The Spirit of St. Louis became almost
a character in the movie itself. Lindbergh spent more than 33 hours alone in the airplane’s cramped cockpit on his transatlantic flight, and dramatizing that proved challenging when writing the screenplay.
One solution was to have Lindbergh talk to a fly that took refuge in
the airplane. “Mr. Stewart did not object to talking to insects,” said Wilder. “After all, he had to deal all of his life with agents and producers.”