Reason for Airworthiness Concern:
Latent failure of FreeFlight Systems ADS-B unit, model number FDL-978-XVR, to display air traffic or transmit location to other aircraft with active ADS-B In.
Federal Aviation Administration (FAA) Description of Airworthiness Concern:
Request for Information (For example: Proposed alternate inspection or repair procedures, cost impact, etc. Your comments or replies to the FAA need to be as specific as possible. Please provide specific examples to illustrate your comments or concerns.)
We have received reports of latent failures of FreeFlight model FDL-978-XVR ADS-B units. Troubleshooting determined that some units failed completely, while other units failed intermittently. Attempts to update the software and change any unit settings failed, as most parameters were “greyed out” and unable to be changed. Additionally, the failed units gave no indication of failure to the pilot.