{"id":"F2006B09867","name":"AD/F50/40 - Fire Wire Connector Replacement","slug":"ad-f50-40-fire-wire-connector-replacement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":54971,"registerId":"commonwealth-F2006B09867-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/F50/40 - Fire Wire Connector Replacement","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/F50/40 Fire Wire Connector Replacement 2/91\n\nApplicability: All Fokker F27 MK 50 aircraft as listed in the Requirement document. Requirement: In accordance with the technical Requirements of the Netherlands AD BLA 90-127.\n\nNote: Fokker SB F50-26-008 also refers.\n\n \n\nCompliance: As specified in Requirement document with an effective date of 9 November 1990.\n\n \n\nBackground:  Advice has been received that the ingress of moisture into the fire wire connectors can cause false fire warnings.\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 discrete, targeted safety directive addressing a specific technical defect in a specific aircraft type. It has not expanded beyond its original purpose of mandating connector replacement to prevent false fire warnings."},"complexity_factors":["Very short document (under 200 words)","Only one substantive requirement: replace fire wire connectors","No defined terms section","No conditional logic or nested exceptions","Single cross-reference to Netherlands AD and Fokker Service Bulletin","Clear applicability statement (all Fokker F27 Mk 50 aircraft)"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for aircraft.\n\n**What it does:**\n- Requires owners and operators of **Fokker F50 aircraft** (also known as F27 Mk 50) to replace certain **fire wire connectors**.\n- These connectors are part of the aircraft's fire detection system. If moisture gets into them, they can trigger **false fire warnings** — which is dangerous because it could distract pilots during flight or cause unnecessary emergency responses.\n\n**Who it affects:**\n- Anyone who owns, operates, or maintains Fokker F50 series aircraft in Australia.\n\n**Why it matters:**\n- False fire warnings can lead to unnecessary emergency landings, evacuation of passengers, or pilots ignoring real warnings later (the \"cry wolf\" problem). This directive prevents that by fixing a known design flaw.\n\n**How to comply:**\n- Follow the technical instructions in **Netherlands AD BLA 90-127** (the Dutch aviation authority's equivalent directive) and **Fokker Service Bulletin F50-26-008**.\n- The deadline for compliance was **9 November 1990**."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive implements the remedial action specified in the referenced Netherlands AD and Fokker service bulletin for the listed Fokker F27 Mk 50 aircraft. The document confines scope to the aircraft identified in the Requirement document and specifies the effective compliance date. Nothing in the provided text expands or narrows that remedial scope beyond implementing the referenced technical requirements. (Applicability; Requirement; Note; Compliance)"},"complexity_factors":["Scope limited to a specific aircraft model and the aircraft listed in the Requirement document (Applicability).","Directive cross-references an external technical document (Netherlands AD BLA 90-127) and a service bulletin (Fokker SB F50-26-008), requiring operators to follow those detailed instructions (Requirement; Note).","A fixed compliance effective date creates a scheduling constraint for operators (Compliance).","Technical nature of the remedy (electrical connector replacement) requires certified maintenance capability and parts, introducing operational logistics despite the narrow technical focus (Requirement; Compliance).","Issued under Part 39 as an airworthiness directive, i.e. a mandatory regulatory instrument rather than voluntary guidance (Header)."],"plain_english_summary":"What this instrument does (mechanical change)\n\n- This airworthiness directive requires the replacement of the fire wire connectors on the listed Fokker F27 Mk 50 (F50) aircraft. The replacement must be done in accordance with the technical requirements referenced in the directive (the Netherlands AD BLA 90-127 and Fokker Service Bulletin F50-26-008). (Applicability; Requirement; Note)\n- The work must be carried out as specified in the Requirement document and by the effective date given: 9 November 1990. (Compliance)\n\nWhy the change is required (official rationale)\n\n- The directive says moisture can get into the fire wire connectors and cause false fire warnings. The replacement is intended to address that risk. (Background)\n\nWho this affects and who decides\n\n- The directive applies to all Fokker F27 Mk 50 aircraft listed in the Requirement document, so operators of those aircraft must carry out the replacement. (Applicability)\n- The directive is issued as a Schedule of Airworthiness Directives under the Civil Aviation Regulations (Part 39), i.e. a regulatory direction from the Civil Aviation Safety Authority (CASA). (Header)\n\nWho pays and what behaviour changes\n\n- Aircraft operators are the parties required to comply with the directive and therefore will bear the direct costs and operational disruption of replacing the connectors. (Applicability; Compliance)\n- Operators must arrange the maintenance and parts necessary to meet the technical specification cited in the Requirement document; this changes maintenance scheduling and procurement decisions for the affected aircraft. (Requirement; Compliance)\n\nCompliance burden, implementation risk and trade-offs\n\n- Compliance requires following an external technical document (the Netherlands AD BLA 90-127 and the referenced Fokker service bulletin). That creates a dependency on another document for the detailed work steps. (Requirement; Note)\n- There is an implementation window defined by the effective date (9 November 1990). Operators face scheduling and potential downtime costs to perform the work by that date. (Compliance)\n- The directive targets a specific technical fault (connector ingress of moisture). Replacing connectors is a discrete maintenance task, but it requires parts, technical labour and possibly access to certified maintenance organisations. These are the concrete sources of cost and operational impact. (Requirement; Compliance)\n\nEffects on private enterprise and markets (mechanisms, not conclusions)\n\n- Maintenance organisations and parts suppliers for Fokker F50 connectors are likely to see increased demand from operators complying with the directive; operators will decide whether to use their existing maintenance providers or source alternative suppliers. (Applicability; Requirement)\n- The directive constrains operators’ short-term choices by mandating a particular remedial action (replacement in accordance with the referenced technical requirements). It does not itself set prices, ownership, or long-term market structure. (Requirement)\n\nConcentrated benefits and diffuse costs (mechanism)\n\n- The immediate technical benefit—reduced false fire warnings from moisture ingress—accrues to the individual aircraft operators and to the safety systems on each aircraft. (Background)\n- The cost of doing the replacements is concentrated on the operators of the listed aircraft, and may be spread over passengers or owners depending on commercial arrangements. (Applicability; Compliance)\n\nImplementation discretion and legal mechanism\n\n- The directive delegates the how-to to the referenced technical Requirement document (Netherlands AD BLA 90-127 and the Fokker service bulletin). This leaves the detailed method and technical judgement to that document and the maintenance organisations that apply it. (Requirement; Note)\n\nSource citations (from the document provided)\n\n- Header: COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - SCHEDULE OF AIRWORTHINESS DIRECTIVES. (Header)\n- Applicability: \"All Fokker F27 MK 50 aircraft as listed in the Requirement document.\" (Applicability)\n- Requirement: \"In accordance with the technical Requirements of the Netherlands AD BLA 90-127.\" (Requirement)\n- Note: \"Fokker SB F50-26-008 also refers.\" (Note)\n- Compliance: \"As specified in Requirement document with an effective date of 9 November 1990.\" (Compliance)\n- Background: \"Advice has been received that the ingress of moisture into the fire wire connectors can cause false fire warnings.\" (Background)\n"}},"importantCases":[],"_links":{"self":"/api/acts/ad-f50-40-fire-wire-connector-replacement","history":"/api/acts/ad-f50-40-fire-wire-connector-replacement/history","analysis":"/api/acts/ad-f50-40-fire-wire-connector-replacement/analysis","conflicts":"/api/acts/ad-f50-40-fire-wire-connector-replacement/conflicts","importantCases":"/api/acts/ad-f50-40-fire-wire-connector-replacement/important-cases","documents":"/api/acts/ad-f50-40-fire-wire-connector-replacement/documents"}}