Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to all British Aerospace Model Viscount 744, 745D, and 810 airplanes. This proposal would require an inspection of certain fittings of the engine mount structure to determine whether fasteners have been installed in inspection holes and to determine whether those holes are oversized. It would also require various follow-on actions, depending upon the results of the inspection. This proposal is prompted by reports indicating that fasteners were installed in the inspection hole of the engine ``W'' frame socket fittings and the inspection hole was oversized due to fatigue cracking. The actions specified by the proposed AD are intended to prevent such fatigue cracking, which could lead to failure of the fasteners and consequent separation of the engine from the airframe.