{"id":"F2006B08949","name":"AD/DH114/38 - Drag Bracing Member, Centre Section Spar Lower Boom - Inspection and Replacement","slug":"ad-dh114-38-drag-bracing-member-centre-section-spar-lower-boom-inspection-and-replacement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52587,"registerId":"commonwealth-F2006B08949-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DH114/38 - Drag Bracing Member, Centre Section Spar Lower Boom - Inspection and Replacement","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/DH114/38 Drag Bracing Member, Centre Section Spar Lower NK\n\nBoom - Inspection and Replacement\n\n \n\nApplicability: All models with S/Nos. prior to 14135 not incorporating modification 1102 or 1103. Document:               Hawker Siddeley TNS Heron (114) No. F.18.\n\nCompliance: 1. Inspect fittings in accordance with Para. 4 of TNS Heron (114) No. F18. within 100 hours time in service after 29 June 1973 or before 1 August 1973 whichever occurs first.\n\n \n\n2. Replace fittings in accordance with Para. 5 of TNS Heron (114) No. F.18 before 1 July 1974.\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\n \n\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The instrument's scope is the same as stated in the text: it applies only to DH114 (Heron) series aeroplanes with serial numbers prior to 14135 that have not incorporated modification 1102 or 1103, and it mandates inspection and replacement per the referenced TNS document within the timeframes given. There is no indication in the supplied text that the scope was broadened or narrowed from an earlier or original intent."},"complexity_factors":["Applicability limited by serial-number cutoff (S/Ns prior to 14135) requiring record checks","Exclusion for aircraft that have incorporated modification 1102 or 1103 (requires verification of modification status)","Short, specific compliance windows combining both flight hours (100 hours TIS after 29 June 1973) and fixed calendar dates (before 1 August 1973 for inspection cutoff; before 1 July 1974 for replacement)","Technical procedures are not set out in the AD but are referenced to external paragraphs (Para. 4 and Para. 5 of TNS Heron (114) No. F.18), creating dependency on that document","Mandatory nature of actions with limited operator discretion over method (must follow referenced paragraphs) but some scheduling discretion for when within the windows to carry out work"],"plain_english_summary":"This instrument, issued under the Commonwealth Civil Aviation Regulations, requires operators of DH114 (Heron) aeroplanes (serials before 14135, excluding those with mods 1102/1103) to inspect—and, if necessary, replace—specified drag‑bracing/centre‑section lower boom fittings per Hawker Siddeley TNS Heron (114) No. F.18.\n\nThe work must be scheduled and carried out by the owner/operator or their maintenance organisation within short, fixed windows (inspection within 100 TIS hours after 29 June 1973 or before 1 Aug 1973; replacement before 1 Jul 1974)."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific known defect in a specific aircraft type. It has not expanded beyond its original purpose of ensuring the airworthiness of DH114 Heron aircraft regarding this particular structural component."},"complexity_factors":["Very short document (approximately 200 words)","Only 2 operative requirements (inspect and replace)","Single defined applicability criterion (serial number range plus modification status)","No nested exceptions or conditional logic beyond the applicability test","References only one external technical document (TNS Heron No. F.18)","Straightforward compliance deadlines with simple 'whichever occurs first' logic"],"plain_english_summary":"This is an **Airworthiness Directive** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) under the Civil Aviation Regulations 1998.\n\n**What it does:**\nThis directive requires owners and operators of specific **de Havilland DH114 Heron aircraft** to inspect and replace a critical structural part — the **drag bracing member** located on the centre section spar lower boom. This component helps maintain the structural integrity of the aircraft's wing.\n\n**Who it affects:**\n- All DH114 Heron models with **serial numbers below 14135**\n- Aircraft that **have not been modified** with either Modification 1102 or 1103 (these modifications apparently fix the problem)\n\n**What must be done:**\n1. **Inspection:** Within 100 hours of flying time after 29 June 1973, or before 1 August 1973 (whichever comes first), operators must inspect the fittings following the procedures in a specific technical document (TNS Heron No. F.18, paragraph 4).\n\n2. **Replacement:** By 1 July 1974, operators must replace the fittings according to paragraph 5 of the same technical document.\n\n**Why it matters:**\nAirworthiness Directives are legally binding safety instructions. Failure to comply means an aircraft cannot legally fly. This particular directive addresses a potential structural failure risk in the wing spar — a critical safety issue that could lead to catastrophic failure if left unaddressed."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dh114-38-drag-bracing-member-centre-section-spar-lower-boom-inspection-and-replacement","history":"/api/acts/ad-dh114-38-drag-bracing-member-centre-section-spar-lower-boom-inspection-and-replacement/history","analysis":"/api/acts/ad-dh114-38-drag-bracing-member-centre-section-spar-lower-boom-inspection-and-replacement/analysis","conflicts":"/api/acts/ad-dh114-38-drag-bracing-member-centre-section-spar-lower-boom-inspection-and-replacement/conflicts","importantCases":"/api/acts/ad-dh114-38-drag-bracing-member-centre-section-spar-lower-boom-inspection-and-replacement/important-cases","documents":"/api/acts/ad-dh114-38-drag-bracing-member-centre-section-spar-lower-boom-inspection-and-replacement/documents"}}