190-01115-01 G3X/G3X Touch Installation Manual - GDU 37X Config and Post Install Checkout
Rev. AC
Page 33-19
The following are potential causes for failure of the engine run-up test:
a) Excessive flexing of GSU 25/GSU 73 and/or GMU magnetometer mechanical mounting
,
, and for applicable
mounting requirements and instructions).
b) Vibration or motion of GSU 25/GSU 73 and/or GMU magnetometer caused by neighboring
equipment and/or supports.
c) Mounting of GSU 25/GSU 73 at a location that is subject to severe vibrations (for example,
close to an engine mount).
d) Mounting screws and other hardware for GSU 25/GSU 73 and/or GMU magnetometer not
firmly attached.
e) Absence of recommended mounting supports.
f) GSU 25/GSU 73 connector not firmly attached to unit.
g) Cabling leading to GSU 25/GSU 73 or GMU magnetometer not firmly secured to
supporting structure.
h) An engine/propeller combination that is significantly out of balance.
In some aircraft, attempting the engine run-up test on a day with very strong and/or gusty winds may cause
the test to occasionally fail. However, windy conditions should not be taken as evidence that the test would
pass in calm conditions; an actual pass is required before the installation can be considered adequate.