Summary
This document revises an earlier proposed airworthiness directive (AD), applicable to certain Saab Model SAAB SF340A and SAAB 340B series airplanes, that would have required repetitive inspections to detect cracking around certain fastener holes and adjacent areas of the front spar of the horizontal stabilizers; and corrective actions, if necessary. That proposal also would have required cold working of certain fastener holes of the front spar of the horizontal stabilizers, and follow-on actions; and installation of new fasteners, which would have constituted terminating action for the repetitive inspections proposed by that AD. That proposal was prompted by the issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. This new action revises the proposed rule by adding repetitive x-ray inspections. The actions specified by this new proposed AD are intended to prevent failure of the front spar due to fatigue cracking around certain fastener holes of the front spar of the horizontal stabilizers, which could result in reduced structural integrity of the airplane.