CG – Center of Gravity
Airfoil– A structure or body that produces a useful reaction to air displacement which are airplane wings, helicopter blades, and propellers.
Chord Line– an imaginary straight line from the leading edge to the trailing edge of an airfoil.
Relative wind– the wind displaced by an airfoil.
Angle of Attack – the angle between the chord line of the airfoil and the relative wind.
Critical Angle of attack – The angle at which a stall occurs.
Density Altitude – The altitude relative to standard atmospheric conditions at which the air density would be equal to the indicated air density at the place of observation. Density Altitude is generally associated with an air crafts performance under specific weather conditions.
Stall – Aerodynamic condition which occurs when smooth airflow over an aircrafts propellers/wings are disrupted, resulting in loss of lift.