Synopsis by Hans J. Wollstein
An airborne serial killer terrorizes a group of war veterans in this ultra-cheap but fairly engrossing whodunit produced by one of Hollywood's few women executives, Fanchon Royer. Assigned to investigate a series of flight disasters committed by a phantom aircraft bearing only the legend "X," veteran test pilot Jerry Blackwood (John Carroll) learns from Dr. Norris (John Elliott) that the killer in all likelihood is a veteran of the last war suffering from "battle neurosis." Jerry gathers a group of fellow veterans at the plant operated by aircraft manufacturer Henry Goering (Henry Hall), an assembly consisting of Baron Von Guttard (John Peters) of the German Luftwaffe, the French pilot René LaRue (Gaston Glass), the British Captain Saunders (Pat Somerset), and American Douglas Thompson (Wheeler Oakman), late of the famous Lafayette Escadrille. Also present is the mysterious Lieutenant Ives (Reed Howes) and Carl (Leon Kent), Goering's son, who seems to know a great deal about Von Guttard. The German, however, is the first to die during an airborne patrol, closely followed by LaRue. Saunders, meanwhile, seems to come completely unhinged and remains the obvious suspect when Dr. Norris is found murdered. The real "Pilot X," however, is someone completely different, as Jerry and Goering's ward, Helen Gage (Lona Andre), learn the hard way.