TM 55-1520-240-T
11-3.34.2 AFT LCT ACTUATOR OPERATIONAL CHECK
11-3.34.2
INITIAL SETUP
References:
Applicable Configurations:
TM 55-1520-240-23
All
Equipment Condition:
Tools:
TM 55-1520-240-23:
Digital Ohmmeter
Battery Connected
Electrical Power On
Materials:
Hydraulic Power On
None
Work Platform Open
Personnel Required:
Aircraft Electrician
Medium Helicopter Repairer
TASK
RESULT
TASK
RESULT
1.
2.
3.
4.
5.
6.
7.
8.
Set cyclic trim switch (1) to MANUAL po-
sition.
Do not operate the LCT actuators
without hydraulic power on the
helicopter.
Using AFT (EXT-RET) switch (2), fully re-
tract the AFT LCT actuator (3).
Remove electrical power from the actua-
tor and disconnect the connector.
Using a digital ohmmeter, check pins A
and C of AFT actuator connection (Task
11-3.1).
Reconnect the actuator and apply electri-
cal power.
Using AFT (EXT-RET) switch (2), fully ex-
tend the AFT LCT actuator (3).
Remove electrical power from the actua-
tor and disconnect the connector.
Using a digital ohmmeter, check pins B
and C of AFT actuator connection (Task
11-3.1).
9.
10.
11.
12.
Circuit should show open.
13.
14.
15.
Reconnect the actuator and apply electri-
cal power.
Using AFT (EXT-RET) switch (2), operate
the AFT actuator (3) from full extend to
full retract. Clock the travel time.
Using AFT (EXT-RET) switch (2), operate
the AFT actuator (3) from full retract to
full extend. Clock the travel time.
Manually operate the actuator to full re-
tract.
Move cyclic trim switch (1) to AUTO.
Perform an AFCS BITE TEST on the No. 1
and No. 2 systems (Task 11-3.3).
Monitor the cockpit LCT indicator (4).
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
indicates possible actuator defect. Replace defective
actuator (TM 55-1520-240-23).
Erratic indicator movement indicates possible actua-
tor defect. Replace defective actuator (TM 55-1520-
240-23).
Circuit should show open.
FOLLOW-ON MAINTENANCE:
TM 55-1520-240-23:
Hydraulic power off.
Electrical power off.
Battery disconnected.
Work platform closed.
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Change 10
11-132.3