AD/CL-600/89 Fuel Tank Sealant (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-600/89 Fuel Tank Sealant 12/2007

Applicability:

Bombardier Inc. Model CL-600-2B19 aircraft, serial numbers 7003 through 7067 and 7069 through 7924.

Requirement:

Application of Sealant to the Collector Fuel Tank Bolts (Applicable to Aircraft Serial Numbers 7003 through 7067 and 7069 through 7797)

1.    Apply sealant to bolts on the collector fuel tanks according to the Accomplishment Instructions of Revision A of Bombardier Service Bulletin (SB) 601R-28-051, dated 30 March 2005, or later revisions approved by the Chief, Continuing Airworthiness, Transport Canada.

Application of sealant prior to the effective date of this directive according to the original issue of the above-noted SB satisfies the requirement 1 of this AD.

Application of Sealant to the Transfer Ejector Pumps (Applicable to Aircraft Serial Numbers 7003 through 7067 and 7069 through 7924)

2.    Carry out a general visual inspection of the left and right transfer ejector pumps for the presence of a fillet seal on the edge of the pumps and sealant on the bolts, according to the Accomplishment Instructions of Revision A of Bombardier SB 601R-28-060, dated 30 March 2005, or later revisions approved by the Chief, Continuing Airworthiness, Transport Canada.

3.    If sealant is missing from the edge of the transfer ejector pump or from any of the bolts, prior to further flight, apply sealant to the affected areas according to the Accomplishment Instructions of Revision A of Bombardier SB 601R-28-060, dated 30 March 2005, or later revisions approved by the Chief, Continuing Airworthiness, Transport Canada.

Inspection and application of sealant prior to the effective date of this directive according to the original issue of SB 601R-28-060 satisfies requirements 2 and 3 of this AD.

Note:  Transport Canada AD CF-2007-17 dated 4 September 2007 refers.

Compliance:

Within 5000 flight hours after the effective date of this directive, unless already accomplished.

This Airworthiness Directive becomes effective on 22 November 2007.

Background:

Bombardier Aerospace has completed a system safety review of the CL-600-2B19 aircraft fuel system against new fuel tank safety standards.

The assessment showed that sealant has not been applied to bolts on the collector fuel tanks or the transfer ejector fuel pumps.  Lack of sealant on the above-noted locations, 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 AD mandates the application of sealant to the bolts that attach various fittings on the collector fuel tanks, to the edges of the transfer ejector pumps and to the bolts that attach the transfer ejector pump to the transfer ejector pump casing.

Charles Lenarcic
Delegate of the Civil Aviation Safety Authority

24 September 2007