At the beginning, Bob and Rhoda are flying together. In real life, Robert Cummings was not only a pilot, but also a flight instructor. He was the first instructor to receive a license from the government. He also instructed pilots during World War 2. He was also the godson of Orville Wright who taught him to fly.
Well known for his Humphrey Bogart impersonation, Guy Marks, playing Knuckles, employs his comedic skills as an impressionist to imitate the voice and mannerisms of the classic movie tough guy.