Aviation | 1940 | Sound | B/W
The science of flying and how an aircraft works 1940's
Begins on a diagram designed to show air flow. Four tubes containing water a re attached to a stand. Close up of tubes. Water levels are equal because there is no airflow. Therefore atmospheric pressure remains same. A fan to the side of the stand blows air over the top of the tubes. The water level in some of the tubes rises according to the change in pressure. The tube with the highest level is also the straightest - some of the tubes are bent sideways. Diagram showing what airflow would look like if we could see it. Cut to top of tubes (Venturi ?). The curves surface is replaced with a flat plate which gives little resistance to side air flow. The water level in all the tubes rises less. Flat plate is removed and water level is further reduced, as is the pressure. Section of Venturi (curved plate which holds the top of the tubes together) compared to a diagram of an aeroplane's wing. Shape identical. White diagram of a wing. Small aeroplane (FC.UD) flying - shot from parallel plane in air. Wing section is placed in water flow machine which shows how air would also move along the wing. The water moves more quickly over the top surface of the wing. Cut to profile of man who holds a piece of paper to his lips and blows on it. As he does so, the paper rises. Cut to close shot of a small aeroplane in flight. Aeroplane flying shot from lower altitude. Undercarriage can be seen. Section of miniature wing is attached to a stand. There are small holes in the top surface. Each of these holes have tubes coming from them which can be attached in turn to pressure gauges. Holes are connected to water tubes. Fans switched on. Coloured water rises most where air speed is fastest (the highest point on the top surface). Close up of tubes. Man indicates with pen. Male hand adjusts position of wing. Cut back to hands adjusting the Venturi from the previous experiment. Wing section in water-flow machine. Angle changed and water flow increases. Cut to wing section on stand. Water tubes. Pen indicates holes on underside of wing. Tubes are attached from holes to water gauges. Hand adjusts angle of wing. Water in those tubes is forced down because of change in pressure. An aeroplane can fly because of the changing pressure around its wing. Wing section attached to different equipment. This time it is on a moveable arm and has a scale connected to it. When the fan is switched on, the wing moves up. Hand place two weights on the tray and the wing returns to its original position. Fan is switched on and weights removed by hand holding tweezers. Wing angle increased to five degrees. Fan switched on and wing rises. Three weights placed on tray by hand holding tweezers. Wing returns to normal position. Experiment repeated with wing at 15 degrees. This time, the wing lifts four and a half weights.
Cut to small plane on runway. Plane lands (shot from alongside). Same shown from different angle. Picture freezes just prior to wheels touching down. Model wing moved to 20+ degrees. The lift begins to fall off. The wing has reached its stalling angle. Model wing falls. Hand flicks it up. Wing falls again. Wing section in water flow brought to stalling angle and drops sharply for several hundred feet. Cut to wing model at fifteen degrees. It has equal lift with several weights.
Cut to face on shot of aeroplane flying through clouds.
End credit. Shell symbol.
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