nation in the world to propel an aircraft with biojet fuel. The project's intention was to make the FAA less reliant on fossil fuels. Since 2009 an extensive upgrade of the avionics and major overhaul of the airframes has been carried out by the FAA and FAdeA, creating the IA-58D Pucará Delta. The avionics for the cockpit are as close as possible to the FMA IA-63 Pampa Phase II. Some of the updated components include a new set of communications hardware, DME, ELT, IFF, GPS, EADI, EHSI, RWR, HUD, DEFA 554 cannon and new PT6A-62 950shp engine instead of the original Turbomeca Astazou. The overhaul is intended to keep Argentinian Pucarás in use until 2045. Bureaucratic and economic issues caused delays to the conversion of the entire fleet. The Uruguayan Air Force also showed interest in the maintenance, repair, and overhaul (MRO) program and installation of new engines offered by FAdeA. As of April 2016, Fábrica Argentina de Aviones "Brigadier San Martin" S.A. (FAdeA), successor to Fábrica Militar de Aviones, was in the process of modernizing twenty of the Argentine Air Force's fleet of Pucaras. The first prototype flew in November 2015. In 2019 Argentina retired the Pucará from counterinsurgency light strike operation, converting it to the Pucará Fénix border surveillance and patrol aircraft, with improved Pratt & Whitney Canada PT-6A-62 engines, new four-bladed propellers, a podded Fixview electro-optical/infrared (EO/IR) sensor turret, and datalink. The upgrade was authorised in December 2021, with the Fénix expected to be in operation for at least 15 years. Failed contracts The Peruvian Air Force was reported in mid 1972 to have shown great interest in acquiring up to 25 IA-58A for delivery in 1974. The first foreign contract was in February 1978 with the Islamic Air Force of Mauritania for four IA-58A planes plus support and training at a full cost of U$10.8 million. Another eight units were also negotiated as options. When Mauritanian President Moktar Ould Daddah was ousted in a coup d'état, the contract was cancelled. The plane series n°015 to n°018 were built and ready to ship with Mauritanian registration numbers. Then were incorporated to the Argentine Air Force as A-515 to A-518 keeping the desert camouflage and configuration. In March 1983, negotiations for two Pucarás were going with Central African Republic Air Force for US$9.5 million including support, training and spare parts. The contract was cancelled. In September 1983, another