{"id":"F2010L02250","name":"AD/BN-2/35 Amdt 3 - Airframe Structural Fatigue Life Limitation","slug":"ad-bn-2-35-amdt-3-airframe-structural-fatigue-life-limitation","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":124924,"registerId":"commonwealth-F2010L02250-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Pilatus Britten-Norman BN-2 Series Aerop","sectionType":"division","heading":"Pilatus Britten-Norman BN-2 Series Aeroplanes","content":"### Pilatus Britten-Norman BN-2 Series Aeroplanes\n\n| AD/BN-2/35 Amdt 3 | Airframe Structural Fatigue Life Limitation | 16/2010 |\n| ----------------- | ------------------------------------------- | ------- |\n\n| Applicability: | All BN-2 piston engine models.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |\n| -------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Retire from service the wing and wing attachment fuselage frames.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |\n| Compliance:    | Before 30,000 hours total time in service (for BN-2A model with 49 foot wingspan).Before 28,000 hours total time in service (for BN-2B model).                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |\n|                | This Amendment becomes effective on 9 August 2010.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |\n| Background:    | This amendment increases the retirement life from 28,000 hours to 30,000 hours based on advice from the manufacturer for the BN-2A model only. Recent fatigue data analysis indicates the fatigue life can be safely increased to 30,000 hours for the BN-2A model with 49 foot wingspan, pending further review by the manufacturer.Finalised fatigue lives for the BN-2A and BN-2B models will be provided once Pilatus-Britten Norman have completed their review of fatigue for these variants.The fatigue life for the BN-2T is contained in the maintenance manual, section 4.3 “Wing Structure Safe Life” and is based on utilisation rate. |\n\n![](image.001.png)\n\nMike Higgins  \nDelegate of the Civil Aviation Safety Authority\n\n5 August 2010","sortOrder":0},{"sectionNumber":"AD/BN-2/35 Amdt 3","sectionType":"part","heading":"AD/BN-2/35 Amdt 3","content":"## AD/BN-2/35 Amdt 3","sortOrder":1},{"sectionNumber":"Airframe Structural Fatigue Life Limitat","sectionType":"part","heading":"Airframe Structural Fatigue Life Limitation","content":"## Airframe Structural Fatigue Life Limitation","sortOrder":2},{"sectionNumber":"16/2010","sectionType":"part","heading":"16/2010","content":"## 16/2010","sortOrder":3}],"analysis":{"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":2,"scope_assessment":{"changed":false,"description":"This is a narrow, technical amendment to an existing airworthiness directive. It adjusts a single numerical parameter (flight hour limit) for one aircraft variant based on manufacturer data. The scope remains tightly focused on structural fatigue life limits for the BN-2 series, which was the original purpose of the directive."},"complexity_factors":["Very short document (under 300 words)","Only 2 defined applicability categories (BN-2A and BN-2B)","Single compliance requirement with straightforward hour thresholds","No cross-references to other legislation or regulations","No conditional logic or exceptions — just hard numerical limits","Background section provides context but doesn't create legal complexity"],"plain_english_summary":"This AD requires permanent retirement of wings on Pilatus Britten‑Norman BN‑2 Islander piston models once they reach specified flight-hour limits to address metal fatigue. It affects BN‑2A and BN‑2B piston variants (not the BN‑2T turbine).\n\nThe amendment raises the BN‑2A limit from 28,000 to 30,000 hours (BN‑2B remains 28,000) based on new manufacturer fatigue data; the limits are interim while a full engineering review continues."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"The amendment increases the retirement life for the BN‑2A model from 28,000 to 30,000 hours (for the 49 ft wingspan) based on manufacturer advice. BN‑2B remains at 28,000 hours, and BN‑2T fatigue life is addressed in the maintenance manual; finalised lives for variants are pending the manufacturer’s review (Background)."},"complexity_factors":["Model‑specific retirement limits (different hours for BN‑2A and BN‑2B)","Broad applicability language ('All BN‑2 piston engine models') combined with variant exceptions (BN‑2T life in maintenance manual)","Dependence on manufacturer advice and pending review for finalised fatigue lives","Operational and scheduling burden on operators to retire/replace primary structural components by specified hours","Compliance effective date and enforcement responsibility resting with regulator (effective 9 August 2010)"],"plain_english_summary":"This instrument requires operators of Pilatus Britten‑Norman BN‑2 piston‑engine aeroplanes to retire the wing and wing‑attachment fuselage frames by set total hours: BN‑2A (49 ft wingspan) at 30,000 hours and BN‑2B at 28,000. It is effective 9 August 2010. \n\nOwners and operators must schedule and fund these retirements and replacements; the BN‑2A increase to 30,000 hours follows the manufacturer’s fatigue advice, while finalised lives for variants are pending further manufacturer review (Background)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bn-2-35-amdt-3-airframe-structural-fatigue-life-limitation","history":"/api/acts/ad-bn-2-35-amdt-3-airframe-structural-fatigue-life-limitation/history","analysis":"/api/acts/ad-bn-2-35-amdt-3-airframe-structural-fatigue-life-limitation/analysis","conflicts":"/api/acts/ad-bn-2-35-amdt-3-airframe-structural-fatigue-life-limitation/conflicts","importantCases":"/api/acts/ad-bn-2-35-amdt-3-airframe-structural-fatigue-life-limitation/important-cases","documents":"/api/acts/ad-bn-2-35-amdt-3-airframe-structural-fatigue-life-limitation/documents"}}