DEFINITIONS

1. Airfoil – Any part of an aircraft that is designed to produce lift.

2. Angle of Attack (AOA) – The angle that describes the difference between the airfoil’s chord and the direction of its encounter with the relative wind.

3. Angle of Incidence  (AOI) – The angle that describes the difference between the longitudinal axis of the aircraft and the chord line.

4. Camber – The curve of the upper and lower surfaces of an airfoil.  The camber determines the amount of lift a wing produces as air flows around it.

5. Chord – An imaginary straight line drawn through the airfoil from its leading edge to its trailing edge.

6. Critical Angle of Attack – Angle of the airfoil at which air becomes turbulent as it flows over the airfoil and stops creating lift.

7. Drag – The force that delays or slows the forward motion of an aircraft.

8. Leading Edge – The portion of an airfoil that meets the air first.

9. Lift – The force that opposes gravity or weight.

10. Relative Wind – The airflow produced by the aircraft moving through the air. It is in a direction 90 degrees to the lift vector of the airfoil.

11.  Stall – A condition caused when the critical angle of attack is exceeded. The air flowing over the airfoil becomes turbulent and no longer produces lift.

12. Thrust – The force that gives an aircraft its forward motion.

13. Trailing edge – The portion of an airfoil at which the airflow over the upper surface joins the airflow from the lower surface.

14. Weight – Gravity pulls all objects within its sphere of influence towards the Earth. This pull is known as weight. The greater the mass of the object, the greater the weight.