Section VIII. HEATING, VENTILATION, COOLING, AND ENVIRONMENTAL CONTROL

TM 1-151022310 2-65. CHEMICAL TOILET. a. Description. A side-facing chemical toilet is installed in the aft cabin area, and can also be used as an additional seat Two hinged-lid half-sections must be raised to gain access to the toilet Waste is stored within a removable container located below the seat in the cabinet assembly. This non-flushing system uses a dry chemical preparation to deodorize the stored waste. A toilet tissue dispenser is contained in a slide-out compartment on the forward side of the toilet cabinet A box of disposable waste container liners and a box of chemical deodorant packets are alsostored in the cabinet b. Operation. During use, a removable throw-away plastic liner is attached to the waste container. After use, dry chemical deodorant obtained from the storage cabinet is deposited on the waste and the hinged lid sections are closed over the cavity. After each flight, the waste container must be removed, emptied, relined, and replaced in the cabinet Consumable toilet items should be resupplied as needed. 2-66. SUN VISORS. When adjusting the sun visors, grasp only by the top metal attachment to avoid damage to the plastic shield. Individual sun visors are provided for the pilot and copilot (fig. 2-8). Each visor is manually adjustable. When not needed as a sun shield, each visor may be manually rotated to a position flush with the top of the cockpit so that it does not obstruct view through the windows. 2-67. RELIEF TUBE. One relief tube is provided, located immediately aft of the cargo door on the left side of the fuselage. Section VIII. HEATING, VENTILATION, COOLING, AND ENVIRONMENTAL CONTROL SYSTEM 2-68. HEATING SYSTEM. Warm air for heating the cockpit, mission equipment compartment, and windshield defrosting is provided by bleed air from both engines. Engine bleed air is combined with ambient air in the heating and pressurization flow control unit in each engine nacelle. If the mixed bleed air is too warm for cockpit comfort, it is cooled by being routed through an air-to-air heat exchanger located in the forward portion of each inboard wing. If the mixed bleed air is not too warm, the air-to-air heat exchangers are bypassed. The mixed bleed air is then ducted to a mixing plenum, where it is mixed with cabin recirculated air. The warm air is then ducted to the cockpit outlets, windshield defroster outlets, and to the floor outlets in the mission equipment compartment. The environmental system is shown in figure 2-26. a. Bleed air flow control unit. A bleed air flow control unit, located forward of the firewall in each engine nacelle controls the flow of bleed air and the mixing of ambient air to make up the total airflow to the cabin for heating, windshield defrosting, pressurization, and ventilation. The unit is electronically controlled with an integral electric solenoid firewall shutoff valve, controlled by the bleed air switches located on the overhead control panel (fig. 2-13) and a normally open solenoid valve operated by the right landing gear safety switch b. Pneumatic bleed air shutoff valve. A pneumatic shutoff valve is provided in each engine nacelle to control the flow of bleed air to the surface, antenna, and brake deice systems. These valves are controlled by the bleed air valve switches located on the overhead control panel (fig. 2-13). c. Bleed air valve switches. The bleed air flow control unit shutoff valve and pneumatic bleed air shutoff valves are controlled by two LEFT and RIGHI switches placarded ENVIRO & PNEU BLEED AIR - PNEU ONLY - ON, located on the overhead control panel (fig. 2-13). When set to the ON position, both the environmental flow control unit shutoff valve and the pneumatic shutoff valve are open; when set to the PNEU ONLY position, the environmental flow control unit shutoff valve is closed, and the pneumatic bleed air valve is open; in the ENVIRO & PNEU position, both are closed. For maximum cooling on the ground, turn the bleed air valve switches to the PNEU ONLY position d. Cabin temperature mode selector switch. A switch placarded CABIN AIR MODE SELECT - OFF - AUTO- AC COLD OPN 10�C to -25�C - MAN COOL - MAN HEAT located on the overhead control panel, controls cockpit and mission avionics compartment heating and air conditioning. When the cabin temperature mode selector switch is set to the AUTO position, the heating and 2-58