This Transport Publication (TP) provides guidance for developing enhanced electrical wiring interconnection system (EWIS) maintenance for air carriers, air operators, holders of type certificates, holders of supplemental type certificates (STCs), maintenance providers, repair stations, and persons performing modifications or repairs. The guidance in this TP is based on recommendations submitted from the Aging Transport Systems Rulemaking Advisory Committee (ATSRAC). The information in this TP is derived from the maintenance, inspection, and alteration best practices identified through extensive research by ATSRAC working groups and federal government working groups. This TP provides a means for TCCA to officially endorse these best practices and to dispense this information industry wide so that the safety benefits of this information can be realized. Adoption of the recommendations in this TP will improve the awareness throughout the aviation industry of the importance of visual inspections of aircraft systems, particularly aircraft EWIS. This TP promotes a housekeeping philosophy of "protect, clean as you go" when performing maintenance, repair, or alterations on or around aircraft EWIS. This guidance is equally applicable to non-wiring related maintenance and modification activities where those activities could cause inadvertent contamination or damage to wiring.