Detergent Cleaning With Limited Water Use this method only when water is limited. Prepare the aircraft for cleaning. Then mix the proper amounts of aircraft cleaning compound and water in a bucket. Apply the cleaner with a scrub brush, sponge, rag, or cleaning and polishing pad. Apply to one small area at a time. Scrub the area. Then remove the cleaner and loosened soils with a cloth. For soils that are resistant to the limited water procedure, clean with dry cleaning solvent (P-D-680, Type II or III) then repeat with the cleaning compound and water mixture. Apply water displacing, ultrathin, film corrosion preventive compound MIL-C-81309, type II, and wipe with a clean, dry cloth. Waterless Wipedown Cleaning Use waterless wipedown procedures only when water is not available for rinsing or when cold weather prevents the use of water. Using a plastic spray bottle, apply MIL-C-85570, Type I or II (mixed IAW NAVAIR 01-1A-509). Alternatively, spray the cleaner from an aerosol can and wipe off contaminates from the surface. Spot Cleaning Spot clean light, oily, soiled surfaces by wiping with dry-cleaning solvent. Apply the solvent by using a saturated wiping cloth. Brush or wipe the surface as necessary; then wipe clean with a dry cloth. The solvent wipe may leave a light residue. Remove this residue with soap and water, followed by a fresh water rinse. NOTE: After cleaning an aircraft, relubricate it as specified by the MRCs. Ensure that all low-point drains are open, covers and shrouds are removed, and that aircraft preservatives are applied to clean, exposed, unpainted surfaces. Also make sure that the felt wiper washers on all hydraulic cylinders are moistened, and wipe down actuating cylinder rods with a clean rag saturated with hydraulic fluid. Remove and replace damaged or loosened sealant as specified by the applicable MIM. Q27.  Why is the conformable applicator cleaning pad better than a mop or bristle brush when cleaning aircraft surfaces? Q28.  Types I, II, and IV of what cleaning compound are to be used on tactical paint schemes? Q29. What is the first step in efficiently cleaning an aircraft? Q30. When cleaning an aircraft what are the two directions in which cleaning compound and rinsing are applied? Q31. What substance may be used to spot-clean lightly soiled areas? AVIONICS EQUIPMENT CLEANING Dust and contamination cause corrosion problems in avionics equipment. Cleaning prevents many of these problems. Therefore, cleaning is the first logical step after an inspection. Cleanliness is very important in maintaining the functional integrity and reliability of avionic systems. Dirt may be either conductive or insulating. As a conductor, it may provide an undesired electrical path. As an insulator, it may interfere with proper operation. Dust, fingerprints, surface oxides, contaminants, or other foreign material on a surface can undo all the good provided by protective coatings. A good maintenance practice is to use the mildest cleaning method that will properly decontaminate the equipment. It is also important to use the correct cleaning solutions and cleaning materials to avoid damage to avionics equipment. Some of the hazards associated with the cleaning of electronic and electrical equipment are as follows: Cleaning solvents or materials can be trapped in crevices or seams. This interferes with later applications of preservative coatings and causes corrosion as well. Vigorous or prolonged scrubbing of laminated circuit boards can damage the boards. Certain cleaning solvents soften conformal coatings, wire coverings, acrylic panels, and some circuit components. WARNING Dry-cleaning solvent should not be used in oxygen areas or around oxygen equipment. Dry- cleaning solvent is NOT oxygen compatible and will cause explosion and/or fire. 4-13