Attitude Heading Reference Syste (Ahrs) - Garmin G500H Pilot's Manual

1.1.1.3 Attitude Heading Reference System (AHRS)
NOTE: Aggressive maneuvering while AHRS is not operating in normal
mode may degrade AHRS accuracy.
The Attitude and Heading Reference System (AHRS) unit provides aircraft
attitude information to the G500H display. The unit contains advanced
accelerometers and rate sensors and interfaces with both the ADC and the
GMU 44 magnetometer. The AHRS utilizes GPS data forwarded from the GDU
620. Attitude and heading information is sent to the GDU 620 using an ARINC
429 digital interface.
The International Geomagnetic Reference Field (IGRF) model is contained in
the AHRS and is updated once every five years. The IGRF model is part of the
Navigation Database. At system power-up, the IGRF models in the AHRS and
the Navigation Database are compared. If the IGRF model in the AHRS is out of
date, the user is prompted to update. The prompt will appear after the G500H
splash screen is acknowledged on the MFD.
Attitude and heading information is displayed on the PFD when the AHRS
receives appropriate combinations of information from the external sensor
inputs.
AHRS Inputs
GPS Magnetometer
Available Available
Available Unavailable
Available Unavailable
Unavailable Available
1-4
Figure 1-4 AHRS
AHRS
Mode
Air Data
Available/ Normal
Unavailable
Available No Mag
Unavailable No Air/
No Mag
Available No GPS
Garmin G500H Pilot's Guide
AHRS Outputs
Attitude Heading
Available Available
Available GPS Track
Available GPS Track
Available Available
190-01150-02 Rev. J