There are two variants of this:
- An aircraft symbol is visible right at the center of the display (for moving-map-style displays) or aft (LED-style displays) with a small distance indication.
- An undirected target is shown with small distance / strong signal and at my own altitude. On PowerFLARM Portable, this would show as a small circle around the own aircraft symbol.
In both cases, the problem is due to the PowerFLARM displaying the signal from the own transponder (Mode-C, Mode-S, or ADS-B). Normally, these signals are removed automatically, but there are conditions under which this fails.
The following points should be verified:
- Is the 24-bit address configured correctly on PowerFLARM? In the FLARM configuration tool, the entry "ICAO 24-bit address, hexadecimal" should be verified. The address should be entered as it appears in the aircraft paperwork. It should consist of 6 letter, 0-9 and a-f, the case does not matter.
- Is the "Transponder type" set correctly in the FLARM configuration tool?
- In some rare cases, the own transponder may be configured wrongly. On some models, the programmed ICAO address is visible at startup.
- If this does not help, the "Mode-C filtering method" can be set to aggressive. Removing / filtering own Mode-C signals is more difficult than Mode-S or ADS-B and more aggressive algorithms may be needed.
- Furthermore, "Mode-C processing" can be disabled altogether. In areas where Mode-S adoption is widespread (e.g. Europe), this is a good setting in any case, as the Mode-C signal is simply not needed.