AD/CL-600/94 Fuel Tank Lightning Protection (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-600/94 Fuel Tank Lightning Protection 3/2008

Applicability:

Model CL-600-2B19 aircraft, serial numbers 7003 through 7067, and 7069 through 7929.

Requirement:

Modify bonding jumpers inside the wing and centre fuel tanks, according to the Accomplishment Instructions of Bombardier Service Bulletin (SB) 601R-28-055, Revision D, dated 17 July 2006, or later revisions approved by the Chief, Continuing Airworthiness, Transport Canada.

Note 1:  Modification of bonding jumpers according to the original issue, Revision A or Revision B of the above noted SB DOES NOT satisfy the requirements of this Directive.

Note 2:  Transport Canada AD CF-2007-34 refers.

Compliance:

Within 5000 hours time in service after the effective date of this Directive.

This Airworthiness Directive becomes effective on 13 March 2008.

Background:

Bombardier Aerospace has completed a system safety review of the CL-600-2B19 aircraft fuel system against new 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 assessed using Transport Canada Policy Letter No. 525-001 to determine if mandatory corrective action is required.

This assessment showed that there is insufficient electrical bonding for lightning protection at certain locations inside the fuel tanks.  In addition, the assessment also revealed that existing bonding jumpers across self-bonded couplings are not required.  Insufficient electrical bonding, if not corrected, could result in arcing and potential ignition source inside the fuel tank during lightning strikes and consequent fuel tank explosion.

To correct the unsafe condition, this Directive mandates the modification of certain bonding jumpers inside the fuel tanks.

Charles Lenarcic
Delegate of the Civil Aviation Safety Authority

21 January 2008