{"id":"F2006B09105","name":"AD/DHC-6/18 Amdt 1 - Rudder and Elevator Pulley Bracket Assembly Stn 106 - Inspection","slug":"ad-dhc-6-18-amdt-1-rudder-and-elevator-pulley-bracket-assembly-stn-106-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115658,"registerId":"commonwealth-F2006B09105-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DHC-6/18 Amdt 1 - Rudder and Elevator Pulley Bracket Assembly Stn 106 - 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)  DHC-6 (Twin Otter) Series Aeroplanes\n\n \n\nAD/DHC-6/18\n\nAmdt 1\n\n\nRudder and Elevator Pulley Bracket Assembly Stn 106 - Inspection\n\n\n6/69\n\n \n\nApplicability: All models not incorporating Mod. No. 6/1262.\n\n \n\nRequirement:  Visually inspect the elevator rudder pulley bracket assembly at Fuselage Station 106 with particular attention to the forward flange of the top and bottom beams outboard of the outboard lightening holes for cracking or deformation.\n\n \n\nCompliance: Forthwith, then at intervals not exceeding 25 TIS after 1 September 1971.\n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard, narrow airworthiness directive focused on a specific safety-critical inspection. It has not expanded beyond its original purpose of ensuring structural integrity of flight control pulley brackets on a particular aircraft type."},"complexity_factors":["Single, specific mechanical component addressed","Clear, unambiguous inspection requirement with defined location (Fuselage Station 106)","Simple compliance timeline: immediate + recurring every 25 TIS","Single applicability criterion (absence of Mod. No. 6/1262)","No nested exceptions, cross-references to other legislation, or conditional logic","Technical aviation terminology used but precisely defined (TIS, Fuselage Station, Mod. No.)"],"plain_english_summary":"This is an **Airworthiness Directive** — essentially a mandatory safety notice issued by Australia's Civil Aviation Safety Authority (CASA) for aircraft owners and operators.\n\n**What it does:**\nOrders inspections of a specific mechanical part on **DHC-6 Twin Otter aircraft** — the pulley brackets that help control the rudder and elevator (the parts that steer the plane up, down, and side-to-side).\n\n**Who it affects:**\nAnyone who owns or operates a DHC-6 Twin Otter that **hasn't been modified** with a specific factory update (Mod. No. 6/1262).\n\n**What must be done:**\n- **Immediately** inspect the pulley bracket assembly at \"Fuselage Station 106\" (a specific location on the aircraft frame)\n- Look specifically at the forward flanges of the top and bottom beams, near the outboard lightening holes, for **cracks or deformation**\n- **Repeat this inspection** every 25 hours of \"Time In Service\" (TIS — actual flying hours, not calendar time) after 1 September 1971\n\n**Why it matters:**\nCracked or deformed pulley brackets could cause the pilot to lose control of the rudder or elevator, potentially leading to loss of control of the aircraft. This directive prevents catastrophic failure by catching problems early."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":true,"description":"This is labelled Amendment 1 and the text narrows applicability by excluding aircraft that have incorporated Mod. No. 6/1262 (Applicability). The directive establishes an immediate inspection requirement and a continued inspection interval (forthwith, then at intervals not exceeding 25 TIS after 1 September 1971), which sets a recurring obligation for affected aircraft (Compliance)."},"complexity_factors":["Narrow technical focus — single component/location (rudder/elevator pulley bracket at fuselage station 106). (Requirement)","Clear applicability carve-out based on presence of Mod. No. 6/1262 (exemption). (Applicability)","Simple compliance timing: immediate inspection then repeating at fixed intervals (25 TIS) after a specified date. (Compliance)","Use of operational aviation metric (TIS) may require conversion or tracking in operator maintenance records.","Directive is an amendment (Amdt 1), which may require operators to compare with previous issuance to confirm changes in scope or intervals."],"plain_english_summary":"This CASA airworthiness directive for DHC‑6 (Twin Otter) aircraft mandates a visual inspection of the elevator/rudder pulley bracket at fuselage station 106 for cracking or deformation, to be done forthwith and repeated every 25 TIS after 1 September 1971. It applies to all DHC‑6s except those incorporating Mod. No. 6/1262. Operators must carry out and fund the inspections, creating an incentive to fit the exempting modification."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-6-18-amdt-1-rudder-and-elevator-pulley-bracket-assembly-stn-106-inspection","history":"/api/acts/ad-dhc-6-18-amdt-1-rudder-and-elevator-pulley-bracket-assembly-stn-106-inspection/history","analysis":"/api/acts/ad-dhc-6-18-amdt-1-rudder-and-elevator-pulley-bracket-assembly-stn-106-inspection/analysis","conflicts":"/api/acts/ad-dhc-6-18-amdt-1-rudder-and-elevator-pulley-bracket-assembly-stn-106-inspection/conflicts","importantCases":"/api/acts/ad-dhc-6-18-amdt-1-rudder-and-elevator-pulley-bracket-assembly-stn-106-inspection/important-cases","documents":"/api/acts/ad-dhc-6-18-amdt-1-rudder-and-elevator-pulley-bracket-assembly-stn-106-inspection/documents"}}