The Sound Barrier is a 1952 British aviation drama film directed by David Lean. It is a fictional story about attempts by aircraft designers and test pilots to break the sound barrier. It was David Lean's third and final film with his wife Ann Todd but it was his first for Alexander Korda's London Films, following the break-up of Cineguild. The Sound Barrier stars Ralph Richardson, Ann Todd, John Justin and Nigel Patrick. It was known in the United States as Breaking Through the Sound Barrier and Breaking the Sound Barrier.