{"id":"F2006B09913","name":"AD/F50/82 - Bleed Air Supply Duct Assembly - Inspection/Modification","slug":"ad-f50-82-bleed-air-supply-duct-assembly-inspection-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":55116,"registerId":"commonwealth-F2006B09913-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/F50/82 - Bleed Air Supply Duct Assembly - Inspection/Modification","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  \n\n\n# AIRWORTHINESS DIRECTIVE\n\n![](image.001.png)\n\n![](image.001.png)  For 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.\n\n \n\nFokker F50 (F27 Mk 50) Series Aeroplanes\n\n \n\n# AD/F50/82 Bleed Air Supply Duct Assembly - Inspection/Modification\n\n\n4/2002\n\n \n\n \n\nApplicability:  All Model F.27 Mk.050, 0502 and 0604 aeroplanes, all serial numbers Requirement: Inspect and modify in accordance with RLD AD 2001-130.\n\nNote: Fokker Service Bulletin F50-36-006 refers.\n\n \n\nCompliance: At the inspection and modification times specified in RLD AD 2001-130, from the date that this Airworthiness Directive is effective.\n\n \n\nThis Airworthiness Directive becomes effective on 18 April 2002.\n\n \n\nBackground: Heat damage was discovered during inspection at the engine controls area. Further inspection revealed that the inner wall of the bleed air supply duct assembly had ruptured and blanking plugs in the outer wall of the duct had blown out. This allowed bleed air (200-250 deg C) to escape into an area that contains control cables, electrical wiring, hydraulic components and cross-feed fuel lines. To prevent further similar events, this AD requires a onetime inspection to be carried out and a modification introduced that removes the blanking plugs and seals off the blanking plug holes by installing a clamping device with heat resistant adhesive.\n\n![](image.002.png)  \n\n\n \n\nEugene Paul Holzapfel\n\nDelegate of the Civil Aviation Safety Authority 5 March 2002\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n![](image.001.png)  \n\n\nThe above AD is notified in the Commonwealth of Australia Gazette on 27 March 2002.\n\n \n\n \n\n\nPage 1 of 1\n","sortOrder":0}],"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"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD applies to all F.27 Mk.050, 0502 and 0604 aeroplanes (all serial numbers) and mandates the inspection/modification specified in RLD AD 2001-130. The instrument implements a one‑time corrective action for a specific damaged duct condition described in the Background; the text contains no indication that the affected fleet or required action was expanded or narrowed from that stated intent."},"complexity_factors":["Direct reference to an external directive (RLD AD 2001-130) for inspection and modification details increases implementation dependency (Requirement; Compliance).","Applicability to the entire fleet of specified models, 'all serial numbers', concentrates compliance obligation on every operator of those models (Applicability).","Technical nature of the remedy (removal of blanking plugs; installation of clamping device with heat‑resistant adhesive) requires maintenance resources and parts rather than procedural change (Background; Requirement).","Compliance timing tied to the inspection/modification schedule in RLD AD 2001-130 creates scheduling and record-keeping burden for operators but does not state phased or repeated inspections (Compliance).","Cross-reference to Fokker Service Bulletin F50-36-006 for additional instruction adds another source to consult (Note)."],"plain_english_summary":"This Airworthiness Directive requires operators of all Fokker F.27 Mk.050, 0502 and 0604 aeroplanes (all serial numbers) to perform a one‑time inspection and modification of the bleed‑air supply duct assembly in accordance with RLD AD 2001‑130 (see Fokker Service Bulletin F50‑36‑006). It responds to heat damage and a ruptured inner duct that allowed 200–250°C bleed air into control and services areas; the fix removes blanking plugs and seals the holes with a clamping device and heat‑resistant adhesive."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete safety directive addressing a specific mechanical defect in a specific aircraft type. The scope remains tightly focused on the original safety issue — preventing heat damage from ruptured bleed air ducts — with no expansion into broader operational or regulatory matters."},"complexity_factors":["Very short document (approximately 300 words)","Only 3 operative sections: Applicability, Requirement, and Compliance","Single cross-reference to external technical document (RLD AD 2001-130) for detailed instructions","No defined terms section — uses plain technical language","No nested conditions or exceptions","Single, straightforward mandatory action with clear deadline"],"plain_english_summary":"This AD mandates a one-time inspection and permanent modification of the bleed air supply duct assembly on affected Fokker F.27 Mk.050/0502/0604 aircraft after an inner-wall rupture and blown blanking plugs allowed hot (200–250°C) air into areas with control cables, wiring, hydraulics and fuel lines—creating fire and control-loss risk.  \n\nOperators must remove temporary blanking plugs and seal the holes with a clamping device and heat‑resistant adhesive per RLD AD 2001‑130 (effective 18 April 2002)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-f50-82-bleed-air-supply-duct-assembly-inspection-modification","history":"/api/acts/ad-f50-82-bleed-air-supply-duct-assembly-inspection-modification/history","analysis":"/api/acts/ad-f50-82-bleed-air-supply-duct-assembly-inspection-modification/analysis","conflicts":"/api/acts/ad-f50-82-bleed-air-supply-duct-assembly-inspection-modification/conflicts","importantCases":"/api/acts/ad-f50-82-bleed-air-supply-duct-assembly-inspection-modification/important-cases","documents":"/api/acts/ad-f50-82-bleed-air-supply-duct-assembly-inspection-modification/documents"}}