While the FAA considers the physical act of washing an aircraft, by itself, as neither maintenance nor preventive maintenance, the agency is warning aircraft operators about using auto detailing companies to perform this task, since they cannot ensure compliance with maintenance-related procedures that are part of the washing process.

According to the FAA, manufacturer recommendations and corrosion prevention and control programs usually include sequential steps that are considered maintenance or preventive maintenance. These include aircraft preparation tasks, such as covering static ports; post-wash procedures and maintenance checks/inspections; lubrication and other preservation tasks; replacement of defective environmental gaskets and sealant materials; and documentation.

Thus, the agency is recommending that “appropriately authorized” or certified personnel perform or supervise the work and that operators follow return-to-service procedures for the aircraft. Information and recommended procedures can be found in manufacturers’ published manuals and in Advisory Circular 43-4, “Corrosion Control for Aircraft,” the FAA noted.