Airworthiness Directives; BAE Systems (Operations) Limited Airplanes

We are adopting a new airworthiness directive (AD) for certain BAE SYSTEMS (OPERATIONS) LIMITED Model BAe 146 and Avro 146-RJ series airplanes. This AD was prompted by reports of cracking and surface anomalies of the fuselage skin at the water trap/air dryer unit of the forward discharge valve due to corrosion. This AD requires repetitive detailed inspections for bulging, surface anomalies, and cracking of the fuselage skin adjacent to the discharge valves, repair if necessary, and application of additional sealant in the affected area if necessary. We are issuing this AD to detect and correct bulging, surface anomalies, and cracking that could propagate towards the forward discharge valve outlet, which could result in the failure of the fuselage skin, leading to a possible sudden loss of cabin pressure.