{"id":"F2006B09071","name":"AD/DHC-3/22 - Elevator Tab Control Arm","slug":"ad-dhc-3-22-elevator-tab-control-arm","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52838,"registerId":"commonwealth-F2006B09071-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DHC-3/22 - Elevator Tab Control Arm","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-3 (Otter) Series Aeroplanes\n\n \n\nAD/DHC-3/22 Elevator Tab Control Arm 10/67\n\nApplicability: All models.\n\n \n\nRequirement: Action in accordance with De H Canada SB No 3/4. Compliance:  Within 50 hours time in service after 2 November 1967.\n\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"Based on the instrument text provided, the scope has not been expanded or narrowed within this AD: it applies to all DHC-3 models and requires the actions specified in De Havilland Canada Service Bulletin No. 3/4 to be completed within 50 hours time in service after 2 November 1967. The directive itself contains no language that changes or limits that applicability or the SB-based requirement compared with the directive’s stated mechanics."},"complexity_factors":["Short, single-action directive with a single external reference (De Havilland Canada SB No. 3/4) rather than detailed technical requirements in the text.","Applicability is broad (\"All models\") which raises operational coordination issues despite the AD’s textual simplicity.","Mandatory compliance window is tight (50 hours time in service after a fixed date), creating time-pressure operationally.","Lack of technical detail in the AD means compliance depends on an external document, increasing reliance on access to and clarity of that SB.","Historical dating (2 November 1967) makes the AD procedural but does not affect interpretive complexity of the text itself."],"plain_english_summary":"What this instrument does (mechanics):\n\n- It is an airworthiness directive titled \"AD/DHC-3/22 Elevator Tab Control Arm\" that appears in the Commonwealth schedule of airworthiness directives. (See header: \"SCHEDULE OF AIRWORTHINESS DIRECTIVES\".)\n- It requires owners/operators of De Havilland DHC-3 (Otter) series aeroplanes to carry out the work set out in De Havilland Canada Service Bulletin No. 3/4. (Requirement: \"Action in accordance with De H Canada SB No 3/4.\")\n- The work must be completed within 50 hours time in service after 2 November 1967. (Compliance: \"Within 50 hours time in service after 2 November 1967.\")\n- The directive is stated to apply to all models of the DHC-3 series. (Applicability: \"All models.\")\n\nWho is affected and who decides:\n\n- Affected parties: owners and operators of all DHC-3 (Otter) series aeroplanes registered in the Commonwealth to which this directive applies. (Applicability: \"All models.\")\n- Decision-maker / issuer: the directive appears in the Commonwealth schedule of airworthiness directives under the Civil Aviation Regulations framework. The instrument itself delegates the technical content of the required work to De Havilland Canada Service Bulletin No. 3/4. (Header and Requirement: schedule reference and SB reference.)\n\nWhy it matters (stated purpose and practical implications):\n\n- Stated or implied purpose: by mandating the actions in DHC SB No. 3/4 relating to the elevator tab control arm, the AD is aimed at addressing an identified technical issue with that component. The directive text itself does not set out the technical steps or the safety analysis; it points to the manufacturer service bulletin for the specific work. (Requirement: reference to SB.)\n\nPractical consequences, incentives and costs (mechanisms rather than judgments):\n\n- Who pays: owners/operators must procure the service bulletin (if not already held), supply labour, replacement parts (if required by the SB), and bear aircraft downtime while the work is carried out. (Requirement: SB reference; Compliance timeframe.)\n- Compliance burden and timing: the directive sets a short mandatory compliance window—within 50 hours time in service after 2 November 1967—creating a near-term need to schedule inspections/repairs and possibly limit operations until work is done. (Compliance: \"Within 50 hours time in service after 2 November 1967.\")\n- Delegation of technical detail: the AD delegates the exact inspection/repair/alteration steps to De Havilland Canada Service Bulletin No. 3/4. That concentrates technical discretion with the manufacturer’s bulletin and requires operators to follow that external document. (Requirement: \"Action in accordance with De H Canada SB No 3/4.\")\n- Enforcement and scope: the directive is listed in the Commonwealth schedule of airworthiness directives and is expressed as a mandatory action for the specified fleet (all DHC-3 models). The schedule listing makes the requirement explicit; the AD text does not, however, reproduce the SB’s instructions or list penalties or enforcement mechanisms in this excerpt. (Header; Applicability; Requirement.)\n\nTrade-offs, implementation risks and likely operational effects (based on the instrument’s mechanics):\n\n- Trade-offs: operators trade aircraft availability and maintenance expense (inspection, repair, parts, labour) for compliance with the AD and the outcomes the SB intends to achieve. (Requirement and Compliance.)\n- Implementation risks: because the AD refers to an external service bulletin for the technical steps, risks include the availability of that SB, clarity of the SB instructions, lead times for parts, and potential ambiguity about acceptable corrective actions if the SB is not sufficiently prescriptive. The AD text itself does not specify mitigation measures or alternatives. (Requirement: reference to external SB.)\n- Effects on private choice and operations: operators must prioritise the mandated work within the stated 50-hour window, which may lead to re-scheduling flights, grounding aircraft until compliance, or sourcing parts and labour quickly. These are direct operational decisions for owners/operators. (Applicability; Compliance.)\n\nNotes on evidence limits in this instrument excerpt:\n\n- The directive text supplied does not reproduce the technical content of De Havilland Canada SB No. 3/4, does not state the safety case, and does not list the specific tasks, parts, or inspection criteria. Any assessment of ongoing safety impact, exact costs or precise operational downtime requires consulting the referenced service bulletin and relevant maintenance records. (Requirement: reference to SB.)"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, time-bound safety directive targeting a specific aircraft type and component. It has not expanded beyond its original purpose of mandating a particular maintenance action."},"complexity_factors":["Very short document (under 150 words)","Only 4 defined elements: applicability, requirement, compliance deadline, and reference to external technical document","No nested conditional logic or exceptions","Single cross-reference to manufacturer service bulletin (De H Canada SB No 3/4)","Straightforward command structure: do X by Y date"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for aircraft.\n\n**What it does:**\n- Requires owners and operators of **De Havilland Canada DHC-3 (Otter) series aeroplanes** to inspect or fix a specific mechanical part: the **elevator tab control arm** (a component that helps control the aircraft's pitch).\n- The work must follow instructions in **De Havilland Canada Service Bulletin No. 3/4** (a technical notice from the manufacturer).\n\n**Who it affects:**\n- Anyone who owns, operates, or maintains DHC-3 Otter aircraft in Australia.\n\n**Why it matters:**\n- Elevator control systems are critical for flight safety. This directive addresses a potential defect that could affect the pilot's ability to control the aircraft's nose-up or nose-down movement.\n- **Compliance deadline:** The work had to be completed within **50 hours of flight time** after **2 November 1967**.\n\n**Key point:** This is a **historical directive from 1967**. While it shows the regulatory framework for aviation safety, the compliance deadline passed decades ago. Current operators would need to verify this work was done and check if any subsequent directives apply."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-3-22-elevator-tab-control-arm","history":"/api/acts/ad-dhc-3-22-elevator-tab-control-arm/history","analysis":"/api/acts/ad-dhc-3-22-elevator-tab-control-arm/analysis","conflicts":"/api/acts/ad-dhc-3-22-elevator-tab-control-arm/conflicts","importantCases":"/api/acts/ad-dhc-3-22-elevator-tab-control-arm/important-cases","documents":"/api/acts/ad-dhc-3-22-elevator-tab-control-arm/documents"}}