Stands for Non-Directional Beacon. An aerial navigation facility which simply broadcasts its station identifier in morse code
. Two aerials (one in the front of the aircraft
and one in the rear
- or at least as differently-located as possible) receive the signal. The phase difference between the two signals is computed and displayed as a bearing from the station.
NDB stations, like VOR
stations, only provide position line
information. See also DME