G900X/G950 Installation and Maintenance Manual – Airframe Specific Installation Instructions (G900X Only)
Page B-61
190-00719-00
Revision D
Using the general location for the GRS 77 AHRS noted in Figure B-73, set the bracket assembly in the
aircraft to determine the permanent location. The ideal location places the unit as aft and inboard as
possible. Figure B-79 shows the hole pattern used to install bolts in the floor for attaching the
115-00909-00 angle brackets. Figure B-79 demonstrates the hole preparation in the floor. It is critical the
angle brackets remain parallel to the aircraft centerline (aircraft’s forward direction). This will ensure the
mounting rack and GRS 77 AHRS unit are also aligned with the aircraft’s forward direction upon
installation. The tolerance for installation is ±1º to the aircraft’s forward direction. The box covering the
elevator control tube, that spans the length of the baggage area, provides an adequate surface from which
a parallel reference can be identified. Mark the center of holes as shown to prepare for bolt placement.
Trace the remaining bracket outline for future reference.
115-00909-00
ANGLE BRACKET (REF)
(2 REQ'D)
FORWARD
Figure B-79. Hole Pattern In Fuselage
Beginning with Step 8 on Page B-42 of this manual, prepare the floor of the baggage area for installation
of the mounting hardware and install the hardware. Complete Steps 8 (Page B-42) through 20 (Page
B-47) in this manual. These steps cover mounting hardware as well as installation of the Universal AHRS
Mount assembly and the GRS 77 AHRS unit.