{"id":"F2006B09130","name":"AD/DHC-6/41 - Wing Tip Bonding - Modification","slug":"ad-dhc-6-41-wing-tip-bonding-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115683,"registerId":"commonwealth-F2006B09130-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DHC-6/41 - Wing Tip Bonding - 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)  DHC-6 (Twin Otter) Series Aeroplanes\n\n \n\nAD/DHC-6/41 Wing Tip Bonding - Modification 5/76\n\nApplicability: All models with S/Nos. 1 to 430 incorporating wing tip strobe lighting. Document:  1. De Havilland SB No. 6/318.\n\n2. Canadian AD CF-76-04.\n\n \n\nCompliance: Within 100 hours time in service after 30 June 1976.\n\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The text of the AD sets a focused requirement applying to DHC-6 serial numbers 1–430 with wing tip strobe lighting and cites two technical/regulatory references. There is no text in the instrument indicating an expansion, narrowing, or other alteration of scope from an earlier or original intent; therefore there is no evident change in scope within the supplied material. (Applicability / Document)"},"complexity_factors":["Narrow technical scope: single modification (wing tip bonding) for a defined set of serial numbers (S/N 1–430) and only those with wing tip strobe lighting (Applicability).","Dependence on external technical documents (De Havilland SB No. 6/318 and Canadian AD CF-76-04) for implementation details (Document).","Short, fixed compliance window (within 100 hours time in service after 30 June 1976) which raises scheduling complexity (Compliance).","Mandatory regulatory nature with limited discretion for operators increases operational consequences if not complied with (Header / Compliance).","Potential practical constraints (parts, qualified labour, maintenance slots) that are not detailed in the AD but affect execution (Document)."],"plain_english_summary":"This airworthiness directive requires a wing‑tip bonding modification on De Havilland DHC‑6 (Twin Otter) aircraft, serial numbers 1–430, fitted with wing‑tip strobe lights, carried out to De Havilland Service Bulletin No. 6/318 and Canadian AD CF‑76‑04. The modification must be completed within 100 hours time‑in‑service after 30 June 1976; owners/operators pay the costs and must comply to avoid regulatory enforcement."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue safety directive focused specifically on wing tip electrical bonding modifications. It has not expanded beyond its original narrow technical scope."},"complexity_factors":["Very short document (approximately 150 words)","Only 2 defined applicability criteria (aircraft model range and serial numbers)","Single compliance requirement with clear deadline","No nested exceptions or conditional logic","References only 2 external technical documents","No interpretation section or defined terms"],"plain_english_summary":"**What this is:** This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) that requires aircraft owners to fix a specific safety problem.\n\n**What it does:** It orders owners of certain De Havilland DHC-6 Twin Otter aircraft (serial numbers 1 to 430 that have wing tip strobe lights) to carry out a **modification to the wing tip bonding** (electrical grounding/connection system). This prevents dangerous static electricity buildup or electrical faults at the wing tips.\n\n**Who it affects:** Operators of older Twin Otter aircraft (built up to serial number 430) equipped with strobe lights on the wing tips.\n\n**Why it matters:** Poor electrical bonding can cause:\n- **Static discharge** that interferes with navigation or communication equipment\n- **Fire or explosion risk** from sparks near fuel vapors\n- **Strobe light failure**, reducing visibility to other aircraft\n\n**What must be done:** The modification must be completed within **100 flight hours after 30 June 1976** (a deadline that has long passed, meaning compliant aircraft should already have this done).\n\n**Key documents referenced:**\n- De Havilland Service Bulletin 6/318 (manufacturer's instructions)\n- Canadian Airworthiness Directive CF-76-04 (the same safety issue was identified in Canada)"}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-6-41-wing-tip-bonding-modification","history":"/api/acts/ad-dhc-6-41-wing-tip-bonding-modification/history","analysis":"/api/acts/ad-dhc-6-41-wing-tip-bonding-modification/analysis","conflicts":"/api/acts/ad-dhc-6-41-wing-tip-bonding-modification/conflicts","importantCases":"/api/acts/ad-dhc-6-41-wing-tip-bonding-modification/important-cases","documents":"/api/acts/ad-dhc-6-41-wing-tip-bonding-modification/documents"}}