190-01115-01
G3X/G3X Touch Installation Manual - Maintenance
Rev. AC
Page 36-1
36 MAINTENANCE
36.1 Inspections/Continued Airworthiness/Maintenance
Periodic maintenance of most G3X LRUs is not required and is “on condition” only. Instructions for
Continued Airworthiness (ICA) are not required per 14 CFR Part 21 for these products as they have
received no FAA approval or endorsement. Garmin recommends that the G3X LRUs be inspected for
proper operation, secure attachment, integrity of connectors and wiring, cleanliness, leakage of hoses and
tubes, and any evidence of damage as part of the required annual or periodic aircraft inspection. For more
general inspection guidance, please refer to the applicable sections of CFR Part 43 Appendix D and
Chapter 12 of AC 43.13-1B. For ADAHRS Static Pressure Calibration, refer to
GDU 37X or
LRUs that require periodic maintenance are listed in the following subsections.
36.1.1 GAP 26
Garmin recommends that a leak test (
) be performed following any maintenance action in
which the pitot or AOA pneumatic lines are opened up (i.e. whenever the GAP 26 is removed or replaced).
36.1.2 GSU 25
Per Part 43 Appendix E, paragraph (b)(2), Garmin recommends a test procedure equivalent to part 43
Appendix E, paragraph (b)(1) with two exceptions. The tests of sub-paragraph (iv) (Friction) and (vi)
(Barometric Scale Error) are not applicable because the digital outputs of the GSU 25 are not susceptible to
these types of errors. This procedure is recommended when the static system is opened up (i.e. whenever
the GSU 25 is removed or replaced). Garmin also recommends that a leak test be performed following any
maintenance action in which the pitot or AOA pneumatic lines are opened up (i.e. whenever the GSU 25 is
removed or replaced).
The GSU 25 utilizes an Earth magnetic field model which is updated once every five years. This IGRF
(International Geomagnetic Reference Field) update is expected to be available from Garmin in July of
2020 and every five years thereafter, so long as the GSU 25 remains a Garmin –supported product. The
IGRF model is automatically updated with a GDU software update. Otherwise maintenance of the
GSU 25 is ‘on condition’ only.
NOTE
If the GSU 25 is moved or replaced, the Post Installation Calibration Procedures
(
for GDU 37X systems and
for GDU 4XX systems) must be repeated.
