# Fluid Mechanics Applications/A01 Principle of Flight

The understanding of principle of flights is important in understanding what happens during the various stages of flight. We can also find out the errors takes place during crash of an airplane. Thus we can avoid such accidents by knowing the basics behind the movement of flight.

## Basic Aerodynamics

First let us consider how an airplane stays up in air. Although it seems to be the general view that the airplane is held in the air by the action of propeller, it is of course, the wings that create the lift to suspend the aircraft. The wing is set at alight angle , with the leading edge slightly higher than the trailing. The air passing beneath the wing is forced downwards, owing to the angle of incidence and because it is now in an area of relative pressure, tends to push the wings the wings upward. Over the top of wing there is, because of the angle of incidence and the camber of the upper wing surface, an increase in speed of the airflow, causing an air of relatively low pressure, thus sucking the wing upwards. The combination of the area of high pressure pushing upwards and the low pressure over the wing sucking it upwards are together known as lift. About two-third of the wings total lift is created by the top surface of the wing and one-third from the airflow over the airflow over the lower surface. Lift is directly related to the speed of flight, and therefore follows that if a flight slows down too much there will be insufficient lift created to allow flying- a most important point that should be remember during take-off and landing of a flight.