SYSTEM OPERATION

air-moisture contaminant remover. When the missile cooling loop is not required, the fairing is removed from the aircraft. The ultimate heat sink is ram air and/or refrigeration system air for cooling; hot air from the bleed manifold 400°F temperature control system provides heating. The WCS/missile temperature control system also uses cooling air from the ground cooling system when ground operation is required. SYSTEM OPERATION Setting the liquid cooling switch to the AWG-9/AIM-54 position starts the missile coolant pump motor. The pump circulates 18 gallons of coolant per minute through the missile air-moisture-contaminant remover, heat exchanger, weapon rails, left and right pylons, launchers, and as many as six Phoenix missiles. The heat absorbed by the coolant from the missiles is removed in the air-to-coolant heat exchanger. When the loop is operating in the cooling mode, the missile inlet coolant temperature sensor controls the fluid temperature at 70°± 3°F by opening or closing the cold air modulating valve. The valve varies the amount of cold air flowing from the refrigeration system through the missile heat exchanger. When the temperature of the coolant fluid returning from the missile is below 40°±3°F, as sensed by the missile outlet coolant temperature sensor, the cooling system automatically switches to the warm-up mode. In this mode, the cold air modulating valve closes and the hot air Figure 1-18.—Missile cooling system. 1-24