AD/B767/173 Amdt 1 Thrust Reverser Directional Pilot Valve (Cth)

AIRWORTHINESS DIRECTIVE

On the effective date specified below, and for the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/B767/173 and issues the following AD under subregulation 39.001(1) of CASR 1998.  The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.

Boeing 767 Series Aeroplanes

AD/B767/173 Amdt 1 Thrust Reverser Directional Pilot Valve 3/2008 DM

Applicability:

Model 767 series aeroplanes with General Electric CF6-80C2 series engines.

Requirement:

1.    (a)   For aeroplanes not modified in accordance with Boeing Service Bulletin (SB) 767-78-0063 or production equivalent carry out and successfully accomplish a functional test of the Directional Pilot Valve (DPV) of the thrust reversers to detect pneumatic leakage in accordance with Boeing Alert SB 767-78-0084 dated 21 October 1999.

       (b)   For aeroplanes modified in accordance with Boeing SB 767-78-0063 or production equivalent carry out and successfully accomplish a functional test of the DPV of the thrust reversers to detect pneumatic leakage in accordance with Boeing Alert SB 767-78-0084 dated 21 October 1999.

2.    Repeat and successfully accomplish a functional test of Requirement 1(a).

3.    Repeat and successfully accomplish a functional test of Requirement 1(b).

4.    If any functional test required by Requirement 1, 2 or 3 of this Directive cannot be successfully carried out in accordance with the reference service bulletin, or if any discrepancy is detected during any functional test, repair in accordance with the Aircraft Maintenance Manual.

5.    Repeat Requirement 1 functional tests if any discrepancies have been corrected under Requirement 4 during compliance with requirement 1, 2 or 3.

Production Equivalent

Functional tests accomplished in accordance with a production equivalent for aeroplanes modified during production, are acceptable as equivalent to the initial functional test required by Requirement 1(b) of this Directive. Therefore, in this case, compliance with Requirement 1(b) is not necessary.

Later revisions of the above SB, approved by the United States Federal Aviation Administration (FAA) as an Alternate Method of Compliance (AMOC) to FAA AD 2000-17-06 is considered acceptable for compliance with the equivalent requirements of this Directive.

Note:  FAA AD 2000-17-06 Amdt 39-11880 refers.

Compliance:

For Requirement 1:

(a)   Remains unchanged as detailed in the original issue of this Directive as:  Within 30 days after 5 June 2002 (the effective date of the original issue of this Directive), unless previously accomplished.

(b)   Remains unchanged as detailed in the original issue of this Directive as:  With the exception of aeroplanes modified and functionally tested in accordance with a production equivalent, within 60 days after 5 June 2002, unless previously accomplished.

For Requirement 2: At intervals not exceeding 1,000 flight hours.

For Requirement 3: At intervals not exceeding 6,000 flight hours.

For Requirement 4: Prior to further flight after the effective date of this Directive.

For Requirement 5: Prior to further flight after the effective date of this Directive

This Amendment becomes effective on 23 January 2008.

Background:

A possible leakage of the thrust reverser Directional Pilot Valve (DPV), due to a poppet valve being slightly jammed open or a leaking o-ring, has been identified by a report to the FAA as a latent failure of the fail-safe features of the thrust reverser system.  The actions specified in this Directive are intended to ensure the integrity of the fail-safe features by preventing possible failure modes that could result in inadvertent deployment of the thrust reverser in flight.

This amendment includes a statement approving the use of later FAA approved service bulletins which have been approved by the FAA as an AMOC to the referred FAA AD. There is no change to the requirements or compliance periods.

The original issue of this AD became effective on 5 June 2002.

Charles Lenarcic
Delegate of the Civil Aviation Safety Authority

16 January 2008