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Aviation Alerts and Advisories

GTX 3000 Software Version 3.41


This bulletin is applicable to GTX 3000 units with software version 3.31 or previous software versions installed with ADS-B transmit configured to enabled or pilot controlled.
This bulletin does not apply to GTX 3000 units installed in a Garmin Integrated Flight Deck system (G5000, G3000, G2000, G1000, G1000H, G950, G900X, Cirrus Perspective™, and Embraer Prodigy® Integrated Flight Deck Systems).
The GTX 3000 current software version can be viewed using the GTX install tool.


TSO Authorization


Optional: This Service Bulletin may be incorporated at the owner’s discretion and is not warranty reimbursable.


GTX 3000 software version 3.41 includes the following:

  • Added support for using dual Rockwell Collins RTU-870C transponder controllers, in TCAS II installations
  • Added support for the Gables G7614 transponder controller, including capability to annunciate an ADS-B out function failure on the controller
  • Improved the existing auto moding capability such that the GTX will automatically transition to altitude reporting mode on takeoff, when configured
  • Expanded support for the CTL-92 and CTL-92E transponder controllers, for installations without TCAS II
  • Updated Mode C reply processing to use unconfirmed Gillham altitude in the presence of a Gillham cross-compare failure
  • Added a new discrete output, Standby Alert, to notify the aircrew if the selected transponder is in standby, when configured
  • Improved the flight ID used for ADS-B out in installations that combine the GTX 3000 and GDL 88 for dual band ADS-B out. In the event that the flight ID is not specified by the aircrew, the ADS-B Out flight ID is now synchronized across the ADS-B out system
  • Added support for using the Esterline CMA-5024 GPS as an ADS-B out position source
  • Expanded support for receiving AFCS data for use in ADS-B Out and Enhanced Surveillance
  • Expanded support for receiving pressure altitude data from transponder controllers

ASDN Service Bulletin 1931 Rev A