{"id":"F2006B06738","name":"AD/S-76/62 - Tail Gearbox Forward Fairing to Pylon Attachment Angle","slug":"ad-s-76-62-tail-gearbox-forward-fairing-to-pylon-attachment-angle","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":114565,"registerId":"commonwealth-F2006B06738-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/S-76/62 - Tail Gearbox Forward Fairing to Pylon Attachment Angle","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)  Sikorsky S-76 Series Helicopters\n\n \n\n# AD/S76/62 Tail Gearbox Forward Fairing to Pylon Attachment Angle\n\nApplicability: All Model S-76A, B, and C helicopters.\n\n# 12/99\n\nDM\n\n \n\nRequirement: Perform a visual inspection of the attachment angle on each tail gearbox forward fairing in accordance with the Accomplishment Instructions, paragraph A, of Sikorsky Aircraft Corporation Alert Service Bulletin (ASB) 76-55-16, dated May 12 1999.\n\n \n\nIf the inspection reveals a disbond area that equals or exceeds 1.0 square inch, before further flight, repair or replace the attachment angle with a serviceable angle in accordance with the Accomplishment Instructions, paragraph B, of ASB 76-55-16.\n\n \n\nNote: FAA AD 99-19-30 Amdt 39-11317 refers.\n\n \n\nCompliance: Within 50 hours time in service after 20 October 1999, unless the initial inspection is already accomplished. Thereafter at intervals not to exceed 1500 hours time in service.\n\n \n\nThis Airworthiness Directive becomes effective on 20 October 1999.\n\n \n\nBackground: The FAA received reports of incidents, two in flight and eight on the ground, of tail gearbox forward fairing bonding failures. Separation of the fairing could result in damage to the tail rotor blades and subsequent loss of control of the helicopter.\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_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":2,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope — addressing a specific bonding failure risk in a specific helicopter series. No evidence of scope creep; it targets exactly the safety issue identified in the background (fairing attachment failures) with precisely defined applicability."},"complexity_factors":["Single, specific mechanical component targeted (tail gearbox forward fairing attachment angle)","Straightforward two-part requirement: initial inspection + recurring inspections","Clear numerical thresholds (1.0 square inch disbond, 50 hours, 1500 hours)","Single external reference to manufacturer service bulletin (ASB 76-55-16)","No defined terms section, no nested exceptions, no conditional logic beyond the damage threshold","Document is approximately 250 words with simple sentence structure"],"plain_english_summary":"CASA requires mandatory inspections of the tail gearbox forward fairing‑to‑pylon attachment angle on Sikorsky S‑76A/B/C helicopters after multiple bonding failures. Operators must inspect within 50 flight hours (from 20 Oct 1999) and every 1,500 hours thereafter; any disbond of 1 in² or more grounds the helicopter until repaired. This AD protects Australian operators by preventing fairing loss and potential tail‑rotor damage or loss of control."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"Scope remains focused on tail gearbox forward fairing attachment angles for all S‑76A/B/C helicopters, requiring inspection and remedial action where disbond meets the 1.0 sq. inch threshold. The AD references and follows the cited Sikorsky ASB and FAA AD without expanding applicability or introducing additional defect classes."},"complexity_factors":["Clear, limited applicability: all Sikorsky S‑76A, B, C helicopters (straightforward scope).","Single, quantitative defect threshold (disbond ≥ 1.0 sq. inch) reduces judgment calls.","Dependence on external procedural document (Sikorsky ASB 76‑55‑16) for inspection and repair steps creates a procedural dependency.","Temporal compliance schedule: initial inspection within 50 hours after 20 Oct 1999, then every 1500 hours — simple but operationally binding.","Mandatory ‘before further flight’ repair/replacement increases immediacy and potential on‑ground costs.","High-consequence safety rationale (fairing separation may damage tail rotor) but low regulatory complexity."],"plain_english_summary":"**What this does:** Requires operators of Sikorsky S‑76A/B/C helicopters to visually inspect the attachment angle on each tail gearbox forward fairing, and to repair or replace any fairing with a disbond area of 1.0 square inch or more before further flight, following Sikorsky Alert Service Bulletin 76‑55‑16. **Who pays and why it matters:** Aircraft owners/operators pay for inspections and any repairs; the rule addresses reported bonding failures because a separated fairing can damage the tail rotor and risk loss of control."}},"importantCases":[],"_links":{"self":"/api/acts/ad-s-76-62-tail-gearbox-forward-fairing-to-pylon-attachment-angle","history":"/api/acts/ad-s-76-62-tail-gearbox-forward-fairing-to-pylon-attachment-angle/history","analysis":"/api/acts/ad-s-76-62-tail-gearbox-forward-fairing-to-pylon-attachment-angle/analysis","conflicts":"/api/acts/ad-s-76-62-tail-gearbox-forward-fairing-to-pylon-attachment-angle/conflicts","importantCases":"/api/acts/ad-s-76-62-tail-gearbox-forward-fairing-to-pylon-attachment-angle/important-cases","documents":"/api/acts/ad-s-76-62-tail-gearbox-forward-fairing-to-pylon-attachment-angle/documents"}}