Airworthiness Directives; Dornier Model 328-100 Series Airplanes

This amendment supersedes an existing airworthiness directive (AD), applicable to all Dornier Model 328-100 series airplanes, that currently requires certain revisions to the airplane flight manual, replacement of certain de-icing boots in the air intake duct assemblies of the engine with re-designed units, repetitive inspections of the boots to find discrepancies, and corrective action if necessary. This amendment also requires modification of the engine air inlet de-icing system. This action extends the repetitive inspection interval required by the existing AD, and adds repetitive debonding/delamination and leakage inspections of the de-icing boots, and corrective action if necessary. Initiation of the extended repetitive inspections and new repetitive inspections ends the repetitive inspections required by the existing AD. The actions specified by this AD are intended to prevent engine malfunction due to failure of the engine air inlet de-icing system, which could result in reduced controllability of the airplane. This action is intended to address the identified unsafe condition.