Summary
This document proposes the supersedure of an existing airworthiness directive (AD), applicable to all Aerospatiale Model ATR42-300 and -320 series airplanes. The existing AD requires repetitive ultrasonic inspections to detect cracking of certain lugs on the main landing gear (MLG), replacement of cracked lugs with new or serviceable parts, and a follow-on inspection; and provides for an optional terminating action for the repetitive inspections. This action would remove that terminating action and require new repetitive inspections of the rubber sealant to detect shearing, and corrective action, if necessary. This action also would require new one-time visual and fluorescent penetrant inspections to detect discrepancies of certain lugs and refurbishment of the MLG barrel and swing lever assemblies, which would terminate the requirements of this proposed AD. This action would also revise the applicability of the existing AD. This proposal is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by the proposed AD are intended to detect and correct discrepancies of the MLG barrel lower lugs, which could result in reduced structural integrity and possible collapse of the MLG.