One of the most fruitful cinematic techniques of recent years is combining elements of fiction and documentary. (Best current example: The brilliantly layered Paradise Now.) That isn’t such a new idea, however; it dates back to such films as 1922’s Nanook of the North and, a bit more recently, The Big Lift. Released in 1950, just after the golden age of pure-hokum Hollywood war flicks, this account of the Berlin airlift was shot in and around Templehof Airport, in what was then West Berlin. Montgomery Clift plays the idealistic flight engineer of a coal-carrying transport plane, who faces Soviet fighters, rooftop-shaving descents into the short-runwayed airport, and a German girlfriend with a murky past. (Hildegard Knef, originally cast in the role, was bounced for actually having a murky past.) It’s no wonder that the flying looks so real: So are the transport plane’s on-screen pilots. The film screens at 7 p.m. in the Library of Congress’ Mary Pickford Theater, 101 Independence Ave. SE. Free. (202) 707-5677.