Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Airbus Model A320-111, - 211, -212, and -231 series airplanes. This proposal would require repetitive inspections to detect cracks of the rear bracket attached to the outboard rib of the shroud boxes and the surfaces of the lugs adjacent to the bushes, and replacement, if necessary. This proposal also would require replacement of the outboard aft brackets of the shroud boxes with modified brackets that have floating boxes, which would terminate the repetitive inspections. This proposal is prompted by a report that the lug of the rear outboard bracket failed due to fatigue. The actions specified by the proposed AD are intended to prevent fatigue-related cracking in the subject lug, and the consequent failure of this lug; this condition could result in the loss of the shroud box, and, consequently, lead to reduced controllability of the airplane.