Edna's husband, Jack Squire, flew for a few different airlines during his day. While he did fly passengers planes, his favorite was airmail flights to unique locations.
In the future I will be placing together films from Jack's personal film collection, but until that time here are a few YouTube links to different airplanes before 1940.
Jack did work for Pan Am about the same time as this first film.
• The first is a 38-minute film about Pan Am flights to South America. A very interesting 1935 tour of South America. (Jack and Edna lived in South America in the late 30s and early 40s) - LINK
• Sikorsky S-40 Flying Boat - (NOTE: In Jack's collection, he has a colour film of a similar model of this plane landing and unloading passengers). Great piece!) - LINK
• Latécoère 521 - Biggest Flying boat in its day - LINK
• A short 1931 film showing the first use of autopilot. - LINK