{"id":"F2006B10015","name":"AD/G1159/14 - Hydraulic Power Shut-Off - Modification","slug":"ad-g1159-14-hydraulic-power-shut-off-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":55386,"registerId":"commonwealth-F2006B10015-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/G1159/14 - Hydraulic Power Shut-Off - 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)  Gulfstream (Grumman) G1159 and G-IV Series Aeroplanes\n\n \n\nAD/G1159/14 Hydraulic Power Shut-Off - Modification 1/75\n\nApplicability: All models with S/Nos. 1 to 153 and 775. Document:  Grumman Aircraft Service Change No. 186.\n\nCompliance: Within 150 hours time in service after 31 January 1975.\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\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, time-bound airworthiness directive from 1975 with a single specific purpose. It has not expanded beyond its original scope of mandating one specific safety modification for a defined subset of aircraft."},"complexity_factors":["Very short document (approximately 150 words)","Only 2 defined applicability criteria (model series and serial numbers)","Single compliance requirement with clear deadline","No cross-references to other legislation beyond the parent Civil Aviation Regulations 1998","No conditional logic or exceptions","Straightforward command structure: applies to X, do Y by Z date"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** issued by Australia's Civil Aviation Safety Authority (CASA). It mandates a specific safety modification for certain Gulfstream business jets.\n\n**What it does:**\n- Requires owners/operators of specific Gulfstream G1159 and G-IV series aircraft to install a hydraulic power shut-off system modification\n- The modification is detailed in \"Grumman Aircraft Service Change No. 186\"\n\n**Who it affects:**\n- Owners and operators of Gulfstream (Grumman) G1159 and G-IV series aeroplanes\n- Specifically applies to aircraft with serial numbers 1 through 153, and serial number 775\n\n**Why it matters:**\n- Airworthiness Directives are legally binding safety orders\n- This addresses a potential hydraulic system safety issue that could affect flight safety\n- Non-compliance means the aircraft cannot legally operate in Australian airspace\n\n**Key deadline:**\n- The modification must be completed within 150 hours of flight time after 31 January 1975"},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The instrument, as written, targets a specific corrective modification for a defined set of serial-numbered aircraft and sets a single compliance window. The text does not indicate any expansion or narrowing of scope from an earlier or different instrument; it specifies applicability, the required document (Grumman Service Change No. 186), and the compliance timing without amending other categories of aircraft or broader operations."},"complexity_factors":["Narrow applicability: only specific serial-numbered aeroplanes are affected (S/Nos. 1–153 and 775). (Applicability)","Single, time-limited compliance obligation with a clear deadline and hours metric (150 hours TIS after 31 Jan 1975). (Compliance)","Dependence on an external technical document (Grumman Aircraft Service Change No. 186) for implementation details requires access to and interpretation of manufacturer guidance. (Document)","Regulatory formality: issued as an Airworthiness Directive under Part 39, creating a legal duty for operators (header + AD identifier)."],"plain_english_summary":"This AD requires operators of Grumman/Gulfstream G1159 and G‑IV aeroplanes (S/Ns 1–153 and 775) to modify the hydraulic power shut‑off system per Grumman Service Change No. 186. The work must be done within 150 hours TIS after 31 January 1975.  \n\nOwners/operators bear the cost and legal obligation; the measure addresses an airworthiness/safety concern by mandating the specified manufacturer procedure."}},"importantCases":[],"_links":{"self":"/api/acts/ad-g1159-14-hydraulic-power-shut-off-modification","history":"/api/acts/ad-g1159-14-hydraulic-power-shut-off-modification/history","analysis":"/api/acts/ad-g1159-14-hydraulic-power-shut-off-modification/analysis","conflicts":"/api/acts/ad-g1159-14-hydraulic-power-shut-off-modification/conflicts","importantCases":"/api/acts/ad-g1159-14-hydraulic-power-shut-off-modification/important-cases","documents":"/api/acts/ad-g1159-14-hydraulic-power-shut-off-modification/documents"}}