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System Overview
COMPARATORS
There are various comparators running in the IFD and DFC100
system as noted in the chart below. If conflicting information is
provided, the comparator identifying the conflict with the
accompanying pilot indication and autopilot behavior is noted in
the table below:
Type of
Comparator
Indication to Pilot
Autopilot behavior
Internal kinematic
comparator within
the AHRS
(compares AHRS
state data with
itself, eg. turn rate
without
accompanying
heading change,
etc)
“CROSSCHECK
ATTITUDE 1”
annunciation on
PFD page for minor
issues and indicator
removal and
replacement by
“Red-X” for major
issues
Dual AHRS
Systems
: No
autopilot disconnect
Single AHRS
Systems
: Autopilot
will disconnect with
a “Crosscheck
Attitude 1” but will
allow manual re-
engagement by the
pilot.
Dual AHRS
Systems
: AHRS-to-
AHRS Comparator
Single AHRS
Systems
: AHRS-to-
Turn Coordinator
(TC) Comparator
Miscompare Alert
message(s)
presented to the
pilot on the IFD
(“AHRS
Miscompare” CAS
message) and in
the headset
(“GYRO
MISCOMPARE”)
Autopilot will
disconnect with a
Pitch or Roll
miscompare (dual
AHRS systems) but
not for an AHRS-TC
miscompare (single
AHRS systems)
and allow manual
re-engagement by
the pilot after
selection by the
pilot of the operable
AHRS by reference
to the standbys.
Change 1