Flight Simulation is a flight simulation program written by Psion and marketed by Sinclair Research for the Sinclair ZX81 and ZX Spectrum home computers.It was also marketed as Flug-Simulation in German. In the United States, Timex Sinclair marketed the ZX81 version as The Flight Simulator for the Timex Sinclair 1000 (the American version of the ZX81).The program simulated the essential aspects of "a highly-manoeuvrable light aircraft" in flight.