The Cessna A-37 Dragonfly is a so-called COIN aircraft that is developed from the T-37 beginner jet training aircraft against guerrillas. The A was made of 39 aircraft from the T-37B, followed by the B with a more powerful engine and an aerial oil receiver. In 1980, the US State Air Corps adopted the A-37B for front air control (FAC) and named it OA-37B.