MAINTENANCE SAFETY PRECAUTIONS

performs the primary sensing function, and the other is used for the built-in test (BIT). Fairing Interlock Switch The fairing interlock switch provides an electrical connection for the missile coolant pump motor and pressure switch circuits. The switch is closed when the right Phoenix fairing is installed. Liquid Cooling Control Panel The liquid cooling control panel is located on the NFO’s left side console. When the liquid cool- ing switch is set to the AWG-9/AIM-54 position, it activates both the radar and missile cooling loops of the system. MAINTENANCE SAFETY PRECAUTIONS The Phoenix missile requires a completely contaminant-free cooling system. Keeping the system clean requires the use of toxic fluids that must be used with special care. It is important to handle this system with the same care as you would handle an oxygen system. The following information is of special interest and should be kept in mind when working on this system. 1. If more than 1 gallon of coolant is required to fill the expansion tank, you should flush and refill the system, using the liquid coolant service unit (LCSU) shown in figure 1-19. For detailed LCSU operating procedures, you should refer to the applicable MIM. 2. The cooling system should only be serviced with Flo-cool 180, Coolanol 25, or Coolanol 25-R. If you use another type of coolant, you may damage the missile components. It is a require- ment that you wear a respirator or work in an area with forced ventilation while working with these coolants. Additionally, you must wear chemical splashproof goggles and gloves. 3. When you use trichlorotrifluoroethane, MIL-C-81302, Type I or II, to clean fittings and hoses, exercise extreme caution. You must wear a respirator and chemical splashproof goggles and gloves. The task should be performed in an area with forced ventilation. Smoking is prohibited in the area where this chemical is being handled. Keep the trichlorotrifluoroethane from coming in contact with your skin, eyes, and clothes. Do not breathe the toxic vapors. 4. To prevent contamination of the tem- perature control system and possible damage to its componenets, absolute cleanliness of your equipment, work area, and coolant must be main- tained. You should ensure that dust caps, flushing jumpers, hoses, and bleed lines are thoroughly cleaned with trichlorotrifluoroethane and a lint- free cloth. The cleaned components should be air- dried before installation. Do not allow O-ring seals to soak in cleaning fluid before or after cleaning because this will cause hardening of the O-rings and. premature failure. 5. When adding coolant with the fluid makeup unit (fig. 1-20), add the coolant slowly. Rapid pumping may cause the pressure relief valves on the makeup unit and in the aircraft to open. 6. Coolant spilled on the aircraft can damage the paint. Spillage should be wiped up immediately. Spillage on a coaxial cable may cause the cable to come apart. 7. To take a coolant sample, the coolant must have been circulated for at least 5 minutes by the aircraft, powered pump. This circulation ensures that the sample will be representative of coolant in the entire system. The sample should be taken from the AIM-54 supply bleed port. Figure 1-20.—Liquid coolant fluid makeup unit. l-27