AD FAA-2005-20836

We are adopting a new airworthiness directive (AD) for certain Boeing transport category airplanes. This AD requires replacing any insulation blanket constructed of polyethyleneteraphthalate (PET) film, ORCON Orcofilm[reg] AN-26 (hereafter "AN-26"), with a new insulation blanket. This AD results from reports of in-flight and ground fires on certain airplanes manufactured with insulation blankets covered with AN-26, which may contribute to the spread of a fire when ignition occurs from sources such as electrical arcing or sparking. We are issuing this AD to ensure that insulation blankets constructed of AN-26 are removed from the fuselage. Such insulation blankets could ignite and propagate a fire that is the result of electrical arcing or sparking.