the film's hero is World War I aviator Carbot, played by Pierre Fresnay. After the war, Carbot attempts to establish a commercial airline, for the purpose of delivering the mail to the outermost regions of France. There's plenty of Only Angels Have Wings-style heroics as Carbot's pilots face injury and death while braving the elements to meet their appointed rounds. The film's nominal heroine, Maryse, played by Jeannine Crispin, has little to do but wait anxiously as the pilots go about their duties.
Source : allmovie.com