TM 55-1510-222-MTF
TROUBLESHOOTING GUIDE F - PROPELLERS
CONDITION
F1.
F2.
F3.
F4.
F5.
F6.
PROBABLE CAUSE
Propeller governor system partially or complete-
ly inoperative.
a. Defective propeller governor test switch.
Propeller governor test system inoperative.
a. Tripped propeller governor test circuit
breaker.
b. Defective wiring.
c. Defective switch.
d. Defective propeller governor reset solenoid.
Propeller governor test system inoperative on
one engine.
a. Defective propeller governor system test
switch.
b. Defective propeller governor reset solenoid.
Propeller autofeather system inoperative (propel-
ler autofeather switch in ARM or TEST posi-
tion).
a. Tripped circuit breaker.
b. Defective arming light out relay or feather-
ing relay.
c. Defective arc suppression diode on relays or
feather dump valve.
d. Defective ground blocking diode.
Autofeather circuit breaker trips (autofeather
switch in ARM or TEST position).
a. Defective ARM-TEST switch.
b. Defective wiring.
One autofeather arm light illuminates when
power setting is less than 90 percent N1 (AU-
TOFEATHER switch in ARM position).
3-23
