{"id":"F2008L01912","name":"AD/B727/101 Amdt 2 - Rear Pressure Bulkhead Web","slug":"ad-b727-101-amdt-2-rear-pressure-bulkhead-web","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":74137,"registerId":"commonwealth-F2008L01912-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Boeing 727 Series Aeroplanes","sectionType":"division","heading":"Boeing 727 Series Aeroplanes","content":"### Boeing 727 Series Aeroplanes\n\n| AD/B727/101 Amdt 2 | Rear Pressure Bulkhead Web | 7/2008 |\n| ------------------ | -------------------------- | ------ |\n\n| Applicability: | All Model 727 series aircraft.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n| Requirement:   | Action in accordance with the technical requirements of FAA AD 90-24-11 Amdt39-6814.Note: Boeing Alert Service Bulletins (ASB) 727-53A0171 Revision 1 and727-53A0171 Revision 2, refer.                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |\n| Compliance:    | As specified in the Requirement document.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |\n|                | This Amendment becomes effective on 3 July 2008.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |\n| Background:    | This Directive implemented Boeing Alert Service Bulletin 727-53-0171 Revision 1 which was issued following the discovery of cracks in thirty airframes. Cracking is attributed to fatigue under cabin pressure cycling.Amendment 1 removed the repetitive inspection requirement for aircraft that have incorporated the preventative modification. It also required that, within 15,000 landings after repair with the -1 repair kit, certain aircraft must be modified by incorporation of a reinforcing strap.Amendment 2 is issued to update this Directive to align with the latest FAA AD, which introduces Revision 2 of the related ASB 727-53A0171. |\n\n![](image.001.png)  \nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n23 May 2008","sortOrder":0},{"sectionNumber":"AD/B727/101 Amdt 2","sectionType":"part","heading":"AD/B727/101 Amdt 2","content":"## AD/B727/101 Amdt 2","sortOrder":1},{"sectionNumber":"Rear Pressure Bulkhead Web","sectionType":"part","heading":"Rear Pressure Bulkhead Web","content":"## Rear Pressure Bulkhead Web","sortOrder":2},{"sectionNumber":"7/2008","sectionType":"part","heading":"7/2008","content":"## 7/2008","sortOrder":3}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"flash_summary":{"complexity_score":5,"scope_assessment":{"changed":false,"description":"Amendment 2 does not broaden the directive’s applicability or alter the subject matter; it updates the technical reference to the FAA’s latest AD and the related ASB Revision 2. The directive has always targeted rear pressure bulkhead web fatigue issues on all Model 727 aircraft; Amendment 1 made substantive changes to inspection and modification timing, but Amendment 2 is an alignment/update rather than a scope expansion."},"complexity_factors":["Cross-references and requires action “in accordance with” an external FAA Airworthiness Directive (FAA AD 90-24-11 Amdt39-6814) rather than reproducing technical steps locally","Dependence on multiple Boeing Alert Service Bulletins (ASB Revisions 1 and 2) for technical instructions","Multiple amendment-history effects: original ASB-driven directive, Amendment 1 changed inspection requirements and imposed a 15,000-landing modification window after certain repairs, and Amendment 2 aligns to a further ASB revision","Fleet-wide applicability (all Model 727) increases administrative burden and variation in individual aircraft compliance status","Compliance timing tied to operational metrics (e.g. 15,000 landings after a specified repair) requires record-keeping and tracking","Technical nature of inspections/repairs/modifications implies need for specialised maintenance resources and possible aircraft downtime"],"plain_english_summary":"This directive requires operators of all `Boeing 727` series aeroplanes to carry out inspections, repairs and any specified modifications to the rear pressure bulkhead web in accordance with FAA AD 90-24-11 Amendment 39-6814 and related Boeing Alert Service Bulletins. It follows discovery of fatigue cracking in about thirty airframes; Amendment 2 updates the Australian directive to align with the FAA's latest AD/ASB revision. Operators bear the cost and operational disruption of inspections and repairs; CASA enforces compliance."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This Airworthiness Directive maintains its original narrow scope — addressing a specific structural fatigue issue in Boeing 727 rear pressure bulkheads. While Amendment 2 updates the technical references to align with revised FAA and Boeing guidance, it does not expand the directive to cover additional aircraft types, systems, or safety issues beyond the original 1990 safety concern."},"complexity_factors":["Short, single-purpose instrument (approximately 250 words)","Only 2 defined technical references (FAA AD 90-24-11 and Boeing ASB 727-53A0171)","Heavy reliance on external documents — the actual technical requirements are not reproduced in the text but incorporated by reference","Simple conditional logic: applies to 'all Model 727 series aircraft' with no exceptions or nested conditions","Clear compliance structure: single action required, with timing 'as specified in the Requirement document'","Amendment history provided in plain English background section, aiding comprehension"],"plain_english_summary":"This AD mandates inspection and repair of the Boeing 727 rear pressure bulkhead in Australia after metal‑fatigue cracks were found, requiring operators to follow FAA AD 90‑24‑11 and Boeing Alert Service Bulletin 727‑53A0171 (Rev 1 or 2). It affects all Australian 727 operators (passenger, cargo, charter) because unchecked cracks risk structural failure and decompression. Amendment 2 updates the directive to match the FAA and incorporate Revision 2 of the service bulletin."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b727-101-amdt-2-rear-pressure-bulkhead-web","history":"/api/acts/ad-b727-101-amdt-2-rear-pressure-bulkhead-web/history","analysis":"/api/acts/ad-b727-101-amdt-2-rear-pressure-bulkhead-web/analysis","conflicts":"/api/acts/ad-b727-101-amdt-2-rear-pressure-bulkhead-web/conflicts","importantCases":"/api/acts/ad-b727-101-amdt-2-rear-pressure-bulkhead-web/important-cases","documents":"/api/acts/ad-b727-101-amdt-2-rear-pressure-bulkhead-web/documents"}}