TM 55-1510-219-MTF
PROCEDURE
TROUBLESHOOTING
REFERENCE
f. Load paralleling must be within 1
increment on the loadmeter scale.
*12. Inverter volt-frequency meters -
C38,39
Check voltage between 110 and 120 volts
and frequency between 390 and 410 Hz.
*13. Autofeather system - Check as fol-
F4-18
lows:
a. Condition levers - LOW IDLE.
b. Autofeather switch - Hold to TEST (ARM
lights should remain extinguished).
c. Power levers - Advance to approximately
22% torque, then move autofeather
switch to test mode. Both ARM lights
should illuminate.
d. Left power lever - Retard.
(1) At 16 to 21% torque, check right
AUTOFEATHER light extinguished.
(2) At 9 to 14% torque, check left
AUTOFEATHER light extinguished
(left propeller starts to feather).
e. Left power lever - Set approximately 22%
torque.
f. Repeat steps b, c, and d for right engine.
g. Advance each power lever to above 85 to
90%
N1
individual
ally,
with
the
autofeather switch in the arm mode.
ARM
2-31
