From The Internet Movie Plane Database
Cliff Robertson (Wing Cmdr. Roy Grant)
George Chakiris (Lt. Erik Bergman)
Maria Perschy (Hilde Bergman)
Harry Andrews (Air Vice Marshal Davis)
When Norwegian resistance leader Lieutenant Erik Bergman reports the location of a German V-2 rocket fuel plant, the Royal Air Force's 633 Squadron is assigned the mission to destroy it.
The plant is in a seemingly-impregnable location beneath an overhanging cliff at the end of a long, narrow fjord lined with anti-aircraft guns. The only way to destroy the plant is by collapsing the cliff on top of it, a job for 633 Squadron's fast and manoeuvrable de Havilland Mosquitos.
Miles M.38 Messenger