Summary
This document proposes the adoption of a new Airworthiness Directive (AD) that is applicable to all Shorts Model SD3-30, -60, and -SHERPA series airplanes. This proposal would require a visual inspection to detect signs of exfoliation corrosion on the brackets of the flap hydraulic units, and rework or replacement of corroded brackets. This proposal is prompted by a report that exfoliation corrosion was found on the brackets of the flap hydraulic units. The actions specified by the proposed AD are intended to prevent such corrosion, and consequent reduced structural integrity of the brackets of the flap hydraulic units, which could result in the loss of the flap control and consequent reduced controllability of the airplane.