Lift, Drag, Thrust, and Weight: The Four Forces of Flight

Airplanes are machines that can fly with engine or propeller power. They are able to use aerodynamics (how air and objects move) to fly. Airplanes make it so that we can travel around the world in just a few hours! Airplanes can come in all shapes and sizes like the tiny airplanes that you see at stunt shows, to big passenger airplanes! The shape of an airplane’s wing is very special. It is called an airfoil. Airfoils are a curved piece of aluminum or other metal. As the airplane flies, the warm air goes above the airfoil and the cold air goes under the airfoil. The cold air is heavier than the warm air, so it keeps the airplane from crashing to the ground!

The four forces of flight are lift, drag, thurst, and weight. They all work together to help an airplane fly. Lift is when the air temperature and pressure differs on different sides of the wing. That causes the plane to lift into the air and fly! The force pulling the plane backwards is called drag. We need to overcome this force to help the plane fly. That is why we have thrust. Thrust is when the airplane gets pushed forward by either a jet engine or a propeller. Weight is the force that is pulling the plane down to to the ground. This force helps a plane land on the runway. These are the four forces of flight.