Definition
A cockpit control on a remote indicating compass system that allows the pilot to manually adjust the compass card to match magnetic north when the system is operated in the free gyro (non-slaved) mode, or to correct the heading indicator if it drifts out of agreement with the flux valve.
Plain English
A small knob or switch in the cockpit used to nudge the heading display so it lines up correctly with magnetic north.
Context Anchor
Seen in instrument flying when using a remote indicating compass or heading system that can operate in slaved or free mode.
Derivation
In engineering, one device is said to be 'slaved' to another when it is forced to follow the master device's signal. The slaving control is the means by which the pilot manages or overrides that following relationship.
Why Pilots Care
Keeps heading information accurate during instrument flight by countering gyro drift and precession.
Intuition Check
Slaving does not mean the pilot is constantly adjusting the compass by hand. In this system, it means the heading display can automatically follow a magnetic reference unless the pilot selects free operation.
Example Sentence 1
After noticing the heading indicator was a few degrees off, the pilot used the slaving control to bring it back into agreement with the magnetic compass.
Example Sentence 2
During preflight the slaving control was checked to confirm the gyro was receiving corrections from the flux valve.