{"id":"F2006B08798","name":"AD/DC3/20 - Elevator Hinge Bracket - Inspection","slug":"ad-dc3-20-elevator-hinge-bracket-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52155,"registerId":"commonwealth-F2006B08798-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DC3/20 - Elevator Hinge Bracket - 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)  Douglas DC3 Series Aeroplanes\n\n \n\nAD/DC3/20 Elevator Hinge Bracket - Inspection NK\n\nApplicability: All models.\n\n \n\nRequirement: 1. Inspect the elevator hinge arms, ribs and rear beams for cracks and stress raisers in the form of machining marks, badly formed rivets, rivet snap damage and nicks.\n\n \n\n2.    Replace cracked components.\n\n \n\n3.    If stress raisers are found take the following action:\n\n \n\n(a)     For slight nicks, badly formed rivets, bruised metal around rivets - polish out or replace rivets as applicable.\n\n \n\n(b)     For deep nicks, sharp edged snap damage - replace components. OR ANO 105.1.16.1.6.6.\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\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive’s text sets an applicability of \"All models\" and prescribes inspections and remedial actions for elevator hinge arms, ribs and rear beams (Requirements 1–3). The document itself gives no indication that its scope has been expanded or narrowed relative to any prior instrument; it presents a self-contained set of inspection and corrective-action requirements without stating a change of scope."},"complexity_factors":["Short, focused scope (applies to specified elevator structure) reduces complexity.","Clear mandatory actions for cracked components (replace) provide low ambiguity (Requirement 2).","Qualitative damage categories (\"slight\" vs \"deep\") introduce subjective judgement for inspectors (Requirement 3(a)–(b)).","Phrases such as \"as applicable\" leave procedural discretion to maintenance personnel (Requirement 3(a)).","No inspection intervals or objective measurement thresholds are specified, increasing reliance on operator maintenance programmes (Requirement 1).","Reference to an external alternative procedure (ANO 105.1.16.1.6.6) requires cross-reference and may add procedural complexity (Requirement 3(b))."],"plain_english_summary":"# What this directive does\n\nThis Airworthiness Directive (AD/DC3/20) applies to all Douglas DC3 series aeroplanes (Applicability: All models). It requires inspection and corrective action on parts of the elevator assembly to address cracks and other local damage that could act as stress concentrators.\n\n- Mechanical requirements (how it works):\n  - Inspect the elevator hinge arms, ribs and rear beams for cracks and stress raisers such as machining marks, badly formed rivets, rivet snap damage and nicks (Requirement 1).\n  - Replace any components found to be cracked (Requirement 2).\n  - If stress raisers (non-crack damage) are found, take one of two paths (Requirement 3):\n    - For slight nicks, badly formed rivets, or bruised metal around rivets: polish the damage out or replace the rivets, as applicable (Requirement 3(a)).\n    - For deep nicks or sharp-edged snap damage: replace the affected components, or follow the alternative procedure referenced (ANO 105.1.16.1.6.6) (Requirement 3(b)).\n\n- Who is affected and who pays: owners/operators of Douglas DC3 series aircraft are the parties to whom the directive applies (Applicability). Those owners/operators will be responsible for arranging and paying for the inspections, any polishing or rivet replacement, and for replacement of cracked or severely damaged components.\n\n- Who decides and where the judgement lies: the directive uses qualitative categories (\"slight\" vs \"deep\") and the phrase \"as applicable,\" which places the practical judgement about the extent of damage and the appropriate remedy on the maintenance personnel or certifying engineer who performs the inspection (Requirement 3(a) and 3(b)).\n\n- Behavioural and operational effects: operators must inspect the specified elevator structure and then either perform minor repair work (polishing or rivet replacement) or replace components where cracking or severe damage is found (Requirements 1–3). That creates demand for maintenance work, parts and likely aircraft downtime while work is done.\n\n- Official purpose-claim and an evidence-grounded test: the instrument prescribes inspection and correction of cracks and stress raisers (Requirements 1–3). The directive’s stated measures are consistent with an intent to remove cracked parts and remove or repair local stress raisers. Measures trade off lower-cost, local remediation (polishing or rivet replacement for slight damage) against higher-cost component replacement for cracking or severe damage (Requirements 2 and 3). The document itself does not set inspection intervals, specify who must perform the work by licence or certification category, or quantify acceptable defect sizes; those omissions leave implementation dependent on the operator’s maintenance programme and the judgement of maintenance staff (Requirements 1 and 3).\n\n- Compliance burden, discretion and risks: the text mandates inspection and repair but leaves several practical details open. The lack of defined inspection timing or objective thresholds (\"slight\" vs \"deep\" are qualitative) creates room for operator and maintenance-provider discretion (Requirement 1; Requirement 3). The directive references an alternative procedure (ANO 105.1.16.1.6.6) as a substitute for replacement in some cases (Requirement 3(b)), which permits a different compliance route but requires the operator to consult that external provision.\n\n- Concentrated benefits and diffuse costs (mechanical view): the direct, concentrated benefit accrues to safety of the particular aircraft and its occupants when defects are corrected; costs (inspection time, polishing, rivet replacement, component replacement, parts, and aircraft downtime) are borne by the owners/operators and their maintenance providers. The directive creates explicit remedial options (polish/replace rivets vs replace components) which change the menu of permissible maintenance actions and thus affect maintenance decisions and budgets (Requirements 2–3).\n\nCitations: Requirements 1–3 and subparagraphs (a) and (b); Applicability: All models; alternative compliance reference ANO 105.1.16.1.6.6 (Requirement 3(b))."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete airworthiness directive with a narrow, specific purpose — inspecting and repairing elevator hinge brackets on a single aircraft type. It has not expanded beyond its original safety intent."},"complexity_factors":["Very short document — only 3 main requirements with 2 sub-points","No defined terms section — uses everyday mechanical language ('nicks', 'polish out', 'stress raisers')","No cross-references to other legislation (except a cryptic 'OR ANO 105.1.16.1.6.6' reference to an Air Navigation Order)","Simple conditional logic: if-then structure with clear severity thresholds (slight vs deep damage)","Single applicability criterion ('All models') with no exceptions or exemptions"],"plain_english_summary":"This is a **safety directive for old aeroplanes** — specifically the Douglas DC-3, a famous aircraft from the 1930s-40s still flying in Australia.\n\n**What it does:**\nTells aircraft owners and mechanics they **must inspect the elevator hinge brackets** — the metal parts that connect the tail flaps (elevators) to the plane's body. These parts take a lot of stress during flight.\n\n**What to look for:**\n- **Cracks** in the hinge arms, ribs, and rear beams\n- **Stress raisers** — tiny flaws that can grow into cracks, including:\n  - Rough machining marks from manufacturing\n  - Badly formed or damaged rivets\n  - Nicks and dents in the metal\n\n**What to do if you find problems:**\n- **Cracked parts?** Replace them entirely.\n- **Minor damage** (small nicks, rough rivets)? Polish smooth or replace the rivets.\n- **Serious damage** (deep cuts, sharp dents)? Replace the whole component.\n\n**Who it affects:**\nAnyone operating or maintaining a DC-3 aircraft in Australia — museums, charter operators, cargo carriers, and private owners.\n\n**Why it matters:**\nThe DC-3 is an antique aircraft. Metal fatigue in critical control surfaces can cause catastrophic failure. This directive prevents crashes by catching problems before they become dangerous."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dc3-20-elevator-hinge-bracket-inspection","history":"/api/acts/ad-dc3-20-elevator-hinge-bracket-inspection/history","analysis":"/api/acts/ad-dc3-20-elevator-hinge-bracket-inspection/analysis","conflicts":"/api/acts/ad-dc3-20-elevator-hinge-bracket-inspection/conflicts","importantCases":"/api/acts/ad-dc3-20-elevator-hinge-bracket-inspection/important-cases","documents":"/api/acts/ad-dc3-20-elevator-hinge-bracket-inspection/documents"}}