TM 10-5411-231-13&P CARGO BED COVER (CBC) HMMWV, TYPE I 0006 00 OPERATION UNDER USUAL CONDITIONS THIS WORK PACKAGE COVERS: Operating Procedures,   Preparation for Movement INITIAL SETUP: Maintenance Level Materials/Parts Operator Hardware Kit P/N 103983 Tools and Special Tools Combo Wrench, 9/16” Deep Socket OPERATING PROCEDURES         WARNING   Suffocation hazard.  Door must remain open while occupied. Operation of Upper and Lower Doors.  Both upper and lower doors can be operated separately or, when latched together, as a unit.  The upper door opens and closes by using the handle.  The lower door latch is operated from the inside. NOTE      There is an override which allows the door to be opened        from the inside, in case of emergency. The lower door swings sideways and is locked in place from inside.  When both doors are latched together as a unit, they are operated by the handle on the upper door.  With the lower door closed and locked in place, the upper door can be opened and closed separately. Operation of Cab Access Door.  The cab access door is composed of two sliding halves, which can be operated by web handles.    Operation of 2-Way Ventilators.  The 2-way ventilators can be opened and closed by operating grip bars from inside the CBC. Operation of Folding Steps.  The two folding steps are spring-loaded and are manually operated.  Steps are extended for use when access to top of CBC is required, and retracted when not in use. 0006 00-1