Garmin G900X Pilot's Manual page 325

DR Mode is inherently less accurate than the standard GPS/WAAS Mode due to the lack of satellite measurements
needed to determine a position. Changes in wind speed and/or wind direction will compound the relative
inaccuracy of DR Mode. Because of this degraded accuracy, the crew must maintain position awareness using
other navigation equipment until GPS-derived position data is restored.
As a result of operating in DR Mode, all GPS-derived data is computed based upon an estimated position and
is displayed as yellow text on the display to denote degraded navigation source information. This data includes
the following:
• Navigation Status Box fields except Active Leg, TAS, and DTK
• GPS Bearing Pointer
• Wind data and pointers in the Wind Data Box on the PFD
• Track Bug
• All Bearing Pointer Distances
• Active Flight Plan distances, bearings, and ETE values
Also, while the G900X is in DR Mode, the autopilot does not couple to GPS, and both TAWS and Terrain
Proximity is disabled. Additionally, the accuracy of all nearest information (airports, airspaces, and waypoints)
is questionable. Finally, airspace alerts will continue to function, but with degraded accuracy.
190-00726-00 Rev. A Garmin G900X Pilot's Guide
GPS NAVIGATION
5-167