Airworthiness Directives; Mitsubishi Model YS-11 Series Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to all Mitsubishi Model YS-11 series airplanes, that requires repetitive inspections to detect fatigue cracking in the manhole doublers of the lower wing panels; and repair, if necessary. This amendment also requires eventual modification of screw holes in the manhole doublers of the lower wing panels, which constitutes terminating action for the repetitive inspections required by this AD. This amendment is prompted by the issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to prevent fatigue cracking in the manhole doublers of the lower wing panels, which could result in failure of the wing structure.