NDB stands for what term in aviation navigation?

• A. Nondirectional Beacon
• B. Nondirectional Radio Signaling Beacon
• C. Non-Directional Beacon
• D. Nondirectional Radio Beacon

Answer: (D)

Understanding what NDB stands for in aviation navigation is key. An NDB is a ground-based beacon that transmits a continuous radio signal in all directions, so there isn’t a directional pattern to the signal itself. The expansion used here—Nondirectional Radio Beacon—emphasizes two things: the signal is radio-based and it is non-directional. Aircraft equipped with an ADF (Automatic Direction Finder) receiver pick up this signal and determine a bearing to the station, which helps you navigate by flying toward or away from the beacon as needed. While other options drop or alter parts of the phrase, the full term Nondirectional Radio Beacon most clearly communicates that this is a radio navigation aid that provides an omnidirectional signal.