Editing Celestial navigation (section)

==Training==
Celestial navigation training equipment for aircraft crews combine a simple [[flight simulator]] with a [[planetarium]].

An early example is the [[Link Trainer|Link Celestial Navigation Trainer]], used in the [[Second World War]].<ref>{{cite web|title=World War II|work=A Brief History of Aircraft Flight Simulation|url=http://homepage.ntlworld.com/bleep/SimHist4.html|access-date=January 27, 2005|url-status=dead|archive-url=https://web.archive.org/web/20041209093839/http://homepage.ntlworld.com/bleep/SimHist4.html|archive-date=December 9, 2004}}</ref><ref>{{cite web|title=Corporal Tomisita "Tommye" Flemming-Kelly-U.S.M.C.-Celestial Navigation Trainer −1943/45|work=World War II Memories|url=http://www.geocities.com/CapeCanaveral/Runway/9601/kelly.html|access-date=January 27, 2005|archive-url=https://web.archive.org/web/20050119104703/http://www.geocities.com/CapeCanaveral/Runway/9601/kelly.html|archive-date=2005-01-19}}</ref> Housed in a {{convert|45|ft|m|adj=on}} high building, it featured a [[Cockpit (aviation)|cockpit]] accommodating a whole [[bomber]] crew (pilot, navigator, and bombardier). The cockpit offered a full array of [[Measuring instrument|instruments]], which the [[Aviator|pilot]] used to fly the simulated airplane. Fixed to a [[Astrodome (aviation)|dome]] above the cockpit was an arrangement of lights, some [[collimated]], simulating [[constellation]]s, from which the navigator determined the plane's position. The dome's movement simulated the changing positions of the stars with the passage of time and the movement of the plane around the Earth. The navigator also received simulated radio signals from various positions on the ground. Below the cockpit moved "terrain plates"—large, movable aerial photographs of the land below—which gave the crew the impression of flight and enabled the bomber to practice lining up bombing targets. A team of operators sat at a control booth on the ground below the machine, from which they could simulate [[weather]] conditions such as wind or clouds. This team also tracked the airplane's position by moving a "crab" (a marker) on a paper map.

The Link Celestial Navigation Trainer was developed in response to a request made by the [[Royal Air Force]] (RAF) in 1939. The RAF ordered 60 of these machines, and the first one was built in 1941. The RAF used only a few of these, leasing the rest back to the US, where eventually hundreds were in use.