{"id":"F2006B10064","name":"AD/G159/2 - Fuel Pressure Switches - Relocation","slug":"ad-g159-2-fuel-pressure-switches-relocation","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":55509,"registerId":"commonwealth-F2006B10064-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/G159/2 - Fuel Pressure Switches - Relocation","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 ORDERS CIVIL AVIATION SAFETY AUTHORITY                            PART 105 SCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  GULFSTREAM (GRUMMAN) G.159 SERIES AEROPLANES\n\n \n\n \n\n| AD/G159/2 | Fuel Pressure Switches - Relocation | 3/61 |\n| --- | --- | --- |\n| Applicability:<br> <br>Document: | S/Nos. 2 to 65 and 114.<br> <br>Grumman Service Changes No. 43 and 43A. |  |\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 \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 excerpt shows the AD applies to Gulfstream (Grumman) G.159 aeroplanes with serial numbers 2–65 and 114 and references Grumman Service Changes No. 43 and 43A (Applicability). The document excerpt contains no indication that the applicability or substantive scope has been broadened or narrowed from an earlier or different intent; therefore there is no evidence in the provided text of a scope change."},"complexity_factors":["Narrow and specific technical scope limited to fuel pressure switch relocation on one aircraft type and listed serial numbers (Applicability).","Dependence on external technical documents (Grumman Service Changes No. 43 and 43A) to provide the procedural detail required to comply (Applicability).","Regulatory form is straightforward (an AD listed under Part 105) but requires certified maintenance actions and operational scheduling, introducing practical complexity for operators (Header; Applicability).","Limited public text in the excerpt — no stated rationale, compliance timeframes, or enforcement details — which forces users to consult the referenced documents and broader AD schedule for full implementation steps (Title; Applicability)."],"plain_english_summary":"What this instrument does (mechanics)\n\n- The document is an Airworthiness Directive (AD) titled \"AD/G159/2 Fuel Pressure Switches - Relocation\". (Title)\n- It requires the relocation of fuel pressure switches on Gulfstream (Grumman) G.159 series aeroplanes of the serial numbers listed. The required work is to be carried out in accordance with Grumman Service Changes No. 43 and 43A. (Applicability)\n\nWho it affects\n\n- Aircraft owners and operators that hold or operate Gulfstream (Grumman) G.159 aeroplanes with serial numbers 2 to 65 and 114. (Applicability)\n- Maintenance organisations and licensed personnel who will perform the relocation work under the referenced Grumman service instructions. (Applicability)\n- The Civil Aviation Safety Authority (CASA) as the issuing regulator, responsible for listing the AD in the Part 105 Schedule of Airworthiness Directives. (Header)\n\nWhy it matters (purpose claims and operational implications)\n\n- The title and form of the AD indicate it mandates a specific maintenance modification (relocation of fuel pressure switches) for the named aircraft. The source text does not state an explicit safety rationale inside the excerpt provided; the AD’s instruction is to follow the referenced Grumman service changes. (Title; Applicability)\n\n- Who pays: costs of parts, labour and aircraft downtime fall to the owners/operators of the affected aircraft because they must implement the service changes. (Applicability)\n\n- What changes in behaviour: operators must schedule and complete the relocation work per Grumman Service Changes No. 43 and 43A and record the maintenance as required by airworthiness regulations. Maintenance providers will perform the physical modification and associated inspections. (Applicability)\n\n- Compliance burden and implementation risk: the AD ties compliance to external technical documents (Grumman Service Changes No. 43 and 43A). That creates dependence on those documents for exact steps, parts lists and labour estimates; operators need access to and must follow those service changes. The action is technical and will typically require certified maintenance personnel and facilities, causing operational downtime while the work is completed. (Applicability)\n\n- Effects on private enterprise and markets: the directive concentrates work on a limited set of aircraft (serial numbers 2–65 and 114). That creates a limited pool of customers for maintenance providers and suppliers of any specific parts required. For owners/operators, it is a discrete compliance cost; for maintenance providers it is additional billable work. (Applicability)\n\n- Discretion and enforcement: as an item in the Part 105 Schedule of Airworthiness Directives, CASA lists and enforces the AD framework; the AD itself references manufacturer service changes for technical details, leaving little operational discretion to operators beyond scheduling and using approved maintenance organisations. (Header; Applicability)\n\nTrade-offs and opportunity costs\n\n- The directive imposes a near-term cost (parts, labour, aircraft time out of service) on a defined set of operators. The source does not include quantified benefits or the explicit safety failure mode addressed, so a reader must look to Grumman Service Changes No. 43/43A or CASA explanatory material to see the stated justification and any cost–benefit assessment. (Applicability)\n\n- Because the applicability covers a small set of serial numbers, the cost burden is concentrated on a small group of operators rather than spread across a wide fleet. That concentration affects bargaining over timing, sourcing of parts and choice of maintenance provider. (Applicability)\n\nSummary statement\n\n- Mechanically, the AD mandates relocation of fuel pressure switches on specified G.159 aeroplanes according to Grumman Service Changes No. 43 and 43A. Operators of the listed serial-numbered aircraft must arrange and pay for the work, using certified maintenance channels and complying with AD recording and enforcement requirements. The excerpt does not include the explicit safety rationale or detailed technical steps; those are contained in the referenced Grumman service changes. (Title; Applicability)"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This appears to be the original scope — a targeted safety directive for specific serial numbers of a single aircraft type. No evidence of scope creep; it remains a narrow technical airworthiness order."},"complexity_factors":["Extremely short document — essentially a table entry with 3 data points","No defined terms section — relies entirely on external references (Grumman Service Changes)","No conditional logic or exceptions — simple applicability rule based on serial numbers","No cross-references to other legislation or CASA regulations within the text","Single operational requirement: comply with manufacturer service bulletins"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). It requires specific modifications to certain Gulfstream G.159 aircraft.\n\n**What it does:**\n- Orders owners/operators of specific Gulfstream (formerly Grumman) G.159 series aeroplanes to relocate their fuel pressure switches\n- This is a safety modification to address a potential defect or unsafe condition in the aircraft's fuel system\n\n**Who it affects:**\n- Owners and operators of G.159 aircraft with **serial numbers 2 through 65, and serial number 114**\n- These are older aircraft (the G.159 \"Gulfstream I\" first flew in 1958)\n\n**What must be done:**\n- Aircraft must be modified according to **Grumman Service Changes No. 43 and 43A** — these are manufacturer-issued technical instructions for fixing design issues\n\n**Why it matters:**\n- Airworthiness Directives are legally binding. Non-compliance means the aircraft cannot fly legally in Australian airspace\n- Fuel pressure switch relocation likely addresses a safety risk — possibly fuel starvation, false warnings, or fire hazards\n- The \"3/61\" reference suggests this directive was first issued in March 1961, making it a longstanding safety requirement for these vintage aircraft"}},"importantCases":[],"_links":{"self":"/api/acts/ad-g159-2-fuel-pressure-switches-relocation","history":"/api/acts/ad-g159-2-fuel-pressure-switches-relocation/history","analysis":"/api/acts/ad-g159-2-fuel-pressure-switches-relocation/analysis","conflicts":"/api/acts/ad-g159-2-fuel-pressure-switches-relocation/conflicts","importantCases":"/api/acts/ad-g159-2-fuel-pressure-switches-relocation/important-cases","documents":"/api/acts/ad-g159-2-fuel-pressure-switches-relocation/documents"}}