Eastern Airlines flight 401 crashed into a swamp and the two pilots were still alive but only for a short amount of time. They died soon after.
Later on there were sightings of the pilots on various Eastern Airline aircraft spotted by Crew, passengers and even the pilots. Pilot Bob Loft was often seen in first class or in the crews cabin.
There was this one time when the flight attendant saw Loft sitting down and asked him what he was doing on the plane and that she didn't see him board and couldn't identify him on the flight manifest.
He didn't reply so she reported to the pilot of the plane. He walked with her to Loft and recognized him, but then straight away Loft disappeared.
There were so many reported sightings of the ghost pilots that resused parts from flight 401 were removed from the other Eastern Airlines flights and from then on, no more sightings were reported.