As an aircraft flies overhead, it receives radio signals in a 360 degrees circle around the aircraft. So these radio stations must be placed into a database, which contains the address of the main Db. This database must be updated every fifteen minutes or so, for an aircraft doing 100mph. The following things will happen if the selected frequency is in the range:

  • Your RMI flag will now turn off (means it's good).
  • Your RMI will display TO or FROM.
  • Your RMI needles will now the steering cues will now start to move which informs you which was to turn the aircraft. Your DME will display the miles to go.
  • You will hear the Morse Code for the Stations ID on the radio. If the radio is selected.

Since time is short I will not concern myself flying any significant distance so we will only use Meacham Field, Fort Worth and Addison Airport, Addison, Texas.

The Morse Code is basically a tone generator (Arduino). The values that you need for your fist are dot length, dash length, and character inter-spacing and word inter-spacing as every fist is different. Our word inter-spacing as the call is repeated every so often per minute.

The audio output will be handled by an integrated amp as I will only need a few watts, at best.

Normally this system has 5 parts:

  • Control Head (left)
  • RMI (Right)
  • Radio, (not shown as it is in the avionics bay.
  • Radio Antenna
  • DME, Distance Messuring Equipment (optional)