Despite the more overt attractions of Mach 2 aircraft the US Air Forces were forced to consider the CAS (close air support) mission because of the total unsuitability of its existing equipment. In both the Korean and Vietnam war, its aircraft had been worldbeaters but planned for a totally different kind of war. What has needed, it appeared, was something like and up-to-date Skyraider that could carry a heavy load of ordinance, had good endurance and could survive severe damage from ground fire. Between 1963 and 1969 extensive studies gradually refined the AX specification, which had begun by presupposing a twin turbo prop and ended with a larger aircraft powered by two torbofans. After an industry-wide competition the Northop A-9A and the Fairchild A-10A were chosen for prototype fly-off evaulation, which took place with two of each type at Edwards AFB in oct 1972. The A-10 was the winner and by 1975, the Air Force took its first delivery of the Thunderbolts. The Thuderbolt had undergone minor revisions since, with the Thunderbolt II having more up to date electronics and slight modifications in structural design and payload layout.

General Electric the winner of the contest to produce the 30mm tank-busting cannon, the most powerful ever fitted to any aircraft, with a very high muzzle velocity and rate of fire. This gun is considered the main weapon on the A-10. Muzzle horsepower was 20x that of the 75mm gun fitted to some B-25s in WWII. Named the Avenger Cannon, this 7-barreled gatling gun is driven hyraulically at either 2,100 or 4,200 rounds per min and is fed by a drum containing 1,350 rounds (weighing approx 3820lbs). Rounds are each a pound and a half in weight, a foot long and fired at a rate of approx 65 rounds per second. The shells are able to penetrate up to 4 inches of tank armor, thus the origin of it's first nickname, "tank killer". Empty cases are fed back to the rear of the drum. By 1978, ground reloading was made automatic by a specially designed reloading system. Currently, the gun used is a slight variant of the original, the GAU-8/A Avenger 30mm gatling gun. The accuracy of this cannon is exceedingly good, with over 80% of projectiles fired from over a mile away impact within a 30 foot radius. Projectiles fired can be of three types - Target Practice (TP) round, the Armor Piercing Incendiary (API) round, and the High Explosive Incendiary (HEI) round.

Underwing stores can be comprised of any of the Tactical Command inventory on 11 available pylons, 4 under each wing, and 3 under the main fuselage.

Uniquely, when retracted, the landing gear produde enough to allow for a damage free emergency landing. All tail surfaces are interchangeable, the cockpit is enclosed in a shell of titanium armour, and the engines are hung above the fuselage where infra-red signatures are at a minimum. The redundant primary structural sections allow the aircraft to survive direct hits from armor-piercing and high-explosive projectiles up to 23mm. Their self-sealing fuel cells are protected by internal and external foam-producing fire control systems. The A-10's redundant hydraulic flight-control systems are backed up by manual systems allowing pilots to fly and land even when hydraulic power is lost. The ACES II ejection seat system provides a "zero-zero" capability (zero velocity and zero altitude) either with the canopy removed or through the canopy. The toughness of this plane is staggering, thus earning it's nickname - "the Warthog". Upwards of 735 of these planes were ordered from Fairchild by the mid-seventies, with an evenutal inventory of 721 planes being produced. Still in active duty with 317 planes, older retired and modified A-10s are used in firefighting efforts where they can carry heavy loades of water, or deploy smoke jumpers over a forest fire.

The Thunderbolts were essential in the Gulf War, had a mission capable rate of 95.7%, flew 8,100 sorties and launched 90% of the AGM-65 Maverick missiles.

A-10 Thunderbolt II
Manufacturer:	Fairchild Republic Co.
Year Deployed:	March 1976
Crew:	1
Engines:	Two General Electric TF34-GE-100 turbofans
Speed:	420 mph (mach 0.56)
Length:	53' 4" (16.2 meters)
Height:	14' 8" (4.4 meters)
Wingspan:	57' 6" (17.4 meters)
Max Weight:	51,000 pounds (22,950 kilograms)
Range:	800 miles (695 nautical miles)
Cost:	$8.8 Million
No. in Service:	274 (max of 721)
Armorment:	One 30 mm GAU-8/A seven-barrel Gatling gun; up to 16,000 pounds (7,200 kilograms) of mixed ordnance on eight under-wing and three under-fuselage pylon stations, including 500 pounds (225 kilograms) of retarded bombs, 2,000 pounds (900 kilograms) of general-purpose bombs, incendiary and Rockeye II cluster bombs, combined effects munitions, Maverick missiles and laser-guided/electro-optically guided bombs, infrared countermeasure flares, electronic countermeasure chaff, jammer pods, 2.75-inch (6.99 centimeters) rockets, illumination flares and AIM-9 Sidewinder missiles.