(2023) Service Advisory 23053 Rev B: Localizer Only Without a Published ILS

PRODUCTS AFFECTED:

All GI 275 products with software versions 2.60 and earlier interfaced with a GFC 500 autopilot are affected.

ISSUE:

Localizer (LOC) only approaches without a published ILS that do not have an approach course of approximately 360, may cause the GI 275 and GFC 500 autopilot to not track properly.

If the GI 275 and GFC 500 capture a localizer only signal while tracking the localizer the system may (depending on the approach course value):

• drop the autopilot mode
  

Or

• track the LOC in the opposite direction

PILOT ACTION:

Do not engage the GFC 500 autopilot in an approach mode if capturing a LOC only approach that does not have a published ILS.

RESOLUTION:

This has been fixed in GI 275 System Software Version 3.01. Refer to Garmin TSO Service Bulletin 23087.