{"id":"F2006B04734","name":"AD/BN-2/23 Amdt 1 - Woodward Propeller Governor Drive Shaft - Inspection and Replacement","slug":"ad-bn-2-23-amdt-1-woodward-propeller-governor-drive-shaft-inspection-and-replacement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44498,"registerId":"commonwealth-F2006B04734-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BN-2/23 Amdt 1 - Woodward Propeller Governor Drive Shaft - Inspection and Replacement","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)  \nPilatus Britten-Norman BN-2 Series Aeroplanes\n\nAD/BN-2/23\n\nAmdt 1\n\n  \n\nWoodward Propeller Governor Drive NK Shaft - Inspection and Replacement\n\nApplicability: All models fitted with Woodward Governor P/N 210275, F210444, 210655 or 210669.\n\nRequirement: 1. Inspect governor drive shaft P/N 210206, not identified with letter “W” on the drive end, by magnetic particle or an approved dye penetrant method for cracking at the radially disposed slots adjacent to the drive splines.\n\nN.B. Woodward SB 33538 details the field method of removing the shaft.\n\n    2. Retire from service governor drive shafts Woodward P/N 210206, not identified with letter “W” on drive end.\n\n    3. Retire from service governor drive shaft P/N 210206 identified with letter “W” on drive end.\n\nREFERENCE DOCUMENTS: Britten Norman SB BN-2/SB.53 Issue 4 Woodward SBs 33538 and 33539C.\n\nCompliance: 1. Initial inspection within 100 hours time in service after 31 March 1972 and thereafter at intervals not exceeding 200 hours time in service.\n\n    2. For shafts that have completed 1700 or more hours total time in service - within 100 hours time in service; for shafts that have completed less than 1700 hours total time in service - before achieving 1800 hours total time in service.\n\n    3. Before exceeding 4600 hours total time in service.","sortOrder":0}],"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"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is an amendment (Amdt 1) to an existing Airworthiness Directive, but it remains tightly focused on the original safety issue: preventing failure of Woodward propeller governor drive shafts on BN-2 aircraft. The scope has not expanded beyond this specific mechanical defect."},"complexity_factors":["Short, single-purpose directive with only 3 requirements","Limited applicability (one aircraft series, four specific part numbers)","Simple conditional logic based on flight hours and part markings","No nested definitions or extensive cross-referencing","Clear compliance deadlines with straightforward hour-based triggers","Only 2 reference documents cited"],"plain_english_summary":"This CASA Airworthiness Directive requires operators of Pilatus Britten‑Norman BN‑2 aircraft fitted with certain Woodward propeller governors to inspect and replace specific governor drive shafts. Cracks can form near the splines, risking propeller control loss and engine/power failure.\n\nAffected operators must test unmarked shafts and retire shafts by specified flight‑hour limits. The measures prevent in‑flight catastrophic failures and mandate strict tracking of flight hours."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The supplied directive itself mandates inspection and retirement rules for Woodward drive shaft P/N 210206 (including shafts marked \"W\") and sets specific compliance intervals and retirement hours. The text does not provide prior-version content or other materials showing a change from an earlier scope, so no change from earlier intent can be determined from this document alone."},"complexity_factors":["Multiple affected parts and identifiers: affects governor assemblies P/N 210275/F210444/210655/210669 and drive shaft P/N 210206 with/without letter \"W\" marking (Applicability; Requirements).","Differentiated actions: inspection for some shafts and mandatory retirement for others, with both marking-based and hours-based criteria (Requirements 1–3).","Technical inspection standard: requires magnetic particle or approved dye‑penetrant methods, adding specialised labour/equipment (Requirement 1).","Tiered compliance timing: initial and recurring inspection intervals and multiple total‑time retirement thresholds (Compliance).","Cross‑referenced service documents: relies on Britten Norman and Woodward service bulletins for field methods and details, creating dependency on external documents (Reference Documents)."],"plain_english_summary":"This Airworthiness Directive requires operators of Pilatus Britten‑Norman BN‑2 aeroplanes fitted with specific Woodward governors to inspect and, at defined life limits, remove and replace Woodward drive shafts P/N 210206. Inspections use magnetic particle or approved dye‑penetrant methods and recurring intervals and retirement hours are prescribed. The Civil Aviation Safety Authority mandates compliance; aircraft owners/operators pay for inspections, removals and replacements (Requirements 1–3; Compliance)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bn-2-23-amdt-1-woodward-propeller-governor-drive-shaft-inspection-and-replacement","history":"/api/acts/ad-bn-2-23-amdt-1-woodward-propeller-governor-drive-shaft-inspection-and-replacement/history","analysis":"/api/acts/ad-bn-2-23-amdt-1-woodward-propeller-governor-drive-shaft-inspection-and-replacement/analysis","conflicts":"/api/acts/ad-bn-2-23-amdt-1-woodward-propeller-governor-drive-shaft-inspection-and-replacement/conflicts","importantCases":"/api/acts/ad-bn-2-23-amdt-1-woodward-propeller-governor-drive-shaft-inspection-and-replacement/important-cases","documents":"/api/acts/ad-bn-2-23-amdt-1-woodward-propeller-governor-drive-shaft-inspection-and-replacement/documents"}}