 In a 1972 interview with Dick Cavett (qv),  Alfred Hitchcock (I) (qv) revealed that the plane crash scene was  filmed by using footage shot from a stunt plane diving on the ocean,  rear projected on rice paper in front of a cockpit set. Also behind  the rice paper were two chutes aimed at the cockpits windshield  connected to large tanks of water. With the press of a button at the  right moment, water came crashing through the rice paper, into the  plane simulating the plane crashing into the sea from the cockpit  view.