"Q Planes" aka Clouds over Europe (1939)

This espionage thriller comedy stars Ralph Richardson, Laurence Oliver, and Valerie Hobson. A sci fi element beefs up the slight plot when the Germans use an EMP raygun mounted on their salvage ship to knock British test planes out of the sky. Richardson's impeccable comedic timing and Hobson's independent journalistic spirit make this one worth a watch. Richardson should've always gotten top billing on the original movie posters: his character is the star of that show.