Aerodynamics is the study of how an object passes through air. For any flying object their are four basic forces that act on it. These forces are thrust, lift, weight, drag. Thrust is the speed an object is moving. Lift causes the object or airplane to remain in the air. Lift is caused by pressure differences above and below the wing. Weight is the force of gravity pulling down the object that is flying. Finally the last basic force is drag. Drag is the resistance and object receives from pushing the air molecules of air out of the planes flight path.

There are many different types of drag. There is parasite drag which is drag caused by objects on the aircraft that are not necessary for flight like the landing gear. There is total drag which is the drag caused by the entire aircraft. Then there is total wing drag which is the drag caused by the wings

Also there is friction drag which involves the boundary layer. The boundary layer is a line of air that is made up of many tiny layers of air on top of each other. This boundary layer forms along the surface of the wings. As an object increases speed the boundary layer will move closer to the rear and this causes lots of turbulence and loss of lift. Loss of the boundary layer can also be due to bad wing design.

Another type of drag is induced drag. This drag is caused as a byproduct of creating lift. The pressure differences above and below the wing create the drag. Finally the last drag is form drag which is caused by the resistance of moving an object through the air.

Form and friction drag can be reduced by different ways. One important way is to reduce the surface area that is in contact with the air. The more surface area the air can act on the stronger the force of the drag on the object. So then the least amount of surface area for the air to exert force upon, the less the drag.

Another way to reduce drag is to eliminate any rivets or nails sticking out on the wings or the fuselage, and make all the materials that make up the wings or fuselage as smooth as possible. All of this reduces the drag created by the aircraft. This process is called streamlining.

Another very important characteristic of an airplane is it's stability. Stability is a airplanes tendency to level itself after. There are two different types of stability. The two different types are dynamic stability and static stability.

Static stability is the tendency of an object to its state of equilibrium. It's state of equilibrium is when the aircraft is flying level. There are three different types of static stability. The three types are positive static stability, negative static stability, and neutral static stability.

If an airplane has positive static stability it will return to its previous balance after being knocked off coarse. If an aircraft has negative static stability it will continue going in the direction it was pushed off course. If an aircraft has neutral static stability it will not continue going in the direction it was pushed nor will it return to a state of equilibrium. Instead it will remain in the position it was pushed.

Dynamic stability deals with vibrations of motion increasing or decreasing. If an aircraft has positive dynamic stability and is knocked off course then the vibrations slowly decrease each time until the plane is back on course. With negative dynamic stability the vibrations increase with each cycle and neutral the vibrations remain the same.

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