 DATE: When Frank interviews potential stewardesses, one of them  sings a line from the song "Leaving on a Jet Plane". This scene  takes place in 1966 or 1967, long before the song was made popular  by Peter, Paul, and Mary in 1969. The song was written in 1967,  which might have been before the scene in question, but it is highly  unlikely that a student would have known the song before 1969.