{"id":"F2006B10094","name":"AD/G159/9 - Lower Centre Section Skin - Inspection","slug":"ad-g159-9-lower-centre-section-skin-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":55582,"registerId":"commonwealth-F2006B10094-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/G159/9 - Lower Centre Section Skin - 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/G159/9 Lower Centre Section Skin - Inspection 12/67\n\nApplicability: All models.\n\n \n\nRequirement: Remove the lower centre section fairings P/Ns 159 W10400-121 and 159-W10401- 121 and inspect the wing planks for corrosion. If corrosion is found, repair the wingplanks in accordance with a scheme approved by the Secretary before further flight.\n\n \n\nCompliance: Before 1 April 1967 and thereafter at intervals not exceeding 6 months.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\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, single-purpose airworthiness directive focused on a specific corrosion inspection for one aircraft type. It has not expanded beyond its original safety purpose."},"complexity_factors":["Very short document (approximately 150 words)","Only 2 defined part numbers (159-W10400-121 and 159-W10401-121)","Single straightforward requirement with one condition (if corrosion found → repair required)","Simple compliance timeline (one-off deadline + recurring 6-month interval)","No cross-references to other legislation or regulations","No nested exceptions or conditional logic"],"plain_english_summary":"This is an **Airworthiness Directive** (a mandatory safety order) issued by Australia's Civil Aviation Safety Authority for **Gulfstream G.159 aircraft**.\n\n**What it does:**\n- Requires owners/operators to remove specific fairings (protective covers) on the lower centre section of the aircraft\n- Inspect the wing planks (structural components) underneath for **corrosion** (rust or deterioration)\n- If corrosion is found, repairs must be approved by the Secretary (of the relevant government department) before the plane can fly again\n\n**Who it affects:**\n- All operators of Gulfstream (Grumman) G.159 series aeroplanes in Australia\n\n**Why it matters:**\n- Corrosion in wing structures can compromise aircraft safety and lead to structural failure\n- This directive mandates regular inspections to catch problems early\n- Non-compliance means the aircraft cannot legally fly\n\n**Key deadlines:**\n- First inspection required before 1 April 1967\n- Repeat inspections every 6 months thereafter"},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The text specifies an inspection-and-repair requirement applying to all G.159 models and sets initial and recurring compliance dates. The instrument as presented does not indicate any change of scope from an earlier or different intent; it stands as a single airworthiness directive focused on inspecting and repairing the lower centre section skin/wing planks for corrosion (Applicability; Requirement; Compliance)."},"complexity_factors":["Clear, narrow technical action: removal of two specified fairings and inspection of wing planks (Requirement).","Single condition-based outcome: if corrosion is found, repair is required before further flight (Requirement).","Recurring inspection interval specified (initial deadline and six-month repeats) (Compliance).","Administrative discretion introduced by requirement that repairs follow a scheme approved by the Secretary (Requirement).","Operational impact limited to maintenance time, inspection and repair; no multi-stage regulatory process or broad regulatory cross-references in the text."],"plain_english_summary":"The instrument requires removal of two lower centre‑section fairings (P/Ns 159‑W10400‑121, 159‑W10401‑121) to inspect Gulfstream (Grumman) G.159 wing planks for corrosion, with an initial inspection before 1 April 1967 and repeats at intervals not exceeding six months. Any corrosion must be repaired under a repair scheme approved by the Secretary before further flight.\n\nIt applies to all G.159 aircraft; operators/owners bear inspection and repair costs and associated downtime."}},"importantCases":[],"_links":{"self":"/api/acts/ad-g159-9-lower-centre-section-skin-inspection","history":"/api/acts/ad-g159-9-lower-centre-section-skin-inspection/history","analysis":"/api/acts/ad-g159-9-lower-centre-section-skin-inspection/analysis","conflicts":"/api/acts/ad-g159-9-lower-centre-section-skin-inspection/conflicts","importantCases":"/api/acts/ad-g159-9-lower-centre-section-skin-inspection/important-cases","documents":"/api/acts/ad-g159-9-lower-centre-section-skin-inspection/documents"}}