Airworthiness Directives; Airbus Model A320 Series Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to certain Airbus Model A320 series airplanes, that requires repetitive inspections for fatigue cracking of the bottom flanges of the longitudinal floor beams at frame 43; and repair, if necessary. This amendment also requires a one-time inspection for fatigue cracking of the fastener holes in the longitudinal floor beams, and modification of the floor beams, which constitutes terminating action for the repetitive inspections. This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to prevent fatigue cracking on the bottom flanges of the longitudinal floor beams, which could result in reduced structural integrity of the airplane.