The Basics of Flying a Plane (5 – How does it fly?)

Hey All!

These lessons are intended to help you pass ground school without learning all the useless knowledge that goes with reading the whole FAA (Federal Aviation Association) manual. So, I hope you enjoy. This time we are going to start with some definitions!

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• Airfoil – The shape of the wing (a cross-section or side view).
  
• Aerodynamics – How air resistance affects the plane’s flight path.
• Drag – Air resistance vector that acts in the direction opposite the movement.
• Lift – The upward force vector that allows a plane to fly.
• Thrust – The forward force vector of a plane (given by the propeller).
• Weight – The force of gravity (you know that thing that keeps us on Earth).
• Velocity – How fast an object is moving. Usually measured in knots (1 knot is about 1.1 miles per hour).
• Vector – A strength and direction of a force or velocity.

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Now that you know some of the terms, we can go into some of the physics that allows the aircraft to fly. Consider the same airfoil we saw before, with the vectors that apply forces instead of pieces of the wing.

How is the lift force created, you ask? It is actually not that complicated. Two principles allow the “lift” force to exist. Pressure and Bernoulli’s Principle.

• Pressure – All you need to know is that air flows from low pressure to high pressure. The true definition is a force over an area.
• Bernoulli’s Principle – fluids (including air) that move at higher speeds have lower pressure.
  Air must move from the leading edge to the trailing edge of the wing, but since the leading edge is longer (more curved), the air on top is moving faster causing lower pressure. Now, since there is high pressure at the bottom and low pressure up top, air flows upward, giving the plane “lift”. It may take you 20 times to read this and understand it, but these two sentences are the premise of the whole post!!! Read it and look at the diagram and definitions until you understand. I promise you will get it!
  

Thanks for tuning in Steemers! Hope you’ve enjoyed your lesson! Happy trails!