Definition
The movement of a gyroscope's supporting frame (the gimbal) about its pivot axis, allowing the spinning gyro rotor to maintain its orientation in space while the instrument case and aircraft move around it. In the turn coordinator, the gimbal is canted about 30 degrees from the longitudinal axis, so its rotation responds to both roll and yaw, driving the miniature aircraft display.
Plain English
The way the inner frame holding a spinning gyro tilts on its pivot. That tilt is what the instrument measures and shows on the dial.
Context Anchor
Seen in explanations of how the turn coordinator senses both roll and turn, especially in the gyroscopic instruments section of instrument training.
Derivation
Gimbal comes from the Old French 'gemel,' meaning 'twin' or 'linked rings,' originally describing paired rings used to keep a ship's compass level at sea. The term carried into aviation to describe the pivoting rings that let a gyro stay steady while the aircraft moves around it.
Why Pilots Care
The angle and rate of gimbal rotation is what the turn coordinator actually senses. Understanding this helps explain why the instrument shows rate of roll initially and rate of turn once the aircraft is established in the turn.
Analogy
Think of a phone held in a swiveling mount: the phone stays supported, but the mount can turn. In a turn coordinator, the gyro is held in a similar movable frame inside the instrument.
Intuition Check
Do not read “gimbal rotation” as the airplane rotating. Here it means the gyro’s support frame turning inside the turn coordinator.
Example Sentence 1
Because the turn coordinator's gimbal is canted, gimbal rotation occurs during both rolling and turning, which is why the instrument reacts the moment you bank the aircraft.
Example Sentence 2
During preflight checks, a pilot watches for smooth gimbal rotation in the instrument before flight.