f14

[edit] Design







[edit] Overview
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 360 degree visibility. The plane features variable geometry wings that swing automatically during flight. For high-speed intercept, they are swept back; they swing forward to allow the F-14 to turn sharply and dogfight. It was designed to improve on the F-4 Phantom's air combat performance in several 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 U.S. Navy wanted the F-14 to have a thrust-to-weight ratio of one or greater, though this was not achieved until after the F-14 entered service because of delays in engine development.


[edit] Fuselage and wings
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. However, this tunnel provides space to carry Phoenix or Sparrow missiles, assorted bombs, or the TARPS reconnaissance pod, and increases fuel capacity and room for equipment.[7]

The F-14's wing sweep can be varied between 20° and 68° in flight,[15] and is automatically controlled by an air data computer. 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 tail to save space on tight carrier decks. In an emergency, the F-14 can land with the wings fully swept to 68°,[7] although this is far from optimum and presents a significant safety hazard. The F-14 can also fly and land safely with the wings swept asymmetrically, in emergencies.[16]

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,[7] 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.[7] 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.[7] 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 mount points are provided for external fuel tanks.

Two 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 at above Mach 1. They were later disabled, however, owing to their additional weight and complexity.[7]

The airbrakes consist of top-and-bottom extendable surfaces at the rearmost portion of the fuselage, between the engine nacelles. The bottom surface is split into left and right halves, with the arrestor hook hanging between the two halves. This arrangement is sometimes called the "castor tail",[17] or "beavertail."[18] The Tomcat has fully mechanical flying controls,[7] with the only exception being the spoilers, which are hydro-electrically driven.