Non-directional Beacon (NDB)
An Non-directional Beacon (or NDB), is basically a radio transmitter that you can tune in, using a radio receiver. An NDB usually transmits morse code, indicating its identity but can also broadcast other things such as ATIS (Automatic Terminal Information Service) or other handy services. Most, if not all, of the ones you will find inside a flight simulator will broadcast a morse code identifier.
NDBs will also transmit at great distances and it's not rare for you to be able to tune in to an NDB 100 miles away from your position in a flight simulator.
To tune into an NDB frequency and use it to navigate to an oil platform, you will need to use a special navigation equipment in your aircraft: the Automatic Direction Finder -- or ADF.
Automatic Direction Finder (ADF)
To be of any real use in helping navigate using NDBs, the ADF not only allows you tune in but also calculates the direction of the NDB relative to your aircraft, which is then displayed on the Relative Bearing Indicator (RBI) which is located on your panel.
So, once you tune in to the NDB frequency using your ADF, it will start listening to the said frequency and, once it finds a signal being broadcasted, you should start listening to the broadcast and the ADF will start calculating the direction of the NDB, by using an array of antennas. It will then display the direction of the NDB on the RBI, which you will just need to follow towards the NDB antenna.
In the image below, you will see how the RBI behaves in different positions around an oil platform equipped with an NDB. To fly towards the platform we would only need to get the yellow arrow to point up, just like it is on the bottom left of the image.
We would then do the necessary corrections to keep the arrow pointing up and we should get to the oil platform without much hassle.
Please note that, despite the RBI indicates that north is ahead, this doesn't mean that your RBI will need to be displaying the arrow pointing north and that north should be ahead. Your concern while homing towards an NDB is to keep the needle pointing up, regardless of the cardinal point you're flying towards.
Using NDBs to find your oil platforms is not hard and it's actually fun. The only thing that may be annoying is not knowing the distance to the platform. There's a way to find it out but that's out of the scope of this article. Maybe in the future we'll publish another article about it.
Finding an oil platform
In the video below (which you can also find at our YouTube channel) you can see how to use the ADF to follow an NDB signal all the way to an oil platform.