The story for David Lean's film, written by Terrence Rattigan (The Winslow Boy, The Browning Version) was in part inspired by real work being done by the De Havilland Aircraft Company, and the 1946 death of designer and owner Geoffrey De Havilland who perished while testing an experimental jet plane.
Lean's film follows WWII fighter pilot Phil Peel (Justin) who discovers that when he puts his Spitfire into a dive the controls start acting strangely. Phil tries to discuss this with his comrade Tony Garthwaite (Patrick), but Tony's more concerned with proposing to Sue Ridgefield (Todd). Tony and Sue marry and then head north to meet her father, aviation industrialist John 'JR' Ridgefield (Richardson). At JR's factories, his right-hand man, designer Will Sparks (Tomelty), alludes to some top secret work going on at the factory. "Is this top secret going to win the war?" asks Sue. "A good deal more than win the war, if you ask me," replies Will.
Since Tony is now part of the family, JR introduces him and Sue to the secret work: jet engines. JR is obsessed with them and Tony quickly comes come to share his passion. Sue looks anxious, and she has good reason to be worried - aviation is developing fast, and even without the addition of jets to the equation it takes the life of her brother Chris (Elliot), who felt pressured to participate in his father's vision.
After Chris' funeral, the film moves forward to after the war. Tony is now a cocky test pilot for whom every flight is "a piece of cake". It's a phrase that upsets Sue, who knows full well it's never quite that easy.
Tony is particularly nonplussed by talk of breaking the sound barrier - the project which forms the main drive of the film. "What's so ruddy peculiar about the speed of sound? We all know exactly what it is, don't we? Seven-hundred-and-fifty mph at ground level. Now, if we go slower than that we can hear ourselves going, and if we go faster we can hear ourselves coming. It's a mere matter of acoustics." But of course it's not. Every time the test flights come close to Mach 1 (the speed of sound), buffeting sets in. Buffeting very much like that experienced by Phil at the start of the film
JR pushes onwards, driven by a 1950s dream. "I believe that with the right aircraft, and the right man, we can force our way through this barrier, and once through, there is a whole new world, with speeds of 1,500 to 2,000 miles an hour within the grasp of man."
The Sound Barrier has been criticised for being overly Anglocentric. Though it's historically inaccurate, it does feel like a precursor to that US story of rocket technology The Right Stuff. Both deal with bravery, risk and loss in the name of progress.
Here, that clash is represented by the relationship between JR and Sue - he lives a life of monkish devotion to progress while she questions both his obsession and its cost. "You want me to think of you as a man with a vision," she argues with him late in the film. "Well, that vision has killed both my husband and my brother, and while I'm alive it's not going to kill my son too." The combined talents of Lean and Rattigan ensure this is moving, challenging stuff.
Ann Todd was Lean's then wife and had previously appeared in The Passionate Friends and Madeline. Although her stiff upper lip acting style is extremely dated, she manages an affective double-act with Richardson. The latter won a BAFTA and a New York Film Critics Circle award for his nuanced portrayal of the industrialist, who isn't as unfeeling as he seems.
The Sound Barrier closes with the image of a model of a (then) futuristic jet, hanging alongside a telescope in JR's observatory, pointing towards the stars. More than half a century on from the film's release, and the sense of optimism celebrated here has passed. Now airliners are associated with environmental destruction, and Concorde - that signifier of the jet future - has long been grounded. This just serves to give the drama an added layer of irony.