{"id":"F2006B02895","name":"AD/B737/194 - Keel Beam Structure","slug":"ad-b737-194-keel-beam-structure","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42237,"registerId":"commonwealth-F2006B02895-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# AIRWORTHINESS DIRECTIVE\n\n![](image.001.png)\n\n![](image.001.png)  \nFor the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.\n\nBoeing 737 Series Aeroplanes","sortOrder":0},{"sectionNumber":"AD/B737/194 Keel Beam Structure 11/2002","sectionType":"part","heading":"AD/B737/194 Keel Beam Structure 11/2002","content":"# AD/B737/194 Keel Beam Structure 11/2002\n\nApplicability: Model 737-600, \\-700, and \\-800 series aircraft, line numbers 1 through 321. Requirement: Action in accordance with the technical requirements of FAA AD 2000-08-08 Amdt\n\n39-11694.\n\nNote: Boeing Alert Service Bulletin 737-57-1253 refers.\n\nCompliance: As specified in the Requirement document, with a revised effective date of 31 October 2002.\n\nThis Airworthiness Directive becomes effective on 31 October 2002.\n\nBackground: The FAA received a report of severed rear spar stiffeners of the centre wing, which resulted in cracking in the adjacent keel beam structure. This Directive requires certain actions to prevent failure of the keel beam structure.\n\n![Signature of David Villiers, Delegate of the Civil Aviation Safety Authority.](image.002.jpeg)  \n\nDavid Alan Villiers\n\nDelegate of the Civil Aviation Safety Authority 12 September 2002\n\n![](image.001.png)","sortOrder":1}],"analysis":{"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The AD adopts and enforces the FAA's corrective actions for the specified 737 series without expanding the affected fleet or adding new requirements beyond the referenced FAA AD and Boeing service bulletin. Applicability and Requirement align with the stated safety rationale (Applicability; Requirement; Background)."},"complexity_factors":["Cross-reference to external technical documents (FAA AD 2000-08-08; Boeing Alert Service Bulletin 737-57-1253) creates reliance on non‑domestic material for technical detail (Requirement).","Limited applicability to specific models and line numbers (Model 737-600, -700, -800; line numbers 1–321) requires fleet-level filtering by operators (Applicability).","Mandatory compliance timing and revised effective date (effective 31 October 2002) imposes administrative scheduling and potential operational disruption (Compliance).","Technical nature of inspections/repairs means operators need qualified maintenance and possible parts/support from manufacturer or authorised suppliers (Requirement/Background).","Delegated enforcement by CASA increases regulatory compliance risk for operators who do not follow the specified Requirement document (signature/Delegate)."],"plain_english_summary":"Requires operators of Boeing 737-600, -700 and -800 (line numbers 1–321) to carry out inspections and corrective actions set out in FAA AD 2000-08-08 (and Boeing Alert Service Bulletin 737-57-1253) to prevent keel-beam failure after reports of severed rear-spar stiffeners. CASA enforces compliance from 31 October 2002; affected operators pay for inspections/repairs and must follow the technical instructions in the Requirement document. The directive changes aircraft maintenance obligations and sets a mandatory compliance timetable enforced by the CASA delegate."},"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"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope: addressing a specific structural defect in specific Boeing 737 variants. It does not expand beyond its original safety purpose."},"complexity_factors":["Very short document (under 300 words) with minimal conditional logic","Only 3 defined applicability criteria (specific aircraft models and line numbers)","Single requirement that cross-references external technical documents (FAA AD and Boeing Service Bulletin) rather than setting out detailed instructions in the text itself","No nested exceptions or elaborate compliance calculations — effective date and compliance timeline are straightforward","Background section provides clear causal explanation in plain language"],"plain_english_summary":"This AD requires owners/operators of early-production Boeing 737-600/700/800 aircraft (line numbers 1–321) to carry out inspections and any repairs or replacements specified in FAA AD 2000-08-08 and Boeing Alert Service Bulletin 737-57-1253. It responds to broken rear spar stiffeners that have caused cracking in the keel beam, risking structural failure. The Australian order takes effect 31 October 2002 to ensure affected aircraft are inspected and repaired before they become unsafe."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b737-194-keel-beam-structure","history":"/api/acts/ad-b737-194-keel-beam-structure/history","analysis":"/api/acts/ad-b737-194-keel-beam-structure/analysis","conflicts":"/api/acts/ad-b737-194-keel-beam-structure/conflicts","importantCases":"/api/acts/ad-b737-194-keel-beam-structure/important-cases","documents":"/api/acts/ad-b737-194-keel-beam-structure/documents"}}