{"id":"F2006B09764","name":"AD/F28/27 - Liftdumper System - Wire Protection and Segregation in Pedestal Modification","slug":"ad-f28-27-liftdumper-system-wire-protection-and-segregation-in-pedestal-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":54644,"registerId":"commonwealth-F2006B09764-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/F28/27 - Liftdumper System - Wire Protection and Segregation in Pedestal Modification","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 F28 Series Aeroplanes\n\n \n\nAD/F28/27 Liftdumper System - Wire Protection and\n\nSegregation in Pedestal Modification\n\n\n11/75\n\n \n\nApplicability: For Part 1 - S/Nos. 11003 to 11032, 11034 to 11037, 11039 11071, and 11991 to 11993 unless either SB F28/27-101 or F28/27-111 has been accomplished.\n\n \n\nFor Part 2 - S/Nos. 11003 to 11083 and 11991 to 11993 unless SB F28/27-101 has been accomplished.\n\n \n\nDocument: 1. Fokker F28 SB No. F28/27-109; or\n\n \n\n2. RLD AD No. 75-28-27 Fokker F28. Compliance: Before 1 January 1976.\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":3,"scope_assessment":{"changed":false,"description":"The text sets a clear, limited scope: require pedestal wire protection and segregation modification on identified F28 serial numbers unless specified service bulletins have already been done (see \"Applicability\"). The instrument itself contains no language indicating a change from an earlier or original scope within the supplied text."},"complexity_factors":["Serial-number specific applicability (different serial ranges for Part 1 and Part 2) increases administrative complexity","Conditional exemptions based on whether particular service bulletins (SB F28/27-101 or F28/27-111) have already been accomplished","Mandate to follow one of multiple specific technical documents (Fokker SB No. F28/27-109 or RLD AD No. 75-28-27) requires locating and applying external material","Fixed compliance date creates scheduling and operational planning requirements for affected operators","Minimal technical detail in the directive itself — operators must consult the cited documents for the actual work scope and methods"],"plain_english_summary":"### What this instrument does\n\nThis airworthiness directive requires a specified modification to the liftdumper system on certain Fokker F28 series aeroplanes. Mechanically, it mandates that wire protection and segregation work in the cockpit pedestal be carried out in accordance with one of the technical documents listed in the directive.\n\n### Who it applies to\n\n- It applies to Fokker F28 aeroplanes with the serial numbers listed under \"Applicability\" for Part 1 and Part 2 of the directive (see \"Applicability\" section).\n- Aircraft are excluded from the requirement if they have already had particular Fokker Service Bulletins completed: for Part 1, SB F28/27-101 or SB F28/27-111; for Part 2, SB F28/27-101 (see \"Applicability\").\n\n### How it must be done\n\n- The modification must be carried out using one of the documents named in the directive: either Fokker F28 SB No. F28/27-109 or RLD AD No. 75-28-27 (see \"Document\").\n- The work was required to be completed by the compliance date stated: before 1 January 1976 (see \"Compliance\").\n\n### Who decides and who pays\n\n- The directive is issued under the Commonwealth Civil Aviation framework (header shows Civil Aviation Regulations / Civil Aviation Safety Authority); the regulator sets the requirement.\n- Aircraft operators or owners are the parties required to comply with the directive and therefore bear the direct cost and logistical burden of arranging the work (in practice this means contracting approved maintenance organisations or using in‑house maintenance teams to perform the modification per the cited documents) (see \"Applicability\" and \"Document\").\n\n### Why it matters (stated aim and practical trade-offs)\n\n- The directive is titled \"Liftdumper System - Wire Protection and Segregation in Pedestal Modification,\" so its stated technical aim is to change wire protection and segregation in the pedestal of the liftdumper system (title). That is the explicit scope of the mandated work.\n\n- Trade-offs and implementation considerations apparent from the text:\n  - Compliance imposes a discrete compliance cost on operators of the affected serial-numbered aircraft (operator/owner pays and arranges work) (see \"Applicability\").\n  - The directive requires following specific technical documents; operators must obtain and apply those documents (administrative/technical burden) (see \"Document\").\n  - The directive contains conditional exemptions where earlier service bulletins have already been accomplished; therefore prior maintenance history can remove the obligation for particular aircraft (see \"Applicability\").\n  - The directive sets a firm calendar deadline for compliance, creating scheduling pressure that may cause aircraft downtime while the modification is carried out (see \"Compliance\").\n\n### Summary of mechanics (who acts, when, how)\n- Regulator issues the mandatory directive (header).\n- Owners/operators of listed F28 serial numbers must ensure pedestal wire protection and segregation modification is completed by the deadline unless the specified earlier SBs were already done (see \"Applicability\" and \"Compliance\").\n- Work must be performed in accordance with one of the specified technical documents (see \"Document\")."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a historical AD from 1975 with a tightly scoped, single-issue mandate (liftdumper wire protection). It has not expanded beyond its original safety purpose."},"complexity_factors":["Short, single-purpose directive with narrow applicability","Only 2 defined serial number ranges with simple 'unless' exceptions","References to external Service Bulletins (SBs) and Dutch aviation authority (RLD) directive without reproducing their content","No nested conditional logic or cross-referencing within the instrument itself","Binary compliance structure: either applicable or exempted by prior SB accomplishment"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for specific aircraft.\n\n**What it does:**\nOrders owners and operators of certain **Fokker F28 series aeroplanes** to modify the \"liftdumper system\" — a mechanism that helps dump lift (reduce wing lift) during landing. The modification involves improving **wire protection and segregation in the pedestal** (the central column structure in the cockpit where controls run through). This prevents electrical wires from chafing, short-circuiting, or interfering with each other, which could cause the liftdumper system to fail.\n\n**Who it affects:**\n- **Part 1:** Specific Fokker F28 aircraft with serial numbers 11003–11032, 11034–11037, 11039–11071, and 11991–11993 — **unless** they've already had Service Bulletin F28/27-101 or F28/27-111 installed.\n- **Part 2:** Aircraft with serial numbers 11003–11083 and 11991–11993 — **unless** they've already had Service Bulletin F28/27-101 installed.\n\nIn plain terms: If you own one of these specific Fokker F28 planes and haven't already done the specified upgrades, you **must** do this modification.\n\n**Why it matters:**\nThe liftdumper system is critical for safe landings. If wires in the pedestal aren't properly protected and separated, they could fail and prevent the system from working — potentially causing loss of control during landing. This AD mandates a fix before a hard deadline to prevent accidents.\n\n**Compliance deadline:** Before 1 January 1976 (historical — this AD is from 1975)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-f28-27-liftdumper-system-wire-protection-and-segregation-in-pedestal-modification","history":"/api/acts/ad-f28-27-liftdumper-system-wire-protection-and-segregation-in-pedestal-modification/history","analysis":"/api/acts/ad-f28-27-liftdumper-system-wire-protection-and-segregation-in-pedestal-modification/analysis","conflicts":"/api/acts/ad-f28-27-liftdumper-system-wire-protection-and-segregation-in-pedestal-modification/conflicts","importantCases":"/api/acts/ad-f28-27-liftdumper-system-wire-protection-and-segregation-in-pedestal-modification/important-cases","documents":"/api/acts/ad-f28-27-liftdumper-system-wire-protection-and-segregation-in-pedestal-modification/documents"}}