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A-7 Corsair on the Cat

In 1962, the United States Navy began preliminary work on VAX (Heavier-than-air, Attack, Experimental), a replacement for the A-4 Skyhawk with greater range and payload. A particular emphasis was placed on accurate delivery of weapons to reduce the cost per target. The requirements were finalized in 1963 and in 1964, the Navy announced the VAL (Heavier-than-air, Attack, Light) competition. Contrary to USAF philosophy, which was to employ only supersonic fighter bombers such as the F-105 Thunderchief and F-100 Super Sabre, the Navy felt that a subsonic design could carry the most payload the farthest distance. Theoretically, a "slow fat duck" could fly nearly as fast as a supersonic one, since carrying dozens of iron bombs also restricted its entry speed, but a fast aircraft with small wings and an afterburner would burn more fuel.

 

To minimize costs, all proposals had to be based on existing designs. Vought, Douglas Aircraft, Grumman and North American Aviation responded. The Vought proposal was based on the successful F-8 Crusader fighter, having a similar configuration, but shorter and more stubby, with a rounded nose. It was selected as the winner on 11 February 1964, and on 19 March the company received a contract for the initial batch of aircraft, designated A-7. In 1965, the aircraft received the popular name Corsair II, after Vought's highly successful F4U Corsair of World War II. (There was also a Vought O2U Corsair biplane scout and observation aircraft in 1920s.)

 

Compared to the F-8 fighter, the A-7 had a shorter, broader fuselage. The wing was made larger, and the unique variable incidence wing of the F-8 was deleted. To achieve the required range, the A-7 was powered by a Pratt & Whitney TF30-P-6 turbofan producing 11,345 lbf (50.5 kN) of thrust, the same innovative combat turbofan produced for the F-111 and early F-14 Tomcats, but without the afterburner needed for supersonic speeds. Turbofans achieve greater efficiency by moving a larger mass of air at a lower velocity.

 

The aircraft was fitted with an AN/APQ-116 radar, later followed by the AN/APQ-126, which was integrated into the ILAAS digital navigation system. The radar also fed a digital weapons computer which made possible accurate delivery of bombs from a greater stand-off distance, greatly improving survivability compared with faster platforms such as the F-4 Phantom II. It was the first U.S. aircraft to have a modern head-up display, now a standard instrument, which displayed information such as dive angle, airspeed, altitude, drift and aiming reticle. The integrated navigation system allowed for another innovation – the projected map display system (PMDS) which accurately showed aircraft position on two different map scales.

 

The A-7 enjoyed the fastest and most trouble free development period of any American combat aircraft since World War II. The YA-7A made its first flight on 27 September 1965, and began to enter Navy squadron service late in 1966. The first Navy A-7 squadrons reached operational status on 1 February 1967, and began combat operations over Vietnam in December of that year.

USS Midway Aircraft Carrier CV-41 Museum-San Diego Ca.

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Uploaded on February 27, 2009
Taken on July 11, 2008