{"id":"F2006B08891","name":"AD/DH 60/4 Amdt 1 - Cockpit Lateral Tie Rods and Aircraft Structure","slug":"ad-dh-60-4-amdt-1-cockpit-lateral-tie-rods-and-aircraft-structure","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52385,"registerId":"commonwealth-F2006B08891-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DH 60/4 Amdt 1 - Cockpit Lateral Tie Rods and Aircraft Structure","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)  \nDe Havilland DH 60 (Moth) Series Aeroplanes\n\nAD/DH 60/4\n\nAmdt 1\n\n  \nCockpit Lateral Tie Rods and Aircraft Structure 6/99\n\nApplicability: All Variants of DH60 aircraft.\n\nRequirement: 1. Action in accordance with the Paragraph 2.A and 2.C of the Accomplishment Instructions of British Aerospace Technical News Sheet (TNS) CT (Moth) No. 29 Issue 3.\n\n2. Inspect in accordance with Paragraph 2.B of the Accomplishment Instructions of British Aerospace TNS CT (Moth) No. 29 Issue 3.\n\nNote 1: UK CAA AD 006-10-97 refers.\n\nNote 2: A copy of TNS 29 Issue 3 can be obtained from: The Engineering Support Manager\n\nBritish Aerospace Military Aircraft and Aerostructures\n\nMilitary Business Unit, Chadderton Works, Greengate, Middleton Manchester M24 1SA\n\nEngland\n\nFax No. 44 161 955 8798\n\nCompliance: 1\\. Within 2,000 flying hours or 18 years from the last tie rod renewal, whichever occurs first. In cases where no evidence of last renewal date is found to exist, accomplish within 100 flying hours after 21 May 1998 or before 21 November 1998, whichever occurs first. Thereafter at intervals not to exceed 2,000 flying hours or 18 years, whichever occurs first.\n\n2. Within 12 calendar months after 21 May 1998, and thereafter at intervals not to exceed 12 calendar months; and, before further flight after a heavy landing or undercarriage trauma occurrence (as defined in TNS CT (Moth) No. 29 Issue 3).\n\nThe compliance of the original issue of this Directive remains unchanged. This Amendment becomes effective on 17 June 1999.\n\nBackground: During routine maintenance on a DH 82 aircraft, it was found that the lateral fuselage tie rod at the aft position had sheared at its location with the spar attachment fitting. Subsequent investigation found the failure was a result of fatigue cracking in the thread root. This Directive requires that both lateral fuselage tie rods become “lifed items”, and introduces a procedure for the examination of the aircraft structure at annual intervals and following a heavy landing.\n\nAmendment 1 is issued in response to Issue 3 of the Requirement Document which introduces an inspection following an undercarriage trauma event.\n\nThe original issue of this Airworthiness Directive became effective on 21 May 1998.\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"Amendment 1 expands the original directive by adding a requirement to inspect the structure following an undercarriage trauma event (as introduced by Issue 3 of the Requirement Document). The core scope—making lateral tie rods lifed items and imposing recurrent inspections—remains, but the amendment increases event-driven inspection obligations and monitoring frequency."},"complexity_factors":["Reference to an external Requirement Document (British Aerospace TNS CT (Moth) No.29 Issue 3) for detailed procedures rather than embedding procedures in the AD","Mixed compliance metrics: flying hours OR years (2,000 flying hours or 18 years) creating dual tracking requirements (Compliance para 1)","Special handling when no evidence of last renewal exists (shortened compliance window: 100 flying hours after 21 May 1998 or before 21 Nov 1998)","Recurring calendar-based inspections (12-month intervals) plus mandatory inspection after specified events (heavy landing or undercarriage trauma) (Compliance para 2)","Applicability to all variants of DH60 aircraft increases administrative scope","Amendment adds a new trigger (undercarriage trauma) expanding the inspection circumstances from the original issue"],"plain_english_summary":"This Airworthiness Directive requires operators of De Havilland DH60 (Moth) aircraft to treat both lateral fuselage tie rods as parts with a mandatory life limit and to carry out specified inspections and replacements using British Aerospace Technical News Sheet CT (Moth) No. 29 Issue 3. It sets recurrent inspection intervals by flying hours or years and adds mandatory checks after heavy landings or undercarriage trauma. The measure responds to a fatigue failure found in service; operators must obtain the referenced TNS and meet the stated compliance timings."},"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This amendment stays tightly focused on its original purpose — preventing structural failure of DH 60 series aircraft tie rods. Amendment 1 merely expands the inspection trigger to include \"undercarriage trauma\" events alongside heavy landings, reflecting updated technical guidance from the manufacturer. The scope has not crept beyond airworthiness maintenance for this specific aircraft type."},"complexity_factors":["Short, single-purpose directive (approximately 400 words)","Only 4 defined compliance deadlines, though they involve nested conditions (hours OR years, whichever first)","Cross-reference to external technical document (British Aerospace TNS CT (Moth) No. 29 Issue 3) — operators must obtain this separately","Reference to UK CAA AD 006-10-97 for additional context","Simple two-part structure: replacement requirement + inspection requirement","No subordinate legislation, regulations, or extensive definitions within the text itself"],"plain_english_summary":"This safety order requires operators of de Havilland DH 60 series (including Tiger Moth) aircraft in Australia to treat lateral tie rods as lifed components: inspect them annually and replace them on a regular life limit, and inspect after hard landings or undercarriage damage. It responds to a fatigue failure that could cause in‑flight structural collapse, protecting owners, schools and museums that fly these vintage aeroplanes."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dh-60-4-amdt-1-cockpit-lateral-tie-rods-and-aircraft-structure","history":"/api/acts/ad-dh-60-4-amdt-1-cockpit-lateral-tie-rods-and-aircraft-structure/history","analysis":"/api/acts/ad-dh-60-4-amdt-1-cockpit-lateral-tie-rods-and-aircraft-structure/analysis","conflicts":"/api/acts/ad-dh-60-4-amdt-1-cockpit-lateral-tie-rods-and-aircraft-structure/conflicts","importantCases":"/api/acts/ad-dh-60-4-amdt-1-cockpit-lateral-tie-rods-and-aircraft-structure/important-cases","documents":"/api/acts/ad-dh-60-4-amdt-1-cockpit-lateral-tie-rods-and-aircraft-structure/documents"}}