Definition
A mechanism on certain gyroscopic instruments, such as the attitude indicator or directional gyro, that allows the pilot to lock the gyro's gimbals in a fixed, centered position. Caging stabilizes the instrument during maneuvers that would otherwise exceed its operating limits, or resets it to a known reference before flight.
Plain English
A knob or lever on some gyro instruments that lets the pilot freeze the gyro in place so it doesn't tumble or drift during unusual maneuvers, or to reset it to a clean starting position.
Context Anchor
Seen during the before-takeoff instrument check, especially when confirming that the attitude indicator is ready for an instrument takeoff.
Derivation
From 'cage,' meaning to enclose or restrain. The caging mechanism literally restrains the gyro's free movement, holding it still inside the instrument.
Why Pilots Care
Protects the instrument from damage and allows the pilot to reset it quickly if the gyro tumbles, maintaining reliable attitude and heading information.
Intuition Check
Do not read caging as a general safety feature or warning system. Here it means physically locking, centering, or resetting the instrument’s internal mechanism so the display is usable.
Example Sentence 1
Before takeoff, the pilot used the caging feature to set the directional gyro to match the magnetic compass heading.
Example Sentence 2
After encountering turbulence, the pilot used the caging feature to stabilize the heading indicator and realign it with the magnetic compass.