Aviation and War Machine

The AIM-9 Sidewinder is a heat-seeking, short-range, air-to-air missile carried by fighter aircraft and recently, certain gunship helicopters. It is named after the Sidewinder snake, which detects its prey via body heat and also because of the peculiar snake-like path of flight the early versions had when launched.The Sidewinder was the first truly effective air-to-air missile, widely imitated and copied; yet its variants and upgrades remain in active service with many air forces after 5 decades. When a Sidewinder missile is being launched, NATO pilots use the brevity code Fox Two in radio communication, as with all rear-aspect, or “heat seeking” missiles.
Physics of Infrared Detection

In the 1940s, it was discovered that exposing lead sulfide to heat energy reduces the compound’s electrical resistance. This is an example of a property called photoconductivity; photoconductivity is also seen with illumination by other wavelengths of light[1] (see Ron Westrum’s book in reference section). One can measure the resulting current and then link that result to an action - in this case, a seeker head causing the missile to fly toward the heat source (a target aircraft or missile).

History
Early development

The development of the Sidewinder missile began in 1946 at the Naval Ordnance Test Station (NOTS), Inyokern, California, now the Naval Air Weapons Station China Lake, California as an in-house research project conceived by William Burdette McLean. McLean initially called his effort “Local Fuze Project 602″ using laboratory funding, volunteer help and fuze funding to develop what it called a heat-homing rocket. It did not receive official funding until 1951 when the effort was mature enough to show to Admiral “Deak” Parsons, the Deputy Chief of the Bureau of Ordnance (BUORD). It subsequently received designation as a program in 1952. The Sidewinder introduced several new technologies that made it simpler and much more reliable than its United States Air Force (USAF) counterpart, the AIM-4 Falcon that was under development in the same time period. After disappointing experiences with the Falcon in the Vietnam War, the Air Force replaced its Falcons with Sidewinders.

The primary advantage to the Sidewinder is its sophisticated, yet simple detection and guidance system. During WWII the Germans had experimented with infrared guidance systems in a large missile known as the Enzian, but were unable to get it to work reliably. The Enzian was guided by an IR detector mounted in a small, steerable telescope. A vane in front of the mirror shaded the detector, so the system could locate the target. By continually turning toward the telescope, the missile was guided toward the target using what is known as a pure pursuit. The Sidewinder improved on this concept and made it work.
Geometric arrangement of mirror, IR detector and target.
Geometric arrangement of mirror, IR detector and target.
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The Joint Direct Attack Munition (JDAM) is a low-cost guidance kit that converts existing unguided gravity bombs, or “dumb bombs”, into accurate, all-weather “smart” munitions. JDAM equipped bombs are guided to their target by an integrated inertial guidance system coupled with a Global Positioning System (GPS) receiver for enhanced accuracy, giving them a published range of up to 15 nautical miles from the release point. JDAM is a joint United States Air Force and United States Navy program. It is in service with the U.S. Air Force, U.S. Navy and the U.S. Marine Corps.

The F-22 Raptor is a fifth generation fighter aircraft which utilizes fourth generation Stealth technology.[3] It was originally envisioned as an air superiority fighter for use against the Soviet Air Force, but is equipped for ground attack, electronic warfare and signals intelligence roles as well. Faced with a protracted development period, the prototype aircraft was designated YF-22 and, as F/A-22 during the three years before formally entering United States Air Force service

in December 2005 as the F-22A. 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. Along with Lockheed Martin, partner Boeing Integrated Defense Systems provides the wings, aft fuselage, avionics integration, and all of the pilot and maintenance training systems.

Development
The Advanced Tactical Fighter (ATF) contract was a demonstration and validation program undertaken by the United States Air Force to develop a next-generation air superiority fighter to counter emerging worldwide threats, including development and proliferation of Soviet-era Su-27 ‘Flanker’-class fighter aircraft.
The original Lockheed Advanced Tactical Fighter concept, 1986.
The original Lockheed Advanced Tactical Fighter concept, 1986.

In 1981, USAF developed a requirement for a new air superiority fighter intended to replace the capability of the F-15 Eagle. It was envisaged that the ATF would incorporate emerging technologies including advanced alloys and composite material, advanced fly-by-wire flight control systems, higher power propulsion systems, and low-observable/stealth technology.

A request for proposal (RFP) was issued in July 1986, and two contractor teams, Lockheed/Boeing/General Dynamics and Northrop/McDonnell Douglas were selected in October 1986 to undertake a 50 month demonstration/validation phase, culminating in the flight test of two prototypes, the YF-22 and the YF-23.

• The original Boeing Advanced Tactical Fighter concept, 1986.
• The original Boeing Advanced Tactical Fighter concept, 1986.

Following a hard-fought fly-off competition, in August 1991 the YF-22 was declared the winner and Lockheed was awarded the contract to develop and build the Advanced Tactical Fighter.
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The Sukhoi Su-37 (NATO designation: Flanker-F) is a Russian multi-role jet fighter aircraft.

The Su-37 is a single-seat, all-weather, fighter and ground attack prototype aircraft, derived from the Su-27 ‘Flanker’. The Su-27 is a successful Soviet fourth generation jet aircraft that has been exported to over 20 nations. The Su-37 test aircraft made its maiden flight in April 1996 from the Zhukovsky flight testing center near Moscow.

The Su-37 included several updates over the Su-27, including all-weather multi-mode passive electronically scanned array radar with synthetic aperture, terrain avoidance, terrain mapping and a rear facing radar. The airframe includes a percentage of parts made from composites, unlike the all-metal Su-27. Additionally, the Su-37 incorporates the AL-37FU engines equipped with thrust vectoring. The Su-37’s nozzles are variable in pitch only and travel plus or minus 15 degrees, but they can be operated differentially to provide a rolling moment. The aircraft is also the first Russian aircraft with Hands On Throttle and Stick, or HOTAS, system. The Su-37 also stores a radar in the tailcone of the plane that allows it to fire missiles behind the plane.

The engine not only incorporates 2D TVC but also is tough and resistant to engine surge even during classic, inverted and flat spins, giving better reliability and maneuverability, such as when the AOA is as high as 180 degrees.

The Su-37 can carry air-to-air and air-to-surface weapons on 12 stations. The number of missiles and bombs carried can be increased to 14 with the use of multi-payload racks.

Russia has not ordered Su-37s, but it might find customers abroad, a market that now constitutes a sizable share of Sukhoi’s income. Several prototypes have been built, but the aircraft is not in production.

The most recent rumors regarding the development of the Su-37 is that the project was cancelled due to lack of funding. The two Su-37 prototypes were converted into Su-35 ‘Flanker-Es’, another Sukhoi prototype fighter.
From: wikipedia.org