Service Bulletin for Dynon Heated Pitot Tubes

Applicability and Affected Equipment

This bulletin affects the Dynon Avionics Heated AOA/Pitot Probe (p/n 100667-000).



Dynon Avionics has received reports from pilots who have experienced degraded airspeed indications while their Dynon heated pitot probes are in operation. Dynon Avionics has identified an issue where the pitot probe is unable to adequately separate and drain water that is encountered in some flight conditions. As a result, it is possible for water to enter the pitot system and subsequently freeze in unheated areas. This can cause inaccurate, fluctuating, or zero airspeed indications.

Other Considerations

Dynon Avionics EFIS products use airspeed as part of the attitude calculation. While Dynon EFIS products have the ability to use GPS as a backup to airspeed, this mode is only active when the airspeed indication is zero. During inaccurate or fluctuating airspeed indications, Dynon EFIS systems (both SkyView and D10/D100 series) may not provide a reliable attitude indication.

Operating Recommendations

Aircraft equipped with a Dynon Avionics Heated AOA/Pitot probe should be operated as if the aircraft is equipped with an Unheated AOA/Pitot Probe.

Notice to Special Light Sport Aircraft (S-LSA) 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 remove, replace, or update the firmware on a SkyView display(s) if such operations are not permitted in the maintenance manual. Please refer to your aircraft maintenance manual or contact your aircraft manufacturer concerning removing, replacing or updating firmware on your SkyView display(s).

For a list of frequently asked questions about the issue, visit

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

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Omar Filipovic
Omar Filipovic is president of the Glasair Aircraft Owners Association as well as the chief tinkerer and content editor for this website. He is also the web editor for Kitplanes Magazine. Omar is building a GlaStar in Portland, Oregon.