Now that I have explained the four forces of flight, I can explain how each part of the plane generates enough force for flight. In order for a plane to take off, enough lift must be generated so lift is greater than weight. Wings are responsible for generating the majority of lift. As a plane flies through the air, air splits over the top and bottom of the wing. High pressure pushes the bottom of the wing and low pressure on the top of the wing push the wing up, forcing the plane up. This force due to pressure on the plane is known as the Bernoulli component of lift. As the plane flies forward, air flows over the plane in the opposite direction. The velocity of the air that passes over the wing has a net return and results in a downward force on the air. This causes an upward force on the wing (due to Newton’s 3^rd law) known as the Newtonian component of lift.

               Flaps on a plane are moving parts along the trailing edge of the wing which, when rotated downward, deflect air downward. As the amount of air being pushed down increases, an increase in lift is generated. When the air flows off the top of the wing and the flap is too steep, the air breaks off into swirls, creating more drag. This enables the plane to slow down significantly. In this way flaps are responsible for slowing down the plane and permitting the plane to land on a runway much sooner and more safely than landing without flaps. The diagram below shows the difference between a plane landing with flaps, and a plane landing without flaps. The plane’s landing distance in green is the plane with flaps, whereas the plane’s landing distance in blue is the plane without flaps. When flaps are used, wind is able to slow down the plane by pushing against the plane more, causing the plane to slow down and land sooner.