Helicopter: trivia, mystery, or what?
Folks here might be interested in the registration info on the helicopter, at:
http://www.airport-data.com/aircraft/N189B.html
Built in 1948, de-registered in 1959, it currently (Jan 19, 2013) states it is a Bell helicopter, model 47D, a two seater.
But in the movie, there is room for three people. The thing is shown flying with them, so it is not just a ground shot trick.
What I don't know is whether that couch seat, which held two men and a woman with no trouble, would be the usual "two seats", or if the owner (a company in Bakersfield, CA named "Helicopter Surveys, Inc.") installed it. I'm not sure I see how the seat belts worked on them.