NDB
Non-Directional Beacon
Last updated: April 20, 2026 · Maintained by Aviatr Editorial Team
What is NDB?
An NDB (Non-Directional Beacon) is a low- or medium-frequency radio navigation beacon (190-1750 kHz) transmitting an omni-directional signal. Aircraft with an Automatic Direction Finder (ADF) receiver point a needle toward the station, providing relative bearing used for en-route navigation and non-precision instrument approaches.
How is NDB used?
NDBs are the oldest radio navigation aid still in European service, predating VORs by decades. NDB approaches remain published at smaller airfields without ILS or RNAV infrastructure, and EASA Part-FCL requires at least one NDB approach during the IR skill test. The ADF needle points continuously toward the tuned station, requiring the pilot to combine bearing and heading mentally to navigate — a skill that feels unfamiliar to RNAV-trained pilots but is still examined by EASA. NDBs suffer from thunderstorm interference, as electrical discharge biases the ADF needle away from the station, and terrain effects can distort signals over mountainous regions. Many European national aviation authorities have announced phased NDB decommissioning as RNAV and GPS coverage reaches saturation; pilots should check current NOTAMs before planning any NDB-dependent route.