Summary
This document proposes the supersedure of an existing airworthiness directive (AD), applicable to certain British Aerospace (Jetstream) Model 4101 airplanes, that currently requires an inspection to determine the data on the label of certain hose assemblies, and replacement of all hose assemblies from any discrepant batch with certain new hose assemblies. That AD was prompted by a report of the failure of a hose assembly in the fire extinguisher system of the engine nacelle due to cracks, caused during manufacture of the hose assemblies, in the swaged ferrule that attaches the hose to the end fitting. The actions specified by that AD are intended to ensure that such discrepant hose assemblies are replaced. Discrepant hose assemblies could fail and consequently prevent the proper distribution of fire extinguishing agent within the engine nacelle in the event of a fire. This action would require a one-time inspection for different data on the label of certain hose assemblies, and replacement of all hose assemblies from any discrepant batch with certain new hose assemblies. This action also would add airplanes to the applicability of the existing AD.