The General Dynamics F-16 VISTA ("Variable stability In-flight Simulator Test Aircraft"), is an experimental variant of the Lockheed Martin F-16 Fighting Falcon.
It is equipped with a multi-axis thrust vectoring nozzle, to provide optimal control in post-stall situations. The F-16 VISTA is a supermaneuverable aircraft, able to fly at a Angle of Attack, which is higher than on aircraft with conventional control surfaces.
The F-16 VISTA was succesfully tested, but the thrust vectoring nozzle was never installed into in-service F-16 Fighting Falcons.
The F-16 VISTA is not operational, but it is used by the US Air Force´s Test pilot school.