Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to all Mitsubishi Model YS-11 and YS- 11A series airplanes. This proposal would require repetitive removal of the spinner; repetitive detailed visual inspections of the propeller hub to detect fatigue cracking; and replacement of a propeller hub with a new propeller hub, if necessary. 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 of the propeller hub, which could cause the loss of the propeller.