What do the terms "cross-control" and "adverse yaw" refer to?

The terms "cross-control" and "adverse yaw" relate specifically to control inputs and their aerodynamic consequences during flight. Cross-control refers to a situation where the ailerons and rudder are used in opposing directions, such as when a pilot applies opposite control inputs to maintain coordinated flight during a turn. This can lead to a loss of control if not managed properly, as it may result in an increase in drag and potential stall conditions.

Adverse yaw is the tendency of an aircraft to yaw away from the direction of a turn due to differential lift and drag created by aileron deflection. When the aircraft is turned, the upward-deflected aileron produces more lift and drag on that wing, causing it to yaw in the opposite direction—away from the turn. Understanding these concepts is essential for maintaining proper aircraft control and ensuring safe flight operations.