Instruction Manual

Instructions for Continued Airworthiness 190-01190-11 Rev. 1
for G500H in Robinson R44 Series Rotorcraft Page 7 of 20
[1] A rotorcraft weight and balance is required after installation of the G500H system. Refer to
installation manual P/N 190-01190-06 for additional information, including overall size and center of
gravity location of all LRUs.
[2] The longitudinal arm is measured in terms of the fuselage station (FS) number.
[3] The lateral arm is measured in terms of the butt line (BL). The centerline of the helicopter is BL 0.00.
The moment arms to the left side (looking forward) are negative (-) and the moment arms to the right
side are positive (+).
2.3 Control, Operating Information
See the G500H Pilot’s Guide or the Installation Manual, listed under the reference documentation in
paragraph 2.1 of this document, for system operation and self-test information.
2.4 Servicing Information
Some metal structures of the GRS 77 may become magnetized if closely exposed to permanent
magnets. While this will not affect the GRS 77 itself, it may slightly affect nearby magnetic instruments in
the area (e.g. whiskey compass). Ordinary use of magnetic screwdrivers to tighten GRS 77 fasteners
will not cause problems, but non-magnetic screw drivers are preferred. It is also recommended to use
non-magnetic screwdrivers near the GMU 44 to prevent magnetizing any nearby metal structures.
In the event of system failure, troubleshoot the G500H system in accordance with Section 2.6
Troubleshooting Information.
2.5 Periodic Maintenance Instructions
Maintenance of the components installed by this STC is on condition, except as noted in the following
table.
Item Interval Description/Procedure
GRS 77H AHRS 5 years
The GRS 77 utilizes an Earth magnetic field model which is
updated once every five years as part of the Aviation Database
maintained by the owner/operator. If the magnetic model is not
current, the unit will issue an alert upon startup indicating the
model has expired. The model can be updated by inserting an
aviation database card with an updated IGRF model and
powering on the system. A prompt will direct the user to press
ENT to update the model.