TM 1-1510-224-MTF
F6.
One AUTOFEATHER arm light illuminates when power setting
is less than 90 percent N1 (AUTOFEATHER switch in ARM
position).
Defective or out of adjustment power lever switch.
F7.
Neither AUTOFEATHER arm light illuminates when POWER
levers are advanced (AUTOFEATHER switch in ARM position).
Defective AUTOFEATHER switch (overhead control panel.)
F8.
One arm light does not illuminate when POWER levers are
advanced (AUTOFEATHER switch in ARM position).
a. Defective or out of adjustment power lever switch.
b. Defective No. 1 (4.7 PSI) torque pressure switch.
F9.
Both arm lights remain illuminated when one POWER lever is
retarded (AUTOFEATHER switch in ARM position).
Defective or out of adjustment power lever switch.
F10.
Propeller does not start to feather after engine torque falls
below 7% (AUTOFEATHER switch in ARM position).
a. Defective No. 2 (3.1 PSI) torque pressure switch on retarded
engine.
b. Defective autofeather dump valve.
F11.
One autofeather arm light does not illuminate when POWER
levers are advanced to 90 percent N1, (AUTOFEATHER ARM -
TEST switch in TEST position).
Defective No. 1 (4.7 PSI) torque pressure switch.
F12.
Both autofeather arm lights extinguish when one POWER
lever is retarded (engine torque 7 to 12% on retarded engine,
AUTOFEATHER ARM - TEST switch in TEST position).
Defective No. 2 (3.1 PSI) torque pressure switch on retarded engine.
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