{"id":"F2006B11100","name":"AD/LEARJET 35/21 Amdt 1 - Engine Hydraulic Line Interference - Inspection","slug":"ad-learjet-35-21-amdt-1-engine-hydraulic-line-interference-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":56760,"registerId":"commonwealth-F2006B11100-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/LEARJET 35/21 Amdt 1 - Engine Hydraulic Line Interference - Inspection","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)  Gates Learjet 35 and 36 Series Aeroplanes\n\n \n\nAD/LEARJET 35/21\n\nAmdt 1\n\n\nEngine Hydraulic Line Interference - Inspection\n\n\n10/83\n\n \n\nApplicability: All model 35 and 36 series aircraft as detailed in Gates Learjet Service Bulletins 35/36-29-1 and 35/36-29-2.\n\n \n\nDocument: 1. Gates Learjet SB 35/36-29-1.\n\n \n\nNote: FAA AD 83-08-3 refers.\n\n \n\n2. Gates Learjet SB 35/36-29-2.\n\n \n\nCompliance: Requirement Document No. 1: Within 100 hours time in service after 30 April 1983.\n\n \n\nRequirement Document No. 2: Within 100 hours time in service after 30 September 1983.\n\n \n\nBackground:  This directive has been raised in issue to include a further manufacturers SB related to interference between hydraulic lines and adjacent components in the tailcone area.\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":true,"description":"The amendment expands the directive to include a further manufacturer's service bulletin addressing hydraulic line interference in the tailcone area: \"This directive has been raised in issue to include a further manufacturers SB related to interference between hydraulic lines and adjacent components in the tailcone area.\" The change therefore broadens the AD by adding an additional SB as a mandatory compliance document."},"complexity_factors":["Narrow applicability limited to Gates Learjet model 35 and 36 series — reduces scope complexity.","Mandates compliance with external technical documents (Gates Learjet SB 35/36‑29‑1 and SB 35/36‑29‑2) — implementation depends on consulting those SBs.","Two separate compliance deadlines (100 hours after 30 Apr 1983 and 100 hours after 30 Sep 1983) — creates schedule tracking requirement.","References an FAA AD (FAA AD 83‑08‑3) — introduces cross-reference to foreign directive for background/consistency.","Requires technical inspection and potential maintenance/repair work — necessitates qualified personnel and creates direct costs for operators.","AD text is brief and delegates substantive corrective detail to the SBs — increases reliance on manufacturer documentation and potential interpretive discretion by maintainers."],"plain_english_summary":"This airworthiness directive requires owners/operators of Gates Learjet 35 and 36 series to inspect the tailcone area for interference between engine hydraulic lines and adjacent components, following Gates Learjet Service Bulletins 35/36‑29‑1 and 35/36‑29‑2. Inspections must be completed within 100 flight hours after the bulletin dates (30 April 1983 and 30 September 1983). CASA enforces the directive; operators pay for inspections and any corrective work and must follow the manufacturers’ service bulletins."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This amendment stays within the original scope of the directive. It simply adds a second manufacturer service bulletin to the inspection requirements, maintaining the same safety purpose (preventing hydraulic line interference) for the same aircraft types. The amendment mechanism is explicitly described in the 'Background' section as adding 'a further manufacturers SB' — a modest, anticipated expansion rather than scope creep."},"complexity_factors":["Very short document (approximately 200 words)","Only 2 substantive requirements with clear deadlines","No defined terms section","Minimal cross-referencing (only 2 service bulletins and 1 FAA AD reference)","Simple conditional structure: 'applies to X, do Y by Z date'","No nested exceptions or complex logical operators"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). It requires owners and operators of specific Learjet aircraft to inspect their planes for a dangerous problem.\n\n**What it does:**\n- **Mandates inspections** of Gates Learjet 35 and 36 series aircraft to check for interference (rubbing or contact) between hydraulic lines and nearby parts in the tailcone area.\n- **References two manufacturer service bulletins** (technical notices from the plane maker) that detail what to look for and how to fix it.\n\n**Who it affects:**\n- Owners and operators of all **Learjet 35 and 36 series aircraft**.\n- Maintenance engineers who work on these planes.\n\n**Why it matters:**\nHydraulic line interference can cause wear, leaks, or failure of critical flight control systems. This AD prevents potential accidents by forcing timely inspections.\n\n**Key deadlines:**\n- First inspection: Within **100 flight hours** after 30 April 1983.\n- Second inspection: Within **100 flight hours** after 30 September 1983.\n\nThis is **Amendment 1**, meaning it updates an earlier directive to add a second manufacturer's service bulletin to the requirements."}},"importantCases":[],"_links":{"self":"/api/acts/ad-learjet-35-21-amdt-1-engine-hydraulic-line-interference-inspection","history":"/api/acts/ad-learjet-35-21-amdt-1-engine-hydraulic-line-interference-inspection/history","analysis":"/api/acts/ad-learjet-35-21-amdt-1-engine-hydraulic-line-interference-inspection/analysis","conflicts":"/api/acts/ad-learjet-35-21-amdt-1-engine-hydraulic-line-interference-inspection/conflicts","importantCases":"/api/acts/ad-learjet-35-21-amdt-1-engine-hydraulic-line-interference-inspection/important-cases","documents":"/api/acts/ad-learjet-35-21-amdt-1-engine-hydraulic-line-interference-inspection/documents"}}