Director Sir Alfred Hitchcock asked if chase scenes could be filmed from a helicopter, which required some ingenuity, as camera mounts did not exist for this purpose at the time. Using a Sikorsky S-51, UK registered G-AJOV, a former BEA airframe, the side door was removed, and the camera jerry-rigged with ropes, wires, and cables. These shots were done in July 1954, according to a "Making of" short documentary included in the DVD release.