1961

With the lengthening development cycle and increasing cost of complex combat aircraft, preliminary studies of designs to replace Lansen attack and reconnaissance aircraft, and eventually Draken fighters, had begun in the early 1950’s. The Swedish Air Force decided on a common "platform" using specialized systems for the attack, reconnaissance and fighter roles.

In December 1961, the Government approved development of Aircraft System 37, the Viggen. The basic platform was the AJ 37 attack aircraft, to be followed by S 37 reconnaissance versions and the JA 37 fighter. The new aircraft had a novel and advanced aerodynamic configuration to meet the short take-off/landing and other performance requirements: a fixed foreplane with flaps was mounted ahead of and slightly above the delta main wing.