Summary
This document proposes the supersedure of an existing airworthiness directive (AD), applicable to certain British Aerospace Model Viscount 744, 745D, and 810 airplanes, that currently establishes time-in-service limits for components of the fuselage pressure vessel, and requires modifications and inspections of various fuselage components to assure the continued structural integrity of these airplanes through the manufacturer's design life goal. This action would require additional modifications and inspections of the fuselage pressure vessel to extend the fuselage pressure vessel life from 30 to 45 years since new. This proposal is prompted by results of a review of fatigue test findings, stress analysis, and in-service history associated with pressure vessel components. The actions specified by the proposed AD are intended to prevent reduced structural capability of the fuselage pressure vessel.