AD 96-21-08 Amendment 39-9785

This amendment adopts a new airworthiness directive (AD), applicable to to all Short Brothers Model SD3-30 and SD3-SHERPA series airplanes, that requires inspections of the vertical fin-to-tailplane joint to detect any loose bolts; and, if necessary, inspections to detect elongation of bolt holes, and replacement with new bolts, if necessary. Additionally, this amendment requires inspections of the upper shear angle to detect pulled or loose rivets, and replacement of the shear angle using new rivets, if necessary. This amendment is prompted by reports of loose bolts in the vertical fin-to-tailplane joint and pulled or loose rivets in an upper shear angle. The actions specified by this AD are intended to prevent reduced structural integrity of the vertical fin to tailplane joint due to such discrepancies of the bolts or rivets.