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The cross section of an aeroplane wing shows a curved upper part, whilst the lower part is straight.  On cutting the air quickly with this type of structure (to achieve this it must be propelled with force), an upward thrust is created which makes the aeroplane "float". The shape of the wing, on movement, causes the lift effect. The faster the aeroplane is driven, the greater the lift.

Four forces make it possible for an aeroplane to fly. The first relates to the aircraft’s own weight, which draws it towards the ground due to the force of gravity. Another is the lift of the aeroplane, which is generated due to the aerodynamic shape of the wings as it glides through the air. The third comes from the force of the engines, which enable the aeroplane to move through the air. Finally, its path is affected by the resistance to travel, which is the force that opposes movement.

Flight conditions

However, in order for an aeroplane to fly, the lift must be greater than the force exerted due to the weight of the aeroplane. At the same time, the force supplied by the engines must also be greater than the air resistance.

The principle of lift that helps us to understand this phenomenon was enunciated by the mathematician Daniel Bernoulli. This complex theorem correctly explains that when a fluid –in this case the air mass that exists in the earth’s atmosphere- circulates around an object, the pressure exerted obliquely on the object by the fluid becomes greater as the velocity of the current increases. By placing a sheet of paper on a ruler you can observe lift. If you put the ruler at mouth height and blow on the paper, this will rise due to the effect of lift.

In an ordinary aeroplane, the wings, which are usually arched on top and almost always smooth underneath, are lifted by the air that passes. As the wings rise, so does the fuselage. A primitive way of making the aircraft move faster is by using a propeller to cut the air forcing it backwards. 

In order to take off, the aeroplane must move forwards along a runway for sufficient time and at sufficient speed to create enough air pressure on the elevation or upward force wings, to make the aeroplane take off. The necessary energy is required from the engines in order to overcome the force of the air that flows around the aeroplane.

Small big sections

All aeroplanes are composed of a fuselage, wing, a tail and several movable surfaces to control the flight. With those elements alone a glider can fly and land without the force of an engine. However, this type of aeroplane also needs an initial force in order to take off, which can be supplied, for example, by a car towing it along the runway by a cable.

It is the small parts and movable sections of the aeroplane that are responsible for really controlling the flight. The most important parts include the ailerons, attached to the edge of the wings and to the horizontal and vertical surfaces of the tail. These make up the height and steering rudders.

The cabin contains a joystick and instruments to control the steering rudder, as well as a steering wheel for turns. Other details must not be forgotten, including the wheels, essential for taking off and landing. There are also aeroplanes equipped with floats which allow them to land and take off on water, or with skids, to do so on snow-covered surfaces.

In commercial aeroplanes, there is normally a jet-propelled engine, also known as a turbojet, which propels the aeroplane forcing matter backwards. The propulsion is obtained exclusively through the exhaust stream of burnt gases, expelled in the opposite direction. As such, aviation fuel, after passing through the turbine, passes through the exhaust nozzle at great velocity providing the aeroplane with the energy it needs to fly. 

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