PC-HFDL 635-3 HFDL Decoder (formerly PC-HFDL)

Communication is a lot more than a simple text message or exchange of ideas. When it comes to aircraft, it is done through a solid infrastructure that enables secure and uninterrupted connectivity. Powerful transmitters and receivers are required since long distances need to be covered. For capturing and processing such signals you can use PC-HFDL, a utility used for decoding packages received through the ARINC 635-3 HF data-link protocol.

The application's main window is home to all tools you get to work with, cleverly spread throughout the interface. Constantly running you find a spectrum displaying wavelengths from received signal. Decoded info can be viewed in a text field below from which you can easily copy it to an external application.

What's more, detected aircrafts are displayed in a list so you can try to connect to the one of interest. These can be deleted so you can only keep the list populated with the ones you see fit.

The application can take advantage of external applications for identifying sources, with the possibility to select DxAtlas or Google Earth.

You can only choose to decode certain information elements which are enlisted in a dedicated panel. Thus, you can select preamble, SPDU to display Squitter protocol data units, MDPU, LDPU, BDU, Verbose output and a few more.

The application can be slightly configured to make sure you can get proper signal. A few options are available to set up DDE, logfile, timeout, soundcard, channel and spectrum. It would have been useful to also be able to save the log file on your computer, but you can bypass this by copying the text from the dedicated field.

Taking everything into consideration, we can say that PC-HFDL is a powerful application you can use to listen to what's going on in airline space. However, you need to own proper equipment that is capable of receiving signal, with the rest being easily handled by the application.