FLARM Range analyzer

By analyzing data from the built-in flight recorder (IGC files), the FLARM Range analyzer can tell you the quality of your FLARM antenna installation, based on received data.

Flights to be analyzed must have a duration of at least 30 minutes and contact with at least 5 other aircraft while flying.

IGC files recorded with firmware prior to version 6.40 will show the range for both antenna A and antenna B as the range for antenna A. Update to version 6.40 or above to get a separate range assessment for antennas A and B.

We take the privacy of your data seriously and you can find our Privacy policy here.

Choose one or several IGC files, recorded with a FLARM device:


Technical information

FLARM devices store some randomly chosen relative positions received from other aircraft in an IGC file. This data is then analyzed to determine the reception range. As the range depends equally on your and the other aircraft’s radio performance, which is unknown, a large number of data points must be collected. The inherent limitation of this analysis is that it can only examine and show successful receptions. Therefore it can indicate areas of confirmed performance, but can only hint at areas with no reception, as there will be little or no data from there. Based on this approach, the transmission range cannot be assessed, but reception range is a reasonably proxy for transmission range, with some exceptions. (Note that some ground-based tools for assessing the transmission range exist e.g. from Ktrax; these however only give indicative information due to a lack of calibration and also require extensive flight time.)

How can I improve the transmission range?

  • Check the Installation Manual to see if all rules and recommendations have been followed
  • Read the Application Note on FLARM Antenna Installations
  • If you have an internal antenna, relocate the FLARM antenna to another position, as far away as possible from any metal / carbon
  • If you have an internal antenna, install instead an external antenna

Should I try to improve the “Maximum distance”?

Distances beyond 12 km in one direction and much worse distances in other directions is normally a sign that the performance is not evenly distributed in all directions. Therefore, a big “Maximum distance” could be bad for overall performance.

Do NOT use directional antennas. Directional antennas will make the range much worse in most directions.


This tool performs a statistical analysis of past data, based on data supplied by the user. The result of this analysis may differ significantly from actual, individual performance.