VOR and NDB
A VOR is a VHR omni range bearing navigation aid. It is a large piece of apparatus on the ground and looks a bit like a birthday cake design (with candles!). It is radiating a signal on each of 360 degrees so you can fly towards or away from it with accuracy, especially as they are usually colocated with distance measuring equipment (DME) to give you a bearing and range. An NDB is a relatively cheap piece of equipment and it can be strung from a tower and the line is sending out a signal in all directions, hence non directional beacon. This used to be used on airways as well as at terminals, but has been replaced largely by the more accurate VORs. Now it is still found at airports for locator beacons from which to start an approach, as well as still being used on some airways.
Last edited by Grasscarp; 19th August 2012 at 19:49.