<p>The A-37 Dragonfly is a small, low-cost combat aircraft that was employed until recently for the FAC (forward air control) mission by elements of the Air National Guard. Developed from the T-37 trainer, the A-37 was initially utilised in the COIN (counter-insurgency) light attack role, before being adapted to serve as a FAC. Today, however, barely a handful of examples are still operated by the USAF on low-speed chase-plane duties with the Air Force Flight Test Center at Edwards AFB, California.
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<p>The aircraft is a conventional, all-metal, twin-jet monoplane with a single functional crew seat (at left) and a second crew position (at right) which is normally not used, both in side-by-side ejection seats beneath a single broad clamshell canopy. The OA-37B is configured with two small engines in the wing roots with nozzles at the trailing edge. Tricycle landing gear is low and wide-tracked. The horizontal tail of the aircraft is mounted above the fuselage about one-third of the way up the fin to assure that the airstream flowing past it is undisturbed by jet exhaust.
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<p>The OA-37B has manual controls with electric trim, hydraulic slotted flaps, and hydraulic landing gear. Its strengthened wing has eight underwing hardpoints for a variety of bombs and rockets, and a GAU-2B/A 7.62-mm Minigun in the fuselage. The OA-37B is powered by two 2,850-lb (1,293-kg) thrust General Electric J85-GE-17A turbojet engines.
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<p>The history of the OA-37B began with the T-37 jet trainer, itself dating to the mid-1950s. The XT-37 prototype (54-0716) first flew on 12 October 1954, and the first T-37A (54-2729) on 27 September 1955. Five hundred and thirty-four T-37As were followed in November 1959 by the T-37B with more powerful engines. The T-37C, with armament and wing hardpoints for ordnance, was exported but not adopted by the USAF.
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<p>Efforts to adopt the basic T-37 design for an air-to-ground combat mission began in 1958 when the US Army evaluated three T-37s at Fort Ord, California. Soon thereafter, the Army looked at the Fiat G91, Douglas A4D-2 Skyhawk and Northrop N.156 fighters, but never overcame the legal bar to the Army operating fixed-wing combat aircraft.
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<p>The USAF tried its own version with the YAT-37D. Two T-37 trainers were modified on the production line to result in the YAT-37D armed version of the trainer, which first flew on 22 October 1963. With crew armor, strengthened wings, J85 engines (replacing J69s on the trainer), and hardpoints for ordnance, the YAT-37D was exhaustively tested but not evaluated.
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<p>During the Vietnam War, efforts to find a combat role for the basic T-37 resumed. The USAF on 2 May 1967 began to fly the A-37A Dragonfly, a converted T-37B, for close air support and Special Operations missions. Thirty-nine A-37As (briefly known, in the planning stage, as AT-37Ds) with de-rated J85s were built by converting T-37Bs on the production line. Some were assigned to the South Vietnamese Air Force.
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<p>The A-37B which followed in January 1967 was virtually a new aircraft, weighing nearly twice as much as a T-37 trainer. A total of 577 A-37Bs was built.
