The Flying Tigers and God Is My Co-Pilot are the two films out of World War II which are dedicated to the American volunteers who flew for the nascent Chinese Air Force both before and after America officially got into World War II.
Though this film is based on fictional people it holds up a lot better than God Is My Co-Pilot because it avoids the racial stereotyping of the Japanese. The Japanese are seen, but only in aerial combat shots with no dialog. And it's true they did have a nasty habit of machine gunning fliers while they were parachuting down, no avoiding that.
The main plot of the film is John Wayne as the disciplined leader of this particular squadron of Flying Tigers based somewhere in western China and an old and rather undisciplined friend John Carroll in a rivalry over nurse Anna Lee. Carroll's irresponsibility causes the death of one man and maybe another.
Still he's not a bad sort, just an overgrown kid. Carroll actually has the best moment in the film consoling Mae Clarke the widow of one of the Flying Tigers.
Some nice aerial combat shots are in this film and it really should be seen today to explain some of the Chinese attitudes towards the Japanese today. We got into World War II on December 7, 1941 which in fact the men in Wayne's squadron hear about in the film. The Chinese were essentially at war with Japan starting in 1931 with the Japanese invasion of Manchuria. It was a longer struggle for them than for any other country.
Other performances of note are Paul Kelly as Wayne's second in command and Gordon Jones are Carroll's sidekick. Check it out if it is shone on TCM.