{"id":"F2006B09844","name":"AD/F50/19 - Engine Controls","slug":"ad-f50-19-engine-controls","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":54894,"registerId":"commonwealth-F2006B09844-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/F50/19 - Engine Controls","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)  Fokker F50 (F27 Mk 50) Series Aeroplanes\n\n \n\nAD/F50/19 Engine Controls 7/89\n\nApplicability: All F27-050 S/No 20103 thru 20108, 20110 thru 20135. Requirement:  Action in accordance with Fokker Service Bulletin SB F50-76-002.\n\nNote: RLD AD 89-39 refers.\n\n \n\nCompliance: Prior to 15 September, 1989.\n\n \n\nBackground:  The manufacturer has advised that when a failure occurs in the power lever control cable system, the automatic flight idle stop mechanism will be ineffective. In certain conditions this may result in an uncontained propeller overspeed.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The source provides no indication that the scope of the measure was changed from its original intent. The directive applies to a defined set of serial numbers, requires action in accordance with a specified service bulletin, sets a compliance date, and references a related AD. Those elements together define the directive’s consistent, narrow scope (Applicability; Requirement; Compliance; Note)."},"complexity_factors":["Narrow applicability limited to specific serial numbers (reduces scope complexity) (Applicability)","Mandates compliance with an external technical document (Fokker Service Bulletin SB F50-76-002) rather than detailing technical steps (Requirement)","Fixed and short compliance deadline creates scheduling and operational pressure for affected operators (Compliance)","Cross-reference to another AD (RLD AD 89-39) requires checking related instruments for full context (Note)","Technical nature of the corrective action implies need for maintenance capability, parts, and downtime though specifics are in the service bulletin (Requirement; Background)"],"plain_english_summary":"This Civil Aviation Safety Authority airworthiness directive requires owners/operators of Fokker F27-050 (F50) serial numbers 20103–20108 and 20110–20135 to carry out the corrective work specified in Fokker Service Bulletin SB F50-76-002 by 15 September 1989. The mandate addresses a power‑lever control cable failure that can disable the automatic flight idle stop and risk an uncontained propeller overspeed; costs and compliance are the operators’ responsibility."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue safety directive from 1989 addressing a specific mechanical defect in a specific aircraft model. It has not expanded beyond its original narrow technical purpose."},"complexity_factors":["Very short document (under 200 words)","Only 1 defined applicability criterion (specific serial number ranges)","Single compliance requirement with reference to external technical document (Fokker Service Bulletin)","No nested exceptions, conditional logic, or cross-references to other legislation","Straightforward command structure: applicability → requirement → deadline → background explanation"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety fix ordered by Australia's aviation regulator (CASA) for a specific aircraft type.\n\n**What it does:**\nOrders owners and operators of certain **Fokker F50 aircraft** (specifically serial numbers 20103-20108 and 20110-20135) to carry out a repair or inspection procedure detailed in **Fokker Service Bulletin SB F50-76-002**.\n\n**The safety problem:**\nIf the power lever control cable system fails, a safety mechanism called the \"automatic flight idle stop\" won't work properly. This could cause the propeller to spin dangerously fast (\"uncontained propeller overspeed\") — a serious flight safety risk.\n\n**Who it affects:**\nAirlines or operators flying these specific Fokker F50 aircraft in Australia.\n\n**What they must do:**\nComplete the required action **before 15 September 1989**.\n\n**Why it matters:**\nThis is a **time-critical safety mandate**. Non-compliance means the aircraft cannot legally fly, as it would pose an unacceptable risk of mechanical failure leading to loss of control."}},"importantCases":[],"_links":{"self":"/api/acts/ad-f50-19-engine-controls","history":"/api/acts/ad-f50-19-engine-controls/history","analysis":"/api/acts/ad-f50-19-engine-controls/analysis","conflicts":"/api/acts/ad-f50-19-engine-controls/conflicts","importantCases":"/api/acts/ad-f50-19-engine-controls/important-cases","documents":"/api/acts/ad-f50-19-engine-controls/documents"}}