TB 1-1520-238-20-136
8.1.1 Safe aircraft per procedures in TM 1-1520-238-23-3, paragraphs 5.
8.1.2 Follow TM procedures to remove, inspect and re-install the retention nut
8.1.3 Drive Plate installed without De-Ice Distribution.
8.1.3.1 Fabricate a temporary drive plate cover per specifications given in paragraph 9.1.
8.1.3.3 Install the temporary cover plate (Figure 4) using the 8 bolts/washers and 4 screws per Figure 301
of TM 1-1520-238-23-P2 normally used to secure the drive plate cover and torque each to 20 inch-pounds
per paragraph 6. of TM 1-1520-238-23-4. Continue the maintenance steps in the TM, which includes the
limited test flight.
8.1.3.4 When the test flight is completed remove the cover plate and perform thee retention nut re-torque
called out in the TM.
8.1.4 Drive Plate installed with De-Ice Distribution.
8.1.4.1 Fabricate a temporary drive plate cover per specifications given in paragraph 9.1.
8.1.4.3 Install the temporary cover plate (Figure 5) using the 6 nuts/washers per Figure 301 of TM
1-1520-238-23-P2 normally used to secure the ADS and torque to 20 inch-pounds per paragraph 6. of TM
1-1520-238-23-4. Continue the maintenance steps in the TM which includes the limited test flight.
8.1.4.4 When the test flight is completed remove the cover plate and perform the retention nut re-torque
called out in the TM.
8.2. AH-64D Procedure.
8.2.1 Safe aircraft per procedures in IETM 1-1520-251-LONGBOW publications.
8.2.2 Follow IETM procedures to remove, inspect and reinstall the retention nut.
8.2.3 Drive Plate installed without Derotation Unit.
8.2.3.1 Fabricate a temporary drive plate cover per specifications given in paragraph 9.1
8.2.3.3 Install the temporary cover plate (Figure 4) using the 8 bolts/washers and 4 screws called out in the
IETM (under Maint Transmission Lube System Installation/Drive Plate Cover -- Remove and Install) normally
used to secure the drive plate cover plate and torque each to 23 inch-pounds. Continue the maintenance
steps, which includes the limited test flight.
8.2.3.4 When the test flight is completed remove the cover plate and perform the retention nut re-torque
called out in the TM.
8.3. Following the limited test flights, remove the main rotor drive plate covers and inspect for damage (none
allowed). Inspect all nuts, bolts, screws, and washers for damage before using to reinstall the ADS (A Model)
or Derotation unit (D Model). Replace any damaged items.
9. COVER PLATE SPECIFICATIONS.
9.1. Cover plate specifications are as follows:
Nomenclature
Material
Dimensions
Processes
Main Rotor Drive Plate
ASTM 1020 HR/CR
Paint cover plate using
Cover Plate, A and D
Steel or AL 7075
yellow primer, NSN
model A/C
De-Ice Distribution
ASTM 1020 HR/CR
Paint cover plate using
Cover Plate, A model
Steel or AL 7075
yellow primer, NSN
A/C only
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