{"id":"F2006B11103","name":"AD/LEARJET 35/24 Amdt 2 - Battery Vent System","slug":"ad-learjet-35-24-amdt-2-battery-vent-system","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":56763,"registerId":"commonwealth-F2006B11103-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/LEARJET 35/24 Amdt 2 - Battery Vent System","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 35 and 36 Series Aeroplanes\n\nAD/LEARJET 35/24\n\nAmdt 2\n\n  \nBattery Vent System 5/86\n\nApplicability: Learjet 35-001 to 35-570 and 35-589 to 35-600. Learjet 36-001 to 36-053 and 36-055.\n\nRequirement: 1. Inspect the interior of the battery cases for evidence of fuel contamination. If evidence of fuel contamination exists inspect the fuel drain valves forward of the battery compartment for evidence of leakage. Replace any defective fuel drain valves.\n\n2. Modify the battery venting system according to the requirements of Gates Learjet SB 35/36-24-10.\n\nNote: FAA AD 86-05-05 Amdt 39-5248 refers.\n\nCompliance: For Para 1: Within 25 hours time in service after 12 December 1985. Thereafter at intervals not exceeding 50 hours time in service until modified in accordance with para 2 of the Requirement.\n\nFor Para 2: Within 200 hours time in service after 31 January 1986.\n\nBackground: 1. To prevent fuel from being drawn into the battery vent system in the event of a fuel leak at the low side of the fuselage. An instance of significant contamination has been reported from overseas.\n\n2. This Directive is amended to reflect the FAA Airworthiness Directive requirement designated in paragraph 2 of this Directive.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"The Directive was amended to reflect the FAA Airworthiness Directive requirement cited in paragraph 2, aligning the local requirement to modify the battery venting system with the FAA-mandated modification (Background; Requirement 2)."},"complexity_factors":["Applicability limited to specific Learjet 35/36 serial ranges — requires operators to identify affected airframes (Applicability).","Two-step mandate: recurring inspections and conditional valve replacement followed by a mandatory modification — requires schedule coordination and record tracking (Requirement 1 & 2).","Short inspection intervals: initial inspection within 25 hours, then every 50 hours until modification — operational scheduling and aircraft availability burden (Compliance for Para 1).","Modification per manufacturer service bulletin (Gates Learjet SB 35/36-24-10) — dependence on external technical instructions and possible parts/bench time (Requirement 2).","Direct maintenance costs and downtime: operators must replace defective fuel drain valves and perform the SB modification — operators bear these costs (Requirement 1 & 2).","Cross-reference and amendment to an FAA Airworthiness Directive — regulatory alignment increases documentation and compliance monitoring (Background; Note: FAA AD 86-05-05 referenced).","Fixed compliance deadlines (e.g. modification within 200 hours after 31 Jan 1986) — requires monitoring against flight-hour accumulation and may force prioritisation of affected aircraft (Compliance for Para 2).","Safety-critical inspection location (interior of battery cases) — inspections may be invasive and could ground aircraft pending findings and rectification (Requirement 1; Background)."],"plain_english_summary":"This Airworthiness Directive requires operators of Gates Learjet 35 and 36 series aeroplanes to inspect battery cases for fuel contamination, replace leaking fuel drain valves, and modify the battery venting system per Gates Learjet SB 35/36‑24‑10. It aims to prevent fuel entering battery vents (an overseas contamination report) by mandating short-term inspections until a permanent modification is fitted; compliance windows run from 25 to 200 flight hours."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is Amendment 2 to an existing Airworthiness Directive. The amendment appears to update the directive to align with the corresponding FAA Airworthiness Directive requirement, but does not expand the scope beyond the original safety purpose of preventing fuel contamination in battery compartments. The applicability (which aircraft are covered) and core safety objective remain consistent with the original 1986 directive."},"complexity_factors":["Very short document (approximately 250 words)","Only 4 defined applicability ranges (specific aircraft serial numbers)","Simple two-step compliance structure with clear timeframes","Single cross-reference to FAA AD 86-05-05 and manufacturer service bulletin SB 35/36-24-10","No nested exceptions or conditional logic","Plain language requirements with minimal aviation jargon"],"plain_english_summary":"This CASA Airworthiness Directive affects specific Gates Learjet 35/36 aircraft and mandates immediate safety actions to stop fuel entering battery compartments. Operators must inspect battery cases for fuel contamination (within 25 flight hours, then every 50 hours until modified) and, within 200 flight hours, modify the battery venting per the manufacturer service bulletin.\n\nIt responds to an overseas fuel-contamination incident and addresses the fire/explosion risk; it applies to Australian-registered owners, operators and maintenance organisations."}},"importantCases":[],"_links":{"self":"/api/acts/ad-learjet-35-24-amdt-2-battery-vent-system","history":"/api/acts/ad-learjet-35-24-amdt-2-battery-vent-system/history","analysis":"/api/acts/ad-learjet-35-24-amdt-2-battery-vent-system/analysis","conflicts":"/api/acts/ad-learjet-35-24-amdt-2-battery-vent-system/conflicts","importantCases":"/api/acts/ad-learjet-35-24-amdt-2-battery-vent-system/important-cases","documents":"/api/acts/ad-learjet-35-24-amdt-2-battery-vent-system/documents"}}