Over the past two years, Washington Dulles International Airport, along with airports in Atlanta; Boston; Bridgeport, Conn.; Manchester, N.H.; Philadelphia; and Newark, have offered hundreds of parents and autistic children “mock boarding” experiences, allowing them to practice buying tickets, walk though security lines and strap themselves into a plane that never leaves the gate.
As of now, Jet Blue, AirTran, Continental, Frontier, Southwest and United Airlines have participated.
http://travel.nytimes.com/2012/10/28/travel/testing-autism-and-air-travel.html?pagewanted=all&_r=2