Definition
The aerodynamic tendency of an airplane, when rolled with the ailerons, to also yaw in a direction opposite to the intended turn. This unwanted yaw is caused primarily by the difference in drag between the upward-deflected and downward-deflected ailerons, and is corrected with coordinated rudder input.
Plain English
When you move the control wheel to bank the airplane into a turn, the nose tries to swing the wrong way at first. You use rudder at the same time to keep the nose pointed where you want it.
Context Anchor
Seen when learning how to establish and maintain a coordinated turn, especially while balancing aileron, rudder, and elevator pressures.
Derivation
From 'cross,' meaning to act across or against, and 'coupling,' meaning a linked or connected effect. The term describes how one control input (aileron) is unintentionally linked to a motion on a different axis (yaw).
Why Pilots Care
Uncorrected cross-coupling produces slips or skids that increase drag, reduce climb performance, and can lead to loss of directional control.
Grounding Statement
In a real turn, rolling, turning, and holding altitude are connected; changing one can make the others need attention.
Intuition Check
Cross-coupling does not mean the pilot is intentionally using the wrong controls. It means the airplane’s motions are linked, so one control input can have more than one effect.
Example Sentence 1
The instructor explained that cross-coupling between the ailerons and yaw is why rudder is needed when rolling into a turn.
Example Sentence 2
Recognizing cross-coupling during roll-out from a steep turn allows the pilot to keep the ball centered without overcontrolling.