Airworthiness Directives; Bombardier Model DHC-8-102, -103, and -301 Series Airplanes

This amendment supersedes an existing airworthiness directive (AD), applicable to certain Bombardier Model DHC-8-102, -103, and -301 series airplanes, that currently requires a one-time inspection for wear and breakage of wire segments of the individual lighting units of the ceiling and sidewall lights, and replacement of any damaged wiring. The existing AD also requires installation of teflon spiral wrap on the wiring of the ceiling and sidewall lights. This amendment adds a requirement for a one-time inspection to determine if teflon spiral wrap is installed on the wiring of the lavatory lighting system, and installation, if necessary. This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to prevent the possibility of a fire on an airplane due to such chafing and consequent short circuiting, overheating, and smoking of the wires on the aircraft structure.