Perhaps if we set the scene during the evacuation of the site...
Officer Commanding is passing out of the main gates when he asks his driver to slow down a moment. He calls out to Fred and Wilf - "You There, yes you. Be good chaps and pop those crates in a hole somewhere will you. Oh and you better be quick about it". Fred and Wilf look at each other as the car speeds off and vanishes around a bend in the road. "Latrine Pit?" said Wilf. Neither were ever asked about the aircraft and neither ever wanted to be.