Angle Of Attack (AOA): The instantaneous angle between a reference line on the airplane
(usually the wing chord line) and the relative wind direction. AOA is depicted in Figure A-1.
Figure A-1 Angle of Attack
Aerodynamic Coupling: An aerodynamic characteristic affecting dynamic stability, which
results when a disturbance about one axis causes a disturbance about another axis (e.g., a
combination of yawing and rolling motion resulting from rudder deflection).
Body Axis System: The system by which the axis of flight or aircraft movement are determined.
The airplane body axis system is shown in Figure A-2.
Figure A-2 Axis