New 633 Squadron (Thanks Steve!)
The film's scenario together with characters were drawn from a new yesteryear Frederick E. Smith published inward 1956, which itself drew on several existent Royal Air Force operations.
The master persuasion was to laid a wooden bomber amongst no guns, only they said laid a image to near them up. Of class the image outran the Spitfire!
When the Norwegian resistance leader, Royal Norwegian Navy Lieutenant Erik Bergman, travels to Great UK to study the place of a German linguistic communication V-2 rocket fuel plant, the Royal Air Force's No. 633 Squadron is assigned to destroy it. The squadron is led yesteryear Wing Commander Roy Grant, an ex-Eagle Squadron airplane pilot (an American serving inward the RAF earlier the U.S.A. entered the war).
The institute is inward a seemingly impregnable place beneath an overhanging cliff at the terminate of a long, narrow fjord lined amongst numerous anti-aircraft guns. The solely agency to destroy the institute is yesteryear collapsing the cliff on exceed of it, a chore for 633 Squadron's fast together with manoeuvrable de Havilland Mosquitos. The squadron trains inward Scotland, where in that place are narrow glens like to the fjord.
They used existent Mosquitos, together with yesteryear the agency Cliff Robertson owned a Spitfire!
https://en.m.wikipedia.org/wiki/633_Squadron#