G1000/GFC 700 Post Installation Checkout Procedure – Hawker / Beechcraft King Air C90
Page 5-1
190-00682-00
Revision 5
5
GRS 77/GMU 44 INITIAL ALIGNMENT and STBY COMPASS CALIBRATION
The GRS 77 AHRS and GMU 44 magnetometer units require calibration before first flight. There are
three procedures to be carried out. The aircraft engine must be started after the first procedure is
complete. When ready to perform the procedures, open PFD1 primary and secondary, PFD2 and MFD
circuit breakers. Restart the displays in configuration mode.
5.1
Procedure A: GRS 77 Pitch/Roll Offset Calibration
Figure 5-1. Pitch/Roll Offset
This procedure must be carried out with the engine off. Rotate the large FMS knob to select the GRS
page group on PFD1. Rotate the small FMS knob clockwise to access the GRS/GMU calibration page on
PFD1.
1. This page is protected and requires a keystroke password to perform the calibration. Press the
following softkeys in sequence:
a) softkey
9
b) softkey
10
c) softkey
11
d) softkey 12 (Far Right softkey)
2. Level the aircraft to zero pitch and zero roll using appropriate Hawker / Beach King Air
maintenance procedures in the C90 Airplane Maintenance Manual.
3. Initiate the AHRS Ground Pitch/Roll Aircraft Level compensation mode by performing the
following steps:
a) Ensure that the GRS is selected.
b) Select
PITCH/ROLL OFFSET
, then press the
ENT
key.
c) Follow the checklist items displayed on PFD1 and press the
ENT
key as each one is
completed or confirmed. When the CALIBRATE field is blinking, press the
ENT
key to begin
the procedure.
