Takeoff In Dg Mode; Flight Operations In Basic Mode; Flight Operations In Dg Mode; In--Air Initialization - Honeywell PRIMUS 1000 Pilot's Manual

TAKEOFF IN DG MODE

Takeoff with one AHRS in the DG mode is not recommended. Return
the system to the normal slaved mode by setting the MAG/DG to MAG.
NOTE: If a third heading source is available, it can be used as the
primary data in place of the AHRS ,if slaved operation cannot
be achieved.

FLIGHT OPERATIONS IN BASIC MODE

If a malfunction causes the AHRS to revert to the basic mode, it is
annunciated on the EICAS. Normal flight operations can be continued
in the basic mode subject to the limitations of the aircraft flight manual.
In the basic mode, the pilot must avoid sustained, shallow banked turns
of less than 6°(e.g., a constant turn to hold DME arc). Keep the aircraft
properly trimmed.
NOTE: If an attitude error develops while in the basic mode, it cannot
be removed by the pilot. The system attempts to maintain the
error within bounds.

FLIGHT OPERATIONS IN DG MODE

If a heading flag is observed during a flight, set the MAG/DG switch to
DG.
The AHRS heading must be checked every 5 minutes with reference
to a known accurate heading source. Any errors can be removed by
using the INC/DEC switch to set the heading card to agree with the
known reference.

IN--AIR INITIALIZATION

In--air initialization is not recommended. If it is necessary to perform an
in--air initialization, the aircraft must be maintained in wings--level
unaccelerated flight during the alignment. In the air, alignment time is
normally 15 seconds. Both power source circuit breakers must be
pulled to restart the system.
NOTE: Since the AHRS continuously attempts to realign itself, if it
does not, pulling the circuit breakers to force a restart may not
be successful.
A28--1146--112--00
PRIMUSr1000 Integrated Avionics System
AHZ--800 Attitude and Heading Reference System (AHRS)
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