Full Scale Development (FSD) F-117A Nighthawk number four was this 79-10783. It was assigned to the 410th Flight Test Squadron at Edwards AFB (CA) for further tests. The aircraft made its first flight on 7 July 1982 and became the Radar Cross Section workhorse of the five FSD aircraft built. Before it was based at Edwards, it flew with the 4450th up to 1992, then it was handed over to the 410th, at least up to 2007 before it was retired.