The plane that Quinn flies is a DeHavilland Beaver. Star Harrison Ford not only owned a DeHaviland Beaver, but he also flew the one in the movie. He had to go through several certifications for the insurance company to allow him not only to fly, but to also fly with the rest of the cast in the plane.
The DeHaviland Beaver used in the film is the exact same one used in the production of The Edge (1997). It crashed in both movies.
Julia Roberts was the original choice for the female lead.
When Robin (Anne Heche) asks Quinn (Harrison Ford) what age he is, Quinn hints that he's over fifty before whispering to her the answer (To which she says "You still look good," and Quinn replies, "I still am good!"). Ford was actually 55 by the time this movie came out.