TM 1-1520-238-23
Change 3
12-173
12.56.
BLADE DE-ICE CONTROLLER ADJUSTMENT
12.56.1. Description
This task covers:
Main Rotor Resistance Measurement. Tail Rotor Resistance Measurement. Adjustment Resist-
ance Determination. Calibration Module Adjustment.
12.56.2. Initial Setup
Tools:
Electrical tool kit (item 378, App H)
Test adapter (item 10, App H)
Multimeter (item 215, App H)
Ohmmeter (item 218, App H)
Temperature probe thermal resistor (item 261, App H)
Materials/Parts:
Wire (item 222, App F)
Personnel Required:
68X
Armament/Electrical System Repairer
68X3F
Armament/Electrical System Repairer/
Technical Inspector
References:
TM 1-1520-238-T
Equipment Conditions:
Ref
Condition
1.57
Helicopter safed
2.2
Access panel R200 removed
CAUTION
Temperature and resistance measurements are performed in a stable temperature environment
with blade temperature as close as possible to air temperature to ensure proper system calibration.
Ensure that blades are not heated or cooled by any energy source during this maintenance. Failure
to maintain stable blade temperature will cause an improper system adjustment.
Do not operate blade de-ice system with rotor blade erosion strips installed. Failure to do so could
result in damage to rotor blades.
NOTE
If TB 1-1520-238-20-62 (Deactivation of Main Rotor and Tail Rotor Blade De-ice Capability) is
complied with, this task is not required.
This task is not required if reinstalling the exact same controller or blade(s) in the exact same
location(s) as a result of performing other maintenance. If controller or blade(s) have been replaced,
perform this task.
This task may be used to adjust one controller calibration module when changing one blade, or for
adjusting all calibration modules when changing controller.
Main rotor blades are identified by the power distributor connector number (P1 = Blade 1; P2 =
Blade 2; etc.).
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