Summary
This document proposes the supersedure of an existing airworthiness directive (AD), applicable to certain Raytheon (Beech) Model 400, 400A, MU-300-10, and 2000 airplanes, and Model 200, B200, 300, and B300 series airplanes, that currently requires replacement of outflow/safety valves with serviceable valves. That AD was prompted by a report of cracking and consequent failure of outflow safety valves in the pressurization system. The actions specified by that AD are intended to prevent such cracking and consequent failure of the outflow/safety valves, which could result in rapid decompression of the airplane. This action would revise the applicability of the existing AD to add an airplane model and to remove other airplanes, as well as to reference additional service bulletins that identify the serial numbers of affected airplanes.