Summary
This document proposes the supersedure of an existing airworthiness directive (AD), applicable to all Raytheon Model DH.125- 1A, -3A, and -400A series airplanes, that currently requires a one-time inspection to detect scoring of the upper fuselage skin around the periphery of the cockpit canopy blister interface, and repair, if necessary. This action would expand the applicability of the existing AD to include additional airplanes, and would require that the actions be accomplished in accordance with revised service information for the newly added airplanes. This AD is prompted by additional reports indicating that scoring has been detected on the upper fuselage skin around the periphery of the cockpit canopy blister interface. The actions specified by the proposed AD are intended to detect and correct scoring of the upper fuselage skin around the periphery of the cockpit canopy blister interface, which could result in reduced structural integrity of the fuselage, and consequent cabin depressurization.