we ee ee a. “ The main rotor-blade hub was reduced to a zero reading following a Tide slurry and water bath which indicated that all the contamination was embedded in the grease at this point. Kerosene followed by water on the engine was found to be the most effective method’on this part of the helicopter. A more thorough cleaning prior to entry into a contaminated area would have decreased engine contamination considerably. Tide slurry scrubbing and rinsing with water was exceptionally effective on the cabin, rotor head, and intermediate gear box. Steam was also effective, but it is harmful to the varfous portions of the head and engine. Trichloroethylene was effective but cannot be used becauseof its volatility and toxic effects. The radio equipment was not contaminated enough to be cleaned, but in event of contamination it should be tmmerred in carbon tetrachloride. However, dynamotors should be hand cleaned. Bei 4 oe PRON Bans ENAERRORAmU:wereeneeennm eee Oil was drained from the engine, gear boxes, and hydraulic system and monitored; no contamination was pregent, The over-all results indicate that Tide soap and water in a 1 to 1 ratio, sprayed on, followed by brushing, and then rinsed with fresh water is considered to be the most effective method. However, if decontamination equipment is available to apply the slurry under pressure with a mixture of 400 gal to 10 boxes of Tide, it should be used and followe“ only by a pressure rinse. The amount of time involved is fairly constant, and it is belfeved that the entire operation of disassembly, washing, and reasse.nbiy can be done in 4 to 5 hr with four men,using the following system: 1, Remove the side transmission panels, engine intake ducts, fan cover, all loose gear in the cabins, and main rotor blades. 2. Purge all grease fittings with new grease. 3. Vacuum radio and baggage compartments, and seal with scotch electrical tape. 4. Cover starter and magnetos. §. Apply Tide slurry and water rinse. 6. Regrease all fittiags. %. Check radio compartments for dryness. 8. Reassemhle the helicopter. e