Engines subject to dust, industrial pollution, saltwater contamination or other chemically laden atmosphere (including pesticides and herbicides) lose performance due to deposits of contaminants on surfaces in the aidgas flow path. Engine wash and engine rinse procedures are utilized to restore turbine engine performance. These procedures are generated by the engine manufacturer and are included in the Engine Maintenance/Service Manuals. For most turbine engines these procedures are similar in concept and practice; however, application details, choice of solvents and many other service features can vary from engine manufacturer to engine manufacturer and may even vary within the range of engine models produced by any manufacturer. The intent of this SAE Aerospace Information Report (AIR) is to outline the general nature, considerations, and background of engine wash and engine rinse and is directed towards the needs of the entry level engineer, service engineer, and those involved in the general maintenance of installed turbine engines. AIR4416 has been reaffirmed to comply with the SAE Five-Year Review policy.