{"id":"F2005L01513","name":"AD/AT-6/1 Amdt 1 - Wing Attach Angles","slug":"ad-at-6-1-amdt-1-wing-attach-angles","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":35390,"registerId":"commonwealth-F2005L01513-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Rockwell (N American) & Autair (Noorduyn","sectionType":"division","heading":"Rockwell (N American) & Autair (Noorduyn)AT-6, BC-1A, SNJ, T-6G, Harvard, & AT-16 Series Aeroplanes","content":"### Rockwell (N American) & Autair (Noorduyn)  \nAT-6, BC-1A, SNJ, T-6G, Harvard, & AT-16 Series Aeroplanes\n\n| AD/AT-6/1 Amdt 1 | Wing Attach Angles | 8/2005 DM |\n| ---------------- | ------------------ | --------- |\n\n| Applicability: | Models AT-6 (SNJ-2), AT-6A (SNJ-3), AT-6B, AT-6C (SNJ-4), AT-6D (SNJ-5), AT-6F (SNJ-6), BC-1A, Harvard (Army AT-16), SNJ-7, and T-6G aircraft; all serial numbers.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |\n| -------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | 1. Perform a fluorescent penetrant inspection of all inboard and outboard, upper and lower wing attach angles (except for the nose angles) of both wings for cracks, in accordance with the Appendix to FAA AD 2005-12-51.If cracks are found, replace cracked angles before further flight.2. Report to FAA the results of the initial Requirement 1 inspection even if no damage is found and even if the inspection was previously accomplished. The report sheet (containing contact information) is part of the FAA AD.3. The aircraft may be operated to position to a home base, hangar, maintenance facility, etc., for the purpose of doing the required initial inspection, subject to the following limitations:Acrobatic manoeuvres are prohibited.Flight into known or forecast moderate or severe turbulence is prohibited.Day visual flight rules (VFR) operation only.Single pilot operation only (passengers prohibited).Positioning an aircraft for the required initial inspection at a time that is later than the Requirement 3 compliance time, will require the issue of a special flight permit subject to the above limitations.Note 1: FAA Emergency AD 2005-12-51 refers.Note 2: The FAA posts Emergency ADs on the internet at www.faa.gov/aircraft/safety/alerts. |\n\n| Compliance: | 1. Before further flight after 10 June 2005, unless previously accomplished within the last 15 hours time in service. Inspect thereafter at intervals not to exceed 200 hours time in service.2. Within 7 days after the Requirement 1 inspection or within 7 days after 10 June 2005, whichever occurs later.3. The aircraft may be operated up to 10 hours time in service provided the flight(s) occur(s) no later than 30 days after 10 June 2005. This is a one-time provision.The compliance times remain unchanged by this issue.                                                               |\n| ----------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n|             | This Amendment becomes effective on 17 June 2005.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |\n| Background: | The FAA received a report of a Model SNJ-6 (AT-6F) aircraft crash that occurred on 9 May 2005, resulting in two fatalities. The ensuing investigation revealed a large fatigue crack in the failed lower inboard wing attach angle. The aircraft was used for hire in aerobatic training. Fatigue cracking may occur in the upper and/or lower attach angles that join the centre and outer wings, and, if allowed to progress, could result in wing failure and consequent loss of control of the aircraft.Amendment 1 is issued to clarify the requirement for the issue of a special flight permit. |\n\n![](image.001.png)  \nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n14 June 2005","sortOrder":0},{"sectionNumber":"AD/AT-6/1 Amdt 1","sectionType":"part","heading":"AD/AT-6/1 Amdt 1","content":"## AD/AT-6/1 Amdt 1","sortOrder":1},{"sectionNumber":"Wing Attach Angles","sectionType":"part","heading":"Wing Attach Angles","content":"## Wing Attach Angles","sortOrder":2},{"sectionNumber":"8/2005 DM","sectionType":"part","heading":"8/2005 DM","content":"## 8/2005 DM","sortOrder":3}],"analysis":{"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"},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"This amendment does not significantly broaden the original instrument's substantive scope. It preserves the core safety action — require inspection of wing attach angles and replacement of cracked parts — and the same affected aircraft. The amendment explicitly clarifies the conditions under which a special flight permit (positioning flight) may be used and requires reporting of inspection results to the FAA; those are procedural clarifications and administrative requirements rather than a material expansion of regulated subjects or additional categories of aircraft. The change is therefore a clarification and tightening of implementation details rather than a scope expansion beyond the original safety objective."},"complexity_factors":["List of multiple specific aircraft models in the Applicability paragraph (several AT‑6 variants, BC‑1A, Harvard/AT‑16, SNJ-7, T‑6G) requiring careful matching by operators","Three substantive Requirements with interlocking actions (inspect, report, restricted positioning flight) rather than a single action","Exemption of nose angles only (an exception inside Requirement 1) creating a targeted scope","Cross-reference to external FAA Emergency AD 2005‑12‑51 and its Appendix for the detailed inspection procedure and reporting form (external dependency)","Conditional compliance timing: (a) initial inspection before further flight after a given date unless done within prior 15 hours TIS, (b) repeat inspections every 200 hours TIS, (c) 7‑day reporting window tied to either inspection date or the reference date, and (d) a one‑time 10‑hour/30‑day positioning allowance","Operational limitations for permitted positioning flights (multiple simultaneous constraints: no aerobatics, no moderate/severe turbulence, day VFR, single pilot, no passengers)","Administrative reporting requirement to an overseas authority (FAA) even where no defect is found, increasing paperwork","Amendment purpose is narrow—clarification of special flight permit—but the instrument still requires operators to consult FAA material (procedural complexity)"],"plain_english_summary":"**What this instrument does (mechanically)\n\n- Requires a one-time detailed inspection of the wing attach angles (the metal brackets that join the centre and outer wings) on a set of older training/utility aircraft (AT-6 family, BC-1A, Harvard/AT-16 and related serial types).  The inspection method mandated is fluorescent penetrant inspection, which is a non‑destructive crack‑detection technique. (See \"Requirement 1\".)\n\n- If any cracks are found in any inspected attach angle (except the nose angles), the cracked part must be replaced before the aeroplane flies again. (Requirement 1.)\n\n- Requires the operator to report the results of that initial inspection to the US Federal Aviation Administration (FAA), even if no damage is found or even if an inspection was already done previously. The report form and contact details are part of the FAA document referenced. (Requirement 2.)\n\n- Allows limited positioning flights to reach a maintenance facility to do the inspection, but only under strict limits: no aerobatics, no flight into known or forecast moderate/severe turbulence, day VFR only, single pilot only (no passengers). Operating beyond the specified positioning allowance after the stated compliance time requires a special flight permit. (Requirement 3; Compliance.)\n\n- Sets firm compliance windows: the initial inspection must be done before further flight after 10 June 2005 unless it was done within the prior 15 hours time-in-service; if initial inspection is completed, repeat inspections are required at intervals not exceeding 200 hours time-in-service thereafter. Reporting to the FAA must be done within 7 days of the inspection (or 7 days after 10 June 2005, whichever is later). A one‑time allowance permits up to 10 hours time-in-service of positioning flight no later than 30 days after 10 June 2005. (Compliance.)\n\n\nWhy it was issued (official rationale, attributed)\n\n- The stated reason is an accident involving an AT-6F (SNJ‑6) on 9 May 2005 where investigation found a large fatigue crack in a lower inboard wing attach angle. The concern is that fatigue cracking in these attach angles can progress to wing failure and loss of control. The document says Amendment 1 clarifies the requirement for issuing a special flight permit. (Background; Amendment note.)\n\n\nPractical effects, incentives and who bears the costs\n\n- Who pays: aircraft owners/operators pay for inspections (labour, material, downtime) and for replacement parts if cracks are detected. If an aircraft needs to be positioned to a maintenance facility, the operator bears the cost and must meet the flight limitations set. (Requirements 1–3; Compliance.)\n\n- Who decides: the Civil Aviation Safety Authority (CASA) published this amendment; the inspection technique and reporting template are drawn from FAA Emergency AD 2005‑12‑51, so the FAA controls the reporting form and technical appendix referenced. CASA enforces compliance in Australia; the FAA will receive the inspection reports. (Requirement references and Background.)\n\n- Behavioural change required: operators must add a fluorescent penetrant inspection of specified attach angles to their maintenance action list, file a mandatory report with the FAA, and restrict flight operations for positioning until the inspection is done or a special permit is obtained. Recurrent inspections at intervals not exceeding 200 hours TIS are required after the initial check. (Requirements and Compliance.)\n\n\nTrade-offs and implementation points to note\n\n- Direct costs vs. safety: the regulation imposes direct inspection and potential replacement costs on operators in order to reduce the risk of in‑flight wing failure caused by undetected fatigue cracking (Background vs. Requirement 1). The text does not quantify cost or downtime.\n\n- Scope of inspection vs. invasiveness: the inspection technique required (fluorescent penetrant) is a standard crack-detection method and is less invasive than full structural disassembly, but it still requires trained personnel, facilities and parts inventory planning if replacements are needed. (Requirement 1.)\n\n- Reporting burden and cross‑jurisdictional paperwork: operators must report results to the FAA regardless of outcome (Requirement 2). That creates an administrative step even where no defect is found; the reporting form and contact details are provided in the FAA AD Appendix.\n\n- Operational flexibility and risk mitigation: a narrow, time‑limited allowance is made to reposition aircraft for inspection purposes (Compliance). The permit/positioning rules reduce the risk of flying in higher‑risk conditions but restrict operators (no passengers, single pilot only, day VFR, no aerobatics, avoid turbulence).\n\n- Implementation risk: the AD references the FAA emergency AD and its Appendix for the inspection procedure. Proper compliance depends on operators having access to that FAA material and ensuring their maintenance providers follow it exactly. Any ambiguity about the special flight permit process could create delays; the amendment states it clarifies the special flight permit requirement (Amendment note), but operators must still coordinate with the regulator to obtain permits outside the narrow repositioning allowance.\n\n\nConcise summary of legal mechanics (who does what)\n\n- Aircraft owners/operators of the listed models must perform a fluorescent penetrant inspection of specified wing attach angles and replace cracked parts before flight. (Requirement 1.)\n- They must report the inspection results to the FAA within seven days. (Requirement 2; Compliance.)\n- They may carry out limited repositioning flights under strict limits to get the inspection done; otherwise further flight is prohibited until compliance. (Requirement 3; Compliance.)\n\n\nSource references (where each point comes from)\n\n- Inspection and replacement duties: \"Requirement 1\" and Appendix to FAA AD 2005‑12‑51.\n- Mandatory reporting: \"Requirement 2\" and FAA AD report sheet.\n- Positioning flight limits and special permit note: \"Requirement 3\" and Compliance section.\n- Compliance time windows and repeat interval: \"Compliance\" section.\n- Rationale (accident and fatigue crack risk): \"Background.\""},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This amendment maintains the original scope of AD/AT-6/1. Amendment 1 specifically clarifies the special flight permit requirements for positioning aircraft after the compliance deadline — a technical refinement rather than scope expansion. The directive remains tightly focused on the wing attach angle inspection mandate triggered by the fatal SNJ-6 crash."},"complexity_factors":["Single discrete safety issue (wing attach angle cracking) with straightforward inspection protocol","Only 3 main requirements with clear conditional logic (if cracks found → replace; if no cracks → report)","Limited cross-referencing: references one external FAA document (AD 2005-12-51) for technical inspection method","Simple applicability table covering specific aircraft models by name and serial number","Clear compliance timeline with specific calendar dates and flight hour thresholds","One nested condition in Requirement 3 regarding special flight permits for late positioning flights","No extensive defined terms section — common aviation terminology used throughout"],"plain_english_summary":"This CASA Airworthiness Directive requires owners/operators of WWII-era North American T-6/Texan family warbirds to inspect wing attach angles using fluorescent penetrant inspection, ground aircraft if cracking is found, and report results to the FAA within seven days. Limited, strictly conditioned ferry flights to maintenance are allowed. The order responds to a 2005 fatal wing-separation caused by fatigue and aims to prevent further in‑flight failures of these aging, aerobatic aircraft."}},"importantCases":[],"_links":{"self":"/api/acts/ad-at-6-1-amdt-1-wing-attach-angles","history":"/api/acts/ad-at-6-1-amdt-1-wing-attach-angles/history","analysis":"/api/acts/ad-at-6-1-amdt-1-wing-attach-angles/analysis","conflicts":"/api/acts/ad-at-6-1-amdt-1-wing-attach-angles/conflicts","importantCases":"/api/acts/ad-at-6-1-amdt-1-wing-attach-angles/important-cases","documents":"/api/acts/ad-at-6-1-amdt-1-wing-attach-angles/documents"}}