True or False: The Angle of Attack (AOA) is the angle between the chord line and the relative airflow.

The statement is true because the Angle of Attack (AOA) is indeed defined as the angle between the chord line of an airfoil and the direction of the relative airflow. In aerodynamics, the chord line is an imaginary straight line drawn from the leading edge to the trailing edge of the wing or airfoil, while relative airflow refers to the motion of air as it interacts with the airfoil. Understanding AOA is crucial because it directly affects lift generation and can influence the stall characteristics of the aircraft. Maintaining the appropriate angle of attack is fundamental to effective flight and safety in both manned and unmanned aerial systems (UAS). While the other options introduce different angles or contexts, they do not pertain directly to the accurate definition of AOA, which reinforces why the statement being true is essential knowledge for UAS operations.