Fairchild C-123K Provider N4410F was bought by Corporate Air Services, which was working on behalf of the CIA. The airplane was re-registered HPF821. In 1986 HPF821 was used on a U.S. government-sponsored covert resupply program for the Contras in Nicaragua. On October 5, 1986 the flight departed San Salvador-Ilopango Airport loaded with 70 Soviet-made AK-47 rifles and 100,000 rounds of ammunition, rocket grenades and other supplies. It flew along the Nicaraguan coastline and entered Nicaraguan airspace near the Costa Rican border. Nearing San Carlos, the plane descended to 2500 feet while preparing to drop off its cargo. At that moment the Provider was shot down by a Sandinista soldier using a 9K32 Strela-2 shoulder-fired, surface-to-air missile (also known as SA-7). As it spiralled down, one crew member was able to parachute to safety. He was captured by the Sandinistas.