The propulsive force that moves the airplane forward is called the thrust. Propellers are airfoils and they act upon the air similar to a wing. The curvature in the propeller produces lift.



Propellers are slightly twisted so that their undersides strike the stream of oncoming air at a positive angle of attack. As the airplane moves forward, it experiences resistance to its motion or drag.

As the wing tilts upward to increase the angle of attack, the increased in induced drag is also caused by the body of the airplane or fuselage, as it naturally tilts up with the wing.

Center of Gravity

An airplane is a balance machine that can rotate on three axes around the center of gravity.

The exact location of the center of gravity will change with how the airplane is loaded up with cargo, people, and fuel.

There are specific limits known as the loading envelope, on exactly where the center of gravity should be, represented by a series of graphs.

It is important to always know where the center of gravity is and will be throughout the flight and also what the weight of the plane is before take off. If you begin your flight with the total weight limit, you will be ok because throughout your flight, your airplane is getting lighter as fuel is being consumed.