{"id":"F2006B02726","name":"AD/B727/26 - Lower Wing Inspar Rib - Inspection and Modification","slug":"ad-b727-26-lower-wing-inspar-rib-inspection-and-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42042,"registerId":"commonwealth-F2006B02726-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B727/26 - Lower Wing Inspar Rib - Inspection and Modification","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Boeing 727 Series Aeroplanes\n\n \n\nAD/B727/26 Lower Wing Inspar Rib - Inspection\n\nand Modification\n\n\n6/66\n\n \n\nApplicability: All models.\n\n \n\nDocument: Boeing SB No. 57-66, Rev. 1. Compliance: Forthwith.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The supplied text sets the scope as applying to all Boeing 727 models (\"Applicability: All models.\") and requires inspection and modification per Boeing SB No. 57-66, Rev. 1 with immediate effect (\"Compliance: Forthwith.\"). The document supplied does not indicate any amendment to or narrowing/expansion from a prior scope; based solely on the text provided there is no evidence the scope has changed from the instrument's stated coverage."},"complexity_factors":["Very short directive text that delegates technical detail to an external manufacturer document (\"Document: Boeing SB No. 57-66, Rev. 1.\")","Immediate compliance requirement increases operational urgency (\"Compliance: Forthwith.\")","Wide applicability to all models increases the number of affected operators (\"Applicability: All models.\")","Lack of technical detail in the AD itself forces reliance on the service bulletin for scope, parts, and labour estimates","No exemptions, alternative compliance paths, or phased timing specified in the AD text — any such options would require separate regulator action"],"plain_english_summary":"This AD mandates immediate inspection and modification of the lower wing inspar rib on all Boeing 727 aeroplanes, directing operators to follow Boeing Service Bulletin No. 57-66, Rev. 1. It affects all owners, operators and maintenance organisations; compliance is required forthwith and will impose inspection, repair and downtime costs on aircraft operators."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue safety directive. Airworthiness Directives are inherently narrow in scope — each addresses a specific technical defect or safety concern. There is no indication this AD has expanded beyond its original purpose of addressing the lower wing in-spar rib issue."},"complexity_factors":["Extremely short document (approximately 150 words)","No defined terms section — uses plain aviation terminology","Single, unambiguous compliance requirement ('forthwith')","No cross-references to other legislation beyond the enabling Civil Aviation Regulations 1998","No conditional logic or exceptions — applies to all models without qualification","References only one external technical document (Boeing Service Bulletin 57-66 Rev. 1)"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). It requires owners and operators of **Boeing 727 aircraft** to inspect and modify the **lower wing in-spar rib** (a structural component inside the wing).\n\n**What it does:**\n- Mandates immediate action (\"forthwith\") to check for potential structural problems in a specific part of the wing\n- Requires compliance with Boeing Service Bulletin No. 57-66, Revision 1 (the manufacturer's official repair instructions)\n\n**Who it affects:**\n- All operators of Boeing 727 series aircraft in Australia\n- Maintenance organisations servicing these aircraft\n\n**Why it matters:**\nAirworthiness Directives are legally binding safety orders. Non-compliance means the aircraft cannot fly legally. This particular AD addresses potential structural integrity issues in the wing that could affect flight safety if left unaddressed."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b727-26-lower-wing-inspar-rib-inspection-and-modification","history":"/api/acts/ad-b727-26-lower-wing-inspar-rib-inspection-and-modification/history","analysis":"/api/acts/ad-b727-26-lower-wing-inspar-rib-inspection-and-modification/analysis","conflicts":"/api/acts/ad-b727-26-lower-wing-inspar-rib-inspection-and-modification/conflicts","importantCases":"/api/acts/ad-b727-26-lower-wing-inspar-rib-inspection-and-modification/important-cases","documents":"/api/acts/ad-b727-26-lower-wing-inspar-rib-inspection-and-modification/documents"}}