AD/CL-600/91 Fuel System Safety (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 (Canadair) CL-600 (Challenger) Series Aeroplanes

AD/CL-600/91 Fuel System Safety 3/2008 DM

Applicability:	Model CL-600-2B19 aircraft, all serial numbers.
Requirement:	1.    Revise the approved maintenance schedule by incorporating the following inspection requirements as contained in Revision 7 of Canadair Regional Jet Model CL-600-2B19 Maintenance Requirements Manual, CSP A-053, Part 2, Appendix D, “Fuel System Limitations”:
Task Number	Task Description
28-11-00-601	Detailed Inspection of the critical bonding jumpers for corrosion and damage
28-11-00-602	Function Check of the critical bonding jumpers
28-11-00-603	Detailed Inspection of the sealant on the in-tank LRUs
28-11-00-604	Detailed Inspection of the fuel tank wiring harness clipping along the front and rear spar of the centre and wing fuel tanks for condition and security
2.    For aircraft with more than 15 000 hours total time in service (TIS) on the effective date of this Directive, carry out the initial inspection of the tasks detailed in Requirement 1.
3.    Revise the approved maintenance schedule by incorporating the following inspection and maintenance requirements as contained in Revision 7 of Canadair Regional Jet Model CL-600-2B19 Maintenance Requirements Manual, CSP A-053, Part 2, Appendix D, “Fuel System Limitations”:
Task Number	Task Description
29-33-01-601	Function Check of the hydraulic system No. 1, No. 2 and No. 3 reservoir temperature transducer
29-33-01-602	Discard of the hydraulic system No. 1, No. 2 and No. 3 reservoir temperature transducer

4.    If not already accomplished, carry out the initial check of task number 29-33-01-601 detailed in Requirement 3.

5.    For aircraft with more than 27 500 hours total TIS on the effective date of this Directive, carry out task number 29-33-01-602 detailed in Requirement 3.

Note:  Transport Canada AD CF-2007-29 refers.

Compliance:

For Requirement 1 - Within 60 days after the effective date of this Directive.

For Requirement 2 - Within 5 000 hours TIS after the effective date of this Directive.

For Requirement 3 - Within 60 days after the effective date of this Directive.

For Requirement 4 - Within 5 000 hours TIS after the effective date of this Directive.

For Requirement 5 - Initially within 2 500 hours TIS after the effective date of this Directive.

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 inside the fuel system, which could result in a fuel tank explosion.  Revision has been made to Canadair Regional Jet Model CL-600-2B19 Maintenance Requirements Manual, CSP A-053, Part 2, Appendix D, “Fuel System Limitations” to introduce the required maintenance tasks.

Charles Lenarcic
Delegate of the Civil Aviation Safety Authority

16 January 2008