AD/AMD 50/47 Amdt 1 - Crew and Passenger Oxygen Lines

An Airworthiness Directive (AD) is a regulatory instrument issued by CASA to mandate corrective action on aircraft or components when an unsafe condition is found to exist or is likely to exist. ADs are part of the continuing airworthiness framework and are legally binding on operators, owners, and maintenance organisations. This particular AD is classified as AD/AMD 50/47 Amdt 1, indicating it is an amendment to an earlier directive concerning the Falcon 50 and 900 series aeroplanes, though the applicability here is restricted to the 900EX variant with specific serial numbers.

The central concept is the service bulletin (SB). An SB is a manufacturer issued document that provides instructions for inspections, modifications, or repairs. An SB alone is generally advisory; operators may choose not to comply. But when an AD mandates compliance with an SB, that SB becomes mandatory. This AD mandates compliance with Dassault SB F900EX-347 Revision 1. The SB has two parts: Part 1 covers inspection procedures, and Part 2 covers replacement and modification instructions.

The Amendment introduces a hierarchy of compliance options for the service bulletin. The primary requirement is to use Revision 1 of the SB. However, actions already performed using the initial issue of the SB (19 March 2009) before the Amendment's effective date are accepted as satisfying the requirements. Additionally, later revisions of the SB approved by EASA are acceptable. This recognises that the SB may be further updated by the manufacturer and approved by the European regulator, and that CASA will accept those revisions without requiring a separate amendment to the AD.

The concept of compliance time is critical. The AD specifies three distinct deadlines. Requirement 1 (inspection) must be completed within two months after the effective date (i.e., by 27 October 2009). Requirement 2 (corrective action if damage found) is triggered by the inspection and must be done before further flight. Requirement 3 (replacement of support assemblies) has a much longer horizon: within 72 months after the effective date (i.e., by 27 August 2015). This staggered approach reflects different risk levels: the inspection is urgent, immediate correction of found damage is safety critical, but the support assembly replacement is a preventative measure that can be scheduled over several years.

Another concept is grandparenting. The AD explicitly states that actions taken using the initial SB before the Amendment's effective date satisfy the requirements. This prevents operators who already complied with the original directive from having to redo the work. However, this grandfather clause applies only to actions completed before 27 August 2009. If an operator performed the initial SB work after that date, it would not meet the Amendment's requirement to use Revision 1, unless that later work used Revision 1 or an EASA approved later revision.

The AD also incorporates by reference the EASA AD 2009-0126, noting that the CASA directive is linked to that European directive. This reflects the international harmonisation of airworthiness directives, as Dassault is a French manufacturer and EASA is the primary certification authority for the type.

The immediate and narrow class of persons affected are operators and owners of Dassault Falcon 900EX aeroplanes with specific serial numbers. The AD lists 44 serial numbers in Table 1: 120, 121, 122, 123, 125, 126, 127, 129, 132, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 147, 151, 153, 155, 157, 158, 159, 163, 165, 168, 169, 170, 172, 174, 178, 182, 183, 194, 196, 197, 199, and 206. This is likely a production batch of Falcon 900EX aircraft. Any operator of a Falcon 900EX with a serial number not in this list is not affected. Notably, the AD title mentions "Falcon 50 and 900 Series Aeroplanes", but the applicability is confined to the 900EX with those serial numbers. This suggests the original AD may have covered a broader population, but the Amendment narrows it. Operators of Falcon 50 series or other Falcon 900 models are not affected by this particular instrument, but they should check whether other ADs apply.

Beyond the direct aircraft operators, the AD affects maintenance organisations that perform work on these aircraft. They must obtain the correct revision of the SB, follow its instructions, and properly document completion. The AD does not specify who must perform the work; it only mandates that the work must be accomplished per the SB. Typically, such work requires appropriately licensed aircraft maintenance engineers (LAMEs) with Falcon 900EX type rating, or work performed under an approved maintenance organisation's exposition.

The AD also indirectly affects Dassault Aviation as the manufacturer that issued the SB, and EASA as the approving authority for the SB. CASA itself is affected as the issuer, but the AD is an instrument of the delegate of CASA (James Coyne), signed on 30 June 2009.

Because the AD is an Australian instrument, it applies to aircraft on the Australian register. If a Falcon 900EX with one of the listed serial numbers is registered in Australia, the operator must comply. If the aircraft is operated in Australia under a foreign registration (e.g., U.S. N registered), the relevant foreign AD (like the FAA equivalent) would apply instead. However, operators of foreign registered aircraft in Australia must also meet Australian airworthiness requirements, so they should verify compliance with CASA.

The AD does not explicitly state any exemptions for private operators, charter operators, or corporate flight departments. All are treated equally. The costs of compliance, including inspection labour, parts (oxygen lines, brackets, support assemblies), and potential aircraft downtime, fall on the operator. For a business aircraft operator, the two month inspection window is manageable but the 72 month support assembly replacement must be scheduled during a heavy maintenance visit.

The AD imposes three clearly defined duties on the operator. The first duty is to inspect the oxygen lines within two months after 27 August 2009, i.e., by 27 October 2009. The inspection must be carried out in accordance with Part 1 of the accomplishment instructions of SB F900EX-347 Revision 1. This is a one time inspection; there is no recurring inspection requirement in this AD.

The second duty is conditional on the inspection outcome. If during the inspection any interference or damage is found, the operator must replace the oxygen lines and install improved brackets. This work must be done before further flight. The AD does not define "interference or damage" but defers to the SB's criteria. The operator must use Part 2 of the SB for this corrective action.

The third duty is unconditional. Regardless of inspection results, the operator must replace the oxygen line support assemblies in accordance with Part 2 of the SB within 72 months after the effective date. This is a hard deadline: by 27 August 2015. There is no provision for extension or alternative means of compliance unless CASA issues a separate approval.

The operator also has certain rights. One right is to use previous work: if the inspection and any corrective action were already accomplished before 27 August 2009 using the initial issue of the SB (19 March 2009), that work is accepted as meeting the requirements. This is important for operators who completed the original AD requirements promptly. However, the grandfather clause does not extend to the support assembly replacement requirement (Requirement 3). That is a new requirement in the Amendment? Actually, the original directive also required modification of the support assembly; the Amendment continues that requirement. So the grandfather clause applies to the inspection and immediate corrective actions but the support assembly replacement must still be done within 72 months from 27 August 2009, even if previously done under the initial SB? The AD says "Inspections and corrective actions accomplished before the effective date... satisfy the requirements of this Amendment". "Corrective actions" likely includes the support assembly replacement if done per initial SB. But careful: initial SB might not have included the support assembly replacement? The Amendment's Requirement 3 is "Replace the oxygen line support assemblies in accordance with Part 2". The initial SB may have had a different Part 2. The AD does not explicitly say that support assembly replacement done per initial SB satisfies Requirement 3. It says "inspections and corrective actions" satisfy the requirements. Since Requirement 3 is a corrective action, it would be covered. However, the compliance time for Requirement 3 is 72 months from effective date; if an operator already replaced the support assemblies under the initial SB before the effective date, they have already complied. If they did it after the effective date but before the 72 month deadline, but using initial SB instead of Revision 1, that might not be accepted because the grandfather only applies to actions done before the effective date. So operators who did the support assembly replacement after 27 August 2009 must use Revision 1 or later.

Another right is to use later revisions of the SB approved by EASA. This allows the operator to use updated instructions without needing CASA to amend the AD. However, the operator must verify that the later revision is indeed approved by EASA. This gives some flexibility but also requires diligence.

The operator has no right to deviate from the AD without CASA approval. If an operator wishes to use an alternative method of compliance, they would need to apply to CASA for an alternative means of compliance (AMOC). The AD does not expressly mention AMOC, but generally CASA can approve alternatives under regulation.

The AD text itself does not specify penalties. Enforcement arises from the broader regulatory framework. Under the Civil Aviation Act 1988, the Civil Aviation Safety Regulations 1998 (CASR), and specifically Part 39 (Airworthiness Directives), failure to comply with an AD is a breach of airworthiness requirements. The aircraft cannot be operated unless it is airworthy, and compliance with all applicable ADs is a condition of airworthiness.

For a Part 91 (general aviation) operator, operating an aircraft that is not in compliance with an AD can result in enforcement action by CASA, ranging from a written warning to infringement notices (fines) or prosecution. Under CASR 42.015, the operator must ensure the aircraft is maintained in an airworthy condition. Operating contrary to an AD could also void insurance coverage.

In practice, the most immediate enforcement mechanism is the requirement for the aircraft's maintenance release or certificate of release to service. If the AD is not complied with and recorded, the aircraft cannot be released to service. The AD will be tracked in the operator's maintenance schedule. CASA also conducts surveillance and audits. If they find non compliance, they can ground the aircraft (issue a grounding direction), or require it to be rectified before further flight.

The AD does not impose a reporting requirement to CASA. The operator merely needs to perform the work and document it in the aircraft maintenance records. However, if an operator discovers a systemic issue or a repeat occurrence, they may have a reporting obligation under other regulations (e.g., CASR 42 about defect reporting).

The penalties for non compliance with an AD are not trivial. Under the Civil Aviation Act, an individual can face fines up to hundreds of penalty units, and the aircraft can be grounded. For a corporate operator, the reputational and operational costs of grounding are often more significant than the fine.

Given that this AD concerns oxygen lines, which are critical for crew and passenger survival in an emergency (decompression, smoke), the safety implications are serious. An oxygen leak could lead to fire or failure of oxygen supply. So compliance is taken seriously by operators and regulators.

This AD does not operate in isolation. It is part of a web of regulatory instruments. Most directly, it references EASA AD 2009-0126. That is the European equivalent directive issued by the European Aviation Safety Agency. For an aircraft that is type certificated in Europe (as Falcon aircraft are), EASA issues ADs. CASA often adopts EASA ADs with modifications, or issues separate Australian ADs that reference them. This AD notes that EASA AD 2009-0126 refers, meaning the CASA directive is consistent with or derived from that EASA AD.

For Australian operators, the hierarchy of airworthiness directives is governed by Part 39 of the Civil Aviation Safety Regulations. Part 39 establishes that ADs are mandatory and that compliance with the AD is required for the aircraft to be maintained in an airworthy condition. The AD does not supersede any other ADs that may apply to the same aircraft. For example, there may be other ADs for Falcon 900EX affecting other systems; all must be complied with.

The AD also interacts with the Civil Aviation Regulations 1998 (CARs), particularly CAR 42A (maintenance) and CAR 51 (airworthiness). However, since the introduction of CASR, many CARs have been replaced. The operator should know that compliance with the AD must be recorded in the maintenance records and signed off by a licensed aircraft maintenance engineer.

The AD also has implications for the aircraft's maintenance program. The operator must schedule the inspection and the support assembly replacement. This may require the operator to amend their approved maintenance schedule or work package. The AD does not require amendment to the maintenance program per se, but the tasks must be incorporated.

Additionally, the SB referenced in the AD is a Dassault document. The use of that SB must be in accordance with the manufacturer's instructions and is subject to the AD's stipulation that only revisions approved by EASA (or the initial approved revision) are acceptable. If Dassault issues a later revision that is not yet approved by EASA, that revision cannot be used for compliance unless and until EASA approves it.

The AD may also interact with international agreements. If the aircraft is operated across borders, the operator must ensure compliance with the ADs of the state of registry. Since this is a CASA AD, it applies to Australian registered aircraft. If the aircraft operates into other countries, those countries may accept the CASA AD as evidence of airworthiness, but some may require their own equivalent AD.

For owners, there may also be contractual interactions. If the aircraft is under a lease or charter agreement, the AD compliance obligations may be allocated between lessor and lessee. The AD itself does not address this; it imposes the obligation on the operator. The parties must define responsibility in their contract.

The instrument is Amendment 1 to AD/AMD 50/47. The original AD/AMD 50/47 was issued with an effective date of 30 July 2009. That original directive was based on the initial issue of Dassault SB F900EX-347 dated 19 March 2009. The original also had its own applicability, which this Amendment revises.

The Amendment changes two things. First, it requires compliance with Revision 1 of the SB (18 May 2009) rather than the initial issue. Second, it revises the applicability. Unfortunately, the instrument as supplied does not detail what the original applicability was, so we cannot compare. The Table 1 in the instrument lists serial numbers; presumably the original might have covered a different set of aircraft, perhaps including Falcon 50 or other 900 series. The background states "This Amendment, whilst continuing the requirements of the original issue, requires compliance in accordance with revision 1 of the service bulletin and revises the applicability."

The Amendment also includes a transition provision: inspections and corrective actions accomplished before the effective date of this Amendment (27 August 2009) using the initial SB are acceptable. This is a typical grandfather clause to avoid double work for operators who acted quickly on the original AD.

The Amendment was signed by James Coyne, a delegate of CASA, on 30 June 2009. The effective date is 27 August 2009. This gives operators about two months from signature to effective date, but the compliance clock for Requirement 1 starts from the effective date, not from the date of signature.

The Amendment also introduces the flexibility to use later revisions of the SB approved by EASA. This was not present in the original? The language "Later revisions of the above SB approved by EASA are acceptable for compliance" appears in the Amendment. Whether that was in the original is unknown, but it is now in force.

There is no further amendment history provided in the source. The source shows only this one amendment. However, the AD reference "9/2009" suggests it was the ninth AD published in 2009 for this type.

The AD does not reference any supersedure of other ADs. It stands alone for the oxygen line issue.

It is important to note that this AD is now historical (effective 2009). Its immediate compliance dates (2 months, 72 months) have long passed. However, for a deep dive understanding, the compliance framework is still relevant for any operator who inherits an aircraft that did not comply. But likely all affected aircraft have complied, or the non compliance would have been discovered through subsequent CASA audits.

The source text does not mention any litigation related to this AD. There is no reference to court cases, AAT reviews, or appeals. This is unsurprising for a routine airworthiness directive. ADs are rarely litigated because they are based on safety findings and are generally accepted as necessary by the industry.

However, one could conceive of potential litigation ground: if an operator disputed the applicability to their aircraft (e.g., serial number dispute), or if the AD was alleged to be beyond CASA's power. No such cases are reported in the source.

Given the AD's specific serial number list and clear compliance instructions, litigation is unlikely. The cost of challenging an AD would exceed the cost of compliance for most operators. Additionally, the AD incorporates a manufacturer SB and EASA approval, so any challenge to the safety basis would require technical evidence.

The only possible scenario is if an operator failed to comply and CASA issued an enforcement decision, which could be appealed to the Administrative Appeals Tribunal (AAT). No such case is referenced.

Therefore, for this deep dive, we note that the instrument has no recorded litigation history. This does not mean the AD was never enforced or that disputes never arose; it simply means the source does not provide that information.

The AD presents several nuances that could trip up an unwary operator.

First, the title is misleading. It says "Falcon 50 and 900 Series Aeroplanes", but the applicability is limited to Falcon 900EX with specific serial numbers. An operator of a Falcon 50 or a Falcon 900 (non-EX) might mistakenly think this AD applies to them. It does not. Conversely, an operator of a Falcon 900EX with a serial number just outside the list might assume it applies because the model matches. It does not. Always check the serial number against Table 1.

Second, the compliance deadlines are relative to the effective date (27 August 2009). For Requirement 1, the two months run from that date, not from the date the aircraft last flew or from the date the operator receives the AD. If an operator acquired the aircraft after 27 August 2009 but before 27 October 2009, they must complete the inspection within the remaining time from acquisition. If they acquire the aircraft after 27 October 2009, they are already in breach of the inspection requirement. The AD does not provide a grace period for new owners. However, the operator could show that the inspection was done by a previous owner? But the AD imposes the duty on the operator. So if the aircraft was not inspected, the current operator must arrange inspection immediately upon becoming aware of non compliance, and then also meet the corrective action deadlines.

Third, Requirement 3 has a 72 month deadline from the effective date, i.e., 27 August 2015. But the AD does not repeat that the support assembly replacement must be done using Revision 1 of the SB. It says "Replace the oxygen line support assemblies in accordance with Part 2 of the accomplishment instructions of SB F900EX-347 Revision 1." So even if the operator performed the inspection and found no damage, they still must do this replacement. It is not optional.

Fourth, the grandfather clause for prior actions. Only actions accomplished before 27 August 2009 using the initial SB (19 March 2009) are accepted. If an operator did the work after that date using the initial SB, that work is not compliant because the applicable standard became Revision 1 from 27 August 2009. However, the AD allows later EASA approved revisions. So if the operator used the initial SB after 27 August 2009, they would need to redo the work using Revision 1 or a later approved revision.

Fifth, the AD does not specify who must perform the work. It does not say "a licensed aircraft maintenance engineer" or "approved maintenance organisation". But by regulatory implication, any maintenance work must be carried out by appropriately authorised personnel under the maintenance regulations. An owner cannot self-certify unless they hold the appropriate licence.

Sixth, the AD does not require notification to CASA of compliance. It only requires that the work be done. The operator must maintain records, and CASA may request them during audit.

Seventh, the AD references EASA AD 2009-0126 but does not say that compliance with the EASA AD is automatically compliance with the CASA AD. They are likely harmonised, but an operator should not assume that compliance with the EASA AD alone meets the CASA AD. The CASA AD is a separate legal instrument. However, because the CASA AD builds on the EASA AD and accepts later EASA approved revisions, in practice compliance with the EASA AD will likely satisfy.

Eighth, the AD does not address what happens if the aircraft is stored or out of service. The compliance deadlines run regardless. If the aircraft is not flown, the inspection deadline still applies. If the aircraft is stored, the operator must still complete the requirements before returning to service. The AD does not exempt stored aircraft.

Ninth, the AD covers crew and passenger oxygen lines. It mentions RH (right-hand) mid cabin oxygen cylinder. The inspection is specifically for interference with frame 8. The SB should detail the exact locations. Operators must ensure their maintenance personnel have the correct SB and understand the inspection criteria.

Tenth, the AD is an amendment. There was an original AD effective 30 July 2009. If an operator complied with that original AD but did not meet the new requirements (e.g., used initial SB after 27 August 2009), they are not compliant. The amendment does not carry forward grace for those who were late on the original AD.

Compliance with AD/AMD 50/47 Amdt 1 requires a systematic approach. The operator must first confirm whether their aircraft is affected. This involves checking the aircraft's serial number against Table 1. To date, the aircraft must be a Falcon 900EX with one of the listed 44 serial numbers. If the serial number is not listed, no action is needed under this AD (though other ADs may apply).

If the aircraft is affected, the operator must obtain Dassault Service Bulletin F900EX-347 Revision 1, dated 18 May 2009. This is the baseline document. The AD also accepts later revisions if approved by EASA, but the operator should ensure they have the correct revision. The SB can be obtained from Dassault Aviation or through an aftermarket service.

The operator must then schedule Requirement 1: inspect the oxygen lines per Part 1 of the SB. This must be completed within two months of 27 August 2009 (i.e., by 27 October 2009). The inspection should be performed by a qualified maintenance engineer with Falcon 900EX type training. The inspection likely involves visual examination of the routing of the crew and passenger oxygen lines near frame 8, checking for signs of chafing, contact, or compression.

If the inspection reveals any interference or damage, Requirement 2 kicks in: before further flight, the operator must replace the affected oxygen lines and install improved brackets per Part 2 of the SB. This is a grounding condition; the aircraft may not be flown until this corrective action is completed. The operator should have the necessary parts on hand or source them urgently.

Regardless of the inspection result, Requirement 3 mandates the replacement of the oxygen line support assemblies within 72 months of 27 August 2009 (by 27 August 2015). This is a scheduled maintenance task that can be planned into a major maintenance check. The operator should coordinate with their maintenance provider to ensure the task is included in the maintenance schedule.

After each action, the maintenance engineer must sign off the work in the aircraft maintenance records, referencing the AD number, the SB revision used, and the date of compliance. The operator should maintain a log of AD compliance.

If the operator has already accomplished the inspection and any corrective actions before 27 August 2009 using the initial SB (19 March 2009), those actions are accepted for Requirement 1 and Requirement 2. However, Requirement 3 must still be done within 72 months, unless it was already done before the effective date. The operator should check their records.

If the operator wishes to use a later revision of the SB (e.g., Revision 2 or later), they must confirm that EASA has approved that revision. They should obtain evidence of EASA approval.

The operator should also be aware that this AD does not have a recurring inspection requirement. After compliance, the only continued obligation is to maintain the aircraft in accordance with the manufacturer's maintenance instructions.

Finally, if the operator is unsure about any aspect, they can contact CASA for an alternative means of compliance, but must apply formally and receive approval before deviating from the AD. Given the AD's clarity, most operators will simply follow the SB.

The cost of compliance includes engineering labour, parts, and potential downtime. The initial inspection may be quick, but if damage is found, the aircraft could be grounded until parts arrive. The support assembly replacement is a scheduled task that can be done during a maintenance visit, minimising downtime.

For an aircraft that has already been maintained in accordance with the AD, the operator's ongoing responsibility is to maintain records and ensure that any future transfer of the aircraft includes AD status documentation.