In addition to numerous others mentioned, a film called "No Highway", based
on the Nevil Shute novel "No Highway in the Sky", is pretty good. Glenn
Ford, and a few other name brand actors, dealing with unexplained airline
crashes. Book was better, but that's not unusual.

There's also a Gann novel called "Blaze of Noon" that was pretty
interesting, dealing with the early airmail/airline days, and might convert
to a pretty good film. It was made into a film in 1947, but I've never seen
it. Anyone?

JG