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Aviation Alerts and Advisories

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


Added the G1000(H) NXi


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 Service Advisory linked below) are affected.


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.


Disable MSAS.

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


MSAS will be 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.

Service Advisory 20109 Rev B