Technical Service Bulletin - Transponder Software Update to Version 2.04

Date: March 27, 2014



Dynon Avionics SV-XPNDR-261 and SV-XPNDR-262 transponders (hereafter, "transponder") with software version 2.02 incorrectly interpret data received from certain TSO'd GPS devices directly connected to the transponder. In this situation, ADS-B transmissions from the transponder contain small errors in position data. The core transponder operation is unaffected.

Transponder software version 2.04, which is available for installation to the transponder in SkyView software version 10.0 and higher, corrects this situation. Additionally, transponders shipped after 2012 are already on this version. Read this entire bulletin to determine whether any action is required.

Applicability and Affected Equipment

This bulletin applies only to some customers that have a SkyView system, a SV-XPNDR-261/262 SkyView transponder, and a Garmin GTN or GNS series IFR GPS that is is wired directly to the transponder to provide position information directly to it. Read this entire section to determine whether or not this bulletin applies to you.

If ALL of the following criteria are met, this service bulletin applies to you:

(1) You have a Dynon Avionics SkyView system, a Dynon Avionics transponder installed, and a Garmin GNS or GTN series IFR GPS installed, AND

(2) Your Garmin GNS (such as GNS 430W) or GTN (such as GTN 650) series IFR GPS is providing GPS position information directly to the transponder to provide a certified position source using Garmin ADS-B format data output. AND

  • If this is the case, SETUP MENU > TRANSPONDER SETUP > GPS DATA will be set to

(3) Your transponder software is exactly version 2.01 or 2.02 or 2.03.

  • To check the software version of the transponder:
    Note the STATUS line.
    Example: ON LINE HW 22.03 FW 01.02 SW 02.02
    The software version of the transponder follows "SW"; in the example above, the
    transponder software version is 2.02

If ALL of the above match your configuration, this service bulletin applies to you and the transponder must be updated to version 2.04. Follow the instructions in the Method of Compliance sections below.

Other Customers that Should Also Update

If the software version of the transponder is 01.06, this service bulletin does not apply to you because the Garmin ADS-B format was not yet supported. However, if you operate your aircraft in the US, your transponder should be updated anyway because it does not meet the latest TSO which is required for 2020 ADS-B mandate compliance. Follow the instructions in the current SkyView System Installation Guide for full procedures on updating the transponder and ensuring that it is TSO compliant.

Method of Compliance - Primary

  1. Update the SkyView system to version 10.0 (or later) software. Go to Software Updates for instructions on obtaining the software and updating SkyView. For current Installation and Operation manuals, go to SkyView Documentation.
  2. After the SkyView system is updated to version 10.0 (or later) software:
  3. Go to SETUP MENU > TRANSPONDER SETUP > (nudge joystick right)
  4. Read and comply with the on-screen instructions before updating
  5. After reading the instructions, push the UPDATE button
  6. After the transponder software update is complete, turn power to the transponder off, then back on, for the software upgrade to be complete.
  7. Go to SETUP MENU > TRANSPONDER SETUP - verify that SW02.04 is shown

Alternate Method of Compliance

If you cannot perform the primary method of compliance, it is acceptable to change the transponder position source to SkyView. This will cause the transponder to transmit a non-certified position, and may not meet an ADS-B out mandate in your country if it has one. In the USA, this alternate method of compliance is acceptable until 2020

To accomplish this:

Goto SETUP MENU > TRANSPONDER SETUP > GPS DATA > (nudge joystick right) > SKYVIEW > ACCEPT (button).

Time in Effect and Warranty Adjustment

This technical service bulletin is in effect indefinitely.

Costs to the Customer

Not applicable

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).

Additional Questions?

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