Definition
A trim device on a helicopter cyclic control that, when pressed, releases or neutralizes the cyclic force gradient so the cyclic stick returns to a centered (neutral) position, allowing the pilot to re-establish a known reference point for cyclic input.
Plain English
A button on the cyclic stick that lets the pilot reset the stick to its center position, so they have a clean starting point for the next control input.
Context Anchor
Seen in helicopter instrument flying when adjusting cyclic trim after setting the desired attitude.
Derivation
Centering comes from center, the middle or neutral position. The name describes exactly what the button does: it returns the cyclic to its centered reference.
Why Pilots Care
Reduces pilot workload by quickly neutralizing unwanted stick forces during trim changes.
Analogy
It is like resetting the resting point of a spring-loaded joystick. After you move the stick to where you want it, the button lets that new position become the place the stick wants to stay.
Intuition Check
Do not assume the cyclic-centering button moves the cyclic back to the physical middle. In this context, centering means setting a new comfortable control position for the attitude being flown.
Example Sentence 1
After leveling off in cruise, the pilot pressed the cyclic-centering button to re-establish a neutral reference before fine-tuning attitude.
Example Sentence 2
During a hover under the hood, the instructor demonstrated using the cyclic-centering button to reset the stick position.