Page 871 - PPL-engelsk 2025

Navigation

9.9 Radio navigation

When you are flying, you can use your radio to determine your position in various

ways.

You can:

- ask an airport for a VDF bearing
- make a bearing yourself to a radio beacon (NDB, locator, VOR, DME)

9.9.1 VDF (VHF Direction Finder)

The VDF system has been in use for many years.

It is a simple system based on the VHF radio in the aircraft (the radio used for
communication). The airport has a direction finder antenna that can find the

direction to an active radio transmitter.

You can see if there is a VDF at an airport here.

Here it is Rønne. We can see the frequency is 118.330, and that it may be used

below FL 150 and

within a radius of

40 NM.

9.9.1.1 Bearings from VDF

If you are unsure about your navigation, you can get the following bearings:

- QDM = Magnetic bearing from aircraft towards the station

- QDR = Magnetic bearing from station (radial = direction from the station to

the aircraft)

- QTE = True bearing from the station

- QUJ = True bearing to the station

Flyveteori PPL(A)(UL)/LAPL Henning Andersen, Midtjysk Flyveskole© 2025 871