{"id":"F2007L04236","name":"AD/B737/310 - Body Station 178 Bulkhead Vertical Beam Webs","slug":"ad-b737-310-body-station-178-bulkhead-vertical-beam-webs","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":70448,"registerId":"commonwealth-F2007L04236-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/B737/310 | Body Station 178 BulkheadVertical Beam Webs | 13/2007 DM |\n| ----------- | ------------------------------------------- | ---------- |\n\n| Applicability: | Model 737-100, -200, -200C, -300, -400, and -500 series aircraft, as identified in Boeing Service Bulletin 737-53A1225 Revision 1, or later FAA approved revision.                                                                                                                                                                                                                              |\n| -------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Action in accordance with the technical requirements of FAA AD 2007-03-03 Amdt 39-14914.                                                                                                                                                                                                                                                                                                        |\n| Compliance:    | As specified in the Requirement document, with a revised effective date of26 October 2007.                                                                                                                                                                                                                                                                                                      |\n|                | This Airworthiness Directive becomes effective on 26 October 2007.                                                                                                                                                                                                                                                                                                                              |\n| Background:    | The FAA received reports of numerous cracks in the vertical beam webs of the body station (BS) 178 bulkhead. Such cracking, unless detected and corrected, could result in loss of structural integrity of the BS 178 bulkhead, and consequently could impair the operation of the control cables for the elevators, speed brakes, and landing gear, or could cause the loss of cabin pressure. |\n\n![](image.001.png)  \nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n24 October 2007","sortOrder":0},{"sectionNumber":"AD/B737/310","sectionType":"part","heading":"AD/B737/310","content":"## AD/B737/310","sortOrder":1},{"sectionNumber":"Body Station 178 BulkheadVertical Beam W","sectionType":"part","heading":"Body Station 178 BulkheadVertical Beam Webs","content":"## Body Station 178 Bulkhead  \nVertical Beam Webs","sortOrder":2},{"sectionNumber":"13/2007 DM","sectionType":"part","heading":"13/2007 DM","content":"## 13/2007 DM","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"This instrument adopts and enforces the scope of FAA AD 2007-03-03 for the specified Boeing 737 model series and references Boeing Service Bulletin 737-53A1225 Rev 1 (or later FAA-approved revision). It does not expand the population or requirements beyond the FAA directive; it transposes that external AD into domestic regulatory effect with the stated effective date."},"complexity_factors":["Cross-reference to an external FAA Airworthiness Directive (Requirement: \"Action in accordance with the technical requirements of FAA AD 2007-03-03 Amdt 39-14914\") — requires access to and alignment with another regulator's detailed mandates.","Dependence on a manufacturer service bulletin for model identification and procedures (Applicability: \"as identified in Boeing Service Bulletin 737-53A1225 Revision 1, or later FAA approved revision\") — creates a documentation dependency and potential revision-tracking burden.","Safety-critical inspection and corrective-action work (Background: reports of cracks that could impair control cables or cause loss of cabin pressure) — requires technically qualified maintenance and possible structural repairs.","Clear compliance timing and formal effective date (Compliance / Effective date: \"This Airworthiness Directive becomes effective on 26 October 2007\") — operators must schedule actions to meet the mandated deadline.","Limited regulatory discretion in the AD text (Requirement directs adherence to FAA AD) — low room for alternative compliance unless FAA/Boeing provide approved deviations."],"plain_english_summary":"**What this does:** Requires operators of specified Boeing 737-100/200/300/400/500 series aircraft to carry out inspections and any required repairs for cracking in the vertical beam webs at body station 178, following FAA AD 2007-03-03 and the Boeing Service Bulletin cited. **Who it affects and why it matters:** Aircraft operators and maintenance organisations must bear inspection and repair costs because undetected cracking could impair control cables or cause loss of cabin pressure."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard single-issue airworthiness directive addressing a specific structural defect in specific aircraft models. It has not expanded beyond its original safety purpose."},"complexity_factors":["Very short document (under 300 words)","Only 1 defined term implicitly referenced (Body Station 178 bulkhead — a technical aviation term, not legally defined in the document)","No nested exceptions or conditional logic — single straightforward requirement","Cross-references only to external technical documents (FAA AD and Boeing Service Bulletin), not to other legislative provisions","No interpretation section or definitions clause"],"plain_english_summary":"This mandatory CASA Airworthiness Directive requires operators of older Boeing 737 models (-100, -200, -200C, -300, -400, -500) to inspect and repair cracks in the Body Station 178 bulkhead vertical beam webs.\n\nCracks could cause loss of cabin pressure or damage control cables, risking controllability; operators must follow FAA AD 2007-03-03 and the Boeing service bulletin. Effective 26 October 2007."},"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"}},"importantCases":[],"_links":{"self":"/api/acts/ad-b737-310-body-station-178-bulkhead-vertical-beam-webs","history":"/api/acts/ad-b737-310-body-station-178-bulkhead-vertical-beam-webs/history","analysis":"/api/acts/ad-b737-310-body-station-178-bulkhead-vertical-beam-webs/analysis","conflicts":"/api/acts/ad-b737-310-body-station-178-bulkhead-vertical-beam-webs/conflicts","importantCases":"/api/acts/ad-b737-310-body-station-178-bulkhead-vertical-beam-webs/important-cases","documents":"/api/acts/ad-b737-310-body-station-178-bulkhead-vertical-beam-webs/documents"}}