Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to all British Aerospace Model Viscount 744, 754D, and 810 airplanes. This proposal would require an inspection to detect corrosion of the tailplane assemblies, and correction of discrepancies. This proposal is prompted by a report of corrosion on the main spar top and bottom forward boom of the tailplane assemblies and reports of cracking in the upper root joint attachment fitting. The actions specified by the proposed AD are intended to prevent such cracking or corrosion of the main spar forward booms or the upper root joint attachment fitting, which consequently [[Page 19550]] could lead to the failure of the tailplane assemblies; this condition could result in reduced controllability of the airplane.