AD/A320/223 - Electronic Instrument System Display Management Computer Software

The directive revolves around several technical aviation concepts integral to the Airbus A320 series flight deck. The Electronic Instrument System (EIS2) is the architecture that generates and displays flight instrument data on the cockpit displays. Within EIS2, the Display Management Computer (DMC) processes video signals and renders the Primary Flight Display (PFD), Navigation Display (ND), and other system pages. The software version installed on the DMC is identified by the disk part number. The AD targets EIS2 standard S4.2, where the DMC disk part number is F1419418. This is a specific software load that was introduced by Airbus Modification 34571 or by Airbus Service Bulletin A320-31A1220 dated 2 July 2004. The improved version, EIS2 standard S7 (DMC disk part number F1461768), modifies the vertical speed indication to improve legibility during a TCAS Resolution Advisory. Specifically, the changes alter the colour of the needle and increase the width of the TCAS green band on the vertical speed scale. The AD also introduces the distinction between “conventional standby instruments” and the Integrated Standby Instrument System (ISIS). Conventional standby instruments include the standby indicated airspeed (IAS) indicator, standby horizon, and standby altimeter. ISIS is a single unit that combines airspeed, altitude, and attitude data on a small display. The directive imposes different dispatch limitations depending on which type of standby system is installed. For aircraft with conventional standby instruments, dispatch with the standby IAS indicator inoperative is no longer authorised. Dispatching with an inoperative standby horizon or standby altimeter may be authorised only if the crew maintains Visual Meteorological Conditions (VMC) for the entire flight and operates in daylight. For aircraft with ISIS, dispatch with the ISIS airspeed function inoperative (as per MMEL item 34-22-03-C) is similarly prohibited. Dispatch with the ISIS horizon function or altitude function inoperative may be authorised only under VMC and daylight conditions. The directive also reminds operators that when dispatching with one Display Unit inoperative under MMEL item 31-63-01, that Display Unit must be switched off in accordance with the associated MMEL operational procedure. The Master Minimum Equipment List (MMEL) is the regulatory document that identifies which equipment may be inoperative at dispatch under certain conditions. By overriding specific MMEL relief, the AD effectively narrows the acceptable minimum equipment configuration for compliance. VMC refers to visibility and cloud clearance minima defined in the Civil Aviation Regulations; daylight conditions incorporate sufficient natural light for visual flight. The TCAS system itself is not modified by this AD; only the display of its resolution advisories on the PFD is improved through the software change. The service bulletin A320-31-1276 provides the installation instructions for the upgraded DMC software disk. The AD notes that the directive is based on EASA AD 2008-0032, indicating international harmonisation. The concept of “superseding” means that the previous AD (AD/A320/157 Amdt 2) is cancelled and no longer in force; compliance with the new AD replaces prior requirements. The directive does not define “day-light conditions” but it is typically understood as the period between official sunrise and sunset.

The directive directly applies to any operator, owner, or maintenance provider of an Airbus model aeroplane listed in Table 1 that is fitted with EIS2 standard S4.2. The affected models include all variants of the A318 (111, 112), A319 (111 through 133), A320 (111, 211 through 233), and A321 (111 through 232) as set out in the table. The trigger condition is the presence of DMC disk part number F1419418, installed by either Airbus Modification 34571 during production or by retrofit via Airbus SB A320-31A1220 dated 2 July 2004. However, aircraft that have embodied Mod 36725 during production are excluded from the applicability. Mod 36725 is presumably a later production standard that already includes the improved software or a more advanced version. The directive therefore imposes obligations on the operators of earlier-standard aircraft that have not received Mod 36725. The AD does not distinguish between commercial airlines, charter operators, corporate flight departments, or leasing companies; any entity that has operational control of an affected aircraft must ensure compliance. Maintenance organisations, whether in-house or third-party, will be contracted to perform the DMC software upgrade. Engineering departments must plan the retrofit within the compliance timeline, which may require scheduling aircraft downtime for the service bulletin embodiment. The interim dispatch limitations affect flight operations and dispatch planning: flights that previously could be released with certain standby instruments inoperative must now meet additional conditions (VMC and daylight) or else cannot be dispatched at all if the standby IAS or ISIS airspeed function is inoperative. This may reduce operational flexibility, especially at night or in instrument meteorological conditions (IMC), because an aircraft with a cooperative standby instrument may need to be grounded until repaired. The directive also affects the CASA itself as the regulator responsible for enforcing the AD, processing any exemption applications, and verifying compliance during surveillance activities. Lessors and financiers may have contractual requirements that the aircraft maintain continuous airworthiness; the cost of compliance with this AD is an additional expense that must be accounted for in maintenance reserves or lease agreements. Manufacturers (Airbus) and design approval holders are indirectly affected because they must provide the service bulletin and spare DMC disks. Parts suppliers benefit from increased demand for the upgraded disks. The AD does not explicitly affect aircrew beyond the requirement that dispatch procedures are updated; pilots will need to be briefed on the new limitations and may need to adjust pre-flight planning. The directive also has a timetable effect: within seven days of 5 June 2008, operators must update their MMEL-based dispatch procedures. This is a very short window that likely requires urgent communication to flight dispatchers and maintenance control. For operators with a large fleet, prioritising compliance for aircraft that are currently in a standby-instrument-inoperative status may be necessary. The AD does not impose any special record-keeping beyond normal maintenance entries for the service bulletin embodiment. The directive is self-contained; no alternative compliance plans are offered, so affected parties must complete the actions as specified or ground the aircraft.

The directive imposes three principal duties. First, the operator must apply the specified dispatch limitations within seven days after the effective date (5 June 2008). This duty is not conditional: from the eighth day onward, no affected aircraft may be dispatched in violation of those limitations. The duty applies to all flights, not just revenue flights. The limitations themselves outlaw dispatch with an inoperative standby IAS indicator (conventional) or ISIS airspeed function. For other inoperative standby instruments (horizon or altimeter), dispatch is permitted only if the crew agrees to maintain VMC and daylight conditions for the entire flight. This duty places an operational constraint on dispatch authority and requires the operator to update its MMEL or AOM accordingly. The second duty is to install EIS2 standard S7 software before 31 March 2009. This requires engineering action: procurement of the DMC disk, scheduling aircraft downtime, performing the service bulletin, and recording the embodiment. The third duty is to remove the interim dispatch limitations concurrently with the software installation. The AD does not stipulate that the limitations must be removed only after the installation is complete on each individual aircraft; it says “concurrent with Requirement 2”. This implies that as each aircraft receives the upgrade, the limitations are lifted for that aircraft. The operator does not gain the right to continue using the old limitations after the software installation deadline; the removal must coincide exactly with the embodiment event. The AD does not grant any explicit rights to operators. There is no provision for applying for an alternative means of compliance in this directive; any deviation would require a separate exemption under the Civil Aviation Act. The directive recognises that the service bulletin revision may be updated by EASA, but the operator does not have discretion to choose a different schedule or method. The AD also does not create a right to continued operation: if compliance is not achieved by the deadline, the aircraft must be grounded. Operators have the right to incorporate a copy of the directive or the MMEL changes into the AOM as a means of satisfying Requirement 1; this is an optional method, not a duty to incorporate verbatim. The directive does not specify any right of appeal or review within the instrument itself; general administrative law rights would apply. There is no duty on the regulator to notify the operator of the coming into effect; the AD is published in the Gazette and becomes binding. The operator bears the duty to stay informed. The directive also does not relieve the operator of any other airworthiness obligations; compliance with this AD does not ensure compliance with other ADs or regulations. The duties under this AD are strict liability: there is no defence of ignorance or economic hardship. The costs of compliance (labour, parts, lost revenue) are borne entirely by the operator with no compensation from the state. The directive does not distinguish between aircraft types or operating environments; an A321 used for charter in remote areas has the same duty as an A320 flown by a major airline. The duties are non-delegable: the operator remains responsible even if a maintenance contractor or software provider fails.

The AD itself does not prescribe specific penalty amounts or enforcement mechanisms. Instead, it operates as a legislative instrument made under the Civil Aviation Act 1988. Non-compliance with a CASA-issued airworthiness directive is an offence under the Act and regulations, and may attract civil penalties or criminal sanctions depending on the severity and intention. The Civil Aviation Act provides for maximum pecuniary penalties for strict liability offences; for corporations, these may amount to hundreds of thousands of dollars per contravention. Each day that an aircraft is operated contrary to the AD constitutes a separate offence. Additionally, the CASA may suspend or cancel the airworthiness certificate of any aircraft that does not comply with a mandatory AD. This would ground the aircraft indefinitely, which in economic terms is a far larger penalty than a fine. The operator may also face enforcement action from the Australian Transport Safety Bureau (ATSB) if an incident occurs that arises from non-compliance, leading to possible investigation and adverse findings. The directive does provide a means of demonstrating compliance: incorporating the MMEL changes or a copy of the directive in the AOM. If an operator fails to achieve this within seven days, any subsequent flight that deviates from the limitations is unlawful. The enforcement burden falls on CASA airworthiness inspectors, who may conduct spot checks, audit maintenance records, and inspect aircraft. Because the AD references an EASA AD, there may be coordinated enforcement between Australian and European authorities, especially for aircraft that operate under bilateral airworthiness agreements. The penalty risk is not trivial: an operator who deliberately ignores the limitations could face prosecution. However, the practical risk is low for unwitting non-compliance because the AD is published and becomes effective on a known date. The more likely enforcement scenario is a CASA notice of non-compliance followed by a direction to ground the aircraft until the software is installed. The AD does not contain any grace period beyond the stated compliance times. There is no provision for extension except through an exemption process which the operator must apply for before the deadline. The penalties also extend to maintenance organisations that certify return to service of an aircraft that does not comply; they may face action against their approvals. The AD does not provide for any infringement notice or demerit points system, but such mechanisms exist in broader civil aviation enforcement. In summary, the primary deterrent is the risk of grounding and loss of operational revenue, rather than the specific quantum of any fine. The cost of non-compliance (grounding, legal fees, reputational damage) far exceeds the cost of compliance (software disk and labour), so the incentive to comply is strong. The regulator is likely to show little sympathy for operators who claim ignorance, given the clear publication in the Gazette.

This airworthiness directive is a legislative instrument made under the Civil Aviation Act 1988 and therefore has the force of law in Australia. It overrides any inconsistent provisions in the operator’s approved MMEL or the Airplane Flight Manual (AFM) to the extent that it restricts or removes certain dispatch relief items. For example, MMEL item 34-21-01 (standby IAS indicator) or 34-22-03-C (ISIS airspeed) may allow dispatch with those items inoperative under certain conditions; the AD expressly removes that relief. The operator’s MMEL must be revised to reflect this AD, and the AOM must incorporate the changes. The AD also interacts with the Civil Aviation Regulations (CARs) and Civil Aviation Safety Regulations (CASRs) that govern airworthiness. Under CAR 1988, compliance with ADs is a condition of maintaining the aircraft’s certificate of airworthiness. Non-compliance means the aircraft is not airworthy and cannot be lawfully operated. The AD references EASA AD 2008-0032, indicating that this Australian AD is directly based on a European airworthiness directive. For aircraft that are imported or operated internationally, the operator must also comply with the EASA AD in European airspace. However, the Australian AD is the legally binding instrument in Australia; an operator cannot choose to comply only with the EASA version if it differs. The directive also incorporates by reference Airbus Service Bulletin A320-31-1276 dated 18 April 2007. That service bulletin is a proprietary document owned by Airbus. The operator must acquire a copy and follow its instructions. The AD states that later EASA-approved revisions of the service bulletin are acceptable, which creates a dynamic reference. The AD does not incorporate any other external standards by reference. The directive does not affect or interact with state-based workers compensation laws, environmental laws, or contract laws, except indirectly in that the operator’s failure to comply may trigger contractual remedies under lease or purchase agreements. The AD also does not refer to international treaties such as the Chicago Convention, though Australia’s obligation under that treaty to maintain airworthiness standards is the underlying basis for issuing ADs. In terms of precedence, a CASA AD ranks as a legislative instrument and takes precedence over any less formal guidance material, advisory circulars, or internal company policies. The AD does not supersede any other ADs except AD/A320/157 Amdt 2, which it cancels. Operators who had previously complied with that earlier AD must now comply with this one; any partial compliance under the old AD does not satisfy the new requirements. The directive also interacts with the operator’s airworthiness management system: the maintenance schedule must be updated to include the service bulletin embodiment. The AD does not create any interaction with criminal law beyond the general penalties provisions of the Civil Aviation Act.

The source text provides sparse amendment history. AD/A320/223 is the current directive issued on 22 April 2008, effective 5 June 2008. It supersedes AD/A320/157 Amdt 2, which was based on EASA AD 2006-0108. That earlier AD is cancelled as of the effective date of this directive. There is no indication of any further amendments to AD/A320/223 itself within the source. The directive also references superseded earlier service bulletin versions: Airbus SB A320-31-1263 Revision 1 and the original issue of Airbus SB A320-31-1276 are mentioned as alternative embodiments that would exempt an aircraft from the installation requirement. This suggests that the service bulletin itself has an amendment history, but that history is outside the scope of the legislative instrument. The AD’s requirement 2 specifically calls for the version of the service bulletin dated 18 April 2007 or later EASA-approved revision. This implies that future amendments to the service bulletin, if approved by EASA, would be automatically acceptable without amending the AD. The AD’s own amendment history is thus limited: it was issued in 2008 and has not been replaced by a later AD in the source data. In practice, airworthiness directives often remain in effect until superseded; given that the compliance deadline was 31 March 2009, the directive would have been current until the software was installed. After that date, for aircraft that have embodied the fix, the directive’s remaining requirements are satisfied. The AD does not contain a sunset clause; it remains on the books as a historical directive. Subsequent revisions to the service bulletin do not change the AD text; the AD simply recognises that later revisions are acceptable compliance methods. The source also shows that the earlier AD (A320/157) had two amendments (Amdt 2 was the latest). This indicates that the issue of TCAS display visibility has been addressed through multiple iterations. The new directive’s background section explains that it supersedes the earlier AD by revising the applicability and mandating the improved software. The amendment history of the AD itself is not available beyond what is shown; users seeking a complete chronological record would need to consult CASA’s AD database for any further amendments that may have occurred after 2008. The source provided is the original instrument as gazetted; any subsequent amendments or cancellations would not appear in that document.

The source text contains no information about litigation history. There is no reference to any court case, tribunal decision, or administrative review concerning AD/A320/223. The directive was issued by a delegate of CASA and is a legislative instrument. In the ordinary course, airworthiness directives are rarely litigated because the cost of compliance is usually small relative to the risk of grounding, and because the Civil Aviation Act provides limited grounds for challenge. An operator could theoretically seek judicial review of the decision to issue the directive on grounds such as procedural error or unreasonableness, but such challenges are uncommon. The source does not mention any such challenge. It is possible that a party applied for an exemption or variation, but that administrative process would not be considered litigation. Because the AD is based on an EASA directive, any litigation in Europe regarding the underlying safety assessment could have indirect relevance, but the source does not discuss that. The absence of litigation history is not surprising: airworthiness directives are safety-driven and typically accepted without contest. The directive itself does not create a private right of action for damages; passengers or third parties cannot sue for breach of the AD. In the event of an accident, the AD could be used as evidence of a standard of care in a civil claim for negligence, but that is not litigation about the AD itself. The source provides no references to any court decisions. Therefore, the litigation history of this specific AD is nil. Searching for “AD/A320/223” in Australian legal databases would likely return only the instrument itself and perhaps references in maintenance records. This is a standard outcome for safety regulations that are closely tied to international practice. The directive’s language (e.g., “mandatory”, “must”) leaves no room for interpretation that would invite litigation. The only conceivable dispute might involve whether an aircraft falls within the applicability (e.g., whether Mod 36725 was actually embodied), but such factual disputes would be resolved through administrative review rather than court proceedings. In summary, the litigation history is empty; no known cases have arisen under this AD.

Several aspects of AD/A320/223 could trap the unwary operator. First, the compliance timeline for Requirement 1 is only seven days after the effective date (5 June 2008). This is extremely short. An operator who does not monitor the Gazette or receive timely notifications may inadvertently operate in contravention after day seven. The AD does not provide any grace period or alternative means of notification. Second, the dispatch limitations are not simply an update to the MMEL; they outright override MMEL relief for standby IAS/ISIS airspeed functions. An operator who relies on a previously approved MMEL item after the seven-day deadline without updating procedures is non-compliant, even if the aircraft was otherwise airworthy. Third, the limitations for standby horizon or altimeter (conventional or ISIS) are conditional on the crew agreeing to maintain VMC and daylight for the entire flight. This is not a simple “may be dispatched inoperative” clause; it requires positive and documented crew acceptance. The operator must ensure that dispatchers and pilots are trained on these specific conditions. Fourth, the reminder about dispatch with one Display Unit inoperative is often overlooked. The AD states that the inoperative Display Unit must be switched off per the MMEL operational procedure. This is an existing requirement, but the AD emphasises it to avoid confusion. Failing to switch off the unit could lead to non-compliance even if the operator correctly applies the dispatch limitation for the DU. Fifth, the AD allows incorporation of a copy of the directive itself into the AOM as a compliance method for Requirement 1. An operator who simply files the directive without actually amending the MMEL or AOM text may not have implemented the limitations practically; the incorporation must be effective to produce operational change. Sixth, the exemption for aircraft that have embodied Mod 36725 during production is only for those aircraft. An aircraft that received the mod after production (via a service bulletin) may not be exempt unless that specific SB is one listed (SB A320-31-1263 Rev 1 or original SB A320-31-1276). The AD does not say that any later version of the software automatically exempts; only those specific versions. Seventh, the AD supersedes AD/A320/157 Amdt 2. That earlier AD may have had different dispatch relief. An operator who continues to rely on the old AD’s provisions after the effective date is non-compliant. The supersession is total. Eighth, the software installation requirement (Requirement 2) has a deadline of 31 March 2009, but the AD does not require that every aircraft achieve compliance by that date; it says “before 31 March 2009”. This implies that the installation must be completed on each aircraft by that date, not that the operator must have all aircraft completed by then. For a large fleet, scheduling may be tight. Ninth, the AD does not state that the software installation must be performed by an approved maintenance organisation; it just says “in accordance with the instructions of Airbus SB A320-31-1276”. However, under normal regulatory requirements, such a task would require an appropriately authorised person. Operators must ensure that the person performing the work holds the correct licence. Tenth, the AD’s background mentions two incidents of TCAS indication lack of visibility, but the fix addresses vertical speed indication - not the primary TCAS symbology itself. Operators should understand that the software update changes the vertical speed needle colour and green band width. Fully understanding the change may be important for training crews. Finally, note that the AD refers to “EASA AD 2008-0032” as a reference, not as a substitute. Operators cannot simply comply with the EASA AD and ignore the Australian version; they must comply with the Australian AD as the law in Australia.

Compliance with AD/A320/223 involves a sequence of actions. First, the operator must identify all aircraft in its fleet that fall within the applicability: any Airbus A318, A319, A320, or A321 model listed in Table 1 that is fitted with EIS2 standard S4.2 (DMC disk part number F1419418) and has not embodied Modification 36725. This requires a fleet survey to check the current software version and modification status. Second, within seven days of 5 June 2008 (i.e., by 12 June 2008), the operator must implement the dispatch limitations set out in Requirement 1. The most practical method is to update the operator’s MMEL documents and/or the AOM to restrict the specific MMEL items. The operator may also place a copy of the AD in the AOM as a compliance method. The limitations must be effectively communicated to all flight dispatchers, pilots, and maintenance control personnel. The operator should also ensure that the standby instruments (IAS indicator for conventional, or ISIS airspeed function) are not listed as dispatchable inoperative items even if the MMEL previously allowed it. For standby horizon and altimeter, the operator must add a condition: dispatch is authorised only if the crew agrees to maintain VMC and daylight for the entire flight. This condition should be documented, perhaps in the flight release or the aircraft technical log. The operator should also note the reminder about switching off an inoperative Display Unit per the associated MMEL procedure. Third, the operator must plan and execute the installation of EIS2 standard S7 software (DMC disk part number F1461768) before 31 March 2009. This requires procuring the DMC disk from Airbus (ordering through normal parts channels), scheduling aircraft downtime, and performing the embodiment in accordance with Airbus Service Bulletin A320-31-1276 dated 18 April 2007 (or any later EASA-approved revision). The work should be carried out by a maintenance organisation authorised under Part 145 of CASR. A logbook entry must be made to record compliance. The operator should verify that the software installation is correctly completed by performing a functional test as required by the service bulletin. Fourth, after the software installation on each aircraft, the operator must concurrently remove the interim dispatch limitations for that aircraft. This means restoring the MMEL to its pre-AD state where applicable, and amending the AOM or removing the copy of the AD. The operator should update its airworthiness records to show the date of compliance for each aircraft. Fifth, the operator must maintain records of compliance for at least the period specified in the regulations. Documentation should include the fleet survey, the date of implementation of limitations, the service bulletin completion record, and evidence of the removal of limitations. Because the AD references superseded earlier directives, the operator should ensure that any previous AD compliance records are closed out and that no double counting occurs. The operator should also consider whether the earlier SB A320-31-1263 Revision 1 or original SB A320-31-1276 has already been embodied on any aircraft; if so, Requirement 2 does not apply and those aircraft are already compliant. However, the dispatch limitations still apply until the software is installed; an aircraft with the earlier service bulletin might still have the older software. The operator should check the actual disk part number. If the aircraft already has the S7 software, it is compliant. Finally, the operator should monitor any future revisions of the Airbus service bulletin or any amendment to the AD itself. If EASA approves a later revision of the SB, the operator may use that revision as an alternative compliance method, but the Australian AD still must be complied with. For ongoing compliance, the operator should ensure that any aircraft that later enters the Australian register and falls within the applicability is brought into compliance before operation. For leased aircraft, the operator must verify the software status before taking delivery. The entire compliance process should be assigned to a responsible person within the operator’s continuing airworthiness management organisation.