by General John P. Jumper, former U.S. Air Force Chief of Staff, when his Raptor exceeded Mach 1.7 without afterburners on January 13, 2005. With afterburners, it is "greater than Mach 2.0" (1.317 mph, 2120 kmh). Former Lockheed F-22 chief test pilot Paul Metz stated that the Raptor has a fixed inlet, the absence of variable intake ramps usually limited to speeds of around Mach 2.0. Metz has also stated that the F-22 a higher climb rate 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 (the F- 22 has a ratio closer to 1:1). The U.S. Air Force claims that the Raptor can not be matched by a known or projected fighter types, and Lockheed Martin asserts, "The F-22 is the only aircraft that super cruise speed, super-agility, stealth and sensor fusion fits into a single air dominance platform. "
The ability of hulls for both heat stress and to resist a major design factor, so the F-22 makes use of many polymers, but as a part of the materials are a significant health risk for staff, technicians require protection, such as eye protection, respirators and gloves to work on the plane. The use of internal weapons bays, the aircraft to maintain a relatively higher performance while carrying a heavy load over many other devices due to a lack of resistance of external stores. It is one of only a few of the planes that can super-cruise, durable supersonic flight without using afterburners, reducing fuel consumption. The F-22 can intercept fast-moving or time-critical targets a subsonic aircraft that does not follow the speed-dependent and an afterburner aircraft would have a lack of fuel to reach.
The F-22 is highly maneuverable, at both supersonic and subsonic speeds. It is extremely departure-resistant, making it manageable to extreme pilot inputs. The thrust vectoring nozzles allow Raptor aircraft running tight, and extremely high alpha tasks (angle of attack) maneuvers such as the Herbst maneuver (or J-turn), Pugachev Cobra, and Kulbit. The F-22 is also capable of maintaining a constant angle of attack of more than 60 degrees, but still some control of the roll. During June 2006 exercises in Alaska, F-22 pilots demonstrated that cruising altitude has a significant effect on combat performance has, and often attributed their altitude advantage as a major factor in achieving a flawless kill ratio against other U.S. fighters and 4th/4.5th generation fighters.
The F-22's avionics are BAE Systems E & IS radar warning receiver (RWR) AN/ALR-94, AN / AAR 56 Infra-Red and Ultra-Violet mouths (Missile Approach Warning System) and the Northrop Grumman AN/APG-77 Active Electronically Scanned Array (AESA) radar. The AN/ALR-94 is a passive receiver system to detect radar signals, composed of more than 30 antennas blended into the wings and fuselage to concerns about coverage. It was described by Tom Burbage, the former F-22 program, Lockheed Martin chief, as "the most technically complex device in the plane." It has a longer range (250 + NMI) than the radar, so the F-22 with its own radar emissions limit to maximize stealth. If destination is approaching, the receiver can cue the AN/APG-77 radar to the target track with a narrow beam, which can be directed downwards to 2 ° by 2 ° in azimuth and elevation.
The AN/APG-77 radar, designed for air superiority and strike operations, features a low-observable, active-aperture, electronically scanned array that can track multiple targets in all weather conditions. The AN/APG-77 changes frequencies more than 1,000 times per second to lower probability of interception. In addition, radar emissions are concentrated in an electronic warfare ability to overload enemy sensors.
The radar of the information is processed by two Raytheon Common Integrated Processor (CIP) s. Each CIP can process 10.5 billion instructions per second and has 300 megabytes of memory. Information can be obtained from the radar and other onboard and offboard systems, filtered by the CIP, and offered in easy to digest different ways cockpit displays, enabling the pilot to stay on top of complicated situations. The F-22s avionics software has about 1.7 million lines of code, most relating to the processing of data from the radar. The radar has a range of approximately 125 to 150 miles, but the planned upgrades will be a range of 250 miles (400 km) or more in narrow beams. In 2007, tests conducted 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 megabits per second and at gigabit speeds to receive this is much faster than the Link 16 system used by U.S. and allied aircraft, which transfers data at just over 1 Mbit / s.
The F-22 is a threat detection and identification capabilities compared to the RC-135 Rivet Joint. The F-22's stealth makes it possible to safely operate much closer to the battlefield, to compensate for the reduced capacity. The F-22 is able to function as a "mini-AWACS", but the radar is less potent than dedicated platforms like the E-3 Sentry. The F-22 pilot to late goals to identify the co F-15s and F-16's, and if two friendly aircraft are in the same plane designed to determine. It is reported as "sometimes many times quicker than the AWACS."
The F-22's radar is given a high bandwidth data transfer capability to be used for the transmission of data between friendly units in the operational area as possible. The F-22 can already pass data to other F-22s, resulting in significantly less radio "chatter". The IEEE-1394B data bus developed for the F-22 is derived from the commercial IEEE-1394 "FireWire" bus system, often used on personal computers. The same data bus is employed by the following F-35 Lightning II fighter. Sensor fusion combines the data from all onboard and offboard sensors in a common vision of the pilot being overwhelmed.
In an article criticizing former Navy Secretary John Lehman said "at least the F-22s are safe from cyber attack. Nobody in China knows how to program the 83 vintage IBM software they run." Former Secretary of the USAF Michael Wynne debt using the DoD Ada as a reason for cost overruns and schedule slippage on many major military projects, including the F-22 Raptor. The F-22 uses the INTEGRITY-178B operating system from Green Hills Software, which is also used on the F-35, various commercial aircraft and the Orion Crew Exploration Vehicle.
The Raptor has three internal weapons bays of the bottom and sides of the hull. It can carry six compressed transport medium range missiles in the middle bay and a short-range missiles in each of the two side bays. Four of the medium-range missiles may be replaced by two bomb racks that can carry both a medium-sized bomb or four small diameter bombs. Execution of missiles and bombs internally maintains its stealth capabilities and maintains a lower resistance results in a higher top speed and longer combat ranges. The launch of missiles requires opening the weapons bay doors for less than one second, while the missiles are pushed clear of the airframe by hydraulic arms. This reduces the risk of discovery by the Raptor enemy radar systems due to launched munitions and also allows the F-22 to launch long-range missiles while maintaining super cruise. The F-22 is also room for such air-ground weapons and bombs with the Joint Direct Attack Munition (JDAM) guidance system, and the new Small Diameter Bomb (SDB), but can not themselves be responsible for the laser-guided weapons. Entire air-ground munitions is currently limited to £ 2,000 (£ 17,000 compared to the F/A-18). The Raptor carries an M61A2 Vulcan 20 mm rotary cannon in the wing root. The M61A2 carries 480 rounds, enough ammunition for approximately five seconds of sustained fire. The opening for firing the gun the barrel is covered by a door when not in use stealth in order to maximize. The F-22 has been able to close the gun range in air combat training while avoiding detection.
Very high sustained the Raptor's cruising speed and operational altitude add significantly to the effective range of both air-air and air-ground munitions. This gives a 40% greater employment range air to air missiles than the F-35. The USAF plans to purchase the AMRAAM AIM-120D, reported a 50% increase in range compared to the AIM-120C have. While specific figures remain classified, is expected to employ JDAM in F-22s twice or more the effective range of munitions dropped by legacy platforms. In testing, a Raptor dropped a 1,000 pound (450 kg) of 50,000 JDAM feet (15,000 m) while cruising at Mach 1.5 the, finding a moving target 24 miles (39 km) away.
While the F-22 usually carries the weapons internally, the wings are four hard points, each rated to 5,000 pounds (2,300 kg) process. Each hard point is a pylon that a removable 600 liters fuel tank or a rocket that two air-air missiles can carry. However, the use of external storage has a detrimental effect on the F-22's stealth, agility and speed. The two inner points are hard "water" for external fuel tanks, the hard points can be jettisoned in flight, so the stealth fighter may be to maximize after exhaustion of external stores. A stealth ordnance pod and pylon is designed to house the following additional weapons.
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 can provide a radar return . However, reduced radar cross section is one of the five facets of the presence of lower order in the design of the F-22. The F-22 is designed to disguise its infrared emissions, making the threat of an infrared-homing ("heat scan"), ground-air or air-air missiles, thrust vectoring nozzles including the flat. The aircraft was designed to be less visible to the naked eye, radio, heat and noise are equally controlled.
The F-22 is apparently based 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 are climate-controlled hangars needed, the F-22 can undergo repairs on the flight line or in a normal hangar. Moreover, the F-22 has a "Signature Assessment System", which presents warning indicators such as normal wear-and-tear degrades the aircraft radar signature at the point of substantial repair. The exact radar cross section (RCS), remain classified, but in early 2009 Lockheed Martin released information about the F-22, indicating that the RCS (from certain angles) to have -40 dBsm - the equivalent radar reflectivity of a "steel marbles". Maintenance of the F-22's stealth characteristics mission capable rate reduces to about 62-70%.
The effectiveness of the stealth features is difficult to estimate. The RCS value is a restrictive measure of frontal or side of the plane area from the perspective of a static radar. Once the F-22 maneuvers, it reveals a completely different set of corners and surface, increasing the visibility. Moreover, the use of stealth and radar absorbent material contours are especially effective against high frequency radars, usually found on other aircraft. Low frequency radars, weather radar and in the service of warning stations on the ground, are said to be less affected by stealth characteristics and are more capable of detecting aircraft. The result of this weak and fleeting radar contact is that while the defenders could be aware of the presence of a stealth aircraft, means of interception can not reliably be vectored into shooting down the plane.