Garmin G1000 Pilot’s Guide for the Socata TBM 850/900
190-00709-05 Rev. D
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SYSTEM OVERVIEW
GPS INPUT FAILURE
NOTE:
In-flight initialization of AHRS, when operating without any valid source of GPS data and at true
air speed values greater than approximately 200 knots, is not guaranteed. Under these rare conditions, it
is possible for in-flight AHRS initialization to take an indefinite amount of time which would result in an
extended period of time where valid AHRS outputs are unavailable.
The G1000 system provides two sources of GPS information. If a single GPS receiver fails, or if the
information provided from one of the GPS receivers is unreliable, the AHRS seamlessly transitions to using
the other GPS receiver. An alert message informs the pilot of the use of the backup GPS path. If both
GPS inputs fail, the AHRS continues to operate in reversionary No-GPS mode so long as the air data and
magnetometer inputs are available and valid.
AIR DATA INPUT FAILURE
A failure of the air data input has no effect on AHRS output while AHRS is operating in normal mode. A
failure of the air data input while the AHRS is operating in reversionary No-GPS mode results in invalid
attitude and heading information on the PFD (as indicated by red “x” flags).
MAGNETOMETER FAILURE
If the magnetometer input fails, the AHRS transitions to one of the reversionary No-Magnetometer modes
and continues to output valid attitude information. However, if the aircraft is airborne, the heading output
on the PFD does become invalid (as indicated by a red “x”).
