Garmin G5 Installation Manual page 57

4.1.2.7 GMU 11 Magnetometer Mounting Requirements
The GMU 11 is an extremely sensitive magnetic sensor, more sensitive to magnetic disturbances
than a flux gate magnetometer. For this reason, when choosing a location, distance from
possible magnetic disturbances is critical to a successful installation.
Consider the following items when choosing a mounting location:
•
Maintain as much distance as possible from electric motors, ferromagnetic materials,
electrical devices drawing more than 100 mA and electrical conductors
•
Ensure that any electrical conductor near the GMU 11 is shielded
•
The GMU 11 must not be mounted on an access panel
•
Mounting of the GMU 11 in the wing is preferred
CAUTION
After a location has been selected and a GMU 11 mounting method chosen, a location
survey must be performed at that location prior to fabricating or assembling any parts
for the GMU 11 mounting. It is possible that the location will fail the survey and the
installation will require a new location, with different installation requirements. See
Section 4.1.2.8 for Magnetic Interference Survey instructions.
CAUTION
Failure to meet these specifications may result in a failed magnetometer calibration.
For the installation of the GMU 11 level the aircraft in both the longitudinal and lateral axes.
Refer to the aircraft's maintenance manual for leveling instructions. It is preferred that the
aircraft is placed on jacks while leveled to avoid inadvertently placing the aircraft in a non-
level position when entering, exiting or working the aircraft.
The GMU 11 should be mounted to a surface known to have sufficient structural integrity to
withstand additional inertial forces imposed by the 0.26-pound unit.
In order to satisfy the structural mounting requirements for the GMU 11, the following
conditions must be met:
1) The mounting location must satisfy the alignment requirements shown in Figure 4-37 and
Figure 4-38
2) The mounting structure, existing or new, must be electrically bonded to the airframe per
Section 4.6.
3) Any supporting structure must be rigidly connected to the aircraft primary structure through
strong structural members capable of supporting substantial loads.
4) Mounting platform shall not span greater than 12" in width or length without direct
attachment to primary structure. If mounting platform does span greater than 12", add
necessary stringers, doublers, bulkhead flange reinforcements, etc., to provide adequate
support. Existing honeycomb core sandwich panels with aluminum face sheets are adequate
and do not require additional reinforcement.
5) A minimum of 3" between the connector end of the GMU 11 and any object must be
maintained to ensure clearance for connector and wire harness.
6) If a support bracket or shelf needs to be fabricated, it should be fabricated and attached to
the aircraft structure in accordance with the methods outlined in AC43.13-2B Chapter 1 and
2, AC43.13-1B Chapter 4, and the following requirements:
a) Material shall be 2024-T3 aluminum alloy sheet per AMS-QQ-A-250/4 or Clad 2024-
T3 aluminum alloy sheet per AMS-QQ-A-250/5.
Garmin G5 Electronic Flight Instrument Part 23 AML STC Installation Manual
Page 57
190-01112-10
Rev. 9