L/S then M/S of a group of aviation technicians attaching a model aircraft to a stand in a wind tunnel. The men leave the wind tunnel. L/S of man in white overalls walking to the end of the wind tunnel then closing a louvered door. Exterior shot of man climbing out of the tunnel . Two men then duck under metal construction.
Interior - a glass windowed door is closed on the low speed wind tunnel which has another model aircraft suspended within it. It is a De Havilland Comet 3. M/S of a technician seated at a control panel. C/U of his hand pushing a button. L/S of a fan in action. C/U of a speed gauge. Closer shot of the fan. C/U of the technician concentrating on his work. M/S of two technicians at control panels watching the effect of the wind on the suspended model. Narrator explains that all six forces and movements to which an aircraft is susceptible can be tested by this means. M/S of the model plane. M/S of men at the controls. Low angle of the model being moved by remote control. C/U of the fan.
M/S of group of workers sitting at desks in an office. A man walks into the room down some stairs and looks at the work of some of the staff. They seem to be recording results of tests in the wind tunnel. M/S of a man recording results using a multitube manometer which records pressures on various parts of the model plane. C/U of the manometer in action. C/U of the fan. Low angle of the model aircraft.
M/S of technicians at work in a control room. M/S of a man looking through a circular window as a gauge moves up and down. C/U of the man who wears headphones. M/S of three technicians at work moving levers and pushing buttons. C/U of levers being moved. C/U of one of the technicians speaking into a microphone - he wears headphones.
C/U of a lever being pushed. Various shots of tubes and technical equipment related to the wind tunnel. Narrator informs us that: "The Mach meter gauge measures speeds which make the sound barrier seem like ancient history." Various shots of technicians at work and of measuring equipment, technicians, gauges, etc. The sound on the track is of engines being pushed harder and harder.
Narrator ends by saying: "With the sound barrier broken a speed of Mach 1.6 - equivalent to 1,,220 mph at sea level will be recorded - an exciting symbol of this progressive age."
Note: specifications of the wind tunnels and De Havilland brochures can be found in the documentation file. Filmed at the De Havilland Aircraft Co. works at Hatfield Hertfordshire.