Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to all Mitsubishi Model YS-11 series airplanes. This proposal would require repetitive inspections to detect fatigue cracking in the manhole doublers of the lower wing panels; and repair, if necessary. This proposal also would require eventual modification of screw holes in the manhole doublers of the lower wing panels. 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 fatigue cracking in the manhole doublers of the lower wing panels, which could result in failure of the wing structure.