AD/A330/30 Amdt 4 - Argo-Tech/Intertechnique Vent Float Valves

Trim Tank Vent Float Valve (TTVFV). This is a component of the aircraft’s fuel system, mounted in the trim tank (the horizontal stabiliser’s fuel tank used to adjust the aircraft’s centre of gravity). The valve vents the tank to the atmosphere while preventing fuel spillage. Its failure, particularly the detachment of internal parts, creates risks of spark ignition sources or structural overload. The directive addresses two specific TTVFV models: Argo‑Tech PN 61600 (RH position) and Intertechnique PN L87‑13‑001 (LH position).

Borescope inspection. This is a non‑destructive inspection technique using a flexible or rigid optical device inserted into the valve assembly to visually examine internal condition without disassembly. The directive requires a “detailed visual borescope inspection” referencing specific Airbus Service Bulletins. The detail level implies the inspector must be trained and equipped to detect small cracks, loose fasteners, corrosion, or displaced components.

DGAC approved revisions. The DGAC (Direction Générale de l’Aviation Civile of France) is the primary airworthiness authority for Airbus. The directive permits later DGAC‑approved revisions of the referenced service bulletins, meaning operators must monitor for superseding bulletins and ensure compliance with the latest approved revision. This creates a rolling compliance obligation separate from the publication date of the directive.

Terminating action. A maintenance action that, once accomplished, cancels all repetitive inspection and replacement requirements. In this directive, terminating action consists of replacing the TTVFVs with new‑design part numbers per the specified service bulletins. After terminating action, no further borescope inspections are required for those valves. However, the new‑design valves are not interchangeable between A330 and A340, so operators must ensure correct part numbering.

Compliance times based on flight hours and flight cycles. The directive uses two time metrics: flight hours (total operating time) and flight cycles (one takeoff and landing). The compliance interval is “whichever occurs first”, meaning the more restrictive trigger governs. For example, for a valve never replaced since entry into service: inspect within 7,500 flight hours after the valve reaches 15,000 flight hours or 2,500 flight cycles, whichever occurs first. This dual metric accounts for both operational wear (hours) and pressurisation cycle fatigue (cycles).

Repetitive inspection vs. one‑time replacement. The directive establishes a hierarchy: if the operator chooses to replace a valve with the same original part number (PN 61600 or PN L87‑13‑001), that replacement does not cancel inspections; it resets the compliance clock, but a further borescope inspection is required within 15,000 flight hours or 2,500 flight cycles from the installation date. Only replacement with the new part numbers (PN 62015‑1, PN L87‑13‑002, or PN L87‑13‑003) constitutes terminating action.

Discarding requirement. Valves removed during replacement must be physically discarded, not returned to service or placed in spares inventory. This prevents inadvertently re‑installing a removed valve on another aircraft, and ensures that only new‑design valves are in service after terminating action.

Interchangeability restrictions. The directive explicitly states that the new part numbers installed on the A340 are not interchangeable with the same numbers installed on the A330, and vice versa. This is a common trap: the same PN may have subtle differences in materials, tolerances, or installation instructions that make cross‑use unsafe without additional engineering approval.

The directive applies to operators, owners, and maintenance organisations responsible for Airbus A330 aircraft models -201, -202, -203, -223, -243, -301, -302, -303, -321, -322, -323, -341, -342, and -343. The applicability is narrowed by production and in‑service modifications: aircraft that already incorporate Airbus modification 51953 and either modification 52110 or 53081 in production, or that have incorporated Airbus Service Bulletin A330‑28‑3088 Rev 1 and either A330‑28‑3089 Rev 2 or A330‑28‑3094 in service, are excluded. Therefore, newer aircraft delivered with those modifications, or earlier aircraft that have already completed the terminating action, are not subject to the directive. Conversely, any A330 within the model range that has not yet had the terminating action installed remains within scope until it does. This makes the directive a moving target for fleet managers, who must track modification status for each tail number.

The directive also affects manufacturers and suppliers. Airbus (as the type certificate holder) and DGAC (as the airworthiness authority) are indirectly involved through the service bulletins and their approvals. Maintenance repair and overhaul (MRO) organisations that perform the borescope inspections or valve replacements must have the necessary tooling, training, and parts procurement capabilities. The directive creates a mandatory demand for the new‑design valves (PN 62015‑1 for RH, PN L87‑13‑002 or PN L87‑13‑003 for LH), which affects supply chain planning for airlines and parts distributors. The lack of interchangeability between A330 and A340 adds a logistical burden, because receiving the wrong part number could ground an aircraft pending replacement.

A smaller population of affected entities includes lessors and financiers of aircraft, because the directive creates a cost and scheduling risk that may be passed through lease agreements. An operator that fails to comply risks the aircraft being non‑airworthy, which may trigger defaults under loan or lease covenants. The directive also affects training organisations, as engineers and inspectors must be trained on the specific borescope technique and the service bulletin procedures.

Finally, the directive indirectly affects passengers and the public, because its purpose is to prevent a catastrophic failure that could lead to loss of the aircraft. The social cost of non‑compliance is potentially very high, but the compliance cost is borne entirely by operators and, ultimately, consumers via ticket prices or government subsidies.

Duty to inspect. Operators must perform a detailed visual borescope inspection of the LH and RH trim tank vent float valves within the specified compliance times. The inspection must be done in accordance with Airbus SB A330‑28‑3086 Rev 1 (RH) and SB A330‑28‑3087 Rev 1 (LH), or later DGAC‑approved revisions. This duty arises regardless of whether a defect is suspected. For valves never replaced since entry into service, the trigger is when the valve accumulates 15,000 flight hours or 2,500 flight cycles, whichever occurs first, and the inspection must be performed within 7,500 additional flight hours. For valves that have been replaced in service, the inspection must be conducted within 15,000 flight hours or 2,500 flight cycles from the installation date of the replacement valve.

Duty to rectify defects. If any defects are found during the borescope inspection, the operator must rectify them using the same service bulletins. The directive does not define what constitutes a defect, so operators must rely on the guidance in the service bulletins, typically including cracks, corrosion, loose fasteners, missing parts, or obvious damage.

Duty to replace valves. Operators must replace the TTVFVs with new units within the stated time limits. For the RH valve, replacement must be with Argo‑Tech PN 61600 (if keeping the original design) or with a new‑design valve per SB A330‑28‑3088 Rev 1. For the LH valve, replacement must be with Intertechnique PN L87‑13‑001 (original design) or with a new‑design valve per SB A330‑28‑3089 Rev 2 or SB A330‑28‑3094. The replacement must be accomplished no later than 10,000 flight hours or 1,500 flight cycles after the last borescope inspection under Requirement 1.

Duty to perform further inspections after replacement with original PNs. Where an operator chooses to replace a valve with the same original part number (PN 61600 or PN L87‑13‑001), that does not end the inspection cycle. The directive requires a detailed visual borescope inspection of that valve within 15,000 flight hours or 2,500 flight cycles from the installation date. This effectively imposes a repetitive inspection regime for any aircraft that has not yet received the terminating action.

Duty to accomplish terminating action. By 31 March 2009 at the latest, operators must replace the RH valve with the new part number per SB A330‑28‑3088 Rev 1 and the LH valve with the new part number per SB A330‑28‑3089 Rev 2 or SB A330‑28‑3094, unless already done earlier.

Duty to discard removed valves. Any Argo‑Tech PN 61600 or Intertechnique PN L87‑13‑001 valve removed from an aircraft must be discarded. This means physically destroying the valve or otherwise rendering it unusable, and removing it from the spares pool.

Right to use later DGAC‑approved revisions. Operators may use service bulletins that are later revisions than those listed in the directive, provided they are DGAC‑approved. This allows compliance with updated procedures without requiring a formal amendment of the directive itself.

Right to terminate. Once the terminating action is accomplished (the new‑design valves installed), all prior requirements of the directive are cancelled. The aircraft no longer needs repetitive inspections for these valves. However, the operator must ensure the correct part numbers are used (the interchangeability note is a caveat).

Right to rely on EASA approval. The note references DGAC AD F‑2005‑004 and EASA approval No. 2005‑3642. This indicates that compliance with the underlying European airworthiness directive is considered equivalent to compliance with the Australian AD, for aircraft that operate under a bilateral agreement or are imported/exported.

Burden of recordkeeping. Although not explicit, operators must maintain records of inspections, repairs, replacements, and discarding activities to demonstrate compliance. The compliance times are based on flight hours and cycles, so accurate flight and cycle counting systems are required.

The directive itself does not specify monetary penalties or criminal sanctions, because it is an airworthiness directive issued under the Civil Aviation Act 1988 (Cth) and the Civil Aviation Safety Regulations 1998 (CASR). Enforcement mechanisms are found in those primary instruments. Under s 20A of the Civil Aviation Act, the holder of an air operator’s certificate or a maintenance organisation exposition must comply with all applicable airworthiness directives. Non‑compliance can result in the suspension or cancellation of the certificate. The Civil Aviation Safety Authority (CASA) can also issue a direction under s 20AB requiring immediate compliance, and failure to comply with such a direction is an offence punishable by a penalty of up to 50 penalty units (as at 2005, approximately $5,500) per day of continuing non‑compliance. If an aircraft is operated while non‑compliant with an AD, the aircraft may be considered unairworthy, and operation of an unairworthy aircraft is an offence under s 20A(3) with a maximum penalty of 200 penalty units (approximately $22,000 at 2005 values) for an individual, or 1,000 penalty units ($110,000) for a body corporate.

Beyond financial penalties, the practical consequence is grounding. The aircraft cannot be lawfully flown until the directive is complied with. For an airline, the cost of grounding a single aircraft can run into hundreds of thousands of dollars per day in lost revenue, plus recovery costs. This economic compulsion is typically far more potent than the statutory penalties. Additionally, CASA may refuse to renew or may vary the airworthiness certificate, and may require a special inspection before release to service.

The enforcement risk is heightened because the directive is derived from a European airworthiness directive (DGAC AD F‑2005‑004) with EASA approval. Australia is a member of the International Civil Aviation Organization (ICAO) and has bilateral agreements with the European Union. If CASA discovers non‑compliance, it will likely coordinate with the aircraft’s State of Registry or the operator's flag authority. Given that this directive applies to A330 aircraft that are widely operated by international airlines, the risk of detection during maintenance audits, ramp checks, or registry transfers is material.

The directive also has a cascading enforcement effect: if a maintenance organisation releases an aircraft to service without properly recording TTVFV compliance, the organisation may be liable for a maintenance error under CASR Part 145, and the person who certified the release (the certifying engineer) may face individual liability under s 20A(4). In cases of suspected intentional non‑compliance, CASA may refer the matter to the Commonwealth Director of Public Prosecutions for criminal proceedings.

It is worth emphasising that the directive’s terminating action (replacing with new‑design valves) is a one‑time event. After that, the AD is wholly satisfied and does not recur. Operators who delay compliance only accumulate exposure. The 31 March 2009 hard deadline for terminating action means that after that date, any aircraft not complying is automatically in breach and subject to enforcement action regardless of inspection history.

The directive sits within a hierarchy of airworthiness regulations. The primary enabling law is the Civil Aviation Act 1988, which gives CASA power to issue airworthiness directives. The directives are legislative instruments under the Legislation Act 2003. Section 20A of the Civil Aviation Act provides that each AD must be complied with by the operator (or the owner in certain cases). The Civil Aviation Safety Regulations 1998 (CASR) prescribe the procedural framework: Part 21 deals with type certification and airworthiness directives; Part 39 (now Part 39A) specifically governs ADs. Under CASR 39.009, the operator of an Australian‑registered aircraft must ensure that each AD applicable to the aircraft is complied with. A failure to do so is a breach of the certificate of airworthiness conditions.

The directive also interacts with maintenance regulations under CASR Part 42 (continuing airworthiness) and Part 145 (maintenance organisations). The borescope inspection and valve replacement constitute maintenance tasks that must be performed by an appropriately authorised organisation or person. The service bulletins incorporated by reference become legally binding maintenance instructions. If a later DGAC‑approved revision changes the inspection method or the replacement part, that revision supersedes the version listed in the directive, but only if it is actually DGAC‑approved. Operators must therefore monitor DGAC and EASA regulatory databases to ensure they are using the correct revision.

The directive references DGAC AD F‑2005‑004 and EASA approval No. 2005‑3642. This acknowledges the European airworthiness action as the root source. Under the bilateral aviation safety agreement between Australia and the European Union, CASA accepts DGAC directives as equivalent, subject to Australian adoption. However, the Australian AD remains the domestic legal instrument. An operator in Australia cannot simply comply with the French AD and ignore the Australian AD; the Australian AD must be complied with, though the technical content is identical. For non‑Australian aircraft operated into Australia by foreign operators, they must comply with their own registry’s airworthiness directives. CASA may accept compliance with the EASA AD as sufficient for overflight or landing rights, but the Australian AD applies primarily to Australian‑registered aircraft and to foreign aircraft operating under an Australian air operator’s certificate.

The directive interacts with leasing laws through contract provisions. A lease may require the lessee to comply with all applicable ADs. If the lessee fails to perform the terminating action by 31 March 2009, the lessor could declare a default and repossess the aircraft. Similarly, insurance policies typically exclude coverage for losses arising from non‑compliance with mandatory airworthiness directives. An operator that flies a non‑compliant aircraft risks having insurance claims denied in the event of an accident.

Finally, the directive interacts with trade practices law indirectly. If a part distributor sells a removed Argo‑Tech PN 61600 or Intertechnique PN L87‑13‑001 valve without disclosing that it must be discarded under the AD, the distributor may face liability for misleading conduct under the Competition and Consumer Act 2010. The directive’s explicit discarding requirement creates a positive duty to destroy, and any secondary sale of such a valve would be illegal.

The directive’s preamble provides a full amendment history. The original issue of AD/A330/30 became effective on 15 April 2004. It required repetitive inspections and correction of defects found during those inspections. No terminating action was included in the original issue. Amendment 1 became effective on 13 May 2004 and clarified the compliance time for Requirement 2 (rectification of defects). The original language apparently created ambiguity about when the rectification must occur relative to the inspection. Amendment 2 became effective on 14 April 2005 and mandated the modification (the terminating action) for the vent float valves, and extended the applicability to two new A330 models (likely -223 and -243, which are derivatives of the -200 series). Amendment 3 became effective on 7 July 2005 and introduced a new part number for the LH trim tank vent float valve as an additional replacement option. This suggests that the manufacturer (Intertechnique) had developed an alternative valve design (PN L87‑13‑002 or PN L87‑13‑003) and Airbus issued a new service bulletin (A330‑28‑3094) to provide that option. Amendment 4, the current version, became effective on 24 November 2005 and clarifies that the inspection requirements under Requirement 4 apply only to the original part number valves (PN 61600 and PN L87‑13‑001), not to the new design valves. The amendment also incorporates minor word changes and updates the references.

The history reveals that CASA was actively responsive to manufacturer developments, updating the directive within months of each Airbus SB revision. The two‑year progression from a purely inspection regime (April 2004) to a mandated modification with a hard deadline (November 2005, with compliance by March 2009) reflects a typical airworthiness pattern: initial inspection to gather fleet data, then determination that the risk could not be managed by inspection alone, leading to a mandatory design change. The 31 March 2009 deadline allowed operators approximately 3 years and 4 months to schedule the terminating action, which is reasonable for a fleet‑wide modification given the lead time for parts, heavy maintenance checks, and cost spreading. The directive does not provide for alternative means of compliance or extensions, so the deadline is absolute.

From a compliance perspective, the amendment history means that an operator who fell out of the loop at any point must ensure they are applying the latest version. For example, an operator who complied with Amendment 2 by installing a new‑design valve might not have met the clarification introduced in Amendment 4 about the scope of Requirement 4. In practice, the amendments are cumulative, and the current version (Amdt 4) replaces all prior versions. Any work performed under an earlier amendment would still be valid if it meets the requirements of the current amendment, but a careful auditor would check.

The directive text does not mention any litigation, and no Australian case law directly concerning AD/A330/30 or its prior amendments appears in publicly accessible records. This is unsurprising for an airworthiness directive, which is typically complied with as a matter of regulatory necessity rather than challenged in court. The costs of litigating a few thousand dollars in penalties against the risk of grounding and reputational damage are prohibitive. It is possible that a dispute arose between an operator and a maintenance organisation over liability for a defective inspection or installation, but if so it would be a contract or tort case not directly challenging the validity of the AD.

The directive’s reference to DGAC AD and EASA approval means that any legal challenge would more likely occur in the European frame, where the underlying technical data was developed. However, even in Europe airworthiness directives are rarely litigated except on procedural grounds (e.g., failure to consult, improper delegation). The A330 fleet has been in service since the 1990s, and no catastrophic event attributable to TTVFV failure is publicly known, so the directive is likely a product of proactive safety analysis rather than a reaction to an accident. There are no Australian Federal Court or Administrative Appeals Tribunal decisions on this directive.

For a lawyer advising a client on this directive, the absence of litigation history means there is no judicial interpretation of ambiguous terms, such as “detailed visual borescope inspection” or “defects found.” The meaning of those terms is governed by the service bulletins and accepted industry practice. If a dispute arises, a tribunal would rely on expert evidence from aviation maintenance engineers. The directive itself is a legislative instrument and is subject to judicial review under the Administrative Decisions (Judicial Review) Act 1977, but the scope for review is narrow: an applicant would need to show that CASA acted beyond power, took an irrelevant consideration into account, or made an error of law. Given the directive is based on DGAC/EASA analysis and multiple amendments, a challenge on the merits would likely fail.

The practical implication is that operators should treat the directive as a strict liability requirement. No defence of reasonable mistake or due diligence is available; either the aircraft is in compliance or it is not. The only flexibility is in the means of compliance (e.g., which approved revision of the service bulletin to use) and the scheduling within the allowed intervals. A missed deadline is a breach, regardless of the reason.

Several traps are embedded in the directive that could lead to inadvertent non‑compliance. The first is the interplay between compliance times. For a valve that has been replaced in service, the inspection must be performed within 15,000 flight hours or 2,500 flight cycles from installation, whichever occurs first. But if that valve was replaced as a result of a defect found during a previous inspection, the operator might mistakenly believe that the replacement reset the clock to zero for a new repetitive cycle. The directive, however, treats replacement with the same PN as merely starting a new inspection interval rather than cancelling the need for inspection. This is counterintuitive: most maintenance actions on critical components are either “on‑condition” (inspect at intervals) or “hard‑time” (replace at intervals), but the directive imposes both inspection and replacement sequentially for the same component. Operators who only replace without inspecting, or who inspect but do not replace within the required interval after inspection, will be non‑compliant.

The second trap is the discarding requirement. Removed PN 61600 and PN L87‑13‑001 valves must be discarded, not returned to stores. If a maintenance organisation inadvertently places a removed valve in inventory and later installs it on another aircraft, that aircraft will be non‑compliant unless the valve is a new‑design PN. The directive does not require a unique identification method, so good traceability is essential. A simple “removed due to AD” tag might not be sufficient if the part is later mistaken for a new part.

The third trap is the interchangeability note. The new part numbers on the A330 (PN 62015‑1 for Argo‑Tech; PN L87‑13‑002 or PN L87‑13‑003 for Intertechnique) are exactly the same part numbers used on A340 aircraft, but the directive explicitly states they are not interchangeable. This means an operator with both A330 and A340 fleets must ensure that parts are segregated and not cross‑used. A parts‑room clerk or a maintenance engineer might assume that a PN 62015‑1 is universal and install it on the wrong type, causing a serious airworthiness issue. The directive provides no engineering rationale for the non‑interchangeability, so reliance on memory or assumption is dangerous.

The fourth trap is the “whichever occurs first” rule for flight hours and cycles. An operator that tracks only flight hours and ignores cycles could miss the earlier cycle limit. For short‑haul operators that perform many cycles per flight hour, the cycle limit will bite first. For long‑haul operators, the flight hour limit will likely govern. Failure to monitor both metrics is a common cause of AD non‑compliance.

The fifth trap is the reference to DGAC‑approved revisions. The directive says operators may use later DGAC‑approved revisions of the service bulletins, but it does not say that using an earlier revision after a later one is issued is acceptable. Industry practice is that once a revision is approved, the earlier revision becomes obsolete and its use may be non‑compliant. Operators must therefore establish a system to track SB revisions and ensure their procedures reference the current approved revision. This is especially tricky for sub‑contractors who may still hold old revision data.

The sixth trap is the hard deadline for terminating action: 31 March 2009. This date is independent of flight hours or cycles. An operator could have a very low‑utilisation aircraft that has not accumulated enough hours to trigger the earlier inspection requirements, but still must accomplish terminating action by that calendar date. If the aircraft is stored or in heavy maintenance on 31 March 2009, the operator must still perform the modification before that date or face non‑compliance. There are no provisions for extensions.

The seventh trap involves aircraft that have been modified in production with the terminating modifications (51953 and 52110 or 53081). Those aircraft are excluded from the directive. But if a production‑line aircraft has only a partial modification (e.g., incorporated 51953 but not 52110), it remains subject. Similarly, an aircraft that had the terminating action installed in service via SB A330‑28‑3088 Rev 1 and A330‑28‑3089 Rev 2 is excluded only if both SBs were accomplished. A one‑side modification does not exempt the aircraft.

Compliance with AD/A330/30 Amdt 4 requires a systematic approach. Step one: determine applicability. For each aircraft in the fleet, verify the model number and the incorporation status of modifications 51953, 52110, and 53081, and whether service bulletins A330‑28‑3088 Rev 1 and A330‑28‑3089 Rev 2 or A330‑28‑3094 have already been embodied. If any aircraft is excluded (i.e., has both the production modifications or the terminating SBs), no further action is needed, but keep records of the exclusion basis.

Step two: for aircraft that are applicable, determine the compliance status of each TTVFV (RH and LH). Record the part number installed (PN 61600 or PN L87‑13‑001) and its installation date, as well as whether it is the original valve since entry into service or a replacement. Obtain the flight hours and flight cycles accumulated since installation. For original valves, note the hours and cycles at which the valve reached 15,000 hours or 2,500 cycles.

Step three: schedule a detailed visual borescope inspection for both valves at the required interval. This requires access to the service bulletins (SB A330‑28‑3086 Rev 1 for RH, SB A330‑28‑3087 Rev 1 for LH, or later DGAC‑approved revisions). The inspection must be performed by appropriately qualified personnel using the required borescope equipment. Document the inspection findings.

Step four: if any defects are found, rectify them immediately using the same SBs. This may involve repairing the valve or replacing it. If replacement is done using a new unit of the same PN (61600 or L87‑13‑001), note that this triggers a new inspection interval under Requirement 4. If replacement is done using the new‑design PN, that counts toward terminating action.

Step five: replace the valves with new‑design PNs (Argo‑Tech PN 62015‑1 for RH; Intertechnique PN L87‑13‑002 or PN L87‑13‑003 for LH) no later than 10,000 flight hours or 1,500 flight cycles after the last borescope inspection under Requirement 1, and in any case by 31 March 2009. This can be done at the same time as the inspection to save labour costs, but the compliance intervals must be satisfied. For the terminating action to be effective, the RH valve must be replaced per SB A330‑28‑3088 Rev 1 and the LH valve per SB A330‑28‑3089 Rev 2 or SB A330‑28‑3094.

Step six: discard all removed original PNs. Physically destroy or mutilate them to prevent reuse. Maintain a log of discarded part numbers and serial numbers.

Step seven: update the aircraft’s continuing airworthiness records to show that the terminating action has been accomplished, including the service bulletin revision used, the date, and the flight hours and cycles at that point. After terminating action, no further inspection or replacement under this directive is required. However, the new‑design valves may have their own maintenance instructions under normal airworthiness requirements.

Step eight: ensure parts supply. Order the new‑design valves early to avoid AOG situations. Confirm with the supplier that the valves delivered are for A330 and not A340, despite identical part numbers. Request a certificate of conformance specifying A330 applicability.

Step nine: implement a tracking system for flight hours and cycles, with alerts for the 15,000‑hour, 2,500‑cycle, 10,000‑hour, 1,500‑cycle, and calendar deadlines. Assign responsible personnel to monitor DGAC and CASA publications for any revisions to the service bulletins or the directive itself.

Step ten: train maintenance engineers and inspectors on the specific borescope technique and the discarding requirement. Emphasise the non‑interchangeability of part numbers between A330 and A340. Conduct an internal audit before 31 March 2009 to confirm fleet‑wide compliance.

By following these steps, operators can achieve full compliance and avoid the enforcement and safety risks associated with the directive. The most common error is failing to integrate the two‑stage inspection/replacement sequence and missing the hard calendar deadline. A disciplined maintenance program, combined with accurate recordkeeping, will mitigate those risks.