AD/B767/246 - AN-26 Insulation Blankets

The AD operates through a small number of interlocking technical and administrative concepts drawn from the aviation safety and certification framework present in the text.

Scope and applicability: The AD applies to Boeing 767-200 and 767-300 series aeroplanes limited to the serial numbers referenced in Boeing Special Attention Service Bulletin 767-25-0411 (Applicability). The AD does not list serial numbers in the body; instead it delegates precise identification to the Boeing service bulletin.

Hazard identification: The background asserts reports of in‑flight and ground fires involving insulation blankets constructed of a PET material identified as ORCON Orcofilm AN-26 (all variants AN-26, AN-26A, AN-26B). The AD states the hazard is propagation of fire following ignition from electrical arcing or sparking, and sets the remedial objective as removal of AN-26 from the fuselage (Background).

Choice of compliance paths: Two alternative compliance paths are provided. One path requires using a replacement method approved by the Manager, Seattle ACO, FAA and mandates replacement material compliance with 14 CFR 25.856(a) (Requirement 1.a.). The other path requires following Boeing Special Attention Service Bulletin 767-25-0411 Accomplishment Instructions (Requirement 1.b.). Hence compliance can be achieved either by following the OEM service bulletin or by an FAA-approved alternative method that meets the cited flammability regulation.

Identification rule and safe harbours: The AD supplies an immediate identification shortcut: part-marked insulation with a manufacture date before July 1981 or after December 1988 is not AN-26 (Note 1). It also provides a process to determine non-AN-26 via methods approved by the Manager, Seattle ACO or via Appendix A of Boeing SB 767-25-0411 (Requirement 1.b., Applicability).

Prohibition on reinstallation: The AD contains a standing prohibition on fitting AN-26 as replacement material unless the insulation has been modified to meet 14 CFR 25.856(a) (Requirement: 2.). That effectively prevents later reuse of the identified material unless its flammability characteristics are altered and certified to meet the referenced regulation.

Timing: Compliance is required within 96 months after the effective date for the removal/replacement action (Compliance: 1.). The prohibition on installing AN-26 as a replacement applies immediately after the AD becomes effective (Compliance: 2.).

Institutional delegation: Approval authority for alternative methods of compliance and identification is assigned to the Manager, Seattle Aircraft Certification Office (ACO), FAA (Requirement: 1.a.; Requirement: 1.b.). The AD also cross-references FAA AD 2008-23-09 (Note 2) and Boeing Special Attention Service Bulletin 767-25-0411, integrating FAA and OEM instruments into CASA’s mandatory requirement.

These concepts frame how operators and maintenance organisations must act: identify affected aircraft and insulation using defined methods, choose one of two compliance routes, replace material in specified areas within 96 months, and avoid the reinstatement of AN-26 unless modified to meet 14 CFR 25.856(a).

Primary affected parties are explicitly described by the AD text and implied by the operational mechanics.

Operators and owners of Boeing 767-200 and 767-300 series aircraft listed in Boeing Special Attention Service Bulletin 767-25-0411 are the direct payers and implementers of the work. The AD’s Applicability clause restricts the instrument to those aeroplanes whose serial numbers are defined in the Boeing service bulletin; therefore, only operators of those serial-numbered aeroplanes are bound by the AD’s removal and replacement requirements (Applicability).

Maintenance organisations, airlines’ engineering departments, and approved maintenance providers carrying out major structural and systems work must perform the removals and installations in accordance with the chosen compliance route. They must be able to identify AN-26 material using a method approved by the Manager, Seattle ACO, or Boeing SB Appendix A (Requirement: 1. b.; Note 1). These tasks will involve inspection access to crown areas, flight deck and circuit breaker panels, sidewalls, lavatories, closets, galleys, cargo compartments, air ducting, waste and water tubing, and underfloor areas (Requirement: 1. a. (i)-(vii)), so maintenance planners and rosters will be affected by the scope and timing.

Parts suppliers and manufacturers of replacement insulation blankets are affected because the AD requires new blankets to comply with 14 CFR 25.856(a) when the FAA-approved route is used (Requirement: 1. a.). Suppliers must either supply material that meets 14 CFR 25.856(a) or supply parts whose installation follows Boeing SB 767-25-0411 instructions.

National and foreign civil aviation authorities are indirectly implicated. The AD references FAA entities , the Manager, Seattle ACO, and FAA AD 2008-23-09 , making FAA approvals and guidance a material part of compliance (Requirement: 1.; Note 2). For international operators with Australian operations, coordination among CASA, FAA and OEM service bulletins will be required.

CASA and its delegate (David Villiers, who signed the instrument) are the issuing authority and decision point for the AD becoming effective (Delegate of the Civil Aviation Safety Authority; signature block). The AD delegates certain approvals to the Manager, Seattle ACO, FAA, so that FAA officer will decide on identification methods and alternative replacement methods in some circumstances (Requirement: 1.).

Lastly, passengers and other third parties bear diffusion of the cost through potential ticket pricing and reduced aircraft availability during maintenance; the AD text establishes the work but does not quantify economic impact. In sum, aircraft operators, maintenance providers, parts suppliers and FAA/Boeing-certification authorities are the concrete actors who must act or make decisions under the AD.

The AD prescribes specific duties, limited rights to choice between compliance paths, and delegated decision rights.

Primary duties

• Identification duty: Operators must determine which insulation blankets are constructed of AN-26. The AD allows identification either by an identification method approved by the Manager, Seattle ACO, FAA or in accordance with Appendix A of Boeing Special Attention Service Bulletin 767-25-0411 (Requirement: 1. b.). Note 1 provides a strictly usable marker: insulation material part-marked with a date of manufacture before July 1981 or after December 1988 is not AN-26.
• Removal and replacement duty: For any insulation determined to be AN-26 in pressurised fuselage areas, operators must remove the blankets and install approved replacements within 96 months after the AD’s effective date (Requirement: 1.; Compliance: 1.). The AD lists the pressurised areas where affected insulation may be found (Requirement: 1. a. (i)-(vii)).
• Prohibition duty: After the effective date, no person may install insulation blankets constructed of AN-26 as replacement material unless the AN-26 has been modified to comply with 14 CFR 25.856(a) (Requirement: 2.; Compliance: 2.).

Allowed choices and rights

• Method choice: Operators have the right to elect between two prescribed methods of accomplishing the replacement work: either use a method approved by the Manager, Seattle ACO, FAA that results in replacement insulation meeting 14 CFR 25.856(a) (Requirement: 1. a.), or perform the work in accordance with the Boeing Special Attention Service Bulletin 767-25-0411 Accomplishment Instructions (Requirement: 1. b.). This is a substantive right to select an OEM-prescribed remediation or an FAA-approved alternative method.
• Approval routes: Where operators choose the FAA-approved method route, they must obtain approval from the Manager, Seattle ACO, FAA for identification or method. That gives the Manager operational decision‑making authority over equivalence (Requirement: 1. a.; Requirement: 1. b.).

Recordkeeping and certification duties: The AD text does not specify explicit recordkeeping or certification steps, nor does it list forms, but the mechanics of any FAA/CASA approval process imply that operators will have to demonstrate compliance either through accomplishment records aligned to Boeing SB 767-25-0411 or through documentation of FAA approval of the alternative method. The AD itself does not set a document-retention period or format.

Rights regarding non-applicability: The AD provides a limited safe harbour: insulation part-marked with a manufacture date outside July 1981-December 1988 is declared not to be AN-26 (Note 1). That grants operators a clear basis to exclude certain materials without further testing where the mark is present and reliable.

Scope limitations and delegations: The AD confines applicability to discrete serial numbers as listed in Boeing SB 767-25-0411, so operators whose aircraft are not listed are not subject to these duties (Applicability). Decisions about identification methods and acceptance of replacement methods are delegated to the FAA Manager, Seattle ACO, rather than to CASA in isolation, creating an inter‑authority approval pathway (Requirement: 1.).

The AD imposes duties to inspect, remove, and replace particular insulation material within set deadlines, permits a choice between prescribed compliance methods, delegates specific approval powers to the FAA Manager, and provides a narrow identification safe harbour via factory date marks.

The AD text itself does not enumerate criminal or pecuniary penalties, nor does it set out an enforcement regime within its body. The instrument records an effective date, the compliance timeline, and the signature of a CASA delegate, but does not specify sanctions or civil enforcement procedures in the printed text (This Airworthiness Directive becomes effective on 15 January 2009; Delegate of the Civil Aviation Safety Authority).

Because the AD is a mandatory airworthiness directive issued by CASA, compliance is a regulatory requirement; the AD requires removal and replacement of AN-26 insulation and prohibits installing AN-26 as replacement unless modified to comply with 14 CFR 25.856(a) (Requirement: 1.; Requirement: 2.). The AD cross-references FAA material (14 CFR 25.856(a) and FAA AD 2008-23-09) and Boeing service instructions, integrating these instruments into the technical standard to be met (Note 2; Requirement: 1. a.; Requirement: 1. b.). The text does not state who enforces compliance in operational terms, but the declaration of effectiveness and the requirement timeline are features typical of compulsory regulatory instruments.

Enforcement implications that follow from the AD’s mechanics, without being specified in the text:

• Aircraft grounded or placed out of service: The AD requires physical work to be carried out within 96 months. The AD itself does not say that non-compliant aircraft are unairworthy, nor does it set out suspension or grounding procedures. The AD does not state whether CASA will issue further directions for operations pending compliance, or whether operators must obtain special permission to continue flying. The document does not explain remedial processes for non-compliance.
• Approval enforcement: The AD assigns approval roles to the Manager, Seattle ACO, FAA for identification and methods. The AD does not set enforcement consequences if an operator uses an unapproved method or fails to obtain Manager approval where required; it simply conditions validity of the alternative route on such approval (Requirement: 1. a.; Requirement: 1. b.).
• Cross-jurisdictional effect: The AD references FAA AD 2008-23-09 and Boeing SB 767-25-0411; it does not specify whether CASA will accept FAA approvals or how CASA will coordinate enforcement with foreign authorities. The AD makes FAA approvals part of the means of compliance, implying mutual recognition for these purposes (Requirement: 1.; Note 2).

In short, the AD mandates remedial actions and prescribes approval channels but does not itself state enforcement processes or penalties. Readers must therefore look to CASA’s broader regulatory framework and administrative practices for explicit enforcement tools and sanctions, which are not contained in this text.

The AD explicitly anchors compliance to other regulatory and manufacturer instruments. It cross-references federal US regulation, an FAA airworthiness directive, and a Boeing service bulletin, each of which becomes operationally relevant for compliance.

14 CFR 25.856(a): The AD requires replacement insulation installed under the FAA-approved-method route to comply with 14 CFR 25.856(a) (Requirement: 1. a.). That US Federal Aviation Regulation sets flammability performance standards for thermal/acoustic insulation associated with transport category aeroplanes. By referencing 14 CFR 25.856(a) as the performance target, the AD imports a US federal standard for material flammability into its compliance criteria. The AD does not reproduce the contents of 14 CFR 25.856(a); it relies on the operator or maintainer to ensure the replacement material meets that regulation.

FAA AD 2008-23-09: The AD notes that FAA AD 2008-23-09 is a related document (Note 2). That FAA AD is referenced presumably because it addresses the same or similar hazard for US-registered aeroplanes. The CASA AD thereby aligns its action with FAA remedial measures, integrating their findings and directives into Australian regulatory action. The text does not assert whether compliance with FAA AD 2008-23-09 satisfies the CASA AD, though it uses FAA documents as identification and approval touchstones.

Boeing Special Attention Service Bulletin 767-25-0411: The AD’s Applicability and one of its two compliance routes point to Boeing SB 767-25-0411. Applicability is limited to serial numbers defined in that service bulletin, and one full compliance option is to perform the replacement per the Boeing SB’s Accomplishment Instructions and use Appendix A for identification (Applicability; Requirement: 1. b.). That makes the OEM service bulletin an incorporated, operative document for owners and operators. The AD therefore places reliance on manufacturer technical instructions as a lawful means of compliance.

Interconnection and administrative delegation: The AD delegates approval of identification methods and alternative replacement methods to the Manager, Seattle ACO, FAA (Requirement: 1. a.; Requirement: 1. b.). That creates cross‑authority reliance: CASA mandates compliance but refers specific technical judgments to an FAA officer. The AD does not explain the legal basis for delegating approval to a foreign authority, but the text makes clear that FAA approvals are an accepted pathway to satisfy CASA’s requirement.

Gaps in statutory text: The AD does not cite Australian statute or CASA regulatory provisions authorising the AD within the printed text. It does not specify procedural relationships, such as how a CASA exemption or variation might be sought, or how FAA approvals are to be recorded with CASA. Those interactions are therefore practical and procedural rather than textual in this instrument.

In sum, the AD interacts with other laws and instruments by making compliance contingent on meeting 14 CFR 25.856(a), by incorporating Boeing SB 767-25-0411 as an alternate compliance method, and by referencing FAA AD 2008-23-09. It relies on FAA managerial approvals for identification and alternative methods, making the FAA’s technical standards and approvals central to satisfying the CASA requirement.

The instrument text presented contains a single AD issuance: AD/B767/246 , AN-26 Insulation Blankets, dated 1/2009, with an effective date of 15 January 2009 (header and effective date lines). The signature block records David Villiers as Delegate of the Civil Aviation Safety Authority, dated 24 November 2008 (Delegate of the Civil Aviation Safety Authority; 24 November 2008). The AD text includes internal notes and cross-references (Note 1; Note 2) but there is no information within the supplied text indicating any subsequent amendments, revisions, superseding ADs, or revocations.

What the text shows about history:

• Issuance timeline: The AD was signed on 24 November 2008 and made effective 15 January 2009, giving a formal timeframe between signature and effectiveness (Delegate signature date; This Airworthiness Directive becomes effective on 15 January 2009).
• AD identifier and date: The AD is labelled AD/B767/246 and carries a publication reference 1/2009 (headers). These identifiers indicate sequence and year but the instrument text does not present a history of prior ADs for the same matter nor does it state that it supersedes any earlier CASA AD.

Absence of amendment entries: There are no entries in the supplied text that indicate amendments, corrigenda, or updates. No "amendment" or "as amended" language is included. If CASA subsequently amended the AD after the effective date, that information is not present in the provided material.

Practical implication: The supplied instrument should be treated as the original 2009 issuance. Readers seeking any later modifications, extensions, or revocations must consult CASA’s AD repository or subsequent legislative instruments; no amendment history is contained in the provided text.

The AD text does not reference, summarise, or annex any litigation, appeals, or judicial review proceedings related to the directive. There are no case names, court references, or administrative appeals described in the instrument. The document contains only the AD’s substance, dates, signature and cross‑references to FAA and Boeing documents (Background; Delegate of the Civil Aviation Safety Authority; Note 2).

What this absence implies for the user relying on this source:

• No in-source case law: There are no judicial or tribunal decisions included within or attached to this AD that interpret the AD’s requirements or resolve disputes arising from it.
• No contested history disclosed: The AD does not disclose whether the instrument was the subject of any legal challenge before or after issuance, nor whether any party sought judicial review or merits review. If litigation or appeals occurred elsewhere, they are not part of the text provided.
• Need for external research if litigation matters are relevant: If a reader requires knowledge of whether the AD generated disputes over technical compliance, enforcement, or authority, they must seek external legal databases, court records, or CASA administrative records. The AD as supplied does not provide that information.

In short, there is no litigation history recorded in the AD text. Any assertion about subsequent legal challenges would require sources outside the document provided.

The AD contains a number of provisions and cross‑references that create practical traps for operators, maintenance organisations, and compliance officers if taken at face value without careful reading.

Serial-number limitation and reliance on Boeing SB: Applicability is limited to Boeing 767-200 and 767-300 series aircraft whose serial numbers are defined in Boeing Special Attention Service Bulletin 767-25-0411 (Applicability). The AD therefore requires operators to consult the Boeing service bulletin to determine whether particular airframes are within scope. Failure to consult Appendix A or to correctly identify the serial numbers listed in the Boeing SB could lead to mistaken non‑compliance or unnecessary work.

Dual compliance routes with differing evidentiary burdens: The AD offers two compliance routes: an FAA‑approved method requiring replacement materials to meet 14 CFR 25.856(a), or performance of the work per Boeing SB 767-25-0411. The FAA-approved alternative requires Manager, Seattle ACO approval for identification or method (Requirement: 1. a.), which involves interaction with a foreign authority and potential documentation burdens. Operators who choose this path must secure that approval; assuming approval is automatic is a mistake.

Identification method dependency and ambiguous labelling: The AD allows identification via a method approved by the Manager, Seattle ACO, or via Appendix A of Boeing SB 767-25-0411 (Requirement: 1. b.). While Note 1 provides a date‑mark safe harbour (manufacture date before July 1981 or after December 1988 is not AN-26), many parts may lack clear part‑marking or the mark may be obscured. In those cases, operators must rely on Appendix A or seek FAA-approved identification, creating time and cost exposure.

Broad list of affected locations: The AD lists a range of locations where AN-26 may be installed: crown areas, behind flight deck and circuit breaker panels, behind sidewalls, lavatories, closets, galleys, cargo compartments, air ducting, waste and water tubing, and areas under floor panels (Requirement: 1. a. (i)-(vii)). Those spaces are extensive and in many cases difficult to access for inspection and replacement, raising the likelihood of longer maintenance durations than anticipated.

Reinstallation prohibition applies immediately: The AD states that no person may install AN-26 as a replacement unless modified to meet 14 CFR 25.856(a), with the prohibition effective after the AD’s effective date (Requirement: 2.; Compliance: 2.). Operators sourcing replacement blankets during the compliance window must ensure replacement stock meets the requirement; otherwise they risk installing prohibited material.

Interplay of FAA approval and CASA mandate: The AD delegates technical approvals to the Manager, Seattle ACO, FAA for identification and replacement method acceptance (Requirement: 1.). This delegation can cause process complexity: Australian operators must engage an FAA office for approvals that are material to satisfying a CASA AD. Assuming that local CASA processes alone suffice would be a mistake.

No explicit recordkeeping or verification procedure specified: The AD does not set out paperwork or certification procedures for documenting compliance. Practitioners must therefore devise or seek guidance on what constitutes adequate evidence of compliance, for example, Boeing SB accomplishment records or FAA approval letters. Relying on informal or inadequately documented work could cause regulatory exposure if an audit or inspection occurs.

No penalties or enforcement detail in the AD text: The AD does not state enforcement measures or sanctions; it records the requirement and timing but not the procedural steps CASA will use to enforce. Assuming leniency or the absence of enforcement would be unwise; the AD is a mandatory instrument and requires action within the specified timetable.

In short, the gotchas are: reliance on external documents for serial numbers and identification, the need for FAA approvals for certain routes, potentially inaccessible locations increasing labour/time, immediate prohibition on reinstalling AN-26, and lack of procedural detail on recordkeeping and enforcement in the AD itself.

The AD prescribes practical steps and options; below is a compliance roadmap derived from the AD’s explicit text. Operators should treat this as an instrument‑specific checklist and retain or obtain authoritative approvals and records.

1. Confirm applicability

   • Obtain Boeing Special Attention Service Bulletin 767-25-0411 and check the serial-number list to confirm whether each aeroplane in the operator’s fleet is captured by the AD (Applicability). Do not assume all 767-200/-300 series aircraft are affected , check serial numbers.

2. Identify insulation material

   • Inspect the listed fuselage and pressurised areas where AN-26 may be installed: crown areas; behind flight deck and circuit breaker panels; behind sidewalls, lavatories, closets, galleys; cargo compartment areas; air ducting; waste and water tubing; underside of floor panels (Requirement: 1. a. (i)-(vii)).
   • For each piece of insulation located, look for part‑marking date codes. If the insulation is part‑marked with a manufacture date before July 1981 or after December 1988, the AD states it is not AN-26 and no removal for AN-26 reasons is required for that part (Note 1).
   • Where part‑marks are absent or ambiguous, use the identification method set out in Appendix A of Boeing SB 767-25-0411, or obtain an identification method approved by the Manager, Seattle ACO, FAA (Requirement: 1. b.). If using FAA approval, secure written approval from the Manager, Seattle ACO.

3. Choose compliance route

   • Option A (FAA-approved-method route): Seek approval from the Manager, Seattle ACO, FAA for the removal and installation method. Ensure any replacement insulation obtained or modified under this route complies with 14 CFR 25.856(a) (Requirement: 1. a.).
   • Option B (Boeing SB route): Perform removal and install per the Accomplishment Instructions of Boeing Special Attention Service Bulletin 767-25-0411 (Requirement: 1. b.). Use Appendix A of the SB for identification where applicable.

4. Plan operations and logistics

   • Program the work into maintenance planning within the mandated compliance window; the AD requires completion within 96 months after the effective date (Compliance: 1.). Note that replacement parts and access to certain areas may require significant disassembly and scheduled down time.
   • Source replacement insulation material that demonstrably meets 14 CFR 25.856(a) if using Option A, or procure parts and technical instructions aligned with Boeing SB 767-25-0411 if using Option B.

5. Avoid prohibited installations

   • From the AD’s effective date onward, do not install any insulation constructed of AN-26 as replacement unless it has been modified to comply with 14 CFR 25.856(a) (Requirement: 2.; Compliance: 2.). Ensure procurement teams and stores are notified and inventory segregated to prevent inadvertent installation.

6. Documentation and evidence

   • Although the AD does not specify recordkeeping procedures, document identification findings, method selections, approvals (including any FAA Manager approvals), parts serial and batch numbers, and accomplishment reports. If compliance is performed per Boeing SB 767-25-0411, retain the SB accomplishment records.
   • If FAA approval is relied on, retain the Manager, Seattle ACO approval documentation and any technical equivalence findings demonstrating compliance with 14 CFR 25.856(a).

7. Liaise with certification authorities

   • Coordinate with CASA and the relevant regional FAA office where Manager, Seattle ACO approval is sought. Maintain a chain of communication and documentation for audits or airworthiness inspections. The AD explicitly places some decision-making with the Manager, Seattle ACO, FAA, so early engagement reduces approval delays (Requirement: 1.).

8. Quality control and verification

   • After replacement, verify that installed insulation materials meet the specifications required by the chosen compliance route. For Option A, obtain test reports or supplier certifications showing conformity with 14 CFR 25.856(a); for Option B, verify conformity with Boeing SB instructions.

9. Schedule and resource allocation

   • Work within the 96‑month compliance window, but anticipate lead times for parts, FAA approvals, and extensive labour requirements for inaccessible locations. Early scheduling reduces risk of fleet shortages and compressed maintenance periods.

10. Update maintenance manuals and supply chain

• Ensure maintenance manuals, procurement lists, and parts catalogues are updated to reflect the prohibition on AN-26 and to specify approved replacement materials. Notify stores, purchasing and maintenance teams of the change control.

This roadmap follows the AD’s explicit requirements and references. Operators should prepare documentation that demonstrates adherence to the AD’s two‑path compliance model, secure any required FAA approvals in writing, and ensure that replacement materials satisfy 14 CFR 25.856(a) or Boeing SB 767-25-0411 instructions.