TM 55-1510-215-MTF
F10. Neither autofeather arm light illuminates when power levers
are advanced (AUTO-FEATHER switch in ARM position).
a.
Defective autofeather switch.
F11. One arm light does not illuminate when power levers are
advanced (AUTO-FEATHER switch in ARM position).
a.
Defective or out of adjustment power switch.
b.
Defective No. 1 (12 PSI) torque pressure switch.
F12. Both arm lights remain illuminated when one power lever is
retarded (AUTOFEATHER switch in ARM position).
a.
Defective or out of adjustment power switch.
F13. Propeller does not start to feather after engine torque
falls below 160 ft-lbs (AUTO-FEATHER ARM-TEST switch
in TEST position).
a. Defective No. 2 (6.5 PSI) torque pressure switch on
retarded engine.
b.
Defective autofeather dump valve.
F14. One arm light does not illuminate when power levers are
advanced to 90 percent N1 (AUTOFEATHER ARM-TEST
switch in TEST position).
a.
Defective No. 1 (12 PSI) torque pressure switch.
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