{"id":"F2006B08925","name":"AD/DH114/15 - Top Centre Section Spar Attachment - Inspection and Modification","slug":"ad-dh114-15-top-centre-section-spar-attachment-inspection-and-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52490,"registerId":"commonwealth-F2006B08925-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DH114/15 - Top Centre Section Spar Attachment - Inspection and 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)  DH114 (Heron) Series Aeroplanes\n\n \n\nAD/DH114/15  Top Centre Section Spar NK Attachment - Inspection and Modification\n\nApplicability: All models.\n\n \n\nRequirement:  1. Inspect Channels P/N 14FS2839-42 and Reinforcing Channels P/N 14FS383 and 386 in accordance with Hawker Siddeley Technical News Sheet Heron (114) F.7, Issue 2.\n\n \n\n2. If found cracked, modify the channels in accordance with Heron Modification No. 792.\n\n \n\nCompliance: 1. At intervals not exceeding 300 hours time in service after 30 April 1964.\n\n \n\n2. When Mod. 792 has been incorporated the inspection interval may be extended to 5,000 hours time in service or five years whichever occurs first.\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\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This Airworthiness Directive remains tightly focused on its original purpose: addressing a specific structural fatigue issue in the DH114 Heron aircraft's wing spar attachment. The scope has not expanded beyond the original safety-critical inspection and repair requirement for this particular aircraft type."},"complexity_factors":["Very short document (approximately 150 words of substantive content)","Only 2 main requirements with clear sequential logic","Minimal defined terms (only standard aviation abbreviations like P/N for 'part number')","No cross-references to other legislation or regulations beyond the parent Civil Aviation Regulations 1998","Simple conditional structure: 'If cracked, then modify'","Straightforward compliance schedule with clear time intervals","Single applicability clause ('All models') with no exceptions or exemptions"],"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) for a specific aircraft type.\n\n**Which aircraft:** All models of the **DH114 Heron** — a British-made twin-engine propeller aircraft from the 1950s-60s.\n\n**What it requires:**\n- **Inspection:** Owners/operators must regularly check specific metal channels (structural parts) in the top centre section of the wing spar (the main structural beam running through the wing). These are identified by part numbers 14FS2839-42 and reinforcing channels 14FS383 and 386.\n- **The check must follow:** Hawker Siddeley Technical News Sheet Heron (114) F.7, Issue 2 (the manufacturer's official technical bulletin).\n- **If cracks are found:** The channels must be modified using \"Heron Modification No. 792\" — a specific repair procedure designed by the manufacturer.\n\n**How often:**\n- **Before the repair:** Every 300 hours of flight time (starting from 30 April 1964).\n- **After the repair:** The inspection interval stretches to every 5,000 hours **or** 5 years, whichever comes first.\n\n**Why it matters:** This addresses a critical structural weakness. Cracks in the wing spar attachment could lead to wing failure and catastrophic loss of the aircraft. The directive ensures aging Heron aircraft remain safe to fly through mandatory, recurring inspections and a permanent fix if damage is found."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The instrument sets inspection and modification requirements for specific components of DH114 (Heron) series aeroplanes. The text provides no indication that the directive alters or expands an earlier scope; it simply prescribes inspections, corrective modification when cracking is found, and two inspection-interval regimes (pre- and post-modification)."},"complexity_factors":["Clear, narrow technical scope limited to specific part numbers (Channels P/N 14FS2839-42; Reinforcing Channels P/N 14FS383 and 386).","Dependency on external technical documents for execution (Hawker Siddeley Technical News Sheet Heron (114) F.7, Issue 2; Heron Modification No. 792).","A conditional change in inspection frequency contingent on incorporation of a modification (short interval until mod; long interval after mod).","Precise time-based compliance requirements (hours time in service and an explicit historical reference date).","Regulatory formality (issued as an airworthiness directive under Part 39) but limited textual length and few operative clauses."],"plain_english_summary":"Owners and operators of DH114 (Heron) aircraft must inspect specified top centre‑section spar channels for cracking per Hawker Siddeley TNS Heron F.7 Issue 2, and if cracks are found, modify them per Heron Mod. 792. Inspections are required every 300 flight hours until Mod. 792 is embodied, after which the interval extends to 5,000 hours or five years. This imposes recurring inspection costs and a one‑off modification incentive."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dh114-15-top-centre-section-spar-attachment-inspection-and-modification","history":"/api/acts/ad-dh114-15-top-centre-section-spar-attachment-inspection-and-modification/history","analysis":"/api/acts/ad-dh114-15-top-centre-section-spar-attachment-inspection-and-modification/analysis","conflicts":"/api/acts/ad-dh114-15-top-centre-section-spar-attachment-inspection-and-modification/conflicts","importantCases":"/api/acts/ad-dh114-15-top-centre-section-spar-attachment-inspection-and-modification/important-cases","documents":"/api/acts/ad-dh114-15-top-centre-section-spar-attachment-inspection-and-modification/documents"}}