The Saab JAS-39 Gripen is a Swedish, single-engine, multi-role fighter with a canard configuration and mid-wing layout. In 1980, the Swedish government approved a research program to develop a successor to the AJ-37 Viggen. The design was completed in June 1981. Following approval, the government placed an order in May 1982 for prototype development and production of 140 JAS-39 Gripen ("Gryf") aircraft. Three months later, flight tests of the electric fly-by-wire control system mounted on a specially adapted Viggen began. Work on the prototypes began in 1984. The first prototype rolled off the assembly line on April 26, 1986.