Did you ever have you wonder because he flies an airplane, to be that these marvels of technology can sail the heavens with the assurance that the airlines offer us today? Basically the flight is due to the combination of four basic forces, see this article. We have used the previous Word Basic, since there are other forces that exert their action on an aircraft, but we will only stop at the main forces that every student must know of primordial form. These forces are the following: the force of gravity, resistance, the lift and thrust. The first two, gravity and resistance, are offset by the effect of the latter two, the lift and thrust, making it possible for the difference among these that the aircraft can fly, achieving the ascent of the aircraft when the lift overcomes the force of gravity and the advance of this when thrust exceeds the resistance caused by the inertia. We will now see each of these forces in more detail. Bearing capacity as we saw above the Airfoil also called L for its acronym in English of the word Lift is the force that is exerted on the address below upward force exerted perpendicular to the relative wind and wingspan of the aircraft. This lift is affected by various factors such as the shape of the wings, surfaces of these, the relative wind, the density of the air by which flies and angle of attack. The wings make it possible through its form a pressure difference due to the different speed of the wind over these thanks to its curved shape. We can say that the greater the curvature of the wings will achieve a greater difference of wind and therefore pressure, although we must have certain repairs in this assertion, since not only with a wing curved on the top and flat or concave below it is possible to achieve the lift, because this can be achieved also with a symmetrical shape.