Pilots, three in number, handle US Mail deliveries, battling all kinds of weather as they attempt to maintain postal service across a country where conditions can shift unexpectedly. “Jake,” portrayed by Pat O’Brien, is at the head of the group; Stuart Erwin plays “Tex,” who's reliable and steady; and James Cagney embodies “Dizzy,” a somewhat unpredictable character. This last fellow frequently creates difficulties for his superior, but events become more somber when he exchanges shifts to pursue some romantic interests—and it doesn’t take long before “Dizzy” finds himself in considerable trouble. The narrative itself is genuinely engaging, illustrating the dangers inherent in their work, where visibility was limited and landing strips weren't illuminated, even at places like Newark, requiring these courageous men to fly largely on instinct. O’Brien occasionally leans toward exaggerated acting, but alongside Cagney he generates a fairly gripping drama that minimizes the romantic elements and keeps the focus squarely on the personalities involved.

Source on TMDB