The big benefit with FLARM is that it only generates warnings when on an actual collision course, and if the collision is going to happen within the next 18 seconds. If you are close to another aircraft but not on a collision course, you will not get a collision warning. If you later turn to a collision course, you will then get a warning, possibly at a close distance.
If you get very late warnings even when on a collision course, this could be due to an incorrect (antenna) installation. Make sure that the installation is done by licensed Part-66 certifying staff. Further information about installation requirement can be found here:
- The Section Safety Equipment Requires Care and Maintenance on the Manuals & Documents page
- Document FTD-041 Application Note FLARM Antenna Installation
- Document FTD-9-65 Installation instructions, part of the EASA Minor Change Approval
In addition, the receive range of a FLARM installation can be tested with the online range analyzer.