What is the full meaning of "NDB"?

The correct answer reflects that "NDB" stands for Non-Directional Beacon. This term is used in aviation to describe a radio beacon that transmits signals in all directions, allowing pilots to navigate using the beacon as a reference point. NDBs are particularly useful for instrument approaches, as they assist in determining a pilot's position relative to the beacon's location.

In the context of aviation, NDBs are essential for aiding navigation and are often paired with Automatic Direction Finders (ADFs) which allow pilots to identify the direction of the beacon relative to their aircraft’s position. The term highlights the non-directional nature of the beacon’s signal, indicating it broadcasts equally in all directions rather than in a specific path, which enhances its utility for navigational purposes.