utorak, 23. ožujka 2010.

F-14 Tomcat

The Grumman F-14 Tomcat is a supersonic, twin-engine, two-seat, variable-sweep wing aircraft. The F-14 was the United States Navy's primary maritime air superiority fighter, fleet defense interceptor and tactical reconnaissance platform from 1974 to 2006. It later performed precision strike missions once it was integrated with the Low Altitude Navigation and Targeting Infrared for Night LANTIRN system. The F-14 was developed after the collapse of the F-111Bproject, and was the first of the American teen-series fighters which were designed incorporating the experience of air combat against MiGs during the Vietnam War.

The F-14 first deployed in 1974 with the U.S. Navy aboard USS Enterprise, replacing the F-4 Phantom II and was retired from the active U.S. Navy fleet on 22 September 2006, having been replaced by the F/A-18E/F Super Hornet. As of 2009, the F-14 is in service with only the Islamic Republic of Iran Air Force, having been exported to Iran in 1976, during a time when the US had good diplomatic relations with the nation.

The F-14 Tomcat was designed as both an air superiority fighter and a long-range naval interceptor. The F-14 has a two seat cockpit with a canopy that affords all-round visibility. It features variable geometry wings that swing automatically during flight. For high-speed intercept, they are swept back and they swing forward for lower speed flight. It was designed to improve on the F-4 Phantom's air combat performance in most respects. The F-14's fuselage and wings allow it to climb faster than the F-4, while the twin-tail arrangement offers better stability. The F-14 is equipped with an internal 20 mm M61 Vulcan Gatling-type gun mounted on the left side, and can carry AIM-54 Phoenix, AIM-7 Sparrow, and AIM-9 Sidewinder anti-aircraft missiles.

The fuselage consists of a large flat area called the "pancake" between the engine nacelles. Fuel, electronics, flight controls, and the wing-sweep mechanism are all housed in the fuselage "pancake". The "pancake" also provides additional lift. The wings pivot from two extensions on either side of the "pancake", called wing gloves. The twin engines are housed in nacelles below and slightly to the rear, with the fuselage smoothly blending into the shape of the exhaust nozzles. The nacelles are spaced apart 1 to 3 feet. This produces a wide tunnel between the nacelles which causes some drag, but adds considerable lift and pitching ability. The resultant tunnel provides space to carry Phoenix or Sparrow missiles, assorted bombs, or the TARPS reconnaissance pod, and increases fuel capacity and room for equipment.

The F-14's wing sweep can be varied between 20° and 68° in flight, and can be automatically controlled by the Central Air Data Computer when the pilot selects "auto" wingsweep mode. This maintains the wing sweep to give the optimum lift-to-drag ratio as the Mach number varies, but the system can be manually overridden by the pilot if necessary. When the aircraft is parked, the wings can be "overswept" to 75°, where they overlap the horizontal stabilizers to save space on crowded carrier decks. In an emergency, the F-14 can land with the wings fully swept to 68°, although this is far from optimum and presents a significant safety hazard due to significantly increased airspeed. An aircraft is typically diverted from the aircraft carrier to a landing field ashore in the rare event that would occur. The F-14 has also flown and landed safely with the wings swept asymmetrically even from an aircraft carrier in emergencies.

The wings have a two-spar structure with integral fuel tanks. Much of the structure, including the wing box, wing pivots and upper and lower wing skins is made of titanium, a light, rigid and strong material, but also difficult to weld, and costly. Ailerons are not fitted, with roll control being provided by wing mounted spoilers at low speed (which are disabled if the sweep angle exceeds 57°), and by differential operation of the all-moving tailerons at high speed. Full-span slats and flaps are used to increase lift both for landing and combat, with slats being set at 17° for landing and 7° for combat, while flaps are set at 35° for landing and 10° for combat. The twin tail layout helps in maneuvers at high AoA (angle of attack) while reducing the height of the aircraft to fit within the limited roof clearance of hangars aboard aircraft carriers. Two under-engine nacelle mount points are provided for external fuel tanks carrying an additional 4,000 lb of fuel.

Two triangular shaped retractable surfaces, called glove vanes, were originally mounted in the forward part of the wing glove, and could be automatically extended by the flight control system at high Mach numbers. They were used to generate additional lift ahead of the aircraft's center of gravity, thus helping to compensate for the nose-down pitching tendencies at supersonic speeds. Automatically deployed at above Mach 1.4, they allowed the F-14 to pull 7.5 g at Mach 2 and could be manually extended with wings swept full aft. They were later disabled, however, owing to their additional weight and complexity.

Two rectangular air intakes located under the wings fed two Pratt & Whitney TF30 (or JT10A) engines, which were relatively powerful for the time (5.670/9.480 kg/t) and being turbofans allowed reduced fuel consumption while cruising, which was important for long patrol missions.The cockpit has two seats, arranged in tandem.

The Tomcat was originally designed to combat both highly maneuverable aircraft and the Soviet cruise missile/bomber threat. As a result, the aircraft was designed to act effectively in every aspect of air combat. For weaponry, the Tomcat was designed as a platform for the formidable AIM-54 Phoenix, but unlike the stillborn F-111B it could also engage medium and short range threats. As such, the F-14 was a full air superiority fighter and not only a long range interceptor.
















Specifications (F-14D)

General characteristics

Performance

Armament

Avionics

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