VERY HIGH FREQUENCY OMNI RANGE (VOR)
VOR is a navigation aid which can be very useful particularly when flying above cloud, at night or
when visibility is poor. It is often used in conjunction with the Distance Measuring Equipment. VOR equipment is in two parts the equipment on board the aircraft and ground based equipment.
The ground base equipment consists of a beacon continuously transmitting narrow beamed radio signals along all radials from the station The equipment on board the aircraft consists of dial with a pointer, compass rose, omni bearing selector (OBS) knob and radio equipment with the means of tuning it to any particular ground beacon.
To use the VOR, the pilot locates the appropriate ground beacon on his chart, (map): he then tunes his VOR to the frequency for that particular beacon. To ensure that he is tuned to the correct beacon the pilot must then listen to the 3 letter Morse code signal transmitted by the ground equipment. Once the pilot has established that he is tuned to the correct beacon he rotates the OBS knob which turns the compass rose. At some point the pointer should centralize with a TO indication. If the pilot then flies on the heading indicated by the compass rose, allowing for any cross wind the pointer should stay in the centre and the aircraft will eventually pass over the VOR ground station. While flying towards the beacon any deviation from the central position by the pointer, indicates that the aircraft has strayed off the desired track. In order to regain track the pilot will have to fly slightly left or right, depending which side the pointer has moved. Once back on track the aircraft should be turned back towards the heading indicated by the pointer and the compass rose.