Plain English Meaning

A way of flying down to a runway in cloud or low visibility by using a simple ground radio beacon. The aircraft has an instrument that always points toward the beacon, and the pilot uses that pointer to fly the published path down to the airport.

Full Definition

An instrument approach procedure that uses a Non-Directional Beacon (NDB) as the primary navigation aid for guiding the aircraft to the runway environment. The pilot tracks bearings to or from the NDB station using an Automatic Direction Finder (ADF) in the aircraft, following published , , and on the until reaching the or with the runway.