Definitions for "Outer Marker"
An Instrument Landing System navigation facility in the terminal area navigation system located four to seven miles from the runways edge on the extended centerline indicating the beginning of final approach.
An LF or VHF facility installed at the site of the outer marker of an instrument landing system (ILS). abbreviation: OM Fr: radioborne extérieure
ILS marker situated on centerline of approach, about 4.5 nm (8.3 km) from runway