{"id":"F2006B06714","name":"AD/S-76/31 Amdt 1 - Upper Fuselage Station 215 Bulkhead","slug":"ad-s-76-31-amdt-1-upper-fuselage-station-215-bulkhead","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":114529,"registerId":"commonwealth-F2006B06714-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/S-76/31 Amdt 1 - Upper Fuselage Station 215 Bulkhead","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nSikorsky S-76 Series Helicopters\n\nAD/S-76/31\n\nAmdt 1\n\n  \nUpper Fuselage Station 215 Bulkhead 9/85\n\nApplicability: All models not incorporating structural modification kits in accordance with Sikorsky Customer Service Notice No. 76-150 or a manufacturer-installed equivalent, which have achieved more than 1000 hours time in service.\n\nRequirement: Inspect in accordance with Sikorsky Alert Service Bulletin 76-53-18 (155) Modify in accordance with either:\n\n    Sikorsky Alert Service Bulletin 76-53-26 (166), Sikorsky Customer Service Notice No. 76-151 or\n\n    2. Sikorsky Customer Service Notice No 76-150.\n\nNote: Modification in accordance with CSN 76-150 constitutes terminating action for this AD.\n\nCompliance: Inspect at intervals not exceeding 50 hours time in service, until modified in accordance with this Directive.\n\nModify within the next 500 hours time in service after 30 September 1985. After modification, inspect at intervals not exceeding 100 hours time in service,\n\nunless terminating action has been accomplished in accordance with Sikorsky CSN No. 76-150.\n\nBackground: Cracks have occurred in Station 215 bulkhead installation, upper fuselage section, left side. Production modifications and two types of retro-fit kits are now available. One of these, a simple skin doubler reinforcement, minimises the potential of a crack developing but still requires repetitive inspections. The other, a more extensive reinforcement of the upper left fuselage longeron, constitutes terminating action.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is an amendment (Amdt 1) to an existing Airworthiness Directive. The scope remains tightly focused on the original safety issue — cracking in the Station 215 bulkhead of S-76 helicopters. The amendment appears to update compliance intervals or modification options without expanding beyond the original technical scope of addressing this specific structural defect."},"complexity_factors":["Single, specific technical subject matter (one helicopter model, one structural component)","Clear, linear compliance pathway with only two modification options","Simple temporal triggers (flight hours, calendar date of 30 September 1985)","Minimal cross-referencing (only references specific Sikorsky service bulletins and notices)","No nested exceptions or conditional logic beyond the terminating action clause","Short document length (approximately 200 words of substantive content)"],"plain_english_summary":"This airworthiness directive for Sikorsky S‑76 helicopters in Australia mandates inspection and repair of a cracking left-side upper-fuselage bulkhead at Station 215. It applies to S‑76s with over 1,000 flight hours that haven’t had Sikorsky’s upgrade installed. Operators must inspect the area every 50 flight hours until they complete a required modification within 500 flight hours after 30 September 1985. Two approved kits exist: one needs ongoing 100‑hour inspections, the other is terminating action that stops repetitive inspections."},"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"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"This amendment sets specific inspection intervals (50 hours), a modification deadline (within 500 hours after 30 Sept 1985), and recognises two retrofit options while identifying CSN 76‑150 as terminating action, thereby clarifying and tightening compliance routes compared with the original AD (Applicability; Requirement; Compliance; Note)."},"complexity_factors":["Applicability conditioned on installed modifications and >1000 hours time in service (Applicability).","Multiple compliance pathways: two retrofit kits or manufacturer service bulletins (Requirement; Background).","Repetitive inspection intervals and a modification deadline create operational scheduling burden (Compliance).","External references to Sikorsky Alert Service Bulletins and Customer Service Notices require operators to obtain and follow manufacturer documents (Requirement).","Presence of a terminating action option (CSN 76‑150) changes long‑term inspection obligations (Note; Background).","Date‑specific compliance window (modify within 500 hours after 30 Sept 1985) adds a time constraint (Compliance)."],"plain_english_summary":"Requires operators of Sikorsky S‑76 helicopters (without specified factory or retrofit kits and with over 1,000 hours) to perform recurring inspections and to install a structural modification within a set timeframe. Inspections are every 50 flight hours until modification; modification must occur within 500 hours after 30 September 1985. One retrofit (CSN 76‑150) ends the inspection obligation. Operators bear the inspection and modification cost and must follow Sikorsky service bulletins and customer service notices (Applicability; Requirement; Compliance; Note)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-s-76-31-amdt-1-upper-fuselage-station-215-bulkhead","history":"/api/acts/ad-s-76-31-amdt-1-upper-fuselage-station-215-bulkhead/history","analysis":"/api/acts/ad-s-76-31-amdt-1-upper-fuselage-station-215-bulkhead/analysis","conflicts":"/api/acts/ad-s-76-31-amdt-1-upper-fuselage-station-215-bulkhead/conflicts","importantCases":"/api/acts/ad-s-76-31-amdt-1-upper-fuselage-station-215-bulkhead/important-cases","documents":"/api/acts/ad-s-76-31-amdt-1-upper-fuselage-station-215-bulkhead/documents"}}