Definition
A control, usually a switch or button on the control yoke or stick, that immediately stops electric trim operation by removing electrical power from the trim motor. It is used to halt unwanted or runaway trim movement so the pilot can regain manual control of pitch, roll, or yaw trim.
Plain English
A switch the pilot uses to instantly cut power to the trim system if the trim starts moving on its own or in the wrong direction. Pressing it stops the trim where it is so the pilot can take over by hand.
Context Anchor
Found inside the airplane, often on the control yoke, control stick, or instrument panel, especially in airplanes with electric trim or an autopilot.
Derivation
Trim refers to the small adjustments that relieve control pressures in flight. Disconnect comes from Latin dis- (apart) and connectere (to join together) — literally to break the connection. Together, the term describes the action of breaking the electrical connection to the trim system.
Why Pilots Care
Provides an immediate way to stop a runaway trim condition or autopilot trim fault and restore direct manual pitch control.
Intuition Check
Do not read “trim disconnect” as removing trim from the airplane. It means stopping the powered trim system from moving or commanding trim.
Example Sentence 1
When the trim began running nose-down on its own, the pilot pressed the trim disconnect and flew the airplane manually.
Example Sentence 2
Before engaging the autopilot, the instructor demonstrated pressing trim disconnect to confirm the system would release.