{"id":"F2006B10068","name":"AD/G159/23 - Fuselage Aft Pressure Dome - Inspection and Modification","slug":"ad-g159-23-fuselage-aft-pressure-dome-inspection-and-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":55513,"registerId":"commonwealth-F2006B10068-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/G159/23 - Fuselage Aft Pressure Dome - Inspection and 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 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\nAD/G159/23 Fuselage Aft Pressure Dome - Inspection and\n\nModification\n\n\n10/73\n\n \n\nApplicability: All models.\n\n \n\nDocument: Grumman Customer Bulletin No. 240.\n\n \n\nCompliance: Within 100 hours time in service after 31 October 1973.\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":2,"scope_assessment":{"changed":false,"description":"The AD text, as supplied, applies to all models of the G.159 series and mandates inspection/modification per Grumman Customer Bulletin No. 240 within a specified 100‑hour time window after 31 October 1973. The instrument itself does not indicate any change to scope from an earlier stated intent; it sets a single, broadly applicable requirement with an external technical reference."},"complexity_factors":["Short, narrowly framed directive with a single external reference (Grumman Customer Bulletin No. 240).","Mandatory compliance measured in flight hours (100 hours after a fixed date), requiring operators to track hours and schedule work.","Applies to all models of the G.159 series, increasing the population affected but not the technical scope in the AD text.","AD text contains no technical instructions or parts lists; compliance requires consulting the external bulletin, which adds a dependency.","No discretionary exceptions or alternate compliance methods provided in the AD text."],"plain_english_summary":"- What this instrument does, mechanically\n\n  - Declares an airworthiness directive that requires inspection and modification of the fuselage aft pressure dome on Gulfstream (Grumman) G.159 series aeroplanes. The required technical steps are those given in Grumman Customer Bulletin No. 240 (Document: Grumman Customer Bulletin No. 240). (See: \"Document: Grumman Customer Bulletin No. 240.\")\n  - Sets a mandatory compliance deadline: the inspection/modification must be completed within 100 hours time in service after 31 October 1973. (See: \"Compliance: Within 100 hours time in service after 31 October 1973.\")\n\n- Who is affected\n\n  - All owners and operators of Gulfstream (Grumman) G.159 series aeroplanes (Applicability: All models). (See: \"Applicability: All models.\")\n  - Maintenance organisations and technicians who carry out the inspection and modification steps required by the manufacturer's bulletin.\n\n- Why it matters (mechanical effect and operational consequences)\n\n  - The directive makes the manufacturer's customer bulletin mandatory: operators must follow the bulletin's inspection and modification instructions within the specified flight‑hour window. (See: \"Document: Grumman Customer Bulletin No. 240\" and \"Compliance: Within 100 hours...\")\n  - Practically, affected aircraft will need to be scheduled for maintenance within the compliance window, which can impose direct costs (parts, labour) and aircraft downtime for owners/operators. The AD text itself does not list parts, procedures or cost estimates; those details are contained in the referenced bulletin. (See: \"Document: Grumman Customer Bulletin No. 240.\")\n\n- Implementation, incentives and trade-offs (source‑grounded)\n\n  - Who pays and who decides: The directive applies to all models of the G.159; therefore, responsibility for arranging and paying for the inspection/modification falls to the aircraft owners or operators, who must ensure the work meets the bulletin's requirements. (See: \"Applicability: All models.\" and \"Compliance: Within 100 hours...\")\n  - Compliance burden: The AD imposes a time‑limited obligation (100 hours time in service after 31 October 1973), so operators must track flight hours and schedule work within that window. The AD text does not provide procedural detail, so compliance requires consulting the referenced Grumman bulletin. (See: \"Compliance...\" and \"Document...\")\n  - Bureaucratic discretion and enforcement: The AD sets a clear requirement and deadline; the text does not itself create discretionary exemptions or alternatives. Any technical interpretation or scope of work is determined by the referenced customer bulletin and by the enforcing authority following normal airworthiness enforcement practices. (See: entire AD text.)\n  - Opportunity costs and substitution effects: Operators must choose between scheduling this mandated work (with associated cost and downtime) and other maintenance or operational priorities within the same period. The AD makes the bulletin's actions compulsory rather than optional.\n\n- Implementation risk\n\n  - The AD text provides minimal technical detail; successful compliance depends on access to and clarity of Grumman Customer Bulletin No. 240. If the bulletin lacks clarity or parts are required, that can create delays or additional costs; the AD itself does not specify remedies or parts sources. (See: \"Document: Grumman Customer Bulletin No. 240.\")\n\nSource citations: the summary is based solely on the AD headings and fields presented in the instrument: \"Applicability: All models.\", \"Document: Grumman Customer Bulletin No. 240.\", and \"Compliance: Within 100 hours time in service after 31 October 1973.\""},"kimi_summary":{"content_quality":"ok","complexity_score":1,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue airworthiness directive from 1973 addressing a specific technical defect in a specific aircraft type. It has not expanded beyond its original purpose of mandating inspection and modification of the aft pressure dome."},"complexity_factors":["Extremely short document — only 4 substantive lines of regulatory content","No defined terms section","No cross-references to other legislation or regulations","Simple, unqualified directive structure: applicability + document reference + deadline","Single compliance condition with clear metric (100 hours time in service) and fixed calendar date","No exceptions, exemptions, or conditional logic"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order — issued by Australia's Civil Aviation Safety Authority (CASA) for a specific type of aircraft: the **Gulfstream (Grumman) G.159 series**.\n\n**What it does:**\n- Requires owners and operators of these aeroplanes to **inspect and modify the fuselage aft pressure dome** — that's the rear part of the aircraft's pressurised cabin structure.\n- The work must follow instructions in **Grumman Customer Bulletin No. 240** (the manufacturer's official technical notice).\n\n**Who it affects:**\n- Anyone who owns, operates, or maintains a Gulfstream G.159 aircraft in Australia.\n\n**When it must be done:**\n- Within **100 hours of flight time** after **31 October 1973**.\n\n**Why it matters:**\nAirworthiness Directives are legally enforceable safety requirements. They are issued when authorities identify a condition that makes an aircraft unsafe unless corrected. Failing to comply means the aircraft cannot legally fly. This particular AD addresses a potential structural issue with the rear pressure dome that could affect cabin pressurisation or structural integrity."}},"importantCases":[],"_links":{"self":"/api/acts/ad-g159-23-fuselage-aft-pressure-dome-inspection-and-modification","history":"/api/acts/ad-g159-23-fuselage-aft-pressure-dome-inspection-and-modification/history","analysis":"/api/acts/ad-g159-23-fuselage-aft-pressure-dome-inspection-and-modification/analysis","conflicts":"/api/acts/ad-g159-23-fuselage-aft-pressure-dome-inspection-and-modification/conflicts","importantCases":"/api/acts/ad-g159-23-fuselage-aft-pressure-dome-inspection-and-modification/important-cases","documents":"/api/acts/ad-g159-23-fuselage-aft-pressure-dome-inspection-and-modification/documents"}}