Summary
This document proposes the supersedure of 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 action would also require modification of the engine air inlet de-icing system. This action would extend the repetitive inspection interval required by the existing AD, and would add 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 would end the repetitive inspections required by the existing AD. The actions specified by the proposed 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.