Action
Notice of proposed rulemaking (NPRM).
Summary
We propose to supersede Airworthiness Directive (AD) 98-18-26, for certain Airbus Model A320 series airplanes. AD 98-18-26 currently requires repetitive inspections to detect fatigue cracking of the front spar vertical stringers on the wings; and repair, if necessary. Since we issued AD 98-18-26, we have received reports that indicate new repetitive inspections having new thresholds and intervals are needed and that additional work is needed to accomplish the inspections on airplanes on which a previous modification has been accomplished. This proposed AD would require repetitive high frequency eddy current (HFEC) inspections for cracking of the radius of the front spar vertical stringers and the horizontal floor beam on frame 36, and a rototest inspection for cracking of the fastener holes of the front spar vertical stringers on frame 36, and repair if necessary. We are proposing this AD to detect and correct fatigue cracking of the front spar vertical stringers on the wings, which could result in the reduced structural integrity of the airframe.