Figure 4-29 Example Gmu 11 Mounting Shelf - Garmin GI 275 Installation Manual

4.6.1.2.1 GMU 11 Custom Mounting Shelf
A custom mounting shelf for the GMU 11 can be fabricated from 2024-T3 aluminum per AMS-QQ-A-
250/5 or 6061-T6 per AMS-QQ-250/11, minimum 0.032 inches thick. The mounting shelf shall not span
greater than 12.0 inches in width or length without direct attachment to the structure. If the mounting
platform does span greater than 12.0 inches, add the necessary stringers, doublers, bulkhead flange
reinforcement, etc., to provide adequate support. Existing honeycomb core sandwich panels with
aluminum face sheets are adequate and do not require additional reinforcement. If corrosion protection
methods are not specified by the model-specific aircraft standard practices manual, the shelf must be
conversion coated per MIL-DTL-5541 Type II or MIL-DTL-81706 Type II and primed with high-solids
chemical and solvent resistant epoxy primer per MIL-PRF-23377, Class N. An example of a custom
mounting shelf is shown in Figure 4-29.
NOTE
A minimum of 3.0 inches between the connector end of the GMU 11 and any object must
be maintained to ensure clearance for connector and wire harness.
2
1
190-02246-10
Rev. 11
1.50 MAX
MS20426AD4
AIRFRAME (REF)
MATERIAL:
2024-T3 PER AMS-QQ-A-250/4 OR 6061-T6
PER AMS-QQ-250/11
THICKNESS: MIN 0.032 IN
NOTE:
1 MINIMUM HEIGHT IS 1.0 INCH
2 MAXIMUM FASTENER SPACING IS 3.5 INCHES

Figure 4-29 Example GMU 11 Mounting Shelf

Ø0.138 (4 PLACES)
2.00
2.28
0.50
GI 275 Part 23 AML STC Installation Manual
Page 4-44