četvrtak, 25. ožujka 2010.

A-10 Thunderbolt II


The A-10 Thunderbolt II is an American single-seat, twin-engine, straight-wing jet aircraft developed by Fairchild-Republic in the early 1970s. The A-10 was designed for a United States Air Forcerequirement to provide close air support (CAS) of ground forces by attacking tanks, armored vehicles, and other ground targets with a limited air interdiction capability. It is the first U.S. Air Force aircraft designed exclusively for close air support.

The A-10 was designed around the GAU-8 Avenger, a heavy automatic cannon which forms the aircraft's primary armament. The aircraft's hull incorporates over 900 lb (410 kg) of armor plating and was designed with survivability as a priority, with protective measures in place which enable the aircraft to continue flying even after taking significant damage.

The A-10's official name comes from the Republic P-47 Thunderbolt of World War II, a fighter that was particularly effective at close air support. The A-10 is more commonly known by its nickname "Warthog" or simply "Hog". As a secondary mission, it provides airborne forward air control, guiding other aircraft against ground targets. A-10s used primarily in this role are designated OA-10. The A-10 is expected to be replaced in 2028 or later.

The A-10 has superior maneuverability at low speeds and altitude, due to large wing area, high wing aspect ratio, and large ailerons. The large high aspect ratio wing also allows for short takeoffs and landings, permitting operations from primitive forward airfields near front lines. The aircraft can loiter for extended periods of time and operate under 1,000 ft (300 m) ceilings with 1.5 mi (2.4 km) visibility. It typically flies at a relatively slow speed of 300 knots (560 km/h; 350 mph), which makes it a much better platform for the ground-attack role than fast fighter-bombers, which often have difficulty targeting small and slow-moving targets.

Engine exhaust passes over the aircraft's horizontal stabilizer and between the twin tails, decreasing the A-10's infrared signature and lowering the likelihood that the aircraft can be targeted by heat-seeking missiles. The placement of the engines behind the wings partially shields them from anti-aircraft fire. The leading edge of the wing is honeycomb panel construction to provide strength with minimal weight compromise. Honeycomb panels of this type on the A-10 include the flap shrouds, elevators, rudders and other sections of the fins.

The A-10 is exceptionally tough. Its strong airframe can survive direct hits from armor-piercing and high-explosive projectiles up to 23 mm. The aircraft has triple redundancy in its flight systems, with mechanical systems to back up double-redundant hydraulicsystems. This permits pilots to fly and land when hydraulic power or part of a wing is lost. Flight without hydraulic power uses the manual reversion flight control system; this engages automatically for pitch and yaw control, and under pilot control (manual reversion switch) for roll control. In manual reversion mode, the A-10 is sufficiently controllable under favorable conditions to return to base and land, though control forces are much higher than normal. The aircraft is designed to fly with one engine, one tail, one elevator and half a wing torn off. Self-sealing fuel tanks are protected by fire-retardant foam. The A-10's main landing gear is designed so that the wheels semi-protrude from their nacelles when the gear is retracted so as to make gear-up landings (belly landing) easier to control and less damaging to the aircraft's underside. A belly landing would be required in the case of a landing gear failure. Additionally, the landing gear are all hinged toward the rear of the aircraft, so if hydraulic power is lost the pilot can simply drop the gear and a combination of gravity and wind resistance will open and lock the gear in place.

Although the A-10 can carry considerable disposable stores, its primary built-in weapon is the 30 mm GAU-8/A Avenger Gatling-type cannon. One of the most powerful aircraft cannon ever flown, it fires large depleted uranium armor-piercing shells. In the original design, the pilot could switch between two rates of fire: 2,100 or 4,200 rounds per minute; this was changed to a fixed rate of 3,900 rounds per minute. The cannon takes about half a second to come up to speed, so 50 rounds are fired during the first second, 65 or 70 rounds per second thereafter. The gun is precise; it can place 80% of its shots within a 40-foot (12.4 m) circle from 4,000 feet (1,220 m) while in flight. The GAU-8 is optimized for a slant range of 4,000 feet (1,220 m) with the A-10 in a 30 degree dive.

Specifications (A-10A)

General characteristics

  • Crew: 1
  • Length: 53 ft 4 in (16.26 m)
  • Wingspan: 57 ft 6 in (17.53 m)
  • Height: 14 ft 8 in (4.47 m)
  • Wing area: 506 ft² (47.0 m²)
  • Airfoil: NACA 6716 root, NACA 6713 tip
  • Empty weight: 24,959 lb (11,321 kg)
    • Loaded weight: 30,384 lb (13,782 kg)) On CAS mission: 47,094 lb (21,361 kg)
    • On anti-armor mission: 42,071 lb (19,083 kg
  • Max takeoff weight: 50,000 lb (23,000 kg)
  • Powerplant: 2× General Electric TF34-GE-100A turbofans, 9,065 lbf (40.32 kN) each

Performance

Armament

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