Four of the De Havilland Mosquitos seen in this film were airworthy and three could taxi on the ground. The same crash at Abindon Airfield, U.K., shot from a different angle, was used with matte painting (by 'Tommy Howard (IV)''s Special Effects team) to look like it was crashing in Norway. No shooting was done in Norway in fact. For "Norway" scenes, the mountains of Scotland were pressed into service.
more