AD/A330/68 - Fight Controls - Back-Up Control Module

The AD is built on a small set of technical and regulatory concepts set out in the text. These are the concepts you must understand to apply or advise on the directive.

• Applicability and exclusions: The directive applies to "A330 aircraft, all certified models, all serial numbers" provided Airbus Modification 49144 (install rudder fly by wire) was embodied during production. It explicitly excludes aeroplanes on which Airbus Modification 55185 has been embodied during production, or those on which Airbus SB A330-27-3142 dated 17 August 2006 has been embodied whilst in service (Applicability). That exclusion identifies two alternate production or in-service states that render the AD unnecessary for that airframe.

• Built-in Test Equipment (BITE) operational test: The AD mandates an operational test of the BCM and the back-up power supply by means of BITE. The test procedure and the corrective actions that flow from it are specified in Airbus SB A330-27-3147 dated 4 August 2006 (Requirement 1, Requirement 2). The AD therefore delegates technical execution to Airbus-prescribed test procedures, and accepts later approved SB revisions as alternative compliance.

• Repetitive monitoring vs terminating action: The AD creates a repeating compliance obligation (test within 900 hours TIS and every 900 hours thereafter) as an interim risk-control measure, and a terminating action (install modified BCM per SB A330-27-3142) that stops the repetition once accomplished (Compliance; Background). This is a common AD structure: detection and containment until a retrofit eliminates the root cause.

• Component-level root cause and remedy: The Background identifies the root-cause mechanism as resistor oxidation in resistors manufactured by SRT, producing abnormal resistance drift through humidity absorption and subsequent oxidation. The terminating remedy is BCMs fitted with resistors manufactured by VISHAY (Background). The AD therefore links the operational symptom (BITE-detectable degraded piloting laws) to a specific hardware replacement.

• Grounding-on-discrepancy: If discrepancies are found during the BITE operational test, corrective actions must be applied "before further flight" (Requirement 2, Compliance). Practically, that creates an immediate operational constraint: affected aircraft cannot resume flight until Airbus-prescribed corrective actions are carried out.

• Acceptable documentation: The AD requires compliance with named Airbus SBs (A330-27-3147 and A330-27-3142) dated 4 August 2006 and 17 August 2006 respectively, but permits later approved revisions of those service bulletins to be used (Requirement text). It also refers to EASA AD 2006-0313 as related material ("Note: EASA AD 2006-0313 refers.").

These concepts structure how compliance will be implemented: identify application status, run the specified BITE test and record results, apply mandatory corrective actions if discrepancies are present, repeat testing at the mandated interval until the retrofit BCM is installed, and perform the retrofit by the given deadline. The AD ties detection and remedy to the specific manufacturing source of the resistor (SRT) and the manufacturer of replacement resistors (VISHAY).

The AD identifies directly affected parties and implicates a handful of secondary stakeholders. The source text provides specific categories.

• Aircraft operators of Airbus A330 aeroplanes that were produced with Airbus Modification 49144 (install rudder fly by wire) and that have not had Airbus Mod 55185 embodied or SB A330-27-3142 embodied while in service. The Applicability clause covers "A330 aircraft, all certified models, all serial numbers" but then narrows this to those with Mod 49144 and excludes those with Mod 55185 or SB A330-27-3142 embodied. Operators of aircraft meeting the first set who have not carried out the exclusionary modifications are obliged to comply with the AD.

• Maintenance organisations and engineers responsible for line and base maintenance. The AD prescribes a BITE operational test (Requirement 1) and corrective actions required by Airbus SB A330-27-3147 (Requirement 2) and installation of a modified BCM per SB A330-27-3142 (Requirement 3). Those tasks fall to licensed maintenance organisations or appropriately authorised engineering personnel. The "before further flight" requirement creates operational decisions for those who determine airworthiness after maintenance.

• Airbus, as the manufacturer and the issuer of the service bulletins referenced in the AD, is a secondary stakeholder. The AD accepts Airbus SBs as the method of compliance and notes later approved revisions may be used.

• Parts manufacturers implicated in the root-cause and remedy. The Background identifies resistors manufactured by SRT as the component associated with the defect, and resistors manufactured by VISHAY as the terminating remedy fitted to the modified BCMs to be installed. Those suppliers are not named as parties to the AD, but the AD’s mechanics treat their products as determinants of applicability and remediation.

• Regulators and certification authorities. The AD is issued under the Civil Aviation Safety Authority (CASA), with signature by a CASA delegate. The AD references EASA AD 2006-0313 for related guidance. CASA, EASA, or other civil aviation authorities are operationally implicated where later approved revisions of the SBs or corresponding AD actions are considered.

• Operators’ commercial and flight-planning functions. The "before further flight" corrective action requirement and the repetitive 900-hour testing intervals create scheduling and availability consequences that affect crew rostering, dispatch, and operational planning.

Who is not affected: the AD explicitly excludes airframes with Mod 55185 embodied in production or those with SB A330-27-3142 embodied whilst in service. Those aircraft are outside the AD’s scope.

In practical terms, the immediate compliance cost and operational impact fall on operators and their maintenance providers. The AD assigns technical method to Airbus SBs rather than prescribing new procedures; this frames Airbus and its SB revisions as the primary technical decision source. The AD also signals a manufacturer supply-chain element by referencing resistors by their manufacturer names, which will affect spare-parts procurement and component traceability practices.

The AD creates affirmative duties, conditional duties, and a limited set of rights related to methods of compliance. These are stated directly in the text; the following summarises them.

Duties

• Conduct the BITE operational test on the BCM and BPS in accordance with Airbus SB A330-27-3147 dated 4 August 2006 (Requirement 1). This is an affirmative duty to perform a named diagnostic procedure.

• If the BITE test reveals any discrepancies, apply the corrective actions specified in SB A330-27-3147 (Requirement 2). The duty to correct arises only on a positive test result but must be completed prior to further flight.

• Install a modified BCM in accordance with SB A330-27-3142 (Requirement 3). This is the terminating duty, with an expressed deadline (no later than 31 December 2008).

• Observe timing constraints. The first BITE test must take place within 900 hours time in service after the AD’s effective date, and the BITE must be repeated at intervals not exceeding 900 hours until the BCM is replaced in accordance with SB A330-27-3142 (Compliance for Requirement 1). Corrective actions are mandatory "before further flight" (Compliance for Requirement 2). Installation of modified BCM must occur by 31 December 2008 (Compliance for Requirement 3).

Rights and permitted alternatives

• Use of later approved revisions of the referenced Airbus service bulletins to achieve compliance is expressly permitted ("Later approved revisions of the above service bulletins may be utilised to achieve compliance with the relevant Requirements of this Directive."). This gives operators and maintenance organisations the right to comply by following updated SB material if those revisions are approved.

• The AD sets out applicability exceptions as a right-to-exemption: aircraft that have Airbus Mod 55185 embodied during production, or aircraft that have Airbus SB A330-27-3142 embodied whilst in service, are excluded from the AD’s applicability (Applicability).

Delegations and decision-makers

• The AD was issued by the Civil Aviation Safety Authority, signed by James Coyne, Delegate, which identifies the issuing authority and the delegate responsible for the directive (signature block).

Conditional operational consequences

• The phrase "before further flight" makes the continuation of flight operations conditional on successful corrective action when a discrepancy is found during testing. That gives maintenance authorities the duty to withhold release to service until SB-prescribed corrections are performed.

Documentation and evidence

• While the AD does not specify record-keeping rules within its text, compliance necessarily requires adherence to the SB procedures; therefore operators will need to retain maintenance records demonstrating the BITE tests, any corrective actions, and the installation of modified BCMs in order to show compliance with the AD. That follows from the nature of the duties imposed (Requirement and Compliance clauses).

In short, the AD imposes specific maintenance and retrofit duties on operators and maintenance providers, prescribes Airbus SBs as the method for those duties while permitting later approved revisions, and sets timing constraints including an interim repetitive testing regimen and a final retrofit deadline. The AD's "before further flight" requirement operates as an immediate operational constraint where a discrepancy appears.

The AD text itself does not set out monetary penalties, criminal sanctions, or an explicit enforcement mechanism within the document. What the AD does include is an effective date and mandatory compliance timings that create legal obligations for operators in the jurisdiction where the directive is issued. The relevant facts from the text are as follows.

• Effective date: "This Airworthiness Directive becomes effective on 21 December 2006." The AD was signed by the CASA delegate on 9 November 2006 (signature block). An effective date creates a temporal trigger for compliance obligations such as the 900-hour testing window.

• Mandatory nature: The AD uses mandatory language ("Perform an operational test", "apply the corrective actions", "Install a modified BCM") and prescribes specific compliance windows ("within 900 hours TIS", "before further flight", "no later than 31 December 2008"). That mandatory phrasing establishes obligations.

• No penalties stated in the text: The AD does not itself state what penalties or enforcement actions will follow for non-compliance. There is no section within the AD that specifies fines, licence suspensions, or civil/criminal sanctions; nor does the AD specify an enforcement authority beyond the issuance by the Civil Aviation Safety Authority and signature by the CASA delegate.

• Implicit consequences through airworthiness: The AD’s requirements are framed as airworthiness actions. In aviation regulatory practice, an AD is a legally enforceable instrument that affects an aircraft's continuing airworthiness. The AD’s "before further flight" requirement creates immediate operational constraints; carriage of an aircraft that has not complied with an AD may render that aircraft non-compliant with airworthiness regulations. However, the AD text itself does not articulate those downstream regulatory consequences or specify enforcement procedures.

• Reference to other regulatory material: The AD notes "EASA AD 2006-0313 refers." That cross-reference may indicate a corresponding European Aviation Safety Agency directive that contains parallel or related obligations; the AD does not restate enforcement provisions from that referenced document.

Practical enforcement implications derived from the text

• Regulatory enforcement of the AD’s requirements would follow from the issuing authority’s normal regulatory powers (not spelled out in the AD). The AD’s language creates conditions under which aircraft must be taken out of service for corrective actions (when discrepancies are found) and imposes a retrofit deadline, which may be enforced through the issuing authority’s airworthiness certification, surveillance, and oversight functions.

• Because the AD requires specific maintenance actions to be performed in accordance with Airbus SBs, non-compliance can normally be identified during regulatory audits or airworthiness inspections by examining maintenance records for evidence of the BITE tests, corrective actions, and BCM installations.

Summary statement

The directive establishes clear, mandatory maintenance and retrofit duties with precise timings, but it does not itself include express penalty clauses or an enforcement mechanism in its text. Enforcement will therefore depend on the issuing authority’s statutory powers and airworthiness oversight processes, which are not set out in the AD itself. The AD does, however, impose operational constraints that directly affect flight release decisions when discrepancies are discovered.

The AD references and integrates with certain external regulatory and manufacturer-issued instruments, and it sets explicit relationships that affect how it is applied. The source text contains the following interaction points.

• Relation to Airbus Service Bulletins: Compliance is defined in terms of Airbus SBs. The operational test and associated corrective actions are to be carried out "in accordance with Airbus SB A330-27-3147 dated 4 August 2006" (Requirement 1 and Requirement 2). The modified BCM installation is to be carried out "in accordance with instructions SB A330-27-3142" (Requirement 3). The AD therefore delegates substantive technical compliance pathways to manufacturer SBs, and permits later approved revisions of those SBs as compliance alternatives ("Later approved revisions of the above service bulletins may be utilised to achieve compliance with the relevant Requirements of this Directive."). This creates an interaction where the AD establishes the legal obligation but the detailed technical method and potential updates are derived from manufacturer documentation, subject to approval.

• Cross-reference to EASA AD 2006-0313: The AD includes a note stating "EASA AD 2006-0313 refers." That indicates the directive is cognisant of, and linked to, an EASA airworthiness directive addressing the same or similar issue. The AD does not reproduce EASA’s text or enforcement terms, but the reference signals that operators and maintenance organisations should consult the EASA AD for related guidance and possibly for harmonised technical instructions.

• Applicability carve-outs based on other Airbus modifications/SBs: The AD excludes aircraft on which Airbus Modification 55185 has been embodied during production, or Airbus SB A330-27-3142 has been embodied whilst in service. This creates an interaction in which prior manufacturer modifications or SB embodiments determine whether the AD applies to a given airframe. Therefore, the legal applicability of the AD depends on the aircraft’s modification and service bulletin embodiment history.

• Deference to airworthiness authority process: Although the AD does not itself set out enforcement mechanisms or broader regulatory obligations, it is issued by the Civil Aviation Safety Authority and signed by a CASA delegate. The AD thereby sits within the statutory airworthiness regime administered by CASA; compliance will be enforced pursuant to CASA’s regulatory powers and airworthiness oversight, though those powers are not described in the AD.

• Interaction with operational release-to-service practices: The "before further flight" requirement interacts with standard operational and maintenance rules about releasing aircraft to service. While the AD does not stipulate specific release-to-service paperwork, its mandatory corrective-action-before-flight requirement will intersect with operators’ operational control, flight release, and maintenance release procedures.

• Effect on parts procurement and traceability: By identifying the resistor manufacturer (SRT) as associated with the defect and VISHAY as the manufacturer of the resistors used in the terminating BCMs, the AD creates an implicit link between component traceability records and AD applicability. Operators will need to track component provenance to know whether their BCMs incorporate SRT resistors (and thereby fall within the AD’s rationale) or VISHAY resistors (the terminating solution). The AD does not create new statutory parts-traceability obligations on its face, but it makes traceability practically necessary for determining applicability.

In summary, the AD interacts with manufacturer service bulletins and an EASA AD, uses prior modifications and SB embodiments as applicability gates, and relies on existing airworthiness oversight mechanisms for enforcement. The AD establishes legal duties while delegating technical execution and later updates to Airbus SBs and referencing the corresponding EASA instrument.

The AD text supplied contains a limited chronology and explicit statements about revisions but does not record any subsequent amendments to itself. The relevant facts in the text are:

• Issuance and signature: The directive text is signed by James Coyne, Delegate of the Civil Aviation Safety Authority, on 9 November 2006 (signature block).

• Effective date: The AD states "This Airworthiness Directive becomes effective on 21 December 2006." That is the operative commencement date provided within the document.

• Permitted use of later service bulletin revisions: The AD expressly allows "Later approved revisions of the above service bulletins may be utilised to achieve compliance with the relevant Requirements of this Directive." That language provides internal flexibility for compliance without requiring an amendment to the AD itself, so long as subsequent SB revisions are "approved" for use in the relevant jurisdiction.

• References to specific SB dates: The AD identifies the Airbus SBs and their dates as the methods of compliance: SB A330-27-3147 dated 4 August 2006 and SB A330-27-3142 dated 17 August 2006. Those dates anchor the technical baseline at the time of issuance.

What the AD does not record

• The supplied text does not contain any amendment logs, no later AD revision numbers, and no rescission date. It does not state whether the AD was superseded or amended after the effective date. There is no explicit retrospective amendment history within the document.

• There is no record in the text of approval dates for any "later approved revisions" of the referenced SBs, nor is there a record of which later revisions were approved. The AD leaves those matters to the approving authority or to subsequent public notices.

Practical implications of the AD’s amendment language

• Operators and their compliance teams should note that while the AD allows later approved SB revisions as compliance tools, the AD itself remains pinned to the effective date and the retrofit deadline (31 December 2008) unless formally amended or superseded. The AD text provides no indication that it has been amended, so in the absence of a subsequent instrument, the explicit dates and requirements remain binding.

• Because the AD delegates the technical steps to Airbus SBs and allows later approved revisions, an operator relying on a later SB revision should ensure that the revision is in fact "approved" for compliance with the AD, and should retain evidence of that approval as part of the compliance record.

Summary

The AD provides an issuance date, an effective date, and an express allowance for later approved SB revisions but contains no internal amendment record or subsequent versioning information. The AD’s amendment history, beyond its initial issuance and the practical allowance for later SB revisions, is not documented in the supplied text.

The supplied AD text contains no references to litigation, court decisions, administrative appeals, or dispute resolution arising from this directive. The document does not cite any judicial or tribunal cases, nor does it indicate that the AD has been the subject of legal challenge. The only external reference provided is to a corresponding EASA AD ("EASA AD 2006-0313 refers."), which is a regulatory cross-reference, not a litigation record.

What the absence of litigation references in the text means for practitioners

• There is no litigation history recorded in this AD to inform legal strategies, compliance disputes, or precedent. Any questions about the legal enforceability, interpretation of "before further flight", or interplay with other statutory obligations would need to be addressed through standard administrative or judicial processes in the usual way, but the AD itself contains no report of past litigation.

• If a party seeks to challenge an obligation imposed by the AD, the appropriate judicial or administrative record would be located outside this document. Practitioners should not infer from the absence of litigation references that challenges are impossible or have not occurred; the AD simply does not record any history of litigation.

• Because the AD allows later approved SB revisions as means of compliance, disputes could arise in practice about whether a particular SB revision is "approved" for AD compliance, whether corrective actions specified in the SB sufficiently address identified discrepancies, or about the interpretation of applicability exceptions. None of these potential disputes is documented in the AD text supplied.

In short, the AD contains no litigation history; practitioners requiring information on legal challenges or precedent will need to consult court records, administrative decisions, or subsequent regulatory notices outside the AD text provided.

The AD contains several operationally significant details and potential traps for the unwary. These are factual points derived directly from the AD text that can cause non-compliance or operational disruption if overlooked.

• Narrow applicability carve-outs: The AD applies to A330 aircraft with Airbus Modification 49144 embodied during production, but it expressly excludes aircraft on which Airbus Modification 55185 has been embodied during production or on which SB A330-27-3142 has been embodied whilst in service (Applicability). Practitioners must check both production modification status and in-service SB embodiment history. An operator who only checks one dimension (for example, production mods) but not service bulletin embodiment whilst in service could misclassify applicability.

• Component provenance matters: The Background describes the root cause as resistors manufactured by SRT that are prone to humidity absorption and oxidation. The terminating action is installation of BCMs fitted with resistors manufactured by VISHAY. Determining whether a given BCM contains SRT resistors will require component traceability. Lack of clear parts-traceability records could make it difficult to know whether tests and retrofits are required for a particular aircraft, potentially leading to either unnecessary work or missed obligations.

• Repetitive testing until retrofit: The BITE test must be performed within 900 hours TIS after the AD’s effective date and thereafter at intervals not exceeding 900 hours until the BCM is replaced in accordance with SB A330-27-3142 (Compliance for Requirement 1). That creates an ongoing maintenance scheduling obligation and recurring cost until the retrofit is completed. Operators who delay the retrofit face a continuing compliance burden.

• Immediate grounding risk: Requirement 2 requires application of corrective actions "before further flight" if the test detects any discrepancies. That can impose immediate out-of-service time and require either parts availability and maintenance resources or lead to flight cancellations if corrective actions are extensive or parts are not on hand.

• Deadline for terminating action: Installation of the modified BCM must be accomplished "No later than 31 December 2008" (Compliance for Requirement 3). Missing that deadline could leave the operator with an ongoing testing obligation and potentially regulatory exposure. The AD does not contain an extension mechanism in the text; any departure from the deadline would require separate approval not described in the AD.

• Reliance on Airbus SBs and approvals: The AD requires compliance with named Airbus SBs and allows later approved revisions. If an operator intends to use a later revision, they must ensure it is approved for use to comply with the AD. The AD does not specify who grants that approval or the administrative pathway; practical approval is likely to involve the relevant aviation authority or designated entity, but the AD text does not specify the mechanism.

• Cross-jurisdictional considerations: The AD states "EASA AD 2006-0313 refers." For operators outside the issuing jurisdiction or operating across jurisdictions, there may be parallel or differing ADs and approval paths. The AD does not reconcile cross-border differences, so operators engaged in multi-jurisdiction operations must ensure compliance with each applicable authority’s directives.

• Records and evidence: The AD does not set out explicit record-keeping instructions within the text, but compliance necessarily requires documentation of BITE tests, corrective actions, and BCM installations. Failure to maintain clear, auditable records could lead to enforcement risk during oversight or inspection, even though the AD does not itself specify paperwork requirements.

• Timing anomalies in the document: The AD is signed on 9 November 2006 but becomes effective on 21 December 2006. Practitioners should not assume the signature date equals the effective date; compliance windows (e.g., perform the first BITE within 900 hours TIS after effective date) are measured from the effective date specified in the AD.

These "gotchas" are concrete mechanics derived from the AD text: applicability nuance, component provenance, recurring obligations until retrofit, immediate corrective-action-before-flight requirements, a firm retrofit deadline, reliance on SB approvals, cross-jurisdictional references, and record-keeping practicalities. Each of these can create operational friction or non-compliance risk if not managed.

The AD prescribes the technical steps and timing for compliance. The following checklist-style guidance restates those steps and highlights practical compliance tasks directly supported by the AD text.

1. Determine applicability precisely

   • Confirm whether each A330 airframe in the fleet had Airbus Modification 49144 (install rudder fly by wire) embodied during production (Applicability).
   • Confirm that the airframe has not had Airbus Modification 55185 embodied during production and has not had Airbus SB A330-27-3142 embodied while in service. If either of those exceptions applies, the AD does not apply to that airframe (Applicability).

2. Schedule the initial BITE operational test

   • Arrange to perform the BITE operational test of the BCM and BPS in accordance with Airbus SB A330-27-3147 dated 4 August 2006 (Requirement 1).
   • Ensure the first test is completed within 900 hours time in service after the AD's effective date of 21 December 2006; thereafter schedule repeat BITE tests at intervals not exceeding 900 hours time in service until the BCM is replaced in accordance with SB A330-27-3142 (Compliance for Requirement 1).

3. Prepare for corrective action and grounding risk

   • Ensure maintenance personnel are briefed that if the BITE test reveals any discrepancies, corrective actions specified in SB A330-27-3147 must be applied before further flight (Requirement 2; Compliance for Requirement 2).
   • Confirm parts availability, tooling and personnel resources to implement SB-prescribed corrective actions immediately if a discrepancy is found, to avoid prolonged grounding.

4. Plan and execute the terminating retrofit

   • Schedule installation of the modified BCM in accordance with SB A330-27-3142 (Requirement 3). The AD requires this by "No later than 31 December 2008" (Compliance for Requirement 3).
   • Coordinate procurement to ensure the BCMs installed are the modified units fitted with resistors manufactured by VISHAY, which the AD’s Background identifies as the terminating solution.

5. Use approved SB revisions where appropriate

   • The AD allows later approved revisions of the referenced Airbus SBs to be used to achieve compliance. If relying on a later revision, obtain written evidence that the revision is approved for compliance with this AD and retain that approval documentation with maintenance records. The AD does not describe the approval pathway; confirm approval status with the regulator or authorised representative (Requirement text).

6. Maintain records

   • Document each BITE test, including date, time in service at test, test results, and any corrective actions undertaken in accordance with SB A330-27-3147. Document the installation of the modified BCM in accordance with SB A330-27-3142.
   • Retain records sufficient to demonstrate compliance with the AD, including any approvals for use of later SB revisions and parts provenance demonstrating resistor manufacturer where relevant.

7. Trace parts provenance

   • Verify the manufacturer of resistors installed in existing BCMs when feasible. The AD’s Background links the issue to resistors manufactured by SRT and identifies the terminating BCM solution as those fitted with resistors manufactured by VISHAY. Component traceability will assist in applicability assessment and in planning the retrofit.

8. Coordinate with oversight authorities

   • Inform the appropriate civil aviation authority or delegated approval holder if there is any uncertainty about the applicability, the approval status of SB revisions, or if an operator needs relief from the AD’s timing requirements. While the AD text does not specify relief mechanisms, approvals for alternative means of compliance or extensions may be required to be sought through the regulator.

9. Operational planning

   • Incorporate the 900-hour test intervals and the retrofit deadline into maintenance planning, spares inventory planning, and flight scheduling to minimise operational disruption. Plan to avoid clustering BCM retrofit on multiple fleet aircraft simultaneously unless spares are sufficient.

10. Cross-reference EASA material

• Consult EASA AD 2006-0313, which the AD references, for harmonised or related technical guidance. The AD’s note indicates EASA has issued a related AD, which may have additional technical detail useful for compliance planning.

This compliance pathway follows the AD’s structure: test, correct if necessary, and retrofit by the deadline. The operator’s compliance responsibilities are procedural and time-limited by the retrofit deadline, but the recurring nature of the test until retrofit means practitioners should prioritise timely procurement and installation of the modified BCMs to stop the recurring compliance burden.