Abstract: An air combat simulator including a part spherical screen, a remotely controlled horizon projector positioned so as to project onto the screen a scene consisting of sky and ground terrain, and a t.v. projection system for projecting onto the screen an image of an opponent's aircraft. A simulated manned aircraft consisting of a pilot's control station is positioned to view the screen and has flight controls arranged to generate flight control signals and a computer is arranged to control the horizon projector and opponent's aircraft image projector in dependence upon the flight control signals and upon a tactical decision making process programmed into the computer. To simulate range variation the size of the opponent's aircraft is varied by controlling the raster dimensions of a t.v. picture formed in the t.v. projection system, which system does not include a zoom lens.