A flight simulator is a device that artificially re-creates aircraft flight and the environment in which it flies, for pilot training, design, or other purposes. It includes replicating the equations that govern how aircraft fly, how they react to
applications of flight controls, the effects of other aircraft systems, and how
the aircraft reacts to external factors such as air density, turbulence, wind
shear, cloud, precipitation, etc. Flight simulation is used for a variety of
reasons, including flight training (mainly of pilots), the design and development of the aircraft itself, and research into aircraft characteristics and control handling qualities.