All GTS Processor (GTS 825/GTS 855/GTS 8000) units with software version 3.05 (or earlier) and interfaced to a GTN 6XX/7XX, GNS 4XX(W)/5XX(W), GNS 480, G500, G500H, G600, GMX 200, MX20, or other 3rd party flight display systems are affected by this bulletin.
The current GTS Processor software version can be viewed by using the GTS Processor Install Tool (refer to the Modification Instructions section of this bulletin), on the software label adjacent to the GTS Processor serial number tag (for installations unable to electronically display the software part number), or on the display for those units interfaced through HSDB (e.g. GTN 6XX/7XX, G500, G500H, and G600).
Optional – Service Bulletin 1755 may be incorporated at the owner’s discretion and is not warranty reimbursable.
GTS Processor software version 3.11 includes the following enhancements:
- Allows the display to enable the ADS-B In processing when GTS is in Standby mode. This requires the new “ADS-B Allow in Standby” configuration to be checked and the feature to be supported by the installed control head or display.
- Improves tracking of Mode S intruders that transition from Altitude Reporting to Non-Altitude Reporting.
- Allows the system to return to Operate Mode if a pressure altitude fault caused the unit to fail but the fault subsequently clears.
- Replaces the protocol used on the Enhanced Com port. The new protocol allows uncertified Garmin displays (e.g. G3X) to now display ADS-B In intruder data.
- Adds support for additional diagnostic information to be displayed on the GTS Processor Install Tool. The data reported include current Pressure Altitude, Radar Altitude, and Magnetic Heading inputs and their validity.
- Fixes a traffic display issue where an intruder with a range greater than 127NM would be output as being very close to ownship. No TAs or RAs were generated on the intruder as the intruder was physically very far away. This issue affects systems where the intruder data was output via a configured A735 Display TX port or BCAS Display TX port and the ADS-B Receiver was enabled.
- Improves tracking of TIS-B targets when the “ADS-B Receiver” configuration is On. Improvements include better detection of when ownship is being tracked as an intruder, reducing split TIS-B intruders and nuisance TA alerts from those splits.
- Improved filtering of replies that can cause range rate spikes on intruders (when the GTS Processor is configured as a TCAS II). This resolves a scenario that can cause TAs to be generated on targets that are far away (i.e. >10 NM).