G500/G600 systems installed under the G500/G600 Part 23 AML STC SA02153LA-D that are interfaced to a GFC 600 and dual Garmin GNS/GTN Navigators are affected.
Mandatory: This STC Service Bulletin is mandatory for products listed in the Products Affected section.
STC SA02153LA-D Master Drawing List G600 PFD/MFD System AML STC Rev. T and Master Drawing List G500 PFD/MFD System AML STC Rev. 6 includes GDU 620 Software Version 7.23.
GDU 620 Software Version 7.23 addresses the NAV 2 issue described in Garmin Service Advisory 1805.