{"id":"F2006B02751","name":"AD/B727/5 Amdt 2 - Tailplane Rear Spar Lower Cap - Inspection","slug":"ad-b727-5-amdt-2-tailplane-rear-spar-lower-cap-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42093,"registerId":"commonwealth-F2006B02751-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B727/5 Amdt 2 - Tailplane Rear Spar Lower Cap - Inspection","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/B727/5\n\nAmdt 2\n\n\nTailplane Rear Spar Lower Cap - Inspection 9/66\n\n \n\nApplicability: All models.\n\n \n\nDocument: Boeing SB No. 55-18, Rev. 5. 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":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive focused on a specific structural inspection for a single aircraft type. It has not expanded beyond its original purpose of ensuring airworthiness of the Boeing 727 tailplane structure."},"complexity_factors":["Extremely short document (approximately 150 words)","No defined terms section","No cross-references to other legislation beyond the parent Civil Aviation Regulations 1998","Single, unambiguous compliance requirement ('forthwith')","Simple applicability statement ('All models')","Refers to external technical document (Boeing SB) for implementation details rather than embedding complex technical specifications"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** issued by Australia's Civil Aviation Safety Authority (CASA) that applies to all **Boeing 727 series aircraft**.\n\n**What it does:**\n- Requires an **inspection of the tailplane rear spar lower cap** — a critical structural component at the back of the aircraft that helps control pitch and stability.\n- The inspection must be carried out **\"forthwith\"** (immediately, without delay).\n\n**Who it affects:**\n- Owners and operators of all Boeing 727 models.\n- Maintenance organisations servicing these aircraft.\n\n**Why it matters:**\n- This directive addresses potential structural fatigue or damage that could compromise flight safety. The tailplane (horizontal stabiliser) is essential for aircraft control; failure of this component could be catastrophic.\n- The reference to **Boeing Service Bulletin 55-18, Revision 5** provides the technical instructions for how to perform the inspection.\n\n**Key details:**\n- **AD/B727/5 Amdt 2** — this is the second amendment to the fifth airworthiness directive for the B727 series.\n- **9/66** — likely indicates the original issue date (September 1966), suggesting this is a long-standing safety requirement that has been updated.\n- Compliance is mandatory and immediate."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"The instrument is labelled as Amendment 2 (Amdt 2), indicating it modifies a prior AD. The supplied excerpt does not include the earlier text or a description of what was changed. The current excerpt shows that the AD now (in this form) applies to all Boeing 727 models and requires immediate compliance with Boeing SB No. 55-18, Rev. 5 (see “Amdt 2”, “Applicability: All models”, and “Document: Boeing SB No. 55-18, Rev. 5”). The specific nature of the change from the original AD is not contained in the provided text, so the precise scope differences cannot be identified from this excerpt alone."},"complexity_factors":["Short, narrowly framed directive: the AD contains a single mandatory action (inspection) with immediate compliance.","Broad applicability: applies to all Boeing 727 models, increasing operational coordination needs across an operator’s fleet (see “Applicability: All models”).","Procedural detail is external: the AD refers to Boeing SB No. 55-18 Rev. 5 for inspection methodology, so understanding and implementing the AD requires consulting that external document (see “Document” line).","Immediate timing: the instruction to comply “Forthwith” reduces scheduling flexibility and raises short-term logistical complexity (see “Compliance: Forthwith”).","Lack of detail in the AD itself: the AD excerpt does not state inspection intervals, allowable thresholds, alternative compliance methods, or follow-up requirements, requiring cross-reference to the service bulletin."],"plain_english_summary":"AD/B727/5 Amdt 2 mandates immediate inspection of the tailplane rear spar lower cap on all Boeing 727 models, to be performed per Boeing Service Bulletin No. 55‑18 Rev. 5. It binds owners/operators and their maintenance providers, may incur inspection/repair costs and short‑term operational disruption, and relies on the referenced SB for procedural detail."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b727-5-amdt-2-tailplane-rear-spar-lower-cap-inspection","history":"/api/acts/ad-b727-5-amdt-2-tailplane-rear-spar-lower-cap-inspection/history","analysis":"/api/acts/ad-b727-5-amdt-2-tailplane-rear-spar-lower-cap-inspection/analysis","conflicts":"/api/acts/ad-b727-5-amdt-2-tailplane-rear-spar-lower-cap-inspection/conflicts","importantCases":"/api/acts/ad-b727-5-amdt-2-tailplane-rear-spar-lower-cap-inspection/important-cases","documents":"/api/acts/ad-b727-5-amdt-2-tailplane-rear-spar-lower-cap-inspection/documents"}}