{"id":"F2006B09719","name":"AD/F27/152 - Accessory Gearbox Drive Shaft","slug":"ad-f27-152-accessory-gearbox-drive-shaft","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115899,"registerId":"commonwealth-F2006B09719-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# AIRWORTHINESS DIRECTIVE\n\n![](image.002.png)\n\n![](image.002.png)  \nFor the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.","sortOrder":0},{"sectionNumber":"AD/F27/152 Accessory Gearbox Drive Shaft","sectionType":"part","heading":"AD/F27/152 Accessory Gearbox Drive Shaft 8/2000","content":"# AD/F27/152 Accessory Gearbox Drive Shaft 8/2000\n\nApplicability: Fokker F27 Mks100, 200, 300, 400, 500, 600 and 700 series aircraft. Requirement: Grease and inspect accessory gearbox drive shafts in accordance with Dowty\n\nAerospace Wolverhampton Service Bulletin 83-518 dated 6 October 1999.\n\nNote: CAA (UK) AD 002-09-99 refers.\n\nCompliance: Within 50 hours time in service (TIS) from the effective date of this Directive and, thereafter, at intervals of 50 hours TIS.\n\nThis Airworthiness Directive becomes effective on 10 August 2000.\n\nBackground: This Directive is prompted by reports of accessory gearbox drive shaft failures that resulted in combustion chamber damage and subsequent flame break out. These failures have been attributed to inadequate lubrication.\n\n![Signature of Eugene Paul Holzapfel, Delegate of the Civil Aviation Safety Authority.](image.003.png)  \n\nEugene Paul Holzapfel\n\nDelegate of the Civil Aviation Safety Authority 23 June 2000\n\n![](image.002.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 12 July 2000.","sortOrder":1}],"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 is a discrete, targeted safety directive addressing a specific mechanical failure mode in a specific aircraft type. It has not expanded beyond its original purpose of mandating inspection and lubrication to prevent drive shaft failures."},"complexity_factors":["Single, specific mechanical component targeted (accessory gearbox drive shaft)","Only one substantive requirement with clear cross-reference to manufacturer service bulletin","Simple compliance schedule: 50 hours TIS initially, then recurring every 50 hours TIS","No defined terms section, no nested exceptions, no conditional logic beyond basic applicability criteria","Total length: approximately 250 words of operative text","Single background causal chain: inadequate lubrication → shaft failure → combustion damage → fire risk"],"plain_english_summary":"CASA has issued a mandatory safety order requiring operators of Fokker F27 Series 100–700 aircraft to grease and inspect accessory gearbox drive shafts per Dowty Aerospace Service Bulletin 83‑518 (Oct 1999), initially within 50 flight hours of 10 Aug 2000 and every 50 hours thereafter. The directive addresses lubrication-related shaft failures that can damage combustion chambers and cause fires, and compliance is legally required under the Civil Aviation Regulations."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD’s scope is focused on the specified Fokker F27 marks and prescribes greasing and inspection per Dowty SB with 50‑hour intervals. The text shows no indication the scope was broadened or narrowed from the original stated purpose; it references the UK CAA AD but does not alter applicability or requirements."},"complexity_factors":["Narrow applicability limited to Fokker F27 Mks 100–700 (straightforward target population)","Relies on an external service bulletin (Dowty Aerospace SB 83-518) for technical instructions — operators must obtain and follow it","Short, fixed compliance interval (50 hours TIS) creates repetitive maintenance burden","Safety‑critical failure mode (combustion chamber damage and flame‑out) raises enforcement priority but does not add procedural complexity","AD text does not reproduce detailed inspection criteria, increasing reliance on OEM document for execution"],"plain_english_summary":"This Airworthiness Directive requires operators of specified Fokker F27 series aircraft to grease and inspect the accessory gearbox drive shaft in accordance with Dowty Aerospace Wolverhampton Service Bulletin 83-518 (6 October 1999). The work must be done within 50 hours time‑in‑service from the AD effective date and repeated every 50 hours. It affects aircraft operators and maintenance organisations, who must carry out and pay for the inspections and lubrication; CASA enforces compliance. The AD responds to reported lubrication-related shaft failures that caused combustion‑chamber damage and flame‑outs."}},"importantCases":[],"_links":{"self":"/api/acts/ad-f27-152-accessory-gearbox-drive-shaft","history":"/api/acts/ad-f27-152-accessory-gearbox-drive-shaft/history","analysis":"/api/acts/ad-f27-152-accessory-gearbox-drive-shaft/analysis","conflicts":"/api/acts/ad-f27-152-accessory-gearbox-drive-shaft/conflicts","importantCases":"/api/acts/ad-f27-152-accessory-gearbox-drive-shaft/important-cases","documents":"/api/acts/ad-f27-152-accessory-gearbox-drive-shaft/documents"}}