Summary
We propose to adopt a new airworthiness directive (AD) for certain BAE SYSTEMS (OPERATIONS) LIMITED Model BAe 146 and Model Avro 146-RJ airplanes. This proposed AD was prompted by reports of cracking and surface anomalies of the fuselage skin at the water trap/air drier unit of the forward discharge valve due to corrosion. This proposed AD would require 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 proposing this AD to detect and correct bulging, surface anomalies, and cracking that could propagate towards the forward discharge valve outlet and result in the failure of the fuselage skin, leading to a possible sudden loss of cabin pressure.