{"id":"F2006B10260","name":"AD/GBK 117/13 - Vertical Fin Skin Panelling","slug":"ad-gbk-117-13-vertical-fin-skin-panelling","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":55931,"registerId":"commonwealth-F2006B10260-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# AIRWORTHINESS DIRECTIVE\n\n![](image.001.png)  \n\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 CASR 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\n![](image.001.png)  \n\nEurocopter BK 117 Series Helicopters","sortOrder":0},{"sectionNumber":"AD/GBK 117/13 Vertical Fin Skin Panellin","sectionType":"part","heading":"AD/GBK 117/13 Vertical Fin Skin Panelling 10/2003","content":"# AD/GBK 117/13 Vertical Fin Skin Panelling 10/2003\n\nApplicability: All Model A-1 up to B-2 helicopters, and Model C-1 helicopters with serial numbers 7500 through 7545.\n\nRequirement: Action in accordance with Eurocopter Deutschland MBB-BK117 Alert Service Bulletin MBB-BK117-30-109 Revision 1.\n\nNote: LBA AD 2003-219 refers.\n\nCompliance: Within 100 flight hours after 2 October 2003, unless already accomplished.\n\nThis Airworthiness Directive becomes effective on 2 October 2003.\n\nBackground: The manufacturer has determined that metal sheeting of 0.6mm thickness instead of the specified 0.8mm thickness, was used during production for the skin panelling of several vertical fins. This Directive requires an inspection of vertical fin skin thickness.\n\n![Signature of David Villiers](image.002.png)  \n\nDavid Villiers\n\nDelegate of the Civil Aviation Safety Authority 12 August 2003\n\n![](image.001.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 10 September 2003.","sortOrder":1}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive's scope matches its stated purpose: inspect vertical fin skin thickness on the specified BK117 helicopters. The AD sets applicability, the required action (follow the Eurocopter bulletin), and the compliance timing; no expansion or narrowing of scope from the AD text is indicated (Applicability; Requirement; Compliance; Background)."},"complexity_factors":["Narrow technical scope: single inspection task limited to vertical fin skin thickness (Requirement; Background).","Limited applicability: specific BK117 models and a narrow serial‑number range (Applicability).","Dependence on an external technical document for procedures and corrective actions (Eurocopter Alert Service Bulletin MBB‑BK117‑30‑109 Rev 1) (Requirement).","Short, non‑negotiable compliance window (100 flight hours after 2 October 2003) (Compliance).","Regulatory enforcement by CASA delegate; legal obligation created by AD (Delegate signature; Gazette notice).","Implied potential follow‑on repairs not detailed in the AD, creating variable cost and scheduling burden for operators (Background; Requirement)."],"plain_english_summary":"This AD requires operators of specified Eurocopter BK117 helicopters (Model A‑1 through B‑2, and Model C‑1 s/n 7500–7545) to inspect the vertical fin skin thickness in accordance with Eurocopter Alert Service Bulletin MBB‑BK117‑30‑109 Rev 1, within 100 flight hours of 2 October 2003. CASA issued the AD after the manufacturer found 0.6 mm sheet used where 0.8 mm was specified; operators pay for and must carry out inspections and any corrective work directed by the bulletin."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard airworthiness directive with narrow, specific scope addressing a known manufacturing defect. The scope matches its original safety purpose exactly."},"complexity_factors":["Single, clearly defined applicability (specific helicopter models and serial number range)","Single requirement referencing external technical document (manufacturer's service bulletin)","Simple compliance deadline (100 flight hours from effective date)","No defined terms section","No nested exceptions or conditional logic","Straightforward background explaining the safety issue","Total length: approximately 200 words"],"plain_english_summary":"This is a **safety order for helicopters** issued by Australia's aviation safety regulator (CASA). It applies to specific Eurocopter BK 117 helicopters.\n\n**What it does:**\n- Requires owners/operators to inspect the **vertical fin skin** (the metal covering on the tail fin) on affected helicopters\n- The inspection checks whether the metal skin is the correct thickness (0.8mm) or incorrectly thin (0.6mm)\n\n**Why it matters:**\n- Some helicopters were built with **thinner metal than specified** on the tail fin\n- This could create an **unsafe structural condition** affecting flight safety\n- The directive mandates a fix to prevent potential accidents\n\n**Who must act:**\n- Operators of BK 117 Model A-1 through B-2 helicopters, and Model C-1 helicopters with serial numbers 7500-7545\n\n**When:**\n- Within 100 flight hours after 2 October 2003 (unless already done)\n\n**What to do:**\n- Follow the manufacturer's specific instructions in **Alert Service Bulletin MBB-BK117-30-109 Revision 1**"}},"importantCases":[],"_links":{"self":"/api/acts/ad-gbk-117-13-vertical-fin-skin-panelling","history":"/api/acts/ad-gbk-117-13-vertical-fin-skin-panelling/history","analysis":"/api/acts/ad-gbk-117-13-vertical-fin-skin-panelling/analysis","conflicts":"/api/acts/ad-gbk-117-13-vertical-fin-skin-panelling/conflicts","importantCases":"/api/acts/ad-gbk-117-13-vertical-fin-skin-panelling/important-cases","documents":"/api/acts/ad-gbk-117-13-vertical-fin-skin-panelling/documents"}}