{"id":"F2006B09868","name":"AD/F50/41 - Outboard Flap Drive","slug":"ad-f50-41-outboard-flap-drive","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":54974,"registerId":"commonwealth-F2006B09868-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/F50/41 - Outboard Flap Drive","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/F50/41 Outboard Flap Drive 3/91\n\nApplicability: Model F27 MK 50 with serial numbers 20103 and 20107. Requirement:  Action in accordance with RLD AD 90-148.\n\nNote: Fokker SB F50-27-026 refers.\n\n \n\nCompliance: As specified in the Requirement Document.\n\n \n\nBackground:  Several outboard flap drive assemblies have been identified as not being in compliance with current regulations.\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\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard, narrow Airworthiness Directive targeting a specific mechanical defect in two identified aircraft. It has not expanded beyond its original safety purpose."},"complexity_factors":["Extremely short document (under 150 words)","Only 2 specific aircraft affected by serial number","Single technical requirement with external reference to RLD AD 90-148","No defined terms section — relies entirely on external documents","No conditional logic or nested exceptions","Simple structure: applicability → requirement → compliance → background"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). It applies to **two specific Fokker F50 aircraft** (serial numbers 20103 and 20107).\n\n**What it requires:**\nThe owners or operators of these specific planes must take corrective action on the **outboard flap drive** — a mechanical system that controls the outer sections of the wing flaps (the movable surfaces on the back of the wings that help with takeoff and landing).\n\n**Why it matters:**\nSeveral outboard flap drive assemblies were found to **not meet current safety regulations**. This directive ensures these specific aircraft get fixed to prevent potential mechanical failures during flight operations.\n\n**How to comply:**\nOperators must follow the instructions in **RLD AD 90-148** (a Dutch aviation safety directive — RLD is the Netherlands' aviation authority) and **Fokker Service Bulletin F50-27-026** (the manufacturer's official repair instructions).\n\n**In short:** If you own or operate one of these two specific Fokker F50s, you must inspect and repair the flap drive system according to the Dutch safety directive and manufacturer's instructions."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The text provides no indication that the scope has been altered from an earlier or original intent. The AD plainly applies to two identified aircraft by serial number (Applicability) and directs compliance with RLD AD 90-148 (Requirement). There is no language in the document indicating an expansion, reduction, or amendment of scope beyond those two aircraft and the referenced documents."},"complexity_factors":["Very narrow applicability (only two serial numbers listed) reduces operational complexity (Applicability).","Key actions are not stated in the AD itself but are given by reference to another AD (RLD AD 90-148), requiring cross-document reading (Requirement).","Reference to a manufacturer service bulletin (Fokker SB F50-27-026) adds a second cross-reference and a source of technical detail (Note).","Compliance is delegated to an external \"Requirement Document\" and is unspecified in this text, creating uncertainty about timelines, exact procedures and acceptance criteria (Compliance).","Technical subject matter (outboard flap drive assemblies non-compliant with regulations) will typically require specialist maintenance, parts, or inspections, which adds implementation complexity despite the AD’s short text (Background)."],"plain_english_summary":"This airworthiness directive applies only to two Fokker F27 Mk 50 aeroplanes (S/N 20103 and 20107) and requires those aircraft to undergo the remedial actions set out in RLD AD 90‑148, with reference to Fokker SB F50‑27‑026 for technical detail. \n\nIt was issued because certain outboard flap drive assemblies were found non‑compliant; owners/operators of the two aircraft bear the compliance burden and must consult the referenced documents for specifics, timelines and costs."}},"importantCases":[],"_links":{"self":"/api/acts/ad-f50-41-outboard-flap-drive","history":"/api/acts/ad-f50-41-outboard-flap-drive/history","analysis":"/api/acts/ad-f50-41-outboard-flap-drive/analysis","conflicts":"/api/acts/ad-f50-41-outboard-flap-drive/conflicts","importantCases":"/api/acts/ad-f50-41-outboard-flap-drive/important-cases","documents":"/api/acts/ad-f50-41-outboard-flap-drive/documents"}}