Summary
This document proposes the supersedure of an existing airworthiness directive (AD), applicable to certain Saab Model SAAB 2000 series airplanes, that currently requires repetitive inspections for discrepancies of the upper and lower areas of the backup struts in the left and right nacelles; and corrective actions, if necessary. This action would require repetitive inspections for cracks in the lower areas of the backup struts, and corrective action if necessary. This action would also require the eventual replacement of the backup struts with new, improved struts, which would terminate the repetitive inspections. The actions specified by the proposed AD are intended to prevent failure of the backup struts in the left and right nacelles due to fatigue cracking, which could result in loss of fail-safe redundancy in the design of the nacelle in terms of load capability, and consequent separation of the engine from the airplane and subsequent reduced controllability of the airplane. This action is intended to address the identified unsafe condition.