The 4 Forces Of Flight
By Kai Richer
Whether caused by a jet engine, is the aerodynamic force that pushes or pulls the airplane forward through space.
The aerodynamic force is drag, or the friction that resists the motion of an object moving through a air fluid (or object in a moving fluid like a plane, as occurs when you fly a kite).
Lift is some kind of mechanical force by solid object lifting the plane and makes it fly. The way lift works is pilots ( planes ) need speed to lift the plane with much force and speed.
Weight and lift are equal when a plane flies level at constant velocity. Because more weight requires more lift, and therefore more thrust, heavy planes are more difficult to get off the ground as compared to lighter planes.