{"id":"F2006B10657","name":"AD/HU 269/99 Amdt 1 - Main Rotor Drive Shaft Inspection","slug":"ad-hu-269-99-amdt-1-main-rotor-drive-shaft-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":116578,"registerId":"commonwealth-F2006B10657-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/HU 269/99 Amdt 1 - Main Rotor Drive Shaft Inspection","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)  \nSchweizer (Hughes) 269 Series Helicopters\n\nAD/HU 269/99\n\nAmdt 1\n\n  \n\nMain Rotor Drive Shaft Inspection 6/93 DM\n\nApplicability: All model 269A, A-1, B, C and TH-55A helicopters fitted with main rotor drive shaft P/N 269A5305-3 or 269A5305-11.\n\nRequirement: Unless previously carried out, action in accordance with the Technical requirements of Schweizer Mandatory Service Bulletin B-255.1 dated 01 Feb 1993 except that, X- Ray inspection may be conducted by an approved Australian NDI organisation. Refer Note 2 of Compliance for suitable organisation.\n\nNote: FAA Priority Letter AD 92-25-14 refers to Schweizer SB B-255.\n\nCompliance: As specified in the Requirement Document with a revised effective date of 14 April 1993.\n\nNote 1: Drive shafts previously inspected in accordance with SB B-255 must be re- inspected in accordance with SB B-255.1 mandated by this directive.\n\nNote 2: Operators wishing to discuss the availability of alternative NDI arrangements should contact Mr Chris Wolff of Motor Holdings, the Australian Schweizer agent, at Archerfield Airport on phone 07 277 6955.\n\nBackground: The FAA AD was prompted by the report of a main rotor drive shaft failure resulting in loss of the helicopter and two fatalities. This amendment has been raised to mandate the manufacturer’s NDI procedures on the main rotor drive shaft.","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":2,"scope_assessment":{"changed":false,"description":"This amendment maintains the original scope of the airworthiness directive. It updates the technical requirements to reference a revised manufacturer service bulletin (B-255.1 instead of B-255) and clarifies that Australian-approved NDI organisations may perform the work. The core purpose — mandating inspection of main rotor drive shafts on specific helicopter models following a fatal accident — remains unchanged."},"complexity_factors":["Single, specific technical requirement referencing an external manufacturer document (Schweizer Service Bulletin B-255.1)","Limited applicability — only affects specific helicopter models with specific part numbers","Only 2 substantive notes providing clarifications on re-inspection requirements and local contact information","No nested conditional logic or extensive cross-referencing to other legislation","Short, self-contained document with clear compliance deadline","Single amendment updating an existing directive rather than creating new regulatory framework"],"plain_english_summary":"CASA's mandatory Airworthiness Directive requires owners/operators of Schweizer (Hughes) 269 series helicopters with certain main rotor drive shafts to inspect those shafts for defects using the manufacturer’s updated service bulletin (B‑255.1) and non‑destructive inspection (NDI) methods. Australian‑approved NDI organisations may perform the work.\n\nThe AD follows a fatal shaft failure and tightens inspection requirements to prevent in‑flight failures; non‑compliant aircraft cannot legally fly."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"The amendment narrows implementation by mandating the manufacturer's NDI procedures in Schweizer SB B-255.1 (Requirement) and requires re‑inspection of shafts previously inspected under the earlier SB (Note 1). It also allows X‑ray inspection to be performed by an approved Australian NDI organisation (Requirement; Note 2). The change shifts from an FAA priority letter reference to a mandatory adoption of the manufacturer’s revised procedures (Background; Requirement)."},"complexity_factors":["Narrow applicability: applies only to specific 269 model variants and two part numbers (Applicability).","Cross-reference to external technical document: mandates compliance with Schweizer Mandatory Service Bulletin B-255.1 rather than containing full procedures (Requirement).","Technical inspection method: permits X‑ray/NDI work, requiring access to approved non‑destructive inspection providers (Requirement; Note 2).","Compliance timing: a revised effective date is specified, and previously inspected parts must be re‑inspected (Compliance; Note 1).","Operational coordination: operators may need to liaise with the manufacturer’s local agent or approved NDI organisations for alternative arrangements (Note 2).","Safety‑critical consequence: background cites prior catastrophic failure, increasing urgency and enforcement likelihood (Background)."],"plain_english_summary":"This airworthiness directive requires operators of Schweizer/Hughes 269 series helicopters fitted with main rotor drive shaft P/N 269A5305-3 or -11 to carry out the inspection procedures in Schweizer Mandatory Service Bulletin B-255.1 (01 Feb 1993). X‑ray inspection may be performed by an approved Australian NDI organisation and previously inspected shafts must be re‑inspected. CASA sets the compliance date; operators pay for and arrange the inspections. The directive follows an FAA report of a fatal shaft failure."}},"importantCases":[],"_links":{"self":"/api/acts/ad-hu-269-99-amdt-1-main-rotor-drive-shaft-inspection","history":"/api/acts/ad-hu-269-99-amdt-1-main-rotor-drive-shaft-inspection/history","analysis":"/api/acts/ad-hu-269-99-amdt-1-main-rotor-drive-shaft-inspection/analysis","conflicts":"/api/acts/ad-hu-269-99-amdt-1-main-rotor-drive-shaft-inspection/conflicts","importantCases":"/api/acts/ad-hu-269-99-amdt-1-main-rotor-drive-shaft-inspection/important-cases","documents":"/api/acts/ad-hu-269-99-amdt-1-main-rotor-drive-shaft-inspection/documents"}}