Ahrs Operation - Garmin G900X Pilot's Manual

AHRS OPERATION

Aggressive maneuvering while AHRS is not operating normally may degrade AHRS accuracy.
NOTE:
The Attitude and Heading Reference System (AHRS) performs attitude, heading, and vertical acceleration
calculations for the G900X System, utilizing GPS, magnetometer, and air data in addition to information
from its internal sensors. Attitude and heading information are updated on the PFD while the AHRS receives
appropriate combinations of information from the external sensor inputs.
AHRS Normal
Loss of GPS, magnetometer, or air data inputs is communicated to the pilot by message advisory alerts. Any
failure of the internal AHRS inertial sensors results in loss of attitude and heading information (indicated by red
'X' flags over the corresponding flight instruments).
Two GPS inputs are provided to the AHRS. If GPS information from one of the inputs fails, the AHRS uses
the remaining GPS input and an alert message is issued to inform the pilot. If both GPS inputs fail, the AHRS
can continue to provide attitude and heading information to the PFD as long as magnetometer and airspeed
data are available and valid.
If the magnetometer input fails, the AHRS continues to output valid attitude information; however, the
heading output on the PFD is flagged as invalid with a red 'X'.
Failure of the air data input has no effect on the AHRS output while AHRS is receiving valid GPS information.
Invalid/unavailable airspeed data in addition to GPS failure results in loss of all attitude and heading
information.
190-00726-00 Rev. A
Magnetometer
AHRS no- AHRS no-Mag/
Mag Mode
Operation
Heading Invalid
Figure 1-10 AHRS Operation
Garmin G900X Pilot's Guide
GPS
Airspeed Data
AHRS
no-Air Mode
no-GPS
Mode
SYSTEM OVERVIEW
Attitude/Heading Invalid
1-13