Plain English Meaning

It's the family of navigation tools pilots use to find their way and fly approaches by instruments. Different types do different jobs — some give you a direction to a station, some give you distance, and some guide you down to the runway.

Full Definition

The category headings used to group the different ground-based and space-based navigation aids that pilots use for instrument flight. The main types include the nondirectional radio beacon (NDB), VHF omnidirectional range (VOR), distance measuring equipment (DME), tactical air navigation (TACAN), VORTAC, instrument landing system (), , and (). Each provides a different kind of navigational information, such as , distance, , or .