• This mid-period David Lean picture is one of his most unusual – a drama woven out of a story of scientific exploration. Not an easy kind of picture to make, but one held together by Lean's refined direction, a great cast and a surprisingly good script by Terence Rattigan.

    Although Lean was to make two small-scale pictures between this and Bridge on the River Kwai, this is perhaps more than any other a transition film between his early intimate dramas and the later massive epics he is now best known for. From the start Lean had always tried to photograph the psychological states of his characters, but The Sound Barrier is the first time he tells a bigger story through the personal experiences of individuals. This is the formula that has made Kwai and Lawrence of Arabia so popular and enduring. Like those later pictures, in the Sound Barrier the narrative switches to carry on the story through the eyes of other characters.

    A story like this, concerning test pilots, engineering and scientific breakthroughs, will only work if there is a strong drama underlying it – otherwise it's only going to be of interest to techies. Lean seems totally aware of this and emphasises the human story behind the science. He directs with his editor's eye, composing action sequences with series of still shots, then throwing in the occasional sharp camera move to punctuate an emotional moment. He is moving away a little from the rather obvious expressionistic techniques of his earliest films towards a more straightforward yet effective style.

    By the early 50s the golden age of British film was over, but there was still a good crop of acting talent on offer, and there are plenty of names to mention in The Sound Barrier. Ralph Richardson plays (as he often did) the overbearing father-in-law, and lends the film a touch of class. Ann Todd, who was Lean's wife and not an exceptional actress, here gives what is probably her best performance – she has the most difficult part in terms of emoting, but she carries it off brilliantly. This is also a great before-they-were-famous film, featuring a young Denholm Elliott (best known as Marcus Brody from the Indiana Jones films) and Leslie Phillips in his pre-Ding Dong days. The real acting treat here though is the rarely-seen John Justin, who failed to achieve stardom not through lack of talent, but through lack of interest on his part. His poignant final scene is one of the strongest in the whole picture.

    Of course, it's not just the plot of The Sound Barrier that is a work of fiction – the science is complete nonsense as well, so don't go thinking that pilots really reverse their controls to get through the sound barrier. In many ways, this film reminds me of Dive Bomber, made ten years earlier with Errol Flynn and Fred MacMurray. That's also a test pilot drama, with a fair few plot similarities. One major difference though is that whereas Dive Bomber deliberately and bluntly disposes of any romantic angle, writing the female characters out of the story halfway through, in The Sound Barrier it is the pressures on the wives and sisters that is pushed to the fore. Ultimately, it is the way The Sound Barrier deals with loss and guilt that make it a strong and satisfying film.