AD/CL-600/100 - Fuel Tube Coupling - Electrical Bonding

The AD revolves around three tightly interlinked technical and regulatory concepts drawn from the source text: electrical bonding of fuel-system components, lightning-current capability of fuel-tube couplings, and mandated corrective action by means of a manufacturer service bulletin.

Electrical bonding: Bombardier’s system safety review and lightning tests identified that certain “fuel tube self-bonded couplings” do not provide sufficient lightning-current capability. The source states that single failure of the integral bonding wire of those self-bonded couplings could affect electrical bonding between fuel tubes. The AD therefore targets those couplings to restore or provide a robust electrical bond path between fuel-tank components.

Lightning-current capability: The assessment and tests showed insufficient capability to carry lightning-induced currents safely through the coupling design. The safety consequence described in the source is that insufficient electrical bonding or current capability “could result in arcing and potential ignition source inside the fuel tank during lightning strikes and consequent fuel tank explosion.”

Design and compliance mechanism: The AD prescribes replacement of certain couplings with “redesigned couplings” specified in Bombardier SB 670BA-28-014, Revision A, dated 7 May 2007. The SB is split operationally into Part A (for aircraft that have not incorporated the original issue) and Part B (for aircraft that already have the original SB). The AD ties compliance to the SB’s Accomplishment Instructions and allows only later revisions of the SB if they are approved by the Chief, Continuing Airworthiness, Transport Canada.

Fleet applicability and timing: The AD is confined to two model subtypes and explicit serial number ranges. It prescribes a finite compliance window: within 4,500 flight hours from the effective date of the AD (3 July 2008). The AD cross-references a Transport Canada AD (CF-2008-02) and is issued under the authority of a CASA delegate, James Coyne.

Regulatory linkage: The AD uses a manufacturer-issued SB as the normative technical means to achieve compliance, and places a vesting of approval for later SB revisions in the Chief, Continuing Airworthiness, Transport Canada. The AD therefore creates an obligation to follow manufacturer instructions, subject to regulatory approval channels identified in the source.

The source identifies the affected population narrowly and precisely by model and serial number. The AD applies to Bombardier Inc. Model CL-600-2C10 aircraft with serial numbers 10003 through 10169 and to CL-600-2D24 aircraft with serial numbers 15001 through 15025. The directive is targeted at operators, owners and maintenance organisations responsible for those specific aircraft, because the Requirement section mandates actions to be performed on the aircraft.

The AD does not specify cost allocation, warranties, or reimbursement; it mandates work but leaves the source of funding unstated. Therefore the immediate practical effect is that parties responsible for continued airworthiness of the listed aircraft (most commonly the registered operator or owner) must ensure the required replacement or inspection and replacement is carried out in accordance with the SB. The document does not identify third-party suppliers, lessors, or financiers specifically, but any stakeholder with operational control or maintenance responsibilities for the listed serial numbers will need to take action to meet the directive’s requirements.

Maintenance organisations and personnel are directly affected in execution terms: the AD requires following the Accomplishment Instructions in Parts A or B of Bombardier SB 670BA-28-014, Revision A. Where later revisions to the SB are to be used, the AD requires approval from the Chief, Continuing Airworthiness, Transport Canada, which places an approval step between operators and subsequent SB revisions. The AD also references a Transport Canada AD (CF-2008-02), indicating cross-jurisdictional relevance for Australian-registered aircraft that may be subject to the Canadian AD in parallel.

The AD is signed by a CASA delegate, which indicates that the directive imposes regulatory obligations within CASA’s administrative process. The source does not list enforcement mechanisms, penalties, or administrative procedures beyond specifying the effective date and compliance time. It also does not specify record-keeping or airworthiness release requirements beyond adherence to the specified SB instructions.

Key duties mandated by the AD are explicit and technical. The AD requires operators of applicable aircraft to do one of two things depending on prior incorporation of the original issue of Bombardier SB 670BA-28-014:

• For aircraft that have not incorporated the original SB: Replace the fuel tube couplings inside the wing and centre fuel tanks with redesigned couplings according to Part A of the Accomplishment Instructions of Bombardier SB 670BA-28-014, Revision A, dated 7 May 2007, or later revisions approved by the Chief, Continuing Airworthiness, Transport Canada.

• For aircraft that have incorporated the original SB: Inspect the aft scavenge ejector fuel couplings inside the left-hand and right-hand wing fuel tanks and replace with redesigned couplings if necessary according to Part B of the Accomplishment Instructions of the same SB revision or later approved revisions.

The AD sets a compliance deadline of within 4,500 flight hours after the AD’s effective date. The AD becomes effective on 3 July 2008. The AD does not prescribe a particular maintenance organisation or certificated engineer to carry out the work, and it does not mandate documentary evidence beyond invoking the SB’s Accomplishment Instructions. The AD does, however, condition the use of later revisions of the manufacturer’s SB on approval by the Chief, Continuing Airworthiness, Transport Canada.

Rights or flexibilities spelled out by the source are limited. The AD allows use of later revisions of the SB but only with the specified approval. The AD also separates aircraft into two categories based on prior incorporation of the original SB and prescribes different actions accordingly; this is a procedural recognition of prior compliance. The AD does not include explicit provisions for alternative means of compliance, flight limitations, or extensions. It also does not state routes for dispute or objection within the text; any such administrative remedies are not set out in the provided source.

Practically, the AD imposes an operational duty to perform the specified inspections and replacements within the stated flight-hour window, to follow the detailed steps in the specified SB parts, and to obtain regulatory approval for any later SB revisions used. The AD does not allocate financial responsibility, nor does it supply instructions about grounding, maintenance scheduling, or post‑work airworthiness certification beyond referring operators to the SB.

The source text itself does not include a schedule of penalties nor an explicit enforcement procedure beyond the statement of requirement, the compliance time and the effective date. The AD is issued and signed by James Coyne, Delegate of the Civil Aviation Safety Authority, and the AD becomes effective on 3 July 2008. Those facts establish that the directive is an official regulatory instrument, but the AD document as supplied does not set out civil or criminal penalties, infringement notices, suspension mechanisms, or particulars of administrative enforcement.

What the AD does provide that bears on enforcement is: a precisely stated Requirement (the replacement or inspection and replacement, per parts A and B of Bombardier SB 670BA-28-014, Revision A), a definitive Applicability statement (model and serial-number ranges), and a Compliance time (within 4,500 flight hours after the effective date). A regulator or enforcement body could therefore determine non-compliance against these clear, measurable metrics: whether an affected aircraft had the required work performed within the compliance interval and in accordance with the specified SB instructions or later revisions approved by the named authority.

The AD also cross-references Transport Canada AD CF-2008-02 dated 3 January 2008. The inclusion of that reference indicates that there are parallel regulatory actions, but the supplied text does not describe how those parallel measures interact for enforcement purposes.

Because the document does not itself list penalties or procedures, the source leaves open how non-compliance is to be remedied, what sanctions may follow, what records must be produced, and what administrative processes apply. The document does, however, place an unambiguous technical obligation on operators of the listed aircraft to perform the actions specified in the SB within the flight-hour window. The absence of penalty text in the AD is itself a feature to be noted: the AD establishes a compliance obligation and an effective date, but enforcement modalities and consequences are not articulated in the source material provided.

The AD text explicitly references another regulator’s measure and conditions the acceptability of later technical documents on the approval of a named authority. The AD refers to Transport Canada AD CF-2008-02 dated 3 January 2008, and it specifies that later revisions of Bombardier SB 670BA-28-014 are permissible only if approved by the Chief, Continuing Airworthiness, Transport Canada. These references create a regulatory linkage between this AD and Canadian continuing airworthiness oversight and technical approvals.

Beyond those explicit references, the provided text does not identify other domestic legislation, regulations, or statutory provisions that the AD modifies, supplements, or relies upon. The AD is signed by a Delegate of the Civil Aviation Safety Authority, which situates it within the agency’s administrative framework, but the AD itself does not describe enabling legislation, procedural rules, or how it interacts with other CASA instruments. The source thus limits the observable inter-law effects to the following mechanism: it mandates compliance through a manufacturer service bulletin, while deferring technical approval of later SB revisions to the Chief, Continuing Airworthiness, Transport Canada, and it cites a corresponding Transport Canada AD.

Operationally, this means the AD integrates manufacturer technical instructions with regulatory approval channels and cross-jurisdictional coordination. For operators moving aircraft across registries or maintaining fleets in multiple jurisdictions, the reference to Transport Canada’s AD signals that the technical corrective action has been considered by the state of design/manufacture authority, and thus the AD can be read in tandem with that Canadian AD. The AD does not, within the supplied text, explain whether acceptance of the Canadian AD satisfies the CASA AD absent additional Australian action, nor does it stipulate procedures for bilateral recognition or for alternate means of compliance.

In short, the AD interacts with other laws and regulatory instruments primarily by referencing Transport Canada’s AD and by making approval of later SB revisions conditional on a named Canadian authority. The source does not detail further interactions with Australian statutory provisions, certification processes, or enforcement regimes.

The source provides several discrete documentary milestones but does not present an extended amendment log. The relevant items contained in the AD are:

• Bombardier Service Bulletin 670BA-28-014: The AD requires compliance with Bombardier SB 670BA-28-014. The AD distinguishes between the original issue of that SB and Revision A, dated 7 May 2007. The AD instructs that the actions be carried out “according to Part A” or “according to Part B” of the Accomplishment Instructions of SB 670BA-28-014, Revision A, dated 7 May 2007.

• Revision approvals: The AD allows “later revisions approved by the Chief, Continuing Airworthiness, Transport Canada” to be used in place of SB 670BA-28-014, Revision A. This creates a controlled path for amendment of the normative technical document, conditional on approval by the nominated authority.

• Transport Canada AD CF-2008-02: The AD explicitly states that Transport Canada AD CF-2008-02 dated 3 January 2008 “refers.” That reference indicates that the Canadian authority had issued a related AD earlier in the same year.

• AD issuance date and effective date: The AD document is dated 7/2008 in its heading, signed by James Coyne, Delegate of the Civil Aviation Safety Authority on 22 May 2008, and the AD becomes effective on 3 July 2008. The compliance period is measured as 4,500 flight hours from the effective date.

The source does not include any subsequent amendments to AD/CL-600/100 itself, nor does it supply a revision history of the AD text, nor additional superseding instruments. The only permissive amendment mechanism evident in the source is the ability to use later revisions of Bombardier SB 670BA-28-014 if those revisions receive the specified approval from the Chief, Continuing Airworthiness, Transport Canada.

Because the source’s amendment history is limited to those specific references and the conditional approval route, users should treat the SB’s Revision A dated 7 May 2007 as the baseline technical document for compliance unless a later revision has been formally approved by the named Canadian authority. The AD source does not indicate any retrospective amendments, exemptions, or subsequent ADs that alter the compliance deadline, scope, or technical prescription contained in the present text.

The supplied AD text contains no litigation history. There are no citations to court decisions, no record of challenges to the AD’s validity, and no mention of legal disputes, judicial review, or tribunal proceedings in the source material. The AD records only administrative actions: a Bombardier system safety review and lightning tests that informed the technical finding, issuance of a manufacturer SB (original issue and Revision A), reference to a Transport Canada AD, and the CASA delegate’s signature.

Given the absence of litigation references in the source, there is no source-grounded basis in the supplied material to describe any legal challenges, case law, determinations about procedural fairness, judicial interpretations of the AD, or remedies sought by affected parties. The source therefore provides no material evidence about how courts or tribunals have interpreted the AD, nor whether any enforcement actions arising from this AD have been litigated.

Where litigation history is material for compliance or risk assessment in practice, the absence of litigation information in the AD itself means researchers and practitioners must consult external judicial and regulatory records to establish whether any disputes arose from this directive and, if so, their outcomes. The AD text itself does not supply those records.

The AD contains several specifics and procedural conditions that can create operational pitfalls if overlooked. The following items are drawn directly from the source and describe precise points of attention:

• Narrow serial-number applicability: The AD applies only to CL-600-2C10 aircraft serial numbers 10003 through 10169 and CL-600-2D24 aircraft serial numbers 15001 through 15025. Aircraft outside those serial-number ranges are not covered by this AD as written. Operators must verify serial numbers carefully before acting.

• Two-path compliance tied to prior SB incorporation: Actions differ depending on whether the original issue of Bombardier SB 670BA-28-014 has already been incorporated. For aircraft that have not incorporated the original SB the AD mandates full replacement per Part A. For aircraft that have incorporated the original SB the AD mandates inspection of the aft scavenge ejector fuel couplings and replacement if necessary per Part B. Misclassifying an aircraft’s prior SB status could lead to incorrect work scope.

• Normative reliance on SB Revision A: The AD mandates compliance “according to Part A” or “Part B” of Bombardier SB 670BA-28-014, Revision A, dated 7 May 2007, or later revisions approved by the Chief, Continuing Airworthiness, Transport Canada. Using a later SB revision without the specified approval would be inconsistent with the AD as written.

• Approval gate with another authority: The AD conditions acceptance of later SB revisions on approval from the Chief, Continuing Airworthiness, Transport Canada. That approval channel may introduce administrative lead time and cross-jurisdictional coordination requirements if operators attempt to use newer SB revisions.

• Compliance window measured in flight hours: The compliance timeframe is “within 4,500 hours flight time after the effective date of this directive.” The effective date is 3 July 2008. Operators must track and calculate flight hours in relation to that effective date to determine the deadline; numerical tracking errors could result in missed compliance.

• Technical focus on aft scavenge ejector couplings: For aircraft that have previously incorporated the original SB, the AD requires inspection of the aft scavenge ejector fuel couplings inside the LH and RH wing fuel tanks. These are specific internal tank components; access and inspection may require tank entry, certified procedures, and potential tank draining, which have operational implications not described in the AD.

• Safety rationale tied to lightning and bonding: The AD addresses a risk that “insufficient electrical bonding between fuel tubes or insufficient current capability of fuel tube couplings” could lead to “arcing and potential ignition source inside the fuel tank during lightning strikes and consequent fuel tank explosion.” That description underscores the safety-critical nature of the prescribed work. The AD is not a preventive recommendation; it is a mandated corrective action.

• No stated cost or funding mechanism in the AD: The AD does not assign payment responsibility, compensation, or economic support; the AD mandates the work but leaves who pays unspecified. Operators should plan for parts procurement, labour and possible operational disruption costs.

• No enforcement detail provided: The AD does not set out penalties, remedial enforcement procedures, or record-keeping obligations in the text. The absence of procedural detail requires operators to consult their regulator or the wider regulatory framework for enforcement processes and documentation expectations.

• Reference to Transport Canada AD: The AD states “Transport Canada AD CF-2008-02 dated 3 January 2008 refers.” Operators with aircraft in multiple registries should note the relationship to the Canadian AD and coordinate compliance status and approvals accordingly.

Careful attention to these specific textual requirements and conditions in the AD will reduce the risk of non-compliance or incorrect execution of the required work.

Compliance is achieved by following the precise technical and procedural prescriptions set out in the AD text. The operator’s steps, drawn from the AD, are:

1. Confirm applicability. Determine whether the aircraft is within the stated serial-number ranges: CL-600-2C10 serial numbers 10003 through 10169, or CL-600-2D24 serial numbers 15001 through 15025. If the aircraft is not within those ranges the AD does not apply as written.

2. Establish SB incorporation status. Verify whether the original issue of Bombardier SB 670BA-28-014 has already been incorporated into the aircraft’s records and configuration. The AD prescribes different actions depending on that prior incorporation.

3. Follow the correct SB part. If the original SB has not been incorporated, carry out the replacement of the fuel tube couplings inside the wing and centre fuel tanks with redesigned couplings per Part A of the Accomplishment Instructions of Bombardier SB 670BA-28-014, Revision A, dated 7 May 2007, or a later revision only if approved by the Chief, Continuing Airworthiness, Transport Canada. If the original SB has been incorporated, inspect the aft scavenge ejector fuel couplings inside the LH and RH wing fuel tanks and replace with redesigned couplings if necessary per Part B of the Accomplishment Instructions of the same SB revision or an approved later revision.

4. Comply within the time limit. Ensure all required work is completed within 4,500 flight hours after the AD’s effective date. The AD becomes effective on 3 July 2008, so calculate the deadline in flight hours from that date.

5. Obtain approvals for later SB revisions where applicable. If a later revision of Bombardier SB 670BA-28-014 is to be used, obtain approval from the Chief, Continuing Airworthiness, Transport Canada as required by the AD. Do not substitute an unapproved revision.

6. Use appropriate maintenance procedures. Perform the inspection and replacement work in accordance with the Accomplishment Instructions in the SB. The AD itself does not prescribe which maintenance organisation or licensed personnel must carry out the work, but it requires that the SB instructions be followed. Operators should ensure that personnel performing tank work are qualified under applicable maintenance standards and that any necessary fuel-tank-entry procedures, safety protocols, and environmental controls required by the SB or other applicable directives are observed.

7. Document the work. Although the AD does not specify documentation requirements in the provided text, operators should record the actions taken in the aircraft’s maintenance records, noting the SB number and revision used, the dates, and the serial numbers of replaced parts. If a later SB revision is used with Transport Canada approval, retain that approval documentation to demonstrate compliance with the AD.

8. Coordinate with regulatory and design authorities if uncertain. The AD references Transport Canada and places the approval authority for later SB revisions with the Chief, Continuing Airworthiness, Transport Canada. Where there is uncertainty about acceptable materials, parts, records, or whether particular work satisfies the AD, operators should seek guidance from their authority having jurisdiction or the CASA delegate responsible for airworthiness.

9. Plan for operational impacts. The AD will require physical access to fuel-tank couplings and possibly tank entry or fuel-system work. Schedule the work within maintenance windows and factor in procurement lead times for the “redesigned couplings” specified in the SB. The AD does not allocate costs; operators should plan accordingly.

10. Check related instruments. Review Transport Canada AD CF-2008-02 (3 January 2008) as it is referenced in the AD, and confirm whether there are other relevant directives or bulletins that affect the same components or flight authorisation for the aircraft.

Following these steps will align an operator’s actions with the AD’s explicit textual requirements: using the specified SB parts, complying within the flight-hour window, and using later SB revisions only with the named approval. The AD’s prescriptive elements are the operative compliance criteria; adherence to them and maintenance of contemporaneous records will be central to demonstrating conformity with the directive.