Original Bulletin: June 3, 2019



Early SV-GPS-2020 units output a NACv value that is more accurate than the FAA’s ADS-B monitoring system expects to see. This causes the reports that FAA sends to pilots about their aircraft’s ADS-B compliance to note the NACv in the compliance report.

SkyView system software 15.4.7 or later contains an update to the SV-GPS-2020 software that changes the NACv reporting behavior to alleviate this issue. Similar to the Dynon transponder, the SV-GPS-2020 needs to be updated manually; updating your system software does not apply the software update to the SV-GPS-2020 automatically.

To fly in ADS-B Out rule airspace defined in 14 CFR 91.225, customers must comply with this service bulletin before January 1, 2020.

Applicability and Affected Equipment

This issue affects early SV-GPS-2020 products installed in experimental and light sport aircraft that are running SV-GPS-2020 software version earlier than ver 1.11 and/or have a Public ADSB Performance Report (PAPR) report from the FAA showing a NACv value of 4.0, highlighted in yellow.

Unaffected Equipment

The following equipment is NOT affected by this service bulletin

  1. SV-GPS-2020 units that are installed in Dyonn Certified STC approved SkyView HDX installations.

Interim Operating Recommendations

We recommend that customers that are operating in the US comply with this service bulletin as soon as practical. To fly in ADS-B Out rule airspace defined in 14 CFR 91.225, customers must comply with this service bulletin before January 1, 2020. As always, It is up to the owner/operator to determine the airworthiness of the aircraft for flight.


As the product itself is not physically marked, customers need to update to SkyView system software to version 15.4.7 and use the included software status tool to determine whether their SV-GPS-2020 needs updating. Once the software load is complete on the SkyView system do the following.

  1. Go to SETUP MENU> LOCAL DISPLAY SETUP,>GPS FIX STATUS If the software needs updating, you will notice on the top right a message in yellow that says, SV-GPS-2020 SW OUT OF DATE ENTER TO LOAD.
  2. Press the right CURSR Button and you will see LOAD appear above Button 8. Press the LOAD button.
  3. Read and comply with the warning pages. Press CONTINUE when ready to update.

Please note: The update process will take up to 15 minutes depending on which version is being updated.

Time in Effect

This technical service bulletin is in effect indefinitely or until superseded by a future bulletin.

Notice to Special Light Sport Aircraft (S-LSA), Dynon Certified, and other Non-experimental Customers

You are solely responsible for ensuring that your aircraft is airworthy. In the case of S-LSA aircraft, owners may need special authorization to service the aircraft if such operations are not permitted in the maintenance manual. Please refer to your aircraft maintenance manual or contact your aircraft manufacturer concerning changing the software on your SkyView system.

This service bulletin does not affect installations of SkyView HDX that are approved under Dynon’s STC program.

Additional Questions?

Contact Dynon Avionics Technical Support via phone (425-402-0433) or email