Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Airbus Model A320-111, - 211, and -231 series airplanes. This proposal would require repetitive high frequency eddy current inspections to detect cracks around the fasteners of the lower forward corners of the sliding window frames, and repair, if necessary. This proposal would also require installation of a modification for each affected fastener hole, which would terminate the repetitive inspections. This proposal is prompted by the results of full-scale fatigue tests which indicated that fatigue cracking occurred on the lower forward corner of the sliding window frames at frame 4. The actions specified by the proposed AD are intended to prevent such fatigue cracking, which could result in rapid depressurization of the airplane.