{"id":"F2006B09032","name":"AD/DHC-2/15 Amdt 1 - Main Undercarriage Lower Forward Bolt Attachment - Inspection","slug":"ad-dhc-2-15-amdt-1-main-undercarriage-lower-forward-bolt-attachment-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52725,"registerId":"commonwealth-F2006B09032-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DHC-2/15 Amdt 1 - Main Undercarriage Lower Forward Bolt Attachment - 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-2 (Beaver) Series Aeroplanes\n\n \n\nAD/DHC-2/15\n\nAmdt 1\n\nApplicability: All models.\n\n\nMain Undercarriage Lower Forward Bolt Attachment - Inspection\n\n\n8/84\n\n \n\nRequirement: Inspect the main undercarriage lower forward attachment bolts for cracking as follows:\n\n \n\n1. P/N C2U-487ND (part of bolt assembly No. C2U-185A) : magnetic particle inspect in accordance with ANO 108.8 or fluorescent penetrant inspect in accordance with ANO 108.10.\n\n\n \n\n2.    P/N 02-B-16 (hard chrome plated bolts): fluorescent penetrant inspect in accordance with ANO 108.10.\n\n \n\nCompliance: At intervals not exceeding 100 hours time in service for aircraft engaged in agricultural operations, and 500 hours time in service for other aircraft.\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\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The text supplied (Amdt 1) sets applicability to \"All models\" and prescribes inspection requirements for two specific bolt part numbers with defined inspection methods and intervals. The document itself does not state or show any expansion or narrowing of applicability beyond that wording, nor does it describe changes relative to an earlier text. Based on the supplied text alone, the instrument's operational scope is the inspection requirement as written (Applicability; Requirement 1–2; Compliance)."},"complexity_factors":["Limited subject matter scope: single component (main undercarriage lower forward attachment bolts) and two part numbers (P/N C2U-487ND and P/N 02-B-16). (Requirement 1–2)","Two prescribed inspection techniques (magnetic particle and fluorescent penetrant) that reference external ANO procedures, creating dependency on other technical documents. (Requirement 1–2)","Different compliance intervals for agricultural operations versus other operations (100 h vs 500 h), which add operational scheduling complexity. (Compliance)","Need to measure and record hours time-in-service and arrange qualified inspection personnel/equipment, adding practical compliance burden. (Compliance; Requirement 1–2)","The AD mandates inspection but does not specify corrective actions within the text supplied, leaving follow-up steps to operator maintenance practice or other guidance (potential discretion in corrective response). (Requirement 1–2)"],"plain_english_summary":"What this instrument does\n\n- Requires regular inspections of the main undercarriage lower forward attachment bolts on DHC-2 (Beaver) series aeroplanes. (Applicability; Requirement 1–2)\n\nWho it affects\n\n- Aircraft operators and maintenance organisations responsible for DHC-2 (Beaver) series aeroplanes. The AD is addressed to all models of that type. (Applicability)\n\nWhat must be done, mechanically\n\n- Inspect bolt P/N C2U-487ND (part of bolt assembly No. C2U-185A) for cracking using either magnetic particle inspection (per ANO 108.8) or fluorescent penetrant inspection (per ANO 108.10). (Requirement 1)\n- Inspect hard chrome plated bolt P/N 02-B-16 for cracking using fluorescent penetrant inspection (per ANO 108.10). (Requirement 2)\n- Carry out these inspections at intervals of no more than 100 hours time-in-service for aircraft used in agricultural operations, and no more than 500 hours time-in-service for other aircraft. (Compliance)\n\nWho pays and who decides\n\n- Aircraft operators pay for and arrange the inspections and any follow-up repairs or part replacements. Maintenance organisations or technicians who perform magnetic particle or fluorescent penetrant inspections carry out the work. The regulator prescribes the required inspection methods by reference to ANO 108.8 and ANO 108.10. (Requirement 1–2; Compliance)\n\nIncentives, costs and operational effects (mechanisms)\n\n- Different inspection intervals (100 h for agricultural operations; 500 h for others) create a higher recurring inspection cost and more frequent downtime for aircraft used in agricultural work. (Compliance)\n- The AD prescribes specific inspection techniques (magnetic particle or fluorescent penetrant) and specific part numbers to be inspected, which requires access to the relevant inspection equipment, qualified personnel and the procedures in ANO 108.8 / 108.10. Those are external technical requirements that become part of compliance cost and practice. (Requirement 1–2)\n\nCompliance burden and implementation risks\n\n- Compliance requires tracking hours time-in-service and scheduling inspections at the prescribed intervals. (Compliance)\n- Inspecting to the referenced ANO methods may require specialised equipment and trained inspectors; availability of such services and the time needed to perform inspections affect operational scheduling and direct maintenance costs. (Requirement 1–2)\n- If cracking is found, operators must incur repair or replacement costs and additional downtime; the AD text itself mandates inspection only, not the corrective action wording. (Requirement 1–2)\n\nTrade-offs and substitution effects to note (as mechanisms, not judgments)\n\n- The split inspection interval creates a clear operational trade-off: aircraft used in higher-intensity roles (agricultural) face more frequent inspections and associated costs. (Compliance)\n- Operators may respond by altering use patterns, maintenance scheduling or sourcing inspection services; the AD sets the inspection obligation but does not prescribe how operators meet it. (Compliance)\n\nSource references to requirements cited in this summary: Applicability; Requirement 1; Requirement 2; Compliance."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard Airworthiness Directive maintaining its original purpose: mandating specific safety inspections for a particular aircraft type. The amendment (Amdt 1) appears to be a routine update to an existing directive, not an expansion beyond the original safety intent."},"complexity_factors":["Very short document (approximately 200 words)","Only 2 specific part numbers to identify","Simple binary applicability (agricultural vs non-agricultural operations)","Two inspection methods referenced by external standard numbers (ANO 108.8 and ANO 108.10) but not explained within the document","No nested conditions, exceptions, or cross-references to other legislation sections","Single compliance requirement with straightforward time intervals"],"plain_english_summary":"This is an **Airworthiness Directive** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). It applies to all models of the **DHC-2 Beaver aircraft** (a type of small aeroplane).\n\n**What it requires:**\nOwners and operators must **inspect specific bolts** on the main landing gear (undercarriage) for cracks. These bolts attach the lower forward part of the landing gear to the aircraft structure.\n\n**Two types of bolts are covered:**\n- **P/N C2U-487ND** (part of assembly C2U-185A): Must be checked using **magnetic particle inspection** or **fluorescent penetrant inspection** (specialised non-destructive testing methods that detect surface cracks)\n- **P/N 02-B-16** (hard chrome plated bolts): Must be checked using **fluorescent penetrant inspection** only\n\n**How often:**\n- **Agricultural aircraft** (crop dusters, etc.): Every **100 hours** of flight time\n- **All other aircraft**: Every **500 hours** of flight time\n\n**Why it matters:**\nCracked landing gear bolts can cause **gear collapse on landing**, potentially destroying the aircraft and killing occupants. This directive prevents catastrophic failures by catching cracks before they progress to failure."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-2-15-amdt-1-main-undercarriage-lower-forward-bolt-attachment-inspection","history":"/api/acts/ad-dhc-2-15-amdt-1-main-undercarriage-lower-forward-bolt-attachment-inspection/history","analysis":"/api/acts/ad-dhc-2-15-amdt-1-main-undercarriage-lower-forward-bolt-attachment-inspection/analysis","conflicts":"/api/acts/ad-dhc-2-15-amdt-1-main-undercarriage-lower-forward-bolt-attachment-inspection/conflicts","importantCases":"/api/acts/ad-dhc-2-15-amdt-1-main-undercarriage-lower-forward-bolt-attachment-inspection/important-cases","documents":"/api/acts/ad-dhc-2-15-amdt-1-main-undercarriage-lower-forward-bolt-attachment-inspection/documents"}}