{"id":"F2009L01852","name":"AD/AT/27 Amdt 2 - Wing Lower Spar Cap","slug":"ad-at-27-amdt-2-wing-lower-spar-cap","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":78871,"registerId":"commonwealth-F2009L01852-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Airtractor AT-300, 400 and 500 Series Ae","sectionType":"division","heading":"Airtractor AT-300, 400 and 500 Series Aeroplanes","content":"### Airtractor AT-300, 400 and 500 Series Aeroplanes\n\n| AD/AT/27 Amdt 2 | Wing Lower Spar Cap | 6/2009 |\n| --------------- | ------------------- | ------ |\n\n| Applicability: | Model AT-400, AT-401, AT-401B, AT-402, AT-402A, and AT-402B aircraft, with serial numbers specified in FAA AD 2006-08-08 R1.                                                                                                                                                                                                                                                                                                                                                                                                                                             |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n| Requirement:   | Action in accordance with the technical requirements of FAA AD 2006-08-08 R1 Amdt 39-15849.Report any cracks to CASA within 10 days of the crack finding via the SDR system, providing all details requested by FAA AD 2006-08-08 R1 inspection report form.Note: The Requirement document can be obtained through the FAA web site:www.faa.gov/aircraft/safety/alerts/,or by contactingairworthiness.directives@casa.gov.au                                                                                                                                             |\n| Compliance:    | As specified in the Requirement document, with a revised effective date of4 June 2009.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |\n|                | This Amendment becomes effective on 4 June 2009.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |\n| Background:    | The FAA received in-service reports of fatigue cracking of the wing main spar lower cap 3/8-inch bolt hole at a time below the safe life limit established for applicable aircraft in FAA AD 2002-11-05 (AD/AT/20 Amdt 3 and AD/AT 800/3 Amdt 2). Undetected fatigue cracking in the wing main spar lower cap could result in failure of the spar cap, and lead to wing separation and loss of control of the aircraft.Amendment 1 was issued in response to a corrected issue of the FAA AD Requirement document, which introduced numerous changes to the FAA AD text. |\n\n|     | Amendment 2 is issued in response to a revision of the related FAA AD, which was prompted by information received to update inspection intervals for the ModelsAT-401B, AT-402A and AT-402B aircraft based on a revised damage tolerance analysis. The revised FAA AD retains the currently required actions, but reduces the number of repetitive inspections for all affected Model AT-401B aircraft and certain Models AT-402A and AT-402B aircraft. |\n| --- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n\n![](image.001.png)  \nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n17 April 2009","sortOrder":0},{"sectionNumber":"AD/AT/27 Amdt 2","sectionType":"part","heading":"AD/AT/27 Amdt 2","content":"## AD/AT/27 Amdt 2","sortOrder":1},{"sectionNumber":"Wing Lower Spar Cap","sectionType":"part","heading":"Wing Lower Spar Cap","content":"## Wing Lower Spar Cap","sortOrder":2},{"sectionNumber":"6/2009","sectionType":"part","heading":"6/2009","content":"## 6/2009","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":6,"scope_assessment":{"changed":true,"description":"Amendment 2 does not add new types of actions but revises the scope of repetitive inspections: it retains the FAA AD’s required inspections and corrective actions but reduces the number of repetitive inspections for all affected Model AT-401B aircraft and certain AT-402A/AT-402B aircraft based on an updated damage-tolerance analysis (Background). Applicability remains tied to the serial numbers listed in FAA AD 2006-08-08 R1 (Applicability)."},"complexity_factors":["External-reference dependence: mandates compliance with FAA AD 2006-08-08 R1 (Amdt 39-15849) rather than reproducing technical requirements, so users must obtain and interpret that FAA document (Requirement).","Serial-number specific applicability: only certain serial-numbered aircraft are covered, requiring operators to check serial lists in the FAA AD (Applicability).","Technical inspection and corrective actions: involves fatigue-crack detection and possible structural repair/replacement, which require specialised maintenance resources and engineering judgement (Background; Requirement).","Variable inspection intervals: Amendment 2 changes repetitive-inspection frequencies for specific models (AT-401B, some AT-402A/AT-402B), creating model-specific compliance schedules to track (Background).","Mandatory reporting and administrative burden: any crack finding must be reported to CASA within 10 days via the SDR system, with details per the FAA inspection report form (Requirement).","Regulatory timing and effective date: compliance must follow the FAA document 'as specified' with a revised effective date of 4 June 2009, creating a firm start date for obligations (Compliance; Effective date)."],"plain_english_summary":"This airworthiness directive requires operators of specified Airtractor AT-300/400/500 series aeroplanes (models AT-400, AT-401, AT-401B, AT-402, AT-402A, AT-402B with serials listed in FAA AD 2006-08-08 R1) to follow the inspection and corrective actions set out in FAA AD 2006-08-08 R1 and to report any discovered cracks to CASA via the SDR system within 10 days. Amendment 2 revises inspection intervals for some AT-401B/AT-402A/AT-402B aircraft, reducing repetitive inspections; the rule is aimed at preventing fatigue cracking of the wing main spar lower cap."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This amendment maintains the original safety purpose of preventing wing spar failures. Amendment 2 slightly narrows the scope by reducing inspection frequency for certain models (AT-401B, some AT-402A and AT-402B) based on updated engineering analysis, but this is a refinement rather than expansion beyond the original intent."},"complexity_factors":["Short, single-purpose directive (approximately 300 words)","Only 6 defined aircraft models in applicability","Single cross-reference to external FAA document (FAA AD 2006-08-08 R1) for technical requirements","Simple compliance structure: inspect, report cracks within 10 days, follow FAA timeline","No nested exceptions or conditional logic — straightforward applicability based on aircraft model and serial number","Background provides clear rationale but does not create additional legal obligations"],"plain_english_summary":"This safety directive orders owners and operators of certain Air Tractor AT‑400 series crop‑dusting aircraft to inspect the wing lower spar cap for fatigue cracks and to report any cracks to CASA within 10 days. It affects only the specific serial numbers named via the FAA directive. Prompt inspection and reporting aim to prevent in‑flight wing failure; the amendment relaxes inspection frequency for some models while keeping safety protections."}},"importantCases":[],"_links":{"self":"/api/acts/ad-at-27-amdt-2-wing-lower-spar-cap","history":"/api/acts/ad-at-27-amdt-2-wing-lower-spar-cap/history","analysis":"/api/acts/ad-at-27-amdt-2-wing-lower-spar-cap/analysis","conflicts":"/api/acts/ad-at-27-amdt-2-wing-lower-spar-cap/conflicts","importantCases":"/api/acts/ad-at-27-amdt-2-wing-lower-spar-cap/important-cases","documents":"/api/acts/ad-at-27-amdt-2-wing-lower-spar-cap/documents"}}