Development of the FMA IA 58 Pucara ground-attack aircraft began in August 1966 and led to the flight of an unpowered aerodynamic test vehicle on 26 December 1967. The first powered prototype, by then known as the AX-2 Delfin, and with two 674kW Garrett TPE3311/U-303 turboprop engines installed, was flown for the first time on 20 August 1969. Subsequent prototypes were powered by Turbo-meca Astazou XVIG engines and fitted to all production aircraft. A cantilever low-wing monoplane of all-metal construction, the Pucara has what is virtually a T-tail, a retractable tricycle landing gear, and accommodation for a pilot and copilot in tandem on Martin-Baker ejection seats beneath a large transparent canopy. The initial production version, the IA 58A, flew for the first time on 8 November 1974 and first deliveries of 108 ordered for the Argentine air force began early in 1976 and continued until 1986. Six were also ordered for the air force of Uruguay. Forty improved IA 58B Pucara Bravos with advanced avionics and more powerful armament (30mm instead of 20mm cannon) were ordered for the Argentine air force in 1980 but were completed as IA 58As following the Falklands campaign. A single IA 66, a Pucara with more-powerful 746kW Garrett TPE331 engines, began its flight test programme in 1980 but did not proceed any further. Pucara production ended with a batch of 40 IA 58As built from 1986 onwards but no further sales were subsequently announced and they are believed to be in store as 'white tails'.