Skip navigation links
Unsupported Browser Detected – For best results, please update your browser.

Aviation Alerts and Advisories

Service Advisory 20109 Rev C: Erroneous GPS position and momentary false TAWS alerts

REVISION C:

Added GTN 6XX/7XX and GTN Xi Resolution

PRODUCTS AFFECTED:

All SBAS-enabled Garmin Integrated Flight Decks (G900X, G950, G1000(H) G1000(H) NXi, Cirrus PerspectiveTM, Embraer ProdigyTM, G2000, G3000, G5000, and Embraer Prodigy® Touch systems), GTN Xi Series, GPS 175, GNX 375, GNC 355, GNS 400W/500W Series, GNS 480, GTN 6XX/7XX Series products operating within the area depicted in the attached Service Advisory are affected.

ISSUE:

Affected Garmin equipment may periodically experience GPS position errors for approximately six seconds, and momentary TAWS false alerts when utilizing corrections from the Japanese MSAS (MTSAT Satellite Augmentation System) space-based augmentation system.

ACTION:

Disable MSAS.

NOTE
Refer to the applicable pilot’s guide for instructions on how to disable MSAS.

RESOLUTION:

MSAS was disabled automatically in the November 2020 aviation database cycle. A future software and database update will address the issue and re-enable the use of MSAS in the affected products.

MSAS was re-enabled in aviation database cycle 2103 (except the GNS 480).

For GTN 6XX/7XX products this has been fixed in GTN 6XX/7XX GPS/WAAS Software Version 8.3. GTN 6XX/7XX GPS/WAAS Software Version 8.3 is packaged with GTN 6XX/7XX Main Software Version 6.72. Refer to Garmin TSO Service Bulletin 2141 or Garmin Service Bulletin (Non-Certified Aircraft) 2143.

For GTN Xi products this has been fixed in GTN Xi GPS/WAAS Software Version 8.2. GTN Xi Software Version 8.2 is packaged with GTN Xi Main Software Version 20.20. Refer to Garmin TSO Service Bulletin 2170, Garmin STC Service Bulletin 2171, or Garmin Service Bulletin (Non-Certified Aircraft) 2173.

Service Advisory 20109 Rev C