Definition
A ground-based, low or medium frequency radio transmitter that broadcasts a signal in all directions, allowing an aircraft equipped with an Automatic Direction Finder (ADF) to determine bearing to or from the station. A Compass Locator is a low-power NDB (typically 25 watts or less, with a range of about 15 NM) installed at the outer or middle marker of an Instrument Landing System (ILS) to assist pilots in intercepting and tracking the localizer course during an instrument approach.
Plain English
A simple radio beacon on the ground that sends a signal out in every direction. The aircraft's needle points toward it, so the pilot can tell which direction the station is. A Compass Locator is just a small version of this beacon, placed near a runway to help line up for an instrument approach.
Context Anchor
Seen on instrument approach procedures, in navigation databases, and on GPS pages that list nearby navigation aids.
Derivation
Non-Directional Beacon means the signal is broadcast equally in all directions, with no built-in bearing information — the aircraft's receiver determines the direction. Compass Locator reflects its purpose: helping the pilot 'locate' and align with the approach course, much like a compass pointing the way.
Why Pilots Care
Supplies a reliable navigation reference when GPS signals are unavailable or unreliable during an approach.
Intuition Check
Do not read “compass locator” as a magnetic compass on the panel. Here it means a ground radio station that lets the airplane point toward a known location.
Example Sentence 1
The approach chart showed a Compass Locator at the outer marker, but the facility had been decommissioned, so the pilot used the GPS overlay instead.
Example Sentence 2
When GPS guidance was lost, the crew switched to the NDB/Compass Locator for bearing information to continue the approach.