{"id":"F2006B07576","name":"AD/VAT/41 Amdt 1 - Wing Main Spar and Tailplane Fatigue Life Limit","slug":"ad-vat-41-amdt-1-wing-main-spar-and-tailplane-fatigue-life-limit","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":50189,"registerId":"commonwealth-F2006B07576-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/VAT/41 Amdt 1 - Wing Main Spar and Tailplane Fatigue Life Limit","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)  \nVicta and A.E.S.L. Airtourer Series Aeroplanes\n\nAD/VAT/41\n\nAmdt 1\n\n  \nWing Main Spar and Tailplane Fatigue Life Limit 6/84\n\nApplicability: All models.\n\nRequirement: Retire the following components from service:\n\n    Wing main spar lower cap assembly and wing front attachment spigot fittings.\n\n    2. Tailplane rear spar assembly and tailplane to fuselage attachment fittings.\n\nNote 1: Aircraft fitted with wing main spar reinforcement to Hamilton drawing 90014 are subject to this requirement which shall include retirement of the lower reinforcement strap assembly.\n\nNote 2: Aircraft engaged in competition or display aerobatics as defined in Note 3 below, or in practise for such aerobatics, shall be required to have the flight time so engaged factored as follows: Time engaged in such aerobatic manoeuvres shall be multiplied by a factor of twenty (20) when assessing the total time for structural life limitation purposes. The time so engaged shall be taken as the time from commencement until the time of completion of the manoeuvres or sequence of manoeuvres.\n\nNote 3: Competition or display aerobatics are defined as those manoeuvres which result in consistent high loads being placed on the airframe. Manoeuvres such as Lomcevaks, snap rolls, outside loops, square loops, spins (high exit speed) etc. are included within this definition. The more usual training or pleasure aerobatics, provided that they are only flown occasionally, do not attract the factor of 20 referred to in Note 2 above.\n\nNote 4: Competition aerobatic time not previously recorded shall be conservatively estimated from the known history of the particular aircraft.\n\nNote 5: This life limitation is based on measured stress and Conservative loads data, and will be subject to review on the basis of future measurements of a representative flight loads spectrum.\n\nCompliance: At or before 17200 hours time in service.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"This instrument is labelled as Amendment 1 to AD/VAT/41 and therefore alters the original AD. It prescribes mandatory retirement of specified wing and tail components, explicitly includes reinforced-spar assemblies where Hamilton drawing 90014 applies (Note 1), adds a 20× aerobatic time multiplier and definition for competition/display aerobatics (Notes 2–3), requires conservative estimation of unrecorded aerobatic time (Note 4), and fixes the compliance threshold at 17,200 hours TIS (Compliance). These elements clarify and extend the AD's operational and recordkeeping scope."},"complexity_factors":["Applicability is broad: \"All models\" (Applicability).","Specific retirement scope: multiple discrete structural components listed (Requirement).","Includes reinforcement detail: retirement extends to lower reinforcement strap where Hamilton drawing 90014 applies (Note 1).","Aerobatic time multiplier is high: competition/display aerobatic time counted as 20× toward structural life (Note 2).","Definition-driven compliance: what counts as competition/display aerobatics is defined and excludes occasional pleasure aerobatics (Note 3).","Recordkeeping/estimation burden: unrecorded aerobatic time must be conservatively estimated from known history (Note 4).","Compliance deadline is a single fixed hours threshold: retire at or before 17,200 hours TIS (Compliance).","Future-review clause: life limit based on measured stress and conservative loads; subject to future review with representative load measurements (Note 5)."],"plain_english_summary":"*This AD requires retirement of specified wing main spar lower cap and front spigot fittings, and tailplane rear spar and attachment fittings by 17,200 hours time-in-service.* Aircraft used in competition or display aerobatics must count each minute of aerobatic flight as twenty minutes for life-limit calculations; unrecorded aerobatic time must be conservatively estimated. Owners/operators must remove/replace the listed parts and keep time records; costs and compliance burden fall on them. The AD cites measured stress data and may be reviewed with future load measurements."},"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This amendment appears to maintain the original scope of AD/VAT/41. The amendment number (Amdt 1) suggests revision rather than expansion, and the content remains tightly focused on fatigue life limits for specific structural components of the Airtourer series. No evidence of scope creep into unrelated aircraft systems or types."},"complexity_factors":["Single primary compliance threshold (17,200 hours) with straightforward component list","Five explanatory notes adding conditional logic (aerobatics multiplier, retrospective estimation, future review clause)","No cross-references to other legislation or defined terms section","Self-contained document: applicability, requirement, and compliance clearly delineated","Limited conditional complexity: only the aerobatics multiplier and reinforcement note create exceptions"],"plain_english_summary":"This CASA airworthiness directive orders owners/operators of Victa and A.E.S.L. Airtourer light aircraft to permanently retire key structural parts (wing main spar lower cap/front fittings and tailplane rear spar/attachments) once an aircraft reaches 17,200 flight hours. A history of competition/display aerobatics counts as 20× actual hours for this limit. The rule addresses metal-fatigue risk to prevent in‑flight structural failure."}},"importantCases":[],"_links":{"self":"/api/acts/ad-vat-41-amdt-1-wing-main-spar-and-tailplane-fatigue-life-limit","history":"/api/acts/ad-vat-41-amdt-1-wing-main-spar-and-tailplane-fatigue-life-limit/history","analysis":"/api/acts/ad-vat-41-amdt-1-wing-main-spar-and-tailplane-fatigue-life-limit/analysis","conflicts":"/api/acts/ad-vat-41-amdt-1-wing-main-spar-and-tailplane-fatigue-life-limit/conflicts","importantCases":"/api/acts/ad-vat-41-amdt-1-wing-main-spar-and-tailplane-fatigue-life-limit/important-cases","documents":"/api/acts/ad-vat-41-amdt-1-wing-main-spar-and-tailplane-fatigue-life-limit/documents"}}