AD/CIRRUS/10 - Exhaust Heat Exchanger Cracks

Applicability: The AD applies only to Cirrus Design SR20 aeroplanes with serial numbers 1005 through 1815 (Applicability). Aircraft outside that serial-number range are not covered by the text of this AD.

Required inspection: The core compliance obligation is a "pressurisation inspection/check on the exhaust system" that must be performed in accordance with the specific manufacturer service bulletin identified as SB 2X-78-07 R1, Revision 1, dated 18 December 2007 (Requirement 1). The AD does not include a procedural description of the inspection itself; it delegates the method to the cited service bulletin.

Trigger for mandatory repair: The AD establishes two independent triggers for mandatory replacement of the heat exchanger weldment and shroud: (a) the inspection detailed in Requirement 1 finds the exhaust system defective; (b) an exhaust odour is detected inside the cabin (Requirement 2). Either trigger requires replacement of the heat exchanger weldment and shroud with the new improved parts specified in the service bulletin, and the replacement must follow the service bulletin instructions.

Timing and repetition: The AD sets a two-part timing regime. For Requirement 1, the initial inspection is required "within the next 25 hours time-in-service or within the next 3 months after the effective date of this AD, whichever occurs first," and thereafter at intervals "not to exceed every 100 hours TIS" (Compliance: Requirement 1). For Requirement 2, the replacement is required "before further flight after the inspection/check in which the exhaust system is found defective or an exhaust odour is detected" (Compliance: Requirement 2). The AD became effective on 28 August 2008.

Reference and alternative compliance: The AD expressly relies on a manufacturer service bulletin for the technical method of inspection and repair, and it allows "later revisions of the above SB" only if those later revisions have been approved by the United States Federal Aviation Administration as an Alternate Method of Compliance to FAA AD 2008-11-18 (Requirement). The AD notes FAA AD 2008-11-18 Amdt 39-15541 dated 22 May 2008 as a related instrument (Requirement, note).

Safety objective: The stated safety objective is to detect and correct exhaust-system leaks that could allow engine exhaust gases to enter the cabin heating system, which could result in carbon monoxide in the cabin and incapacitation of the pilot (Background). The AD therefore links the inspection and replacement requirements to a human-safety risk identified by CASA.

Delegation and authority: The directive is issued by the Civil Aviation Safety Authority and signed by a delegate, James Coyne, on 16 July 2008 (signature block). The AD takes formal effect on 28 August 2008 (Compliance paragraph).

Interplay of concepts: In short, the AD combines a limited applicability scope (specific SR20 serial numbers), an externally-defined inspection and repair method (the numbered Cirrus service bulletin), a short initial compliance window and ongoing repetitive inspection cadence, a mandatory replacement requirement triggered by either inspection failure or cabin odour, and a narrowly framed recognition of later service-bulletin revisions only when the FAA has expressly approved them as an AMOC to an FAA AD. The package operationalises a risk-control loop: detect by inspection or subjective odour, remove the faulty heat exchanger/weldment/shroud assembly, and prevent further flights until corrected.

Owners and operators of affected aircraft: The primary economic and legal obligations fall on the registered owners and operators of Cirrus SR20 aircraft in the serial range 1005-1815, because they must ensure the inspections and any required replacements are performed within the stated timeframes (Applicability; Compliance). Those persons bear the direct costs of inspections and replacement parts and any operational downtime while corrective action is carried out.

Maintenance organisations and certificated personnel: Licensed maintenance organisations and technically qualified personnel who perform the "pressurisation inspection/check on the exhaust system" and who carry out the replacement in accordance with the Cirrus service bulletin are operationally responsible for executing the AD’s technical steps (Requirement; Compliance). They also must ensure they follow SB 2X-78-07 R1 Revision 1, or a later revision only where that later SB revision has been approved by the FAA as an AMOC to FAA AD 2008-11-18 (Requirement).

Pilots and flight crews: Pilots operating affected SR20 aeroplanes are stakeholders because a detected exhaust odour in the cabin triggers an immediate requirement that must be remedied before further flight (Requirement 2; Compliance: Requirement 2). Pilots therefore need to be alert for cabin odour and must ground the aircraft if odour is detected until the replacement is completed.

Parts suppliers and manufacturers: The directive requires replacement with a "new improved heat exchanger weldment and new shroud" as specified in the service bulletin (Requirement 2). Suppliers and the manufacturer are therefore affected by demand for the specific replacement parts and by any logistical constraints in delivering the improved components.

Regulator and delegated staff: The Civil Aviation Safety Authority is the issuing regulator; the AD is signed by a CASA delegate (James Coyne) (signature block). CASA is the authority that sets the effective date and enforces compliance under aviation regulatory powers external to the AD text. The AD also references coordination with the FAA by accepting FAA-approved AMOCs for later SB revisions (Requirement). This creates an administrative interaction between CASA, the FAA and the operator when later revisions are contemplated.

Insurers and liability holders: While the AD text does not address insurance, operators’ risk profiles and insurance claims may be affected by mandatory actions that alter aircraft availability and maintenance records. The source does not state insurance consequences; mention here is as a stakeholder implied by operational and maintenance costs that the AD imposes.

Operators of aircraft outside the serial range: Operators of SR20 aeroplanes whose serial numbers fall outside 1005-1815 are not covered by this AD as drafted. They are not required by this AD to perform the specified inspections or replacements, according to the AD’s Applicability heading.

Regulatory equivalence and foreign registrants: The AD allows later revisions of the service bulletin if approved by the FAA as an AMOC to FAA AD 2008-11-18 (Requirement). That creates a route for foreign-recognised compliance where the FAA has considered revisions to the SB, which may be relevant to non-Australian operators who rely on FAA approvals as part of their continuing airworthiness management.

Who pays and who decides: Owners/operators pay for inspections, parts and labour. Maintenance personnel execute the technical decisions required by the service bulletin. CASA sets the AD and enforces compliance; the FAA’s AMOC approvals determine whether later SB revisions are acceptable under this AD.

Core duties

• Perform the pressurisation inspection/check on the exhaust system in accordance with Cirrus Service Bulletin SB 2X-78-07 R1, Revision 1, dated 18 December 2007 (Requirement 1). The AD delegates the inspection method to that service bulletin, making adherence to the SB the operative method of compliance for the inspection duty.

• For Requirement 1, conduct the initial inspection within the next 25 hours time-in-service or within the next three months after the effective date of the AD, whichever occurs first; and thereafter repeat the inspection at intervals not to exceed every 100 hours time-in-service (Compliance: Requirement 1). These timings create a specific inspection cadence that must be followed.

• If the inspection finds the exhaust system defective, or if an exhaust odour is detected inside the cabin, replace the heat exchanger weldment and shroud with the new improved heat exchanger weldment and new shroud in accordance with the cited service bulletin (Requirement 2). The replacement must be done before further flight after the inspection or odour detection (Compliance: Requirement 2).

Rights and procedural options

• Acceptable alternative service-bulletin revisions: The AD allows operators to comply with "later revisions of the above SB" only if those later revisions are approved by the United States Federal Aviation Administration as an Alternate Method of Compliance to FAA AD 2008-11-18. This is an explicit right to rely on an updated service bulletin, but only when the FAA has approved that update as an AMOC to the referenced FAA AD (Requirement). Operators thus have the procedural option to use later SB revisions, subject to FAA AMOC approval.

• Continued operation where inspection is satisfactory: The AD’s compliance structure implies that, where the inspection is performed and does not reveal defects and no cabin odour is detected, the aircraft may continue to operate subject to the repetitive inspection interval (Compliance: Requirement 1). The AD does not prohibit normal operation in those circumstances.

Limits and prescriptive features

• The AD is prescriptive about parts: it requires replacement with the "new improved heat exchanger weldment and new shroud" specified in the service bulletin (Requirement 2). It does not provide alternative parts within the text.

• The AD prescribes immediate grounding until fixed where a defect is found or odour is detected by requiring replacement "before further flight" in such events (Compliance: Requirement 2). That places an operational duty to cease flying until the remedial work is completed.

Delegated technical discretion

• The AD delegates technical details of the inspection and the replacement procedures to the referenced Cirrus Service Bulletin. Maintenance personnel and the holder of the service bulletin exercise technical discretion in executing the inspection and the replacement as specified by the SB. The AD also creates an administrative discretion in accepting later SB revisions, but only where the FAA has granted an AMOC; the AD does not provide CASA’s own process for accepting alternative SBs within the text.

Recordkeeping and documentation

• The AD itself does not state recordkeeping obligations. It does, however, anchor compliance to actions specified in the service bulletin and to time-in-service intervals, which will practically require operators to document hours and inspection dates to demonstrate compliance. The AD does not define the form or recipient of any compliance report.

Effective date and temporal duties

• The AD becomes effective on 28 August 2008 (Compliance paragraph). The initial inspection window is tied to that date via the "next 3 months after the effective date" clause. The AD thereby imposes time-bound duties beginning from the effective date.

Linkage to FAA instrument

• The AD references FAA AD 2008-11-18 (Amdt 39-15541) dated 22 May 2008 and conditions recognition of later service-bulletin revisions on FAA approval as an AMOC to that FAA AD (Requirement, note). That creates a cross-jurisdictional procedural right for operators to rely on FAA-approved later SB revisions.

Textual absence of specified penalties

• The body of the AD as provided does not specify monetary penalties, civil sanctions, criminal consequences, or administrative enforcement mechanisms within its text. The AD sets mandatory technical and timing obligations, but it does not set out the penalty regime that CASA might apply for non-compliance (the AD contains no penalties paragraph).

Enforcement implication

• The AD is issued by the Civil Aviation Safety Authority and takes effect on a specified date; it is a formal directive intended to be complied with by the applicable operators (signature block; effective date). The AD therefore functions as an enforceable instrument within CASA’s broader regulatory framework, but the AD text itself does not list the enforcement powers, inspection mechanisms, or penalty amounts that CASA may use for breaches. Any specific enforcement action would be taken under CASA’s general statutory powers and enforcement procedures external to the AD text.

Operational consequence of non-compliance

• The AD prescribes that replacement must be completed "before further flight" where a defect is found or an exhaust odour detected (Compliance: Requirement 2). By specifying that flight must not continue until remedial work is done, the AD creates an operational consequence: continuing to fly after detection without replacement would be contrary to the AD’s requirements. The AD text does not state the legal or administrative consequences of such non-compliance, but the requirement itself creates an operational prohibition.

Evidence and proof of compliance

• The AD imposes inspection intervals tied to time-in-service hours and dates relative to the effective date. Demonstrably complying with the AD therefore requires factual records of time-in-service and inspection or replacement actions. The AD does not specify the precise documentary form required to prove compliance, nor does it prescribe who must receive compliance reports. Where disputes arise, those records will bear on enforcement decisions; the AD text does not specify evidentiary standards.

FAA AMOC link and enforcement coordination

• The AD allows later revisions of the service bulletin only when approved by the FAA as an AMOC to FAA AD 2008-11-18 (Requirement). That cross-reference can affect enforcement: an operator relying on a later SB revision without FAA AMOC approval would be outside the AD’s permitted compliance route. The AD does not set out how CASA would treat FAA AMOC approvals for enforcement purposes, beyond stating the acceptance provision.

Practical enforcement mechanisms not stated

• The AD does not enumerate who will inspect operators for compliance, how often, or what remedial enforcement (fines, grounding orders, certificate suspensions) CASA may deploy. The AD’s scope is technical and prescriptive; the detail of enforcement procedures remains external to the AD text.

Reference to FAA AD and AMOC process

• The AD explicitly references FAA AD 2008-11-18 Amdt 39-15541 dated 22 May 2008 (Requirement, note). It accepts "later revisions of the above SB" if those revisions are "approved by the United States Federal Aviation Administration (FAA) as an Alternate Method of Compliance (AMOC) to FAA AD 2008-11-18" (Requirement). This creates a specific interaction with FAA regulatory action: CASA’s AD incorporates, by reference, an acceptance mechanism tied to FAA’s AMOC approvals for a related FAA AD.

Delegation of technical method to manufacturer service bulletin

• Technically, the AD interacts with manufacturer-issued documentation by making SB 2X-78-07 R1 Revision 1 the operative method of compliance for the inspection and replacement duties (Requirement). That means that compliance with the AD requires following the contents of the service bulletin, which itself sits outside the AD but is incorporated by reference as the technical standard. The AD therefore depends on the legal and contractual status of service bulletins in Australian airworthiness practice to effect its requirements.

Temporal and operational interaction

• The AD’s specified timing for initial inspection and repetitive inspections interacts with operators’ existing maintenance schedules and time-in-service accounting. Operators must integrate the AD-mandated inspections into their maintenance programmes. The AD does not specify how these inspections interact with other mandatory maintenance tasks; the AD simply imposes its own intervals which must be observed.

Cross-jurisdictional compliance and foreign registrants

• For operators whose airworthiness is overseen by authorities other than CASA (for example, foreign-registered aircraft operated in Australia), the AD’s explicit recognition of FAA AMOCs for later SB revisions provides a mechanism for accepting FAA-reviewed revisions as compliant with this CASA AD. The AD does not state whether CASA will accept other foreign authority approvals in lieu of FAA AMOCs; only FAA AMOCs are mentioned.

No interaction with other Australian statutes set out in text

• The AD does not cite or reference any Australian aviation statute, regulation or instrument such as the Civil Aviation Safety Regulations, nor does it cite specific CASA enforcement or certification provisions within its text. Any legal enforcement or penalty interaction depends on CASA’s statutory powers outside the AD text; those powers are not described in the AD itself.

Parts, design and continuing airworthiness frameworks

• By requiring replacement with a "new improved heat exchanger weldment and new shroud" and tying the method to a manufacturer service bulletin, the AD interacts functionally with continuing airworthiness processes, parts supply chains, and maintenance data systems. The AD does not address how design changes or parts approvals are to be handled administratively; it simply prescribes replacement with specific upgraded assemblies in accordance with the SB.

Limitations and scope interactions

• The AD is limited by its Applicability section to particular SR20 serial numbers 1005-1815. It therefore does not legally apply to SR20 aircraft outside of that serial-number range under the terms of this instrument. The AD does not explain interactions with other ADs that might cover different serial numbers or different systems; only the FAA AD reference is included.

Documented dates and identifiers in the AD

• The AD is titled AD/CIRRUS/10 and is dated 9/2008 in the header (header). The service bulletin specified for compliance is Cirrus Service Bulletin SB 2X-78-07 R1, Revision 1, dated 18 December 2007 (Requirement 1). The AD notes FAA AD 2008-11-18 Amdt 39-15541 dated 22 May 2008 as related (Requirement). The AD was signed by James Coyne, Delegate of the Civil Aviation Safety Authority, on 16 July 2008 (signature block). The AD states that it "becomes effective on 28 August 2008" (Compliance paragraph).

No later amendments recorded in the text

• The provided AD text does not include any subsequent amendments to the AD itself, nor does it list prior versions of AD/CIRRUS/10. It does, however, allow operators to use "later revisions" of the specified Cirrus service bulletin if those later revisions are approved by the FAA as an AMOC to FAA AD 2008-11-18 (Requirement). That provision recognises potential future changes to the service bulletin without itself amending this AD.

Mechanism for accepting later service bulletin revisions

• The AD’s acceptance of later SB revisions is conditional on FAA approval as an AMOC to FAA AD 2008-11-18. That is an explicit procedural route by which later technical instructions can be treated as compliant with this AD without amendment to the AD text. The AD text does not describe any CASA mechanism for accepting SB revisions independently; the only route referred to is FAA AMOC approval.

No change log or versioning in the AD text

• The AD as supplied does not contain a change log, an explicit amendment clause, or a recorded sequence of revisions to the AD itself. The dates and identifiers set out above are the only temporal metadata included in the instrument.

Practical consequence for operators

• Operators relying on later SB revisions must verify that the FAA has granted an AMOC to FAA AD 2008-11-18 for those revisions in order for those revisions to be "considered acceptable for compliance with the equivalent Requirements of this Directive" (Requirement). The AD text does not describe how operators should evidence FAA AMOC approvals to CASA; that practical administrative pathway would be managed under CASA’s broader compliance processes external to the AD text.

No litigation recorded in the AD text

• The provided AD text contains no references to litigation, court decisions, administrative appeals or legal challenges relating to AD/CIRRUS/10. There are no cases, appeal records, or tribunal proceedings cited in the instrument.

Absence of judicial or administrative disputes in the source

• Because the AD does not include litigation references, there is no record in this text of contested interpretation, enforcement actions, or judgments concerning the AD’s requirements. Any litigation or appeals that may have occurred are not documented in the instrument supplied.

Implication for legal research

• To determine whether there has been litigation arising from this AD, an external search of CASA enforcement records, administrative appeal bodies or court databases would be required. The AD text itself contains neither a litigation history nor pointers to dispute resolution pathways.

Scope limitation by serial number: The AD applies only to Cirrus SR20 aeroplanes with serial numbers 1005 through 1815 (Applicability). Aircraft with SR20 serial numbers outside that range are not covered by this AD. Operators must verify aircraft serial numbers precisely; assuming an SR20 model alone suffices would be an error.

Short initial compliance window and use-case sensitivity: The initial inspection must be done within 25 hours time-in-service or within 3 months after the effective date of the AD, whichever occurs first (Compliance: Requirement 1). For high-utilisation aircraft 25 flight-hours can be reached quickly; for low-utilisation aircraft the three-month calendar window still imposes an earlier deadline. Operators must track both calendars and hours to avoid missing the initial window.

Repetitive inspection cadence requires integration into maintenance scheduling: The AD requires repetitive inspections at intervals not to exceed every 100 hours TIS (Compliance: Requirement 1). Operators must fit these checks into existing maintenance cycles and ensure accurate time-in-service accounting; failing to do so will leave an aircraft non-compliant with the AD’s inspection cadence.

Immediate grounding where odour or defect found: If an exhaust odour is detected in the cabin, or the inspection finds the exhaust system defective, replacement with the specified improved heat exchanger and shroud must be completed "before further flight" (Requirement 2; Compliance: Requirement 2). Practically, that means the aircraft is grounded until the replacement is done. Operators planning flight schedules must factor potential grounded time and parts lead times into operational plans.

Parts specificity and availability: The AD requires replacement with a "new improved heat exchanger weldment and new shroud" in accordance with the service bulletin (Requirement 2). The AD does not provide alternative parts or corrective actions other than following the SB. If the improved assembly is subject to supply constraints, operators face operational disruption. The AD text does not address availability or interim measures.

Reliance on external document: The AD delegates technical detail to Cirrus Service Bulletin SB 2X-78-07 R1 Revision 1 dated 18 December 2007 (Requirement 1). That means operators must obtain and follow the SB. The AD itself does not contain step-by-step inspection or replacement procedures. Failure to follow the SB as the method of compliance could mean the operator has not complied with the AD.

Conditional acceptance of later SB revisions via FAA: The AD only accepts later revisions of the service bulletin if they have been approved by the FAA as an AMOC to FAA AD 2008-11-18 (Requirement). Operators may assume that any later SB revision is automatically acceptable; that assumption would be incorrect. Only FAA AMOC-approved revisions are "considered acceptable for compliance" under this AD.

No penalties specified in the AD text: The AD does not state specific penalties or enforcement measures. Some operators might misinterpret that absence as a lack of enforceability. The presence of prescriptive mandatory requirements and an effective date means the AD is a formal directive; enforcement and penalties fall outside the AD text.

No explicit recordkeeping or reporting form required: The AD does not state how compliance should be documented or reported. Operators should not infer that documentation is unnecessary; time-in-service intervals and "before further flight" requirements imply the need for records, but the AD does not set documentary standards.

Potential confusion over FAA vs CASA procedural recognition: The AD accepts FAA-approved AMOCs for later SB revisions, but does not state whether CASA will independently approve other AMOC routes. Relying on non-FAA approvals would be outside the text’s explicit acceptance clause.

Human-detection trigger: An "exhaust odour detected inside the aeroplane cabin" is a subjective trigger for replacement (Requirement 2). Pilots’ or crew members’ subjective detection is sufficient under the AD. Variability in human detection thresholds may lead to different operational outcomes; the AD does not specify objective measurement thresholds.

Step 1 , Identify whether your aircraft is covered: Confirm the SR20 serial number. This AD applies only to Cirrus Design Corporation Model SR20 aeroplanes with serial numbers 1005 through 1815 (Applicability).

Step 2 , Obtain the referenced service bulletin: The AD mandates compliance with Cirrus Service Bulletin SB 2X-78-07 R1, Revision 1, dated 18 December 2007, to perform the required inspection and to carry out mandated replacements (Requirement 1; Requirement 2). Obtain and review that service bulletin to understand the exact inspection procedures and replacement steps.

Step 3 , Schedule the initial inspection within the AD’s initial window: Perform the pressurisation inspection/check on the exhaust system in accordance with the service bulletin within the next 25 hours time-in-service or within the next three months after the effective date of this AD, whichever occurs first (Compliance: Requirement 1). Practically, log the aircraft’s current time-in-service and calendar date to calculate the relevant deadline and schedule the inspection to occur before that deadline.

Step 4 , Integrate repetitive inspections into maintenance programme: Once the initial inspection is complete, schedule subsequent inspections at intervals that do not exceed every 100 hours time-in-service as required by the AD (Compliance: Requirement 1). Ensure that maintenance records capture inspection dates and aircraft hours to demonstrate adherence to the 100-hour maximum interval.

Step 5 , Ground and replace if a defect is found or odour detected: If the inspection identifies that the exhaust system is defective, or if an exhaust odour is detected in the cabin at any time, replace the heat exchanger weldment and shroud with the new improved heat exchanger weldment and new shroud in accordance with the service bulletin (Requirement 2). The replacement must be carried out before further flight after the inspection or odour detection (Compliance: Requirement 2). Arrange parts, qualified maintenance personnel and a slot to carry out the replacement, and do not operate the aeroplane until the replacement is complete.

Step 6 , Ensure parts and technical compliance: When procuring the "new improved heat exchanger weldment and new shroud," confirm that the parts conform to the specifications in SB 2X-78-07 R1 Revision 1. The AD does not set alternative part options in its text; compliance is tied to the parts described in the service bulletin (Requirement 2).

Step 7 , If relying on a later revision of the service bulletin, verify FAA AMOC approval: The AD allows later revisions of SB 2X-78-07 R1 only if the FAA has approved those revisions as an Alternate Method of Compliance to FAA AD 2008-11-18 (Requirement). If you intend to follow a later SB revision, obtain written confirmation that the FAA has granted an AMOC for that revision to FAA AD 2008-11-18, and retain that evidence as part of your compliance records.

Step 8 , Maintain accurate time-in-service and inspection records: Although the AD does not specify recordkeeping format, complying with the AD’s deadlines and repetitive intervals requires accurate time-in-service accounting and dated records of inspections and replacements. Retain invoices, maintenance release documents and any FAA AMOC approvals relied upon.

Step 9 , Train pilots and crews to report cabin odour: Because an "exhaust odour detected inside the aeroplane cabin" is itself a trigger for immediate replacement before further flight, ensure flight crews and regular operators are briefed to report any such odour. Establish a clear procedure for grounding the aircraft, notifying maintenance personnel and arranging the required replacement work.

Step 10 , Coordinate with maintenance providers and parts suppliers: Given the possibility of immediate grounding where a defect is found, ensure maintenance providers know the service bulletin procedures and that parts suppliers can deliver the required improved heat exchanger weldment and shroud in a timely manner. Confirm that maintenance organisations are familiar with SB 2X-78-07 R1 Revision 1 and the AD’s specific timing requirements.

Step 11 , Consider cross-authority approvals where applicable: If you are operating under a non-Australian airworthiness authority, coordinate with your authority and with the FAA if you plan to rely on later service-bulletin revisions. The AD’s acceptance of later SB revisions is conditioned on FAA AMOC approval to FAA AD 2008-11-18. Retain documentation of any cross-authority approvals used to support compliance under this AD.

Step 12 , Act from the effective date: The AD became effective on 28 August 2008; initial compliance windows are calculated from that effective date (Compliance). Ensure that any historical inspections and replacements performed after the effective date are properly recorded to demonstrate compliance if required.

Practical note on any uncertainty: If there is any doubt about whether a particular procedure, part or later service-bulletin revision meets the AD’s requirements, seek clarification from CASA or confirm FAA AMOC status where the AD refers to FAA approvals. The AD itself does not describe CASA’s own approval process for alternate methods; the only explicit conditional acceptance in the text is via FAA AMOC approval to the referenced FAA AD.

Record and retain evidence of compliance: Because the AD ties performance obligations to specific intervals and to replacement "before further flight" where defects are discovered, keep dated inspection reports, parts receipts and maintenance release documentation to evidence that the AD’s requirements were met in accordance with SB 2X-78-07 R1 Revision 1 or an FAA AMOC-approved later revision.

Summary of minimum compliance checklist

• Confirm serial number 1005-1815 (Applicability).
• Obtain SB 2X-78-07 R1 Revision 1 (Requirement 1).
• Perform initial pressurisation inspection within 25 hours TIS or 3 months from effective date, whichever first (Compliance: Requirement 1).
• Repeat inspections no later than every 100 hours TIS (Compliance: Requirement 1).
• If inspection shows defect or cabin odour detected, replace heat exchanger weldment and shroud with new improved parts per the SB before further flight (Requirement 2; Compliance: Requirement 2).
• Use later SB revision only if FAA-approved as an AMOC to FAA AD 2008-11-18 (Requirement).
• Keep accurate time-in-service and dated maintenance records to evidence compliance.