Summary
We propose to adopt a new airworthiness directive (AD) for all BAE SYSTEMS (OPERATIONS) LIMITED Model BAe 146 series airplanes and Model Avro 146-RJ series airplanes. This proposed AD was prompted by reports of excess solder deposited during overhaul on the frangible plug of a fire extinguisher, which prevented the release of the extinguishant. This proposed AD would require a one-time inspection of certain engine and auxiliary power unit (APU) fire extinguishers to determine if the fire extinguishers are affected by excessive solder and corrective actions if necessary. We are proposing this AD to prevent the failure of a fire extinguisher to discharge, which reduces the ability of the fire protection system to extinguish fires in the engine or APU fire zones, possibly resulting in damage to the airplane and injury to the passengers.