{"id":"F2006B10061","name":"AD/G159/17 - Wing Front Beam - Wing to Fuselage Fitting - Inspection","slug":"ad-g159-17-wing-front-beam-wing-to-fuselage-fitting-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":55506,"registerId":"commonwealth-F2006B10061-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/G159/17 - Wing Front Beam - Wing to Fuselage Fitting - 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 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/G159/17 Wing Front Beam - Wing to Fuselage Fitting -\n\nInspection\n\n\n1/72\n\n \n\nApplicability: All models.\n\n \n\nRequirement: Inspect the wing to fuselage fittings at butt line 9.0 and associated areas as detailed in GRUMMAN GULFSTREAM 1 Service Change No. 190. Rework as necessary as detailed in that Service Change or a variation approved by the manufacturer.\n\n \n\nCompliance: Within 6 months after 28 January 1972 and thereafter at intervals not exceeding 1 year.\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 AD, as published, sets out inspection and rework obligations for the wing-to-fuselage fitting at butt line 9.0 and applies to all G.159 models. The text does not indicate any amendment or narrowing/expansion of that original requirement; it imposes the inspection and recurring interval and delegates approval of alternative methods to the manufacturer (Applicability; Requirement; Compliance). Therefore the scope, as stated in the instrument, appears consistent with the directive's own stated requirements and does not show a change from an earlier or different intent within the supplied text."},"complexity_factors":["Requires conforming to an external technical document (Grumman Gulfstream 1 Service Change No. 190) rather than containing all procedural detail in the AD itself","Permits manufacturer-approved variations, creating an approval dependency and potential for case-by-case discretion","Ambiguous scope term \"associated areas\" which can require technical interpretation","Recurring compliance schedule (initial deadline tied to a historical date plus annual inspections) which creates ongoing operational and cost considerations","Inspection results determine whether undefined \"rework as necessary\" is required, introducing uncertainty in cost and downtime"],"plain_english_summary":"What this instrument does (mechanically)\n\n- Requires operators to inspect the wing-to-fuselage fittings at butt line 9.0 and the \"associated areas\" for Gulfstream (Grumman) G.159 series aeroplanes, following the steps set out in Grumman Gulfstream 1 Service Change No. 190. If the inspection shows work is needed, the fittings must be reworked either as described in that Service Change or under a variation that the manufacturer approves. (Requirement)\n- Applies to all models of the G.159 series. (Applicability)\n- Sets a compliance timetable: the first inspection must be done within 6 months after 28 January 1972, and inspections must be repeated at intervals not exceeding one year. (Compliance)\n\nWho this affects and who pays\n\n- Aircraft owners/operators of Gulfstream G.159 series aeroplanes must arrange and pay for the inspections and any required rework (Requirement; Compliance).\n- Maintenance organisations and technicians perform the inspections and rework to the procedures in the cited Service Change (Requirement).\n- The manufacturer retains the authority to approve alternative rework methods; operators must obtain that approval if they do not use the Service Change procedure (Requirement).\n\nWhy it matters (stated purpose and practical consequences)\n\n- The instrument mandates recurrent checks and corrective action on a specific structural fitting (the wing front beam—wing to fuselage fitting at butt line 9.0) to ensure the condition specified by the referenced Service Change is met (Requirement). This creates a recurring maintenance obligation for operators (Compliance).\n\nCosts, incentives and trade-offs\n\n- Direct costs: operators pay for inspections, labour, any parts and the downtime while work is done (Requirement; Compliance).\n- Incentives: operators have an incentive to detect and fix problems early to avoid repeated or more extensive rework later, but also an incentive to minimise downtime by combining this work with other scheduled maintenance.\n- Manufacturer approval for alternative rework methods centralises technical approval: an operator who wants a different repair approach must obtain the manufacturer's approval, creating a gatekeeping role for the manufacturer (Requirement).\n- Trade-offs: the AD imposes recurring compliance costs (annual inspections) in exchange for a regulator-mandated inspection regime; the text does not quantify benefits or specify acceptance criteria beyond referring to the Service Change (Requirement).\n\nImplementation practicalities and risks\n\n- The AD references an external technical document (Grumman Gulfstream 1 Service Change No. 190); operators must obtain and follow that document to perform compliant inspections and rework (Requirement).\n- The phrase \"associated areas\" is open-ended and may require technical judgement to determine the required inspection extent; that can create variability in how different maintenance providers interpret the task (Requirement).\n- Rework scope is determined by inspection findings and by the Service Change or manufacturer-approved variation, so costs and down-time are uncertain until inspections are performed (Requirement).\n\nWho decides and where discretion lies\n\n- The regulator (Civil Aviation Safety Authority, via this AD) prescribes the inspection and interval (Applicability; Requirement; Compliance).\n- The manufacturer controls approvals for variations to the listed rework method; maintenance providers and operators must follow either the Service Change or a manufacturer-approved variation (Requirement).\n\nConcrete behaviour changes required\n\n- Owners/operators must schedule the first inspection within the 6-month window after 28 January 1972 and then at least annually thereafter (Compliance).\n- If inspections find issues, operators must commission rework per the Service Change or a manufacturer-approved alternative before returning the aircraft to service (Requirement)."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific structural inspection requirement for a single aircraft type. It has not expanded beyond its original purpose of ensuring airworthiness of the wing-to-fuselage fitting."},"complexity_factors":["Extremely short document — only 4 substantive paragraphs","No defined terms section — relies on external technical reference (Service Change No. 190)","Single, straightforward requirement with clear compliance dates","No nested conditions, exceptions, or cross-references to other legislation","Simple applicability statement ('All models') with no exclusions"],"plain_english_summary":"This is an **Airworthiness Directive** (a mandatory safety order) issued by Australia's Civil Aviation Safety Authority for **Gulfstream G.159 series aircraft**.\n\n**What it does:**\n- Requires owners and operators to **inspect specific parts of the wing structure** — specifically where the wing attaches to the fuselage at \"butt line 9.0\" (a reference point on the aircraft's structure)\n- The inspection must follow the procedures in **Grumman Gulfstream Service Change No. 190**\n- If problems are found, repairs must be done according to that same document (or an approved alternative)\n\n**Who it affects:**\n- Anyone who owns or operates a **Gulfstream (Grumman) G.159 series aeroplane** — all models are covered\n\n**Why it matters:**\n- This addresses a **critical safety issue**: the wing-to-fuselage fitting is a vital structural connection. If it fails, the wing could separate from the aircraft\n- The directive mandates **repeated annual inspections** to catch potential fatigue or damage before it becomes dangerous\n\n**Key deadlines:**\n- First inspection due within **6 months of 28 January 1972**\n- Then **every year after that**"}},"importantCases":[],"_links":{"self":"/api/acts/ad-g159-17-wing-front-beam-wing-to-fuselage-fitting-inspection","history":"/api/acts/ad-g159-17-wing-front-beam-wing-to-fuselage-fitting-inspection/history","analysis":"/api/acts/ad-g159-17-wing-front-beam-wing-to-fuselage-fitting-inspection/analysis","conflicts":"/api/acts/ad-g159-17-wing-front-beam-wing-to-fuselage-fitting-inspection/conflicts","importantCases":"/api/acts/ad-g159-17-wing-front-beam-wing-to-fuselage-fitting-inspection/important-cases","documents":"/api/acts/ad-g159-17-wing-front-beam-wing-to-fuselage-fitting-inspection/documents"}}