I am looking for the name of a movie about a WWII plane that crashed in the desert and the crew are waiting to be rescued. In the end you find out that they are all ghosts and as their remains are found their ghost disappears. They did not know they were dead.

IT IS NOT SOLE SURVIVOR! In that movie they know they are dead from the beginning.

Someone on another forum suggested that there is another film on this subject, called Catch 22. Not the American 1970 film, an earlier one. Can't find any reference to it though. I've seen the one you mean too, and you're right - it's not Sole Survivor.

It's Soul Survivor, starring William Shatner, and it was based on the discovery of the b-24 Liberator Lady Be Good, a bomber that had lost its way during WWII and ran out of fuel in the middle of the Sahara Desert, hundreds of miles from where it should have been; the bomber wasn't found until the late 1960s