It sounds like you're talking about "Sole Survivor", which was made in the seventies.
The ghosts are the crew of an American B-17, which crashed in the Libyan desert during WW2.
The plane was an American bomber which crashed in the desert.
The crew spend their days playing baseball, not realising they're dead, until many years later a recovery crew locates their bodies.
I sent this very enquiry to "Empire" film magazine last year and they confirmed that the film is indeed Sole Survivior, a TV movie made in the early 1970's and starring , amongst others, William Shatner.
The crew of US airmen had crashed their WW2 plane when a bomb got stuck in the bomb bay.On at least two occasions when talking about films in the pub, someone has asked "anyone remember that film where there's a crashed bomber and a crew that don't know there dead?" The film in question ISN'T "The Survivor" (the film of the James Herbert book).I too have searched on databases and have even gone into chat rooms to ask people!I am afraid I can't help with the title, but I can assure you that it is not your imagination (unless we are both crazy!