TM 55-1520-240-T
11-3.34.2 AFT LCT ACTUATOR OPERATIONAL CHECK
INITIAL SETUP
Personnel Required:
Aircraft Electrician
Applicable Configurations:
Medium Helicopter Repairer
All
References:
Tools:
TM 55-1520-240-23
Digital Ohmmeter
Equipment Condition:
Materials:
TM 55-1520-240-23
None
Battery Connected
Electrical Power On
Hydraulic Power On
Work Platform Open
TASK
RESULT
1.
2.
3.
4.
5.
6.
7.
8.
Set cyclic trim switch (1) to manual position.
Do not operate the LCT
manually without hydraulic
the helicopter.
actuators
power on
Using AFT (EXT-RET) switch (2), fully retract
the AFT LCT actuator.
Remove electrical power from the actuator
and disconnect the connector.
Using a digital ohmmeter, check pins A and
Circuit should show open.
C of AFT actuator connection (TASK 11-3.1).
Reconnect the actuator and apply electrical
power.
Using AFT (EXT-RET) switch (2), fully extend
the AFT LCT actuator (3).
Remove electrical power from the actuator
and disconnect the connector.
Using a digital ohmmeter, check pins B and
Circuit should show open.
C of AFT actuator connection (TASK 11-3.1).
11-134.4
Change 4
TASK
RESULT
9.
10.
11.
12.
13.
14.
15.
Reconnect the actuator and apply electrical
power.
Using AFT (RET-EXT) switch (2), operate the
AFT actuator (3) from full extend to full
retract. Clock the travel time.
Using AFT (RET-EXT) switch (2), operate the
AFT actuator (3) from full retract to full ex-
tend. Clock the travel time.
Manually operate the actuator to full
retract.
Move cyclic trim switch (1) to AUTO.
Perform an AFCS BITE TEST on the No.
No. 2 systems (TASK 11-3.3).
Monitor the cockpit LCT indicator (4).
1 and
Time must not exceed 25 seconds.
Time must not exceed 25 seconds.
If acceptable AFT actuator operation is not obtained in
all preceding steps, replace defective actuator (TM 55-
1520-240-23).
Cockpit LCT indicator (4) should show GND.
Failure of any AFCS BITE steps for LCT operation in-
dicates possible actuator defect. Replace defective ac-
tuator (TM 55-1520-240-23).
Erratic indicator movement indicates possible actuator
defect. Replace defective actuator (TM 55-1520-240-
23).
FOLLOW-ON MAINTENANCE:
TM 55-1520-240-23
Hydraulic Power Off
Electrical Power Off
Battery Disconnected
Work Platform Closed
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