TM 1-1520-238-T-4
Change 10
4–69
4–13.
POWER PLANTS – MAINTENANCE OPERATIONAL CHECK (ENGINE 2) (cont)
4–13
Task
Result
y. On CPG caution/warning panel (fig. 4–32),
check that ENG 2 indicator is not lighted.
If ENG 2 indicator on CPG caution/warning panel is
lighted, refer to TM 1-1520-238-T-6 to troubleshoot
CPG caution/warning system.
z. On pilot power quadrant (fig. 4–26), move
pilot engine NO 2 PWR lever to LOCKOUT,
and at first indication of NG, NR or NP
increase immediately move engine NO 2
PWR lever back to a position midway
between FLY and IDLE. Check that NG, NR,
and NP decrease and stabilize. Move engine
NO 1 PWR lever to IDLE, then to FLY.
If NG, NR or NP does not increase, refer to
TM 55-2840-248-23 to troubleshoot engines.
If NP fluctuates refer to TM 55-2840-248-23 to adjust
engine 2 turbine speed control unit.
aa. Repeat step z. above using CPG engine NO
2 PWR lever on CPG power quadrant
(fig. 4–27).
If CPG NO 2 PWR lever cannot be advanced to
LOCKOUT, go to paragraph 4–48.
ab. On pilot collective stick (fig. 4–36), push
forward and turn CHOP collar clockwise
until ENGINE CHOP indicator lights on pilot
caution/warning panel (fig. 4–29). Release
CHOP collar. Check that engine 2 NG
stabilizes at IDLE. Move engine NO 2 PWR
lever to IDLE. Push forward and turn pilot
CHOP collar counter–clockwise until
ENGINE CHOP indicator goes out. Release
CHOP collar. Check that NG, TGT, and NP
are stabilized. Move engine NO 2 PWR
lever to FLY.
If pilot ENGINE CHOP indicator does not light, go to
paragraph 4–33.
If engine NG does not decrease to and stabilize at
IDLE, replace engine 2 chop relay
(TM 1-1520-238-23).
If NO 2 PWR lever is advanced to FLY and engine 2
does not accelerate, go to paragraph 4–33.
If pilot ENGINE CHOP indicator does not go out, refer
to TM 1-1520-238-T-6 and troubleshoot pilot
caution/warning system.
ac. Repeat step ab. using CPG collective stick
CHOP collar and engine NO 2 PWR lever.
If CPG ENGINE CHOP indicator does not light, go to
paragraph 4–34.
If engine NG does not decrease to and stabilizes at
idle, replace engine 2 chop relay (TM 1-1520-238-23).
If CPG ENGINE CHOP indicator does not go out,
refer to TM 1-1520-238-T-6 to troubleshoot CPG
caution/warning system.
If NP decreases and stabilizes between 100% NP and
idle NP refer to TM 55-2840-248-23 to troubleshoot
engines.
If NO 2 PWR lever is advance to FLY and engine 2
does not accelerate, refer to paragraph 4–35.
