Airworthiness Directives; Aerospatiale Model ATR42-200, ATR42-300, and ATR42-320 Airplanes

摘要

The FAA proposes to supersede an existing airworthiness directive (AD) that applies to all Aerospatiale Model ATR-42-200, ATR 42-300, and ATR42-320 airplanes. The existing AD currently requires inspections to determine the proper installation of rivets in certain key holes and to detect cracks in the area of the key holes where rivets are missing; and correction of discrepancies. The existing AD also requires various inspections of the subject area for discrepancies, and corrective actions if necessary; and replacement of certain cargo door hinges with new hinges. For certain airplanes, the existing AD also requires replacement of friction plates, stop fittings, and bolts with new parts. This proposed AD would require additional corrective actions for certain airplanes. This proposed AD is prompted by discovery of cracks around key holes on certain fuselage frames where rivets were missing. We are proposing this AD to prevent fatigue cracks of the cargo door skin, certain frames, and entry door stop fittings and friction plates, which could result in reduced structural integrity of the airplane.