{"id":"F2006B09885","name":"AD/F50/57 - NLG Hinge Point","slug":"ad-f50-57-nlg-hinge-point","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":55019,"registerId":"commonwealth-F2006B09885-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/F50/57 - NLG Hinge Point","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/F50/57 NLG Hinge Point 13/92\n\nApplicability: Model F27 Mk 050 with serial numbers 20103 through 20243. Requirement:  Action in accordance with Fokker Service Bulletin F50-32-023.\n\nNote: RLD AD 92-100 refers.\n\n \n\nCompliance: Prior to 1 January 1993.\n\n \n\nBackground: An incident has been reported of a F50 aircraft experiencing difficulties when extending the nose landing gear in flight in the NORMAL mode. This Directive requires the inspection and, if necessary, the adjustment of the nose landing gear pintle and bush.\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 directive sets a new, time-limited mandatory inspection and adjustment requirement for a defined subset of Fokker F50 aircraft (serial numbers 20103–20243) and does not, on its face, change or expand applicability beyond that set. It prescribes compliance with a specified service bulletin and a fixed deadline, and references a related AD (Note). There is no text in the document indicating a change from an earlier stated scope."},"complexity_factors":["Narrow applicability limited to specific serial numbers (Applicability).","Single, discrete technical action required (inspect and adjust pintle and bush) rather than a programme of changes (Requirement).","Fixed compliance deadline imposes scheduling pressure (Compliance).","Dependence on an external technical document (Fokker Service Bulletin F50-32-023) creates a compliance dependency and potential for clarification needs (Requirement).","Cross-reference to another directive (RLD AD 92-100) requires checking additional material but does not expand scope in the text (Note)."],"plain_english_summary":"What this directive changes, mechanically:\n\n- It makes a mandatory maintenance action for a defined set of Fokker F50 (F27 Mk 50) aeroplanes. Specifically, operators of aircraft with serial numbers 20103 through 20243 must inspect the nose landing gear (NLG) pintle and bush, and adjust them if necessary, following the procedures in Fokker Service Bulletin F50-32-023 (Requirement). Compliance must be completed before 1 January 1993 (Compliance). The directive is published under the Civil Aviation Safety Authority schedule of airworthiness directives (header).\n\nWhy the rule exists (stated purpose):\n\n- The directive is issued because an incident was reported in which an F50 experienced difficulties extending the nose landing gear in flight when using the NORMAL mode. The stated aim is to address that malfunction risk by inspecting and, if required, adjusting the pintle and bush (Background).\n\nWho this affects and who pays:\n\n- Affected parties are the owners/operators of Fokker F27 Mk 050 aeroplanes with the listed serial numbers (Applicability). Those owners/operators must carry out the inspection and any corrective adjustment in accordance with the service bulletin. Practically, the owners/operators bear the direct costs: labour for inspection and adjustment, any replacement parts, and aircraft downtime while maintenance is carried out (Requirement; Compliance).\n\nHow it is implemented and what decisions are delegated:\n\n- The directive requires compliance with a manufacturer-issued service bulletin (Requirement). That creates a specific technical procedure operators must follow; the bulletin determines the inspection method and adjustment steps. The regulator specifies the action and deadline, but the technical execution and scheduling are the operator’s responsibility.\n\nCompliance burden, incentives and operational effects:\n\n- Operational burden is immediate and time-limited: each affected aircraft must be inspected and adjusted as necessary prior to the compliance date (Compliance). This imposes maintenance scheduling and potential grounding or reduced availability while work is performed.\n- Reliance on the Fokker service bulletin means operators must obtain and follow that manufacturer's technical instructions; if the bulletin requires parts or specialised labour, costs and lead times may increase (Requirement).\n- The directive addresses a specific reported failure mode (Background). The benefit is concentrated on reducing the risk for the affected serial-numbered fleet; the cost is borne by those same operators through maintenance and downtime.\n\nCross-references and scope notes:\n\n- The AD text includes a note referring to RLD AD 92-100, which may contain related or supplementary requirements for the same or similar issue (Note). Operators should check that referenced directive to ensure all related obligations are met.\n\nImplementation risks and trade-offs to consider (source-grounded):\n\n- Timing risk: a fixed compliance deadline requires operators to schedule inspections before that date, which may be challenging depending on fleet utilisation and parts availability (Compliance).\n- Dependence on the service bulletin means the regulator relies on the manufacturer’s technical content; any ambiguities or required clarifications in the bulletin will need resolution by the operator or an approved maintenance organisation (Requirement).\n- The directive is narrowly targeted by serial number, so it changes obligations only for a discrete subset of the fleet (Applicability)."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, time-bound safety directive addressing a specific mechanical defect in a specific aircraft type. It has not expanded beyond its original purpose of mandating a one-time inspection and adjustment."},"complexity_factors":["Very short document (approximately 150 words)","Only 1 defined term implicitly referenced (the Service Bulletin)","No cross-references to other legislation or regulations beyond a note about a Dutch aviation authority directive (RLD AD 92-100)","Simple conditional logic: inspect and adjust 'if necessary'","Single, clear compliance deadline","Narrow applicability (specific model and serial number range)"],"plain_english_summary":"**What this is:** This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). Think of it as a \"recall notice\" for aircraft, but legally binding.\n\n**What it does:** It requires owners or operators of specific Fokker F50 aeroplanes to inspect and potentially fix a problem with the **nose landing gear** (the front wheels of the plane). Specifically, they must check the \"pintle and bush\" — mechanical parts that act like a hinge for the landing gear — and adjust them if needed.\n\n**Who it affects:** Only applies to **Fokker F27 Mk 050 model aircraft with serial numbers 20103 through 20243** (a specific batch of about 140 planes).\n\n**Why it matters:** A plane had trouble extending its nose landing gear during flight using the normal system. If the landing gear doesn't deploy properly, the aircraft cannot land safely. This directive prevents potential accidents by ensuring the mechanical components work correctly.\n\n**What must be done:** Follow the instructions in **Fokker Service Bulletin F50-32-023** (the manufacturer's official repair guide) before **1 January 1993**.\n\n**Key point:** This is not optional. Non-compliance means the aircraft cannot legally fly in Australian airspace."}},"importantCases":[],"_links":{"self":"/api/acts/ad-f50-57-nlg-hinge-point","history":"/api/acts/ad-f50-57-nlg-hinge-point/history","analysis":"/api/acts/ad-f50-57-nlg-hinge-point/analysis","conflicts":"/api/acts/ad-f50-57-nlg-hinge-point/conflicts","importantCases":"/api/acts/ad-f50-57-nlg-hinge-point/important-cases","documents":"/api/acts/ad-f50-57-nlg-hinge-point/documents"}}