Airworthiness Directives; Airbus Model A300, A310, and A300-600 Series Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to certain Airbus Model A300, A310, and A300-600 series airplanes, that requires inspections to detect defects of the flanges of the bleed air ducts of the auxiliary power unit (APU), and to measure the material thickness of the flanges; and repair, replacement of the duct with a new or serviceable duct, or operation of the airplane with the bleed air system of the APU inoperative, if necessary. For certain airplanes, the amendment also requires an inspection to detect cracks of the flanges, and follow-on actions. This amendment is prompted by issuance of mandatory continued airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to prevent rupturing and cracking of the flanges of the bleed air ducts, which could damage the elevator control system and consequently reduce the controllability of the airplane.