Applicability: BAE SYSTEMS - BAe 146 and AVRO 146-RJ series aircraft.

Requirement: 1. Identify suspect batch number accumulators in accordance with BAe 146 series / Avro 146-RJ series aircraft Inspection Service Bulletin ISB.29-A046 initial issue dated 14 March 2006 or later EASA approved revisions. Only one suspect accumulator is allowed to be installed on an individual aircraft.
2. Where such an accumulator is identified, inspect accumulator in accordance with ISB.29-A046.
3. Replace identified accumulator in accordance with para 2.D. of ISB.29-A046

Terminating action: Replacement of identified accumulator with serviceable accumulator is considered terminating action from the requirements of this AD.

Note: EASA Emergency AD number 2006-0061-E dated 17 March 2006 refers.

Compliance: 1. Within 48 hours after the effective date of this AD.
2. On identification of the suspect accumulator and thereafter, repetitively, at 48
hour inspection intervals, until terminated as detailed in ISB.29-A046.
3. Not later than 31 May 2006.

This Airworthiness Directive becomes effective on 23 March 2006.

Background: Following an in-service failure of a hydraulic accumulator, the manufacturer has identified two suspect batches of accumulator cylinders. Suspect hydraulic accumulators are identified in BAE Systems ISB.29-A046. These accumulators may burst in service with the potential to cause a hazardous event on the aircraft, with an unacceptable probability of occurrence. Hazardous event being the resultant flight crew workload associated with the loss of one or more hydraulic circuits, combined with possible fuselage pressure vessel rupture and possible cabin contamination with hydraulic mist.

FMI: www.casa.gov.au