AD/BAe 146/127

Hydraulic Power - Accumulator Cylinders

5/2007

Applicability:

BAe 146 and AVRO 146-RJ aeroplanes - All models.

Requirement:

1. Identify the installed hydraulic accumulator in accordance with paragraph 2C of BAe Systems Inspection Service Bulletin (ISB) 29-047 dated 3 October 2006, which makes reference to APPH Ltd. Service Bulletin (SB) AIR91666-29-03, dated July 2006, or later NAA approved revisions of these documents.

2. When an accumulator is identified as being affected by this directive, remove the accumulator from service in accordance with paragraph 2D of BAe Systems ISB 29-047 and magnetic particle inspect the cylinder in accordance with APPH SB AIR91666-29-03.

3. When any defects are found, replace the accumulator with a serviceable unit.

4. Do not install an accumulator identified by APPH Ltd. SB AIR91666-29-03 on an aircraft, unless it has been inspected in accordance with APPH Ltd. SB AIR91666-29-02 or AIR91666-29-03 (See second Note in paragraph 1D(1) of ISB 29-047 for further explanation).

Note:  EASA AD 2007-0076 dated 21 March 2007 refers.

Compliance:

1. Within 6 weeks after the effective date of this AD

2. No later than 31 October 2009.

3. Before further flight, after the effective date of this AD.

4. After the effective date of this AD

This Airworthiness Directive becomes effective on 10 May 2007.

Background:

A hydraulic accumulator cylinder had material defects and suffered an in-flight burst failure causing damage to the aircraft structure.  This resulted in the issue of CASA telex AD/BAe146/119 requiring the identification and check of cylinders from known suspect batches.  Further investigations and checks by the accumulator manufacturer have concluded that all cylinders from a particular supplier may not have been correctly inspected at manufacture.

To prevent the risk of further failures, this AD requires all accumulators with cylinders from this supplier to be identified and inspected prior to re-installation.