Summary
The FAA proposes to adopt a new airworthiness directive (AD) for all BAE Systems (Operations) Limited Model BAe 146 and Avro 146-RJ airplanes equipped with certain hydraulic accumulators. This proposed AD would require inspecting the hydraulic accumulators to identify certain serial numbers, and replacing any affected accumulator with a new or serviceable accumulator. Operators may delay doing the replacement by doing repetitive inspections of the affected hydraulic accumulators for signs of failure (leaking or cracking), and replacing any failed accumulator with a new or serviceable unit. This proposed AD results from a report that one hydraulic accumulator failed in service, which caused the loss of the yellow hydraulic system when the airplane was configured for landing. We are proposing this AD to prevent damage to the pressure skin, failure of certain hydraulic systems, contamination of the cabin with hydraulic mist, increased workload for the flightcrew associated with the loss of one or more hydraulic circuits, and consequent reduced controllability of the airplane.