Have you ever watched airplanes take off and wondered how something so big and heavy could fly?  Designing planes that fly well is not an easy task!  Through many years of building different models of planes, engineers have learned a lot about what makes a successful plane design.  Engineers and scientists have to study the many forces that are involved in flight.  They have to understand how air and gases react to pressure.

The branch of science that studies flight and the designing of devices that fly is called aeronautics.
(This word comes from the Greek root words that mean air and navigating.)

Aerodynamics studies the movement of air and how it reacts to objects moving through it.  Engineers have to have a good understanding of aerodynamics to design planes that can handle the pressure of flying through the air and allows the air to flow around the plane in certain patterns.  (Do you remember studying about gases, liquids, and solids?  Gases will expand or contract to fill the area available to them.  Knowing when gases do this is important in designing the plane, especially the wings.)

Engineers also have to consider methods of propulsion.  If you throw an airplane into the air, your arm gives the paper airplane the initial propulsion it needs to move.  To keep flying, a plane needs consistent propulsion during flight.  Engines are designed to give airplanes that needed push.

As we study about aeronautics over the next few lessons, you will learn more about what engineers have to understand in order to build planes.

Watch this video to catch a glimpse of the journeys in flight over the years.