missile outlet coolant temperature sensor, the cooling
The functional relationship of the components is
system automatically switches to the warm-up mode. In
represented in figure 5-31.
this mode, the cold air modulating valve closes and the
OPERATION
hot air modulating valve opens. This valve varies the
amount of hot air from the 400F bleed manifold tem-
Setting the LIQ COOLING (liquid cooling)
perature control system used to warm the coolant fluid.
switch to the AWG-9/AIM-54 position starts the
When the heat exchanger outlet fluid temperature
missile coolant pump motor. The pump circulates
reaches 104 4F and the missile outlet fluid
8 gallons of coolant per minute through the missile
temperature reaches 85 3F, the hot air modulating
air-moisture-contaminant remover, the missile section
valve will close. This prevents the cold and hot
of the WCS/missile air-to-coolant heat exchanger, the
modulating valves from being open simultaneously.
weapons rails, left and right pylon, missile launchers,
and through as many as six Phoenix missiles. The heat
The missile supply line sensor, located at the outlet
absorbed by the coolant from the missiles is removed in
of the heat exchanger, is also used to sense an
the air-to-coolant heat exchanger. When the loop is
over-temperature condition. If the coolant temperature
operating in the cooling mode, the missile inlet coolant
exceeds 115 3F, the missile condition (MSL
temperature sensor controls the fluid temperature at 70
COND) advisory indicator light illuminates. The hot or
3F by opening or closing the cold air modulating
cold air-modulating valve will close. If the missile
valve. The valve varies the amount of cold air flowing
pump pressure drops to 60 5 psi, a pressure switch
from the refrigeration system through the missile heat
causes the MSL COND light to illuminate. If coolant
exchanger.
pressure downstream of the coolant pump increases to
89 5 psi, the missile bypass valve opens to return the
When the temperature of the coolant fluid returning
fluid to the pump inlet.
from the missile is below 40 3F, as sensed by the
Figure 5-31.--Missile cooling system.
5-28
