Summary
This document proposes the supersedure of an existing airworthiness directive (AD), applicable to certain Dornier Model 328-300 series airplanes, that currently requires repetitive inspections of motive flow check valves and adjacent parts for fuel leaks, and replacement of the valves if leaks are detected. This action would require new repetitive engine operational tests. This action would also require replacement of the motive flow check valves with new parts, which would constitute terminating action for the repetitive inspections and engine operational tests. The actions specified by the proposed AD are intended to prevent leakage of fuel from the motive flow check valves, which could result in fuel vapors coming into contact with fuel ignition sources and consequent fuel tank explosion and fire. This action is intended to address the identified unsafe condition.