{"id":"F2006B11153","name":"AD/LEARJET/35 - Crew Oxygen Plumbing and Map Light Wire Protection","slug":"ad-learjet-35-crew-oxygen-plumbing-and-map-light-wire-protection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":56844,"registerId":"commonwealth-F2006B11153-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/LEARJET/35 - Crew Oxygen Plumbing and Map Light Wire Protection","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nGates Learjet 24 & 25 Series Aeroplanes\n\nAD/LEARJET/35 Crew Oxygen Plumbing and Map Light Wire Protection\n\n  \n2/93\n\nApplicability: All Learjet 24 and 25 series airplanes with serial numbers 24-100 to 24-357 inclusive and 25-003 to 25-373 inclusive.\n\nRequirement: Modify the cockpit map light wiring in accordance with Learjet Airplane Modification Kit AMK 90-5 dated 11 October 1991.\n\nNote: FAA AD 92-19-12 Amendment 39-8370 refers.\n\nCompliance: Prior to further flight after 4 July 1993.\n\nBackground: The FAA has received a report of an in-flight fire on a Learjet Model 24 series airplane caused by chafing of the cockpit map light wires. The electrical arcing against the oxygen mask tubing caused burn-through and the subsequent fire.\n\nCompliance with this Directive decreases the likelihood of an in-flight fire caused by map light wire chafing.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive sets a specific, targeted requirement for a defined set of aircraft and requires a single modification per the Learjet kit. It does not expand or narrow the population beyond the serial-number ranges stated (Applicability) nor introduce additional compliance options or follow-up duties beyond installing AMK 90-5 by the stated deadline (Requirement; Compliance)."},"complexity_factors":["Narrow applicability limited to specific serial-number ranges (Applicability).","Single, prescriptive technical action required (install AMK 90-5) rather than multiple options (Requirement).","Short, absolute compliance deadline (must be done prior to next flight after 4 July 1993) increases scheduling pressure but does not add procedural complexity (Compliance).","Dependence on external technical kit/documentation (Learjet AMK 90-5) creates a logistical step (Requirement).","No discretionary or conditional compliance pathways included in the text (Requirement)."],"plain_english_summary":"What this directive does (mechanically)\n\n- Requires a physical modification to the cockpit map light wiring on certain Learjet 24 and 25 aeroplanes by installing parts/instructions contained in Learjet Airplane Modification Kit AMK 90-5 (dated 11 October 1991). (Requirement)\n- Applies only to aircraft with serial numbers 24-100 through 24-357 and 25-003 through 25-373. (Applicability)\n- The modification must be completed before the aeroplane’s next flight after 4 July 1993. (Compliance)\n\nWho it affects\n\n- Owners and operators of the specific Learjet 24 and 25 airframes listed by serial number. (Applicability)\n- Maintenance organisations or technicians who will install the Learjet AMK 90-5 modification kit. (Requirement)\n\nWhy it matters (stated purpose and practical effects)\n\n- The directive responds to a reported in-flight fire that began when map light wires chafed and arced against oxygen mask tubing, causing burn-through and fire. The AD’s stated effect is to decrease the likelihood of that type of in-flight fire by changing the wiring arrangement/protection. (Background; Requirement)\n\nPractical implications, incentives and trade-offs\n\n- Who pays: aircraft owners/operators must arrange and pay for the modification and any parts/labour required to implement AMK 90-5. (Requirement)\n- Who decides and who does the work: the operator or owner must ensure the work is done; a suitably certificated maintenance organisation or technician will perform the modification according to the Learjet kit. (Requirement)\n- Timing and opportunity cost: the requirement must be met before the next flight after the compliance date, which can impose grounding time and scheduling work at short notice. (Compliance)\n- Compliance burden: owners must identify affected serial numbers (Applicability), source the AMK kit and associated parts or instructions (Requirement), and document work to show the aircraft complies. (Requirement)\n- Implementation risks: effectiveness depends on correct installation following the AMK instructions; improper installation may fail to mitigate the identified hazard. (Requirement)\n- Effects on private enterprise: the measure creates demand for maintenance work on the affected fleet and therefore business for maintenance providers; it constrains owners’ short-term operational choices until the work is done. (Applicability; Requirement; Compliance)\n\nConcrete costs and benefits (mechanical, not value judgments)\n\n- Benefit claimed in the directive: reduced probability of the specific in-flight fire scenario caused by chafing map light wires against oxygen plumbing. (Background)\n- Costs borne directly by operators: the parts, labour and aircraft downtime required to install the AMK modification. (Requirement; Compliance)\n\nOther notes from the instrument\n\n- The directive cross-references an FAA airworthiness directive (FAA AD 92-19-12). The AD cites that FAA action but prescribes compliance for Australian-registered affected aeroplanes as described above. (Note)\n\nSources within the instrument cited in text: (Applicability), (Requirement), (Compliance), (Background), (Note)."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue airworthiness directive addressing a specific safety defect. It has not expanded beyond its original purpose of preventing in-flight fires from map light wire chafing."},"complexity_factors":["Single, specific technical requirement (install one modification kit)","Narrow applicability (specific aircraft models and serial number ranges)","No defined terms section","No cross-references to other legislation (only a reference to related FAA directive)","Clear compliance deadline with no conditional exceptions","Total length: approximately 150 words"],"plain_english_summary":"This is an **Airworthiness Directive** (a mandatory safety order) issued by Australia's Civil Aviation Safety Authority for specific Learjet aircraft models.\n\n**What it does:**\n- Requires owners/operators of certain Learjet 24 and 25 series planes to modify the cockpit map light wiring\n- The fix involves installing a specific modification kit (Learjet AMK 90-5) to protect wires from rubbing against oxygen tubing\n\n**Who it affects:**\n- Owners and operators of Learjet 24 series planes (serial numbers 24-100 through 24-357)\n- Owners and operators of Learjet 25 series planes (serial numbers 25-003 through 25-373)\n\n**Why it matters:**\n- The FAA (US aviation regulator) reported an in-flight fire caused by map light wires rubbing against oxygen mask tubing, creating electrical sparks that burned through the tubing and ignited a fire\n- This directive prevents that specific fire hazard by mandating a wiring protection fix\n- **Compliance deadline:** Before flying again after 4 July 1993\n\n**Key point:** This is a reactive safety measure—addressing a known defect that already caused one fire—rather than routine maintenance."}},"importantCases":[],"_links":{"self":"/api/acts/ad-learjet-35-crew-oxygen-plumbing-and-map-light-wire-protection","history":"/api/acts/ad-learjet-35-crew-oxygen-plumbing-and-map-light-wire-protection/history","analysis":"/api/acts/ad-learjet-35-crew-oxygen-plumbing-and-map-light-wire-protection/analysis","conflicts":"/api/acts/ad-learjet-35-crew-oxygen-plumbing-and-map-light-wire-protection/conflicts","importantCases":"/api/acts/ad-learjet-35-crew-oxygen-plumbing-and-map-light-wire-protection/important-cases","documents":"/api/acts/ad-learjet-35-crew-oxygen-plumbing-and-map-light-wire-protection/documents"}}