The Lockheed F-117 Nighthawk is a singleat, twin-engine stealth ground-attack aircraft formerly operated by the United States Air Force (USAF). A product of Lockheed Skunk Works and a development of the Have Blue technology demonstrator, the F-117 was the first operational aircraft to be designed around stealth technology. The maiden flight for the type was conducted in 1981, and it achieved initial operating capability status in October 1983. The F-117 was "acknowledged" and revealed to the world in November 1988. The F-117 was widely publicized for its role in the Persian Gulf War of 1991. It was commonly referred to as the "Stealth Fighter", although it was a strictly ground-attack aircraft. The F-117 also saw combat in Yugoslavia; during which the only aircraft of the type to be lost in combat was shot down by a surface-to-air (SAM) battery on 27 March 1999. The Air Force retired the F-117 on 22 April 2008.