AD/DHC-8/135 Fuel System Safety Maintenance Tasks (Cth)

AIRWORTHINESS DIRECTIVE

For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (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.

Bombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes

AD/DHC-8/135 Fuel System Safety - Maintenance Tasks 3/2008 DM

Applicability:	Model DHC-8-102, DHC-8-103, DHC-8-106, DHC-8-201, DHC-8-202, DHC-8-301, DHC-8-311, DHC-8-314, DHC-8-315 aircraft, all serial numbers.
Requirement:	1.    Revise the aircraft approved maintenance schedule by incorporating all the Fuel System Limitations (FSL) tasks contained in the following Temporary Revisions (TR):
a.     For DHC-8-102, DHC-8-103, DHC-8-106 aircraft - DHC-8-100 Maintenance Program Manual, PSM 1-8-7, Part 2 “Airworthiness Limitations List” TR AWL-110.
b.    For DHC-8-201, DHC-8-202 aircraft - DHC-8-200 Maintenance Program Manual, PSM 1-82-7, Part 2 “Airworthiness Limitations List” TR AWL 2-43.
c.     For DHC-8-301, DHC-8-311, DHC-8-314, DHC-8-315 aircraft - DHC-8-300 Maintenance Program Manual, PSM 1-83-7, Part 2 “Airworthiness Limitations List” TR AWL 3-109.
2.    Carry out the initial FSL tasks introduced by the above Maintenance Planning Manual TRs.
Note 1:  The initial completion time of the  Requirement 2 FSL tasks is referred to as ‘phase-in time’ in the Transport Canada AD CF-2007-32 and the Maintenance Planning Manual TRs.
Note 2:  Transport Canada AD CF-2007-32 refers.
Compliance:	For Requirement 1 - Within 60 days after the effective date of this Directive.
For Requirement 2 -
a.    For all aircraft that have accumulated 4000 hours total time in service (TIS) or more, or 24 months or more since new - Within 2000 hours TIS or 12 months after the effective date of this Directive, whichever occurs first, carry out the initial inspection of those FSL tasks with 6000 hours air time/36 months inspection interval.

b.    For all aircraft that have accumulated 12000 hours total TIS or more, or 72 months or more since new - Within 6000 hours TIS or 36 months after the effective date of this directive, whichever occurs first, carry out the initial inspection of those FSL tasks with 18000 hours air time/108 months inspection interval.

This Airworthiness Directive becomes effective on 31 January 2008.

Background:

Bombardier Aerospace has completed a system safety review of the aircraft fuel system against fuel tank safety standards introduced in Chapter 525 of the Airworthiness Manual through Notice of Proposed Amendment (NPA) 2002-043.  The identified non-compliances were then assessed using Transport Canada Policy Letter No. 525-001, to determine if mandatory corrective action is required.

The assessment showed that supplemental maintenance tasks are required to prevent potential ignition sources within the fuel system, which could result in a fuel tank explosion.  Revisions have been made to Part 2 “Airworthiness Limitations List” of the DHC-8 Maintenance Program Manuals to introduce the required maintenance tasks.

Charles Lenarcic
Delegate of the Civil Aviation Safety Authority

16 January 2008