A-10 Thunderbolt

http://en.wikipedia.org/wiki/A-10_Thunderbolt_II

Criticism that the U.S. Air Force did not take close air support seriously prompted a few service members to seek a specialized attack aircraft.^[5] In the Vietnam War, large numbers of ground-attack aircraft were shot down by small arms, surface-to-air missiles, and low-level anti-aircraft gunfire, prompting the development of an aircraft better able to survive such weapons. In addition, the UH-1 Iroquois and AH-1 Cobra helicopters of the day, which USAF commanders had said should handle close air support, were ill-suited for use against armor, carrying only anti-personnel machine guns and unguided rockets meant for soft targets. The F-4 Phantom II was pressed into close air support, but usually in emergencies, as its high cruising speed and fuel consumption hindered its ability to loiter. The lack of a gun on most F-4 variants, coupled with the relative ineffectiveness of the standard 20 mm round on M61 Vulcan-equipped F-4Es against hard targets, made strafing runs either impossible or ineffective.

[edit] A-X

On 6 March 1967, the U.S. Air Force released a Request for Information to 21 defense contractors. Their objective was to create a design study for a low-cost attack aircraft designated A-X, or "Attack Experimental". The officer in charge of the project was Colonel Avery Kay.^[5] In 1969, the Secretary of the Air Force asked Pierre Sprey to write the detailed specifications for the proposed A-X project. However, his initial involvement was kept secret due to Sprey's earlier controversial involvement in the F-X project.^[5] Sprey's discussions with A-1 Skyraider pilots operating in Vietnam and analysis of the effectiveness of current aircraft used in the role indicated the ideal aircraft should have long loiter time, low-speed maneuverability, massive cannon firepower, and extreme survivability;^[5] an aircraft that had the best elements of the Ilyushin Il-2, Henschel Hs 129 and A-1 Skyraider. The specifications also demanded that the aircraft cost less than $3 million.^[5] In May 1970, the USAF issued a modified, and much more detailed request for proposals, as the threat of Soviet armored forces and all-weather attack operations became more serious. Six companies submitted proposals to the USAF, with Northrop and Fairchild Republic selected to build prototypes: the YA-9A and YA-10A, respectively.

USAF A-10 Thunderbolt II from 1975

The YA-10A first flew on 10 May 1972. After trials and a fly-off against the YA-9A, the Air Force selected Fairchild-Republic's YA-10A on 10 January 1973 for production. There was an additional fly-off against the Ling-Temco-Vought A-7D Corsair II, the principal Air Force attack aircraft at the time, in order to prove the need to purchase a new attack aircraft. The first production A-10 flew in October 1975, and deliveries to the Air Force commenced in March 1976 to units at Davis-Monthan Air Force Base, Arizona. The first squadron to use the A-10 went operational in October 1977. In total, 715 airplanes were produced, the last delivered in 1984.^[6]

One experimental two-seat A-10 Night Adverse Weather (N/AW) version was built by converting an A-10A.^[7] The Night Adverse Weather (N/AW) aircraft was developed by Fairchild from the first Demonstration Testing and Evaluation (DT&E) A-10 for consideration by the USAF. It included a second seat for a weapons system officer responsible for ECM, navigation and target acquisition. The variant was canceled and the only two-seat A-10 built now sits at Edwards Air Force Base awaiting a spot in the Flight Test Historical Foundation museum.^[8] The proposed two-seat A-10 trainer aircraft did not go into production, as it was felt that the A-10 was simple enough to fly that a trainer version would not be required.

USAF A-10A Thunderbolt II.

The decision to make the 30 mm GAU-8 gun the main anti-tank weapon of the A-10 was influenced by Vietnam era A-1 pilots and by Hans-Ulrich Rudel and his book, "Trotzdem" (Released in the U.S. as a substantially edited version under the name "Stuka Pilot"). In World War II, Rudel flew the Ju 87G Stuka for the Luftwaffe and destroyed many Soviet tanks using its two underwing Bordkanone BK 3.7 37 mm caliber anti-tank autocannon. His book was required reading for members on the A-X project. The Ju 87G was an outmoded airframe with improvised anti-tank weapons attached, yet still inflicted significant casualties on Soviet tank forces.

[edit] Upgrades

The A-10 has received many upgrades over the years. Aircraft were upgraded with inertial navigation and a Pave Penny laser sensor (marked target seeker) pod that allowed the pilot to detect laser energy for PID (Positive Identification) of an illuminated target. The Pave Penny is a passive seeker and cannot self-designate a target for a Laser Guided Bomb (LGB). Later, the Low-Altitude Safety and Targeting Enhancement (LASTE) upgrade provided computerized weapon-aiming equipment, an autopilot, and ground-collision warning system. The A-10 is now compatible with night vision goggles for low-light operation. In 1999, aircraft began to receive Global Positioning System navigation systems, and in 2005 began getting its LASTE system upgraded with the Integrated Flight & Fire Control Computers (IFFCC).

The A-10 is scheduled to stay in service with the USAF until 2028.^[9] In 2005, the entire A-10 fleet also began receiving upgrades that would result in redesignation to the "C" model that will include improved fire control system (FCS), electronic countermeasures (ECM), and the ability to carry smart bombs. The A-10 will be part of a service life extension program (SLEP) with many receiving new wings.^[9] A contract to build 242 new A-10 wing sets was awarded to Boeing on 29 June 2007.^[10] Modifications to provide precision weapons capability are well underway. The Air Force Material Command's Ogden Air Logistics Center at Hill AFB, Utah completed work on its 100th A-10 precision engagement upgrade in January 2008.^[11] The C model upgrades are to be completed in 2011.^[12]

[edit] Design

An A-10 entering a knife-edge pass.

The A-10 has superior maneuverability at low speeds and altitude, thanks to straight, wide wings with downturned "droop" wing tips. These also allow short takeoffs and landings, permitting operations from rugged, forward airfields near front lines. The aircraft can loiter for extended periods of time and operate under 1,000 feet (300 m) ceilings with 1.5-mile (2.4 km) visibility. It typically flies at a relatively slow speed of 300 knots (345 mph or 555 km/h), 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.