{"id":"F2008L00146","name":"AD/B737/312 Amdt 1 - Aft Pressure Bulkhead Inspection","slug":"ad-b737-312-amdt-1-aft-pressure-bulkhead-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":72288,"registerId":"commonwealth-F2008L00146-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Boeing 737 Series Aeroplanes","sectionType":"division","heading":"Boeing 737 Series Aeroplanes","content":"### Boeing 737 Series Aeroplanes\n\n| AD/B737/312 Amdt 1 | Aft Pressure Bulkhead Inspection | 3/2008 DM |\n| ------------------ | -------------------------------- | --------- |\n\n| Applicability: | Boeing Model 737-600, -700, -700C, -800 and -900 series aircraft, as identified in Boeing Alert Service Bulletin 737-53A1253.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |\n| -------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Perform repetitive inspections and if required, corrective actions, of the aft pressure bulkhead in accordance with the accomplishment instructions of Boeing Alert Service Bulletin 737-53A1253, dated May 18, 2007 or later revision approved by the FAA as an Alternative Method of Compliance (AMOC).Note: FAA AD 2007-25-03 Amendment 39-1528 refers.                                                                                                                                                                                                                                                                                                                          |\n| Compliance:    | As per Boeing Alert Service Bulletin 737-53A1253.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |\n|                | This Amendment becomes effective on 1 February 2008.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |\n| Background:    | This Airworthiness Directive has resulted from several cases of web “oil canning” or bulges or previous repairs which could lead to web cracking and consequent failure of the aft pressure bulkhead.This AD requires repetitive inspection of the aft side and/or forward side of the aft pressure bulkhead to identify and to correct “oil canning” or bulges. There is also a one time inspection for previously installed web repairs and corrective actions if necessary.This amendment adds a reference to the service bulletin in the applicability. There is no change to the requirements or compliance.The original issue of this AD became effective on 14 January 2008. |\n\n![](image.001.png)  \nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n18 January 2008","sortOrder":0},{"sectionNumber":"AD/B737/312 Amdt 1","sectionType":"part","heading":"AD/B737/312 Amdt 1","content":"## AD/B737/312 Amdt 1","sortOrder":1},{"sectionNumber":"Aft Pressure Bulkhead Inspection","sectionType":"part","heading":"Aft Pressure Bulkhead Inspection","content":"## Aft Pressure Bulkhead Inspection","sortOrder":2},{"sectionNumber":"3/2008 DM","sectionType":"part","heading":"3/2008 DM","content":"## 3/2008 DM","sortOrder":3}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"This amendment adds a reference to Boeing Alert Service Bulletin 737-53A1253 in the applicability (clarifying which aircraft are covered) but expressly states there is no change to the substantive inspection or compliance requirements. (Background / Applicability)"},"complexity_factors":["Technical inspection and repair requirements tied to a manufacturer service bulletin rather than self-contained regulatory text (Requirement).","Applicability limited to specific Boeing 737 submodels as identified in the service bulletin, requiring cross-referencing (Applicability).","Repetitive inspections plus potential corrective actions create ongoing operational and maintenance scheduling burdens (Requirement / Background).","Allows use of later FAA‑approved revisions as an AMOC, introducing dependency on another regulator’s approvals (Requirement).","References to FAA AD 2007-25-03 and alignment with that AD require coordination across regulatory documents (Background).","Effective date and enforcement by CASA establish fixed compliance timing and administrative oversight (Compliance).","Costs and resource allocation fall on aircraft operators (inspections/repairs); on-going compliance creates recurrent expense (Background)."],"plain_english_summary":"Requires operators of Boeing 737-600/700/700C/800/900 aircraft identified in Boeing Alert Service Bulletin 737-53A1253 to perform repeated inspections and any needed repairs of the aft pressure bulkhead per that service bulletin because web “oil canning” or bulges can lead to cracking and failure. Aircraft operators pay for and carry out the inspections and corrective work; CASA enforces compliance. The amendment simply adds the service bulletin reference to the applicability and does not change inspection requirements."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a minor amendment that explicitly states it adds only a reference to the service bulletin in the applicability section with no change to requirements or compliance. The scope remains exactly as originally intended: ensuring structural integrity of the aft pressure bulkhead on specified Boeing 737 variants."},"complexity_factors":["Very short document (approximately 250 words)","Only 1 defined term implicitly referenced (Alternative Method of Compliance/AMOC)","No nested conditional logic — simple 'inspect and repair if needed' structure","Single cross-reference to FAA AD 2007-25-03 and Boeing Service Bulletin 737-53A1253","Clear, unambiguous compliance deadline (effective date specified)","Straightforward applicability criteria (specific aircraft models by series)"],"plain_english_summary":"This mandatory CASA Airworthiness Directive amends an existing order for certain Boeing 737 Next Generation (-600, -700, -700C, -800, -900) requiring repeated inspections of the aft pressure bulkhead for \"oil canning\" or bulges, a one‑time check for prior repairs, and corrective action if defects are found.\n\nIt matters because the aft bulkhead preserves cabin pressurisation; discovered bulges and repairs could lead to cracking and catastrophic pressurisation loss. Compliance is legally required."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b737-312-amdt-1-aft-pressure-bulkhead-inspection","history":"/api/acts/ad-b737-312-amdt-1-aft-pressure-bulkhead-inspection/history","analysis":"/api/acts/ad-b737-312-amdt-1-aft-pressure-bulkhead-inspection/analysis","conflicts":"/api/acts/ad-b737-312-amdt-1-aft-pressure-bulkhead-inspection/conflicts","importantCases":"/api/acts/ad-b737-312-amdt-1-aft-pressure-bulkhead-inspection/important-cases","documents":"/api/acts/ad-b737-312-amdt-1-aft-pressure-bulkhead-inspection/documents"}}