TM 55-1510-221-MTF
TROUBLESHOOTING GUIDE F - PROPELLERS
CONDITION
PROBABLE CAUSE
F1.
Propeller
governor
system
partially
or
completely
inoperative.
a.
Defective propeller governor test switch
F2.
Propeller governor test system inoperative.
a.
Tripped propeller governor test circuit breaker.
b.
Defective wiring
c.
Defective switch
d.
Defective propeller speed reset solenoid.
F3.
Propeller governor test system inoperative on one engine.
a.
Defective propeller governor system test switch
b.
Defective propeller speed reset solenoid
F4.
Propeller
autofeather
system
inoperative
(propeller
autofeather switch in ARM or TEST position).
a.
Tripped circuit breaker
b.
Defective arming light out relay or feathering relay
c.
Defective arc suppression diode on relays or feather dump
valve
d.
Defective ground blocking diode.
F5.
Autofeather circuit breaker trips (autofeather switch in ARM
or TEST position).
a.
Defective ARM-TEST switch
b.
Defective wiring
F6.
One autofeather arm light illuminates when power setting
is less than 90 percent N1 (AUTOFEATHER switch in ARM
position).
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