Garmin GI 275 Installation Manual page 117

In most cases, installation of the GI 275 does not require modification to the existing instrument panel if it
is replacing an existing 3-inch diameter flight instrument. Simply remove the existing 3-inch diameter
flight instrument and install the GI 275 unit as shown in Figure 4-11.
CAUTION
The instrument panel coating that surrounds the fastener holes and contacts directly with
the GI 275 unit must be removed prior to installation in accordance with Section 4.3.2.
If modification is required, typically it will be simply trimming the existing 3-inch cutout on the instrument
panel to accommodate the knob on the unit. It may also be necessary to enlarge the instrument panel
fastener holes. Refer to Figure 4-12 for the recommended fastener hole diameter.
190-02246-10
Rev. 11
GI 275 Part 23 AML STC Installation Manual
Page 4-16