TM 5-4220-225-14
5-13.
Helmet Shell.
This task covers:
Repair
INITIAL SETUP
Tools
Equipment Condition
5/64-inch Hex Wrench (Item 17, Appendix B)
Viewports removed (para. 5-8).
0-50 lb-in. Torque Wrench (Item 14, Appendix B)
Helmet communications assembly removed
Adapter, Socket Wrench (Item 41, Appendix B)
(para. 4-26).
Exhaust valve removed (paras. 4-23 and 4-24).
Materials/Parts
Air supply tube removed (para. 4-20).
Air supply valve removed (para. 4-21).
Helmet Shell
Supply duct removed (para. 4-29).
Halocarbon Grease (Item 10, Appendix E)
Return duct removed (para. 4-29).
Diffuser assembly removed (para. 4-22).
Replace. (figure 5-12)
(1)
Remove two speaker retainers (1).
(2)
Remove three screws (2) and nuts (3).
(3)
Remove 25 screws (4) and inserts (5) and separate base (6) from helmet shell (7).
(4)
Apply a thin film of lubricant to helmet shell (7) along all the surfaces that contact the base (6).
(5)
Install helmet shell (7) and secure with 25 screws (4) and threaded inserts (5) finger tight.
(6)
Install three screws (2) and nuts (3) finger tight.
(7)
Torque all screws to 8-10 in.-lb (0.9-1.2 Nm) in a staggered sequence.
(8)
Ensure mounting surfaces on speaker retainers (1) are clean.
(9)
Apply adhesive to speaker retainers (1) and install.
FOLLOW-ON MAINTENANCE
(1) Install air supply valve (para. 4-21).
(2) Install air supply tube (para. 4-20).
(3) Install exhaust valve (para. 4-23 and 4-24).
(4) Install helmet communications assembly (para. 4-26).
(5) Install viewports (para. 5-8).
(6) Install supply duct (para. 4-29).
(7) Install return duct (para. 4-29).
(8) Install diffuser assembly (para. 4-22).
5-28
