TM 55-1520-240-23-3
4-3
TURBINE ENGINE ANALYSIS CHECK (TEAC) (Continued)
4-3
19.
Set NO. 1 & 2 ENGINE BEEP TRIM switch
to RPM DECREASE until rotor rpm begins to
decrease.
20.
Then lower thrust control to decrease N1, rotor
rpm, and engine torque.
CAUTION
Do not move ECL of engine until
speed and torque have decreased.
21.
Set ECL of engine not being TEAC’ed slowly to
FLIGHT.
22.
Repeat steps 11 thru 20 on other engine.
23.
Land aircraft and shut down engines.
24.
Disconnect battery (Task 1-39).
25.
Open engine work platform (Task 2-2).
26.
On No. 1 engine, open engine access cover
(Task 4-49). On No. 2 engine, remove access
cover plate (Task 2-2).
CAUTION
Do not trim engine to exceed PTIT
limits.
NOTE
N1 or PTIT deficiencies require
troubleshooting before trim adjustment
(TM 55-2840-254-23-1).
27.
Trim engine as follows:
a.
To increase N1 or PTIT, turn N1 screws (6)
clockwise.
b.
To decrease N1 or PTIT, turn N1 screw (6)
counterclockwise.
NOTE
1/4 turn of screw is approx 1 percent
change in N1, and 25 C change in
PTIT.
27.1. On No. 1 engine, close engine access cover
(Task 4-50). On No. 2 engine, install access
cover plate (Task 2-2).
28.
Repeat steps 4 thru 18.
WARNING
Stops must be removed from both
engines; otherwise, the aircraft will not
be able to operate with emergency
power.
29.
Remove two stops (1) from two screws (3) on No.
1 engine (4) and No. 2 engine (5).
4-30
Change 1
