SURFACE MAINTENANCE Surface maintenance includes regular cleaning of the aircraft as well as touch-up of protective paint coatings. Since paint touch-up is done after removal of corrosion, it is discussed later in this chapter. Touch-up of new damage to paint finishes prevents corrosion from starting. Aircraft must be washed and cleaned at least every 14 days, unless otherwise directed by NAVAIR. Aircraft must be kept in a clean condition, and repeated cleaning should be done as often as necessary. More frequent cleaning may be needed when the following conditions exist: An excessive amount of soil or exhaust gases accumulation within impingement areas Exposure to salt spray, salt water, or other corrosive materials Evidence of paint surface decay, such as softening, flaking, or peeling The presence of fluid leakage (excessive oil, coolant, hydraulic fluid, etc.) Immediate cleaning of affected areas is always mandatory if: Aircraft is exposed to corrosive fire- extinguishing materials Spilled electrolyte and corrosive deposits are found around battery terminals and battery area The aircraft has been exposed to significant amounts of salt water Salt deposits, relief tube waste, or other contaminants are apparent Fungus growth is apparent Chemical, biological, or radiological contaminants are detected A daily cleaning or wipe-down is required on all exposed, unpainted surfaces, such as struts and actuating cylinder rods. Aircraft must be thoroughly cleaned before they are stored. They should also be thoroughly cleaned when they are depreserved. Unpainted aircraft are cleaned and polished at frequent intervals. Aboard ship, cleaning and removal of salt deposits are needed to prevent possible corrosion. Components that are critically loaded (designed with minimum safety margins to conserve size and weight) are cleaned as often as possible to minimize exposure to corrosive agents. These components include helicopter rotor parts and parts that are exposed to corrosive environments (such as engine exhaust gas, acid, or rocket blast). NOTE: Postcleaning lubrication and preservation of exposed components are necessary to displace any of the cleaning solution entrapped during the cleaning operation. Q14. Q15. Q16. Q17. Q18. What should happen to a good corrosion preventive program when carrier-based aircraft return to a shore activity after a deployment? Operating units that have the best safety records, maximum use of aircraft, and lowest operating costs will also have what program? At a minimum, how often must aircraft be cleaned? List the conditions that require the affected areas of an aircraft to be cleaned immediately. What must be done on a daily basis with unpainted aircraft surfaces and actuating rods? AVIONICS MAINTENANCE A successful avionics cleaning and corrosion prevention and control program depends upon a successful preventive maintenance program. The nature of corrosion requires that everyone involved in the repair and operation of electrical, electromechanical, and electronic systems be concerned with the corrosion control of avionic equipment. You should recognize the difference between the prevention of corrosion and the repair of damage caused by corrosion. Preventive maintenance programs at organizational- and intermediate-level maintenance activities accomplish the following: Reduce the maintenance time spent repairing corrosion damage Ensure the military avionics community is aware of the extent of the corrosion problem Improve avionics system reliability, durability, and service life Report any and every deficiency with material or process involving corrosion control CLEANING MATERIALS LEARNING OBJECTIVE: Identify the hazards of handling and storing aircraft cleaning materials. 4-5