I saw this film some years back on PBS and only wish I could find a copy of it now. A young woman witnesses a murder in New York, and promptly leaves for England. She sees the news in a London paper about a man in New York about to be executed for the murder, and she knows he is innocent. She has to get back to NY as fast as possible to save an innocent man from the electric chair, and so she stows on the Air Boat, Non-stop to New York. Some of the lines are so good that years later, they still echo in my head.
Much of the movie takes place on this incredible aircraft, which takes off from the Thames in London, and is like a flying..., well, boat. Dining room, state rooms, close quarters, nasty travel companions. It's all here.
Borders on Film Noir, but with a wry sense of humor.
If you like the style of the 1940s, and slightly outlandish stories so characteristic of the period, I dare say you will enjoy this English trifle quite a bit!
I won't reveal the ending, so you'll have to see the film to know if she arrives in time!