{"id":"F2006B09841","name":"AD/F50/16 Amdt 1 - Flap Power Drive Unit","slug":"ad-f50-16-amdt-1-flap-power-drive-unit","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":54885,"registerId":"commonwealth-F2006B09841-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/F50/16 Amdt 1 - Flap Power Drive Unit","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/F50/16\n\nAmdt 1\n\n\nFlap Power Drive Unit 8/90\n\n \n\nApplicability: Model F27 Mark 050 with serial numbers 20103 through 20108, 20110 through\n\n20114, 20116, 20118, and 20122.\n\n \n\nRequirement: Action in accordance with Fokker 50 Service Bulletin No F50-27-011 Revision 1.\n\n \n\nNote: RLD AD BLA 89-01 Issue 2 refers.\n\n \n\nCompliance: Prior to the accumulation of 3,500 flight cycles of each affected flap power drive unit.\n\n \n\nBackground: In service flap power drive units have been found to deviate from the production specifications. Affected drive units are replaced with new units having improved position control accuracy.\n\n \n\nThis amendment is raised to reflect an Applicability change.\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":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This amendment maintains the original narrow scope — addressing a specific manufacturing defect in specific aircraft components. The only change is a technical adjustment to the list of affected aircraft serial numbers, which is typical for airworthiness directives as more data becomes available about which units are affected."},"complexity_factors":["Very short document (under 200 words)","Only 3 operative provisions: applicability, requirement, and compliance","Single cross-reference to a Fokker Service Bulletin and a Dutch aviation authority directive (RLD AD BLA 89-01 Issue 2)","No defined terms section","No nested conditions or exceptions","Straightforward compliance trigger (flight cycle count)"],"plain_english_summary":"This is an **Airworthiness Directive** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) that requires specific repairs or inspections on aircraft.\n\n**What it does:**\nOrders owners and operators of specific Fokker F50 aircraft to replace certain **flap power drive units** (the mechanical systems that control the flaps on the wings) before they reach 3,500 flight cycles.\n\n**Who it affects:**\nOwners and operators of Fokker F50 aircraft with specific serial numbers: 20103-20108, 20110-20114, 20116, 20118, and 20122.\n\n**Why it matters:**\nSome flap power drive units were found to be **not built to the correct specifications** in production. This could affect how precisely the flaps move, potentially impacting flight safety during takeoff and landing. The directive mandates replacing these faulty units with improved versions before they accumulate too much use.\n\n**What's changed in this version:**\nThis update (Amendment 1) simply adjusts which aircraft serial numbers are covered by the directive — expanding or refining the list of affected planes."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"This amendment updates the Applicability (the list of affected serial numbers). The core requirement (action per Fokker Service Bulletin No F50-27-011 Rev 1 and compliance before 3,500 flight cycles) remains the same; the amendment narrows/clarifies which airframes are subject."},"complexity_factors":["Narrow applicability by serial number list — requires operators to identify affected airframes","Single mandated remedy references an external manufacturer service bulletin (dependency on that document for procedural detail)","Compliance measured in flight cycles — requires operational tracking and maintenance scheduling","Technical nature of flap power drive units — replacement requires parts, maintenance slots and possible downtime","Amendment changes applicability (cross-check against prior ADs or records)","Note cross-references an earlier RLD AD (BLA 89-01 Issue 2) — requires checking related directives"],"plain_english_summary":"Requires operators of specific Fokker F50 aeroplanes (listed serial numbers) to follow Fokker Service Bulletin No F50-27-011 Rev 1 to replace or correct affected flap power drive units before each unit reaches 3,500 flight cycles.\n\nThe AD responds to units found outside production specifications by mandating replacement with units having improved position-control accuracy. Direct costs and record-keeping fall to aircraft operators; the Civil Aviation Safety Authority enforces compliance."}},"importantCases":[],"_links":{"self":"/api/acts/ad-f50-16-amdt-1-flap-power-drive-unit","history":"/api/acts/ad-f50-16-amdt-1-flap-power-drive-unit/history","analysis":"/api/acts/ad-f50-16-amdt-1-flap-power-drive-unit/analysis","conflicts":"/api/acts/ad-f50-16-amdt-1-flap-power-drive-unit/conflicts","importantCases":"/api/acts/ad-f50-16-amdt-1-flap-power-drive-unit/important-cases","documents":"/api/acts/ad-f50-16-amdt-1-flap-power-drive-unit/documents"}}