{"id":"F2006B08877","name":"AD/DH 104/34 Amdt 2 - Centre Section Main Spar Top and Bottom Boom Joint - Inspection","slug":"ad-dh-104-34-amdt-2-centre-section-main-spar-top-and-bottom-boom-joint-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52301,"registerId":"commonwealth-F2006B08877-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DH 104/34 Amdt 2 - Centre Section Main Spar Top and Bottom Boom Joint - Inspection","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nDH 104 (Dove) Series Aeroplanes\n\nAD/DH 104/34\n\nAmdt 2\n\nApplicability: All models.\n\n  \n\nCentre Section Main Spar Top and Bottom Boom Joint - Inspection\n\n  \n9/77\n\nRequirement: 1. Inspect the Centre Section Main Spar Top boom in accordance with Hawker Siddeley TNS CT(104) No. 237 Appendix 1, or in accordance with a technique approved by the Secretary. Technique ATG/NDI/US/1 constitutes such an approved technique.\n\n2. Inspect the Centre Section Main Spar Bottom boom of those aircraft without Modification 779 embodied, in accordance with Hawker Siddeley TNS CT(104) No. 238 appendix 1, or in accordance with a technique approved by the Secretary. Technique ATG/NDI/US/1 constitutes such an approved technique.\n\nNote: Where crack indications are found the Airworthiness Branch, Central Office, is to be notified before further flight.\n\nCompliance: Inspect at intervals in accordance with Hawker Siddeley TNS CT(104) Nos. 237 and 238 Issue 2 as applicable.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"This amendment explicitly approves the inspection technique ATG/NDI/US/1, directs compliance with Issue 2 of Hawker Siddeley TNS CT(104) Nos. 237 and 238 for inspection procedures and intervals, and clarifies that the bottom boom inspection applies only to aircraft without Modification 779. Those additions and clarifications adjust the practical scope and approved methods of compliance."},"complexity_factors":["References to external technical documents (Hawker Siddeley TNS CT(104) Nos. 237 and 238 Issue 2) create dependency on non‑statutory material for procedural detail.","Approval discretion: inspections may instead follow a technique \"approved by the Secretary,\" introducing administrative approval processes and potential delay.","Specific approved technique named (ATG/NDI/US/1) implies use of specialised inspection methods; operators must ensure capability or procure contractors.","Conditional applicability: bottom boom inspection applies only to aircraft without Modification 779, requiring operators to check modification status.","Operational constraint: any crack indications require notifying the Airworthiness Branch before further flight, imposing immediate reporting and grounding decisions.","Compliance tied to inspection intervals set in the referenced documents rather than in the directive text, requiring cross‑referencing and recordkeeping."],"plain_english_summary":"Mandates mandatory inspections of the centre‑section main spar top and (for aircraft without Modification 779) bottom booms on DH.104 (Dove) aeroplanes. Operators must carry out inspections using Hawker Siddeley technical notes (TNS CT(104) Nos. 237/238 Issue 2) or an approved technique (explicitly ATG/NDI/US/1). Any crack indications must be reported to the Airworthiness Branch before further flight. This affects all owners/operators of DH.104 aircraft and sets the required inspection standard and schedule."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is Amendment 2 of an existing Airworthiness Directive (AD/DH 104/34), indicating it has been updated but remains focused on its original purpose: ensuring structural integrity of DH 104 Dove aircraft spars. The scope has not expanded beyond this specific safety issue."},"complexity_factors":["Short, single-purpose directive focused on one aircraft type and specific structural components","Only 2 main requirements with straightforward conditional logic (bottom boom inspection excludes aircraft with Modification 779)","Heavy reliance on external technical documents (Hawker Siddeley TNS CT(104) Nos. 237 and 238) — the actual inspection procedures are not reproduced in the legislation itself","Minimal defined terms — assumes technical aviation knowledge (e.g., 'Modification 779', 'Secretary', 'Airworthiness Branch')","Simple compliance structure: recurring inspections at specified intervals","No nested exceptions or complex cross-referencing within the instrument itself"],"plain_english_summary":"This Airworthiness Directive mandates regular inspections of the Centre Section Main Spar top and bottom boom joints on DH 104 (Dove) aeroplanes. It affects all owners, operators and maintenance organisations of these vintage twin‑engined aircraft.\n\nThe checks follow specified Hawker Siddeley procedures (or approved alternatives); aircraft with certain factory modifications are exempt for the bottom boom. Cracks must be reported to CASA and the aircraft grounded until addressed — preventing catastrophic wing failure from metal fatigue."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dh-104-34-amdt-2-centre-section-main-spar-top-and-bottom-boom-joint-inspection","history":"/api/acts/ad-dh-104-34-amdt-2-centre-section-main-spar-top-and-bottom-boom-joint-inspection/history","analysis":"/api/acts/ad-dh-104-34-amdt-2-centre-section-main-spar-top-and-bottom-boom-joint-inspection/analysis","conflicts":"/api/acts/ad-dh-104-34-amdt-2-centre-section-main-spar-top-and-bottom-boom-joint-inspection/conflicts","importantCases":"/api/acts/ad-dh-104-34-amdt-2-centre-section-main-spar-top-and-bottom-boom-joint-inspection/important-cases","documents":"/api/acts/ad-dh-104-34-amdt-2-centre-section-main-spar-top-and-bottom-boom-joint-inspection/documents"}}