Author John Irving's mother was not married at the time he was conceived. He never met his father nor would his mother talk about him. He eventually told her that if she didn't tell him about the father he would invent the man and circumstances of his conception. Her reply was "Go ahead, dear." "The World According to Garp" was that result.
John Irving recalls how funny and profane Williams was while being waxed for the role of young Garp in his novel "My Movie Business". Williams was a very hairy man.
The house that the plane crashes into was built at one end of the only runway at Lincoln Park Airport, a very small airstrip in Lincoln Park, New Jersey, (about 35 miles NW of New York City). The wrecked house was not removed for several weeks. While no planes have hit houses in the vicinity, one did bounce off the roof of a passing car several years earlier.