Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain BAe Systems (Operations) Limited Model BAe 146 and Avro 146-RJ series airplanes. This proposal would require identifying the discharge valves and cabin pressure controllers, and replacing them with new parts if necessary. This action is necessary to prevent the installation of incorrect pressurization discharge valves and cabin pressure controllers, which could subject the airframe to excess stress and adversely affect the airframe fatigue life. This action is intended to address the identified unsafe condition.