{"id":"F2006B10069","name":"AD/G159/25 - Aileron and Elevator Tabs - Inspection","slug":"ad-g159-25-aileron-and-elevator-tabs-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":55514,"registerId":"commonwealth-F2006B10069-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/G159/25 - Aileron and Elevator Tabs - 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/G159/25 Aileron and Elevator Tabs - Inspection 10/71\n\nApplicability: All Gulfstream 1 and TC4C aeroplanes. Document:  Grumman Customer Bulletin No. 255.\n\nCompliance: Within 100 hours time in service after 31 October 1974.1\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 safety directive issued in 1971 (effective 1974). It has not expanded beyond its original narrow purpose of mandating a specific inspection on a specific aircraft type. Airworthiness Directives are inherently limited in scope by design."},"complexity_factors":["Extremely short document — only 4 substantive lines of regulatory text","No defined terms section — all language is plain operational aviation terminology","Single compliance pathway with one clear deadline (100 hours TIS after fixed date)","No cross-references to other legislation or CASA regulations","No exceptions, exemptions, or conditional logic","Simple applicability test (aircraft model only)"],"plain_english_summary":"**What this is:** This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). Think of it as a \"recall notice\" for aircraft, but legally binding.\n\n**What it requires:** Owners and operators of **Gulfstream G.159 series aeroplanes** (including the military TC4C variant) must inspect the **aileron and elevator tabs** — small movable surfaces on the wings and tail that help control the aircraft.\n\n**Why it matters:** The directive references a **Grumman Customer Bulletin No. 255**, suggesting a potential structural or mechanical defect was discovered that could affect flight safety. The inspection must be completed **within 100 hours of flying time after 31 October 1974**.\n\n**Who must comply:** Anyone operating these specific Gulfstream aircraft in Australia — typically charter companies, corporate flight departments, or military operators.\n\n**Key deadline:** The clock started ticking in October 1974, with a 100-hour \"time in service\" window to complete the work."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"Based solely on the text of AD/G159/25, the directive sets out its applicability (all Gulfstream 1 and TC4C aeroplanes), cites the procedural source (Grumman Customer Bulletin No. 255) and prescribes a compliance deadline (within 100 hours after 31 October 1974). The instrument itself contains no indication that its scope has been amended or altered from an earlier or different intent; therefore there is no evidence in this document that the scope has changed from its original stated requirements (Applicability; Document; Compliance)."},"complexity_factors":["Narrow applicability limited to specific models (Gulfstream 1 and TC4C) reduces scope complexity (Applicability).","Single required action (inspection) simplifies substantive requirements.","Procedural details are externalised to Grumman Customer Bulletin No. 255, requiring operators to consult another document for full instructions (Document).","A fixed, short compliance window (within 100 hours after 31 October 1974) creates scheduling and operational complexity (Compliance).","The AD text does not provide acceptance criteria, corrective actions, or enforcement details, creating potential ambiguity about next steps if defects are found (Applicability; Document; Compliance)."],"plain_english_summary":"This AD requires operators of Gulfstream (Grumman) G.159 series aeroplanes (Gulfstream 1 and TC4C) to inspect the aileron and elevator trim tabs following Grumman Customer Bulletin No. 255.  \n\nThe inspection must be completed within 100 flight hours after 31 October 1974; costs, downtime, and scheduling fall to the aircraft owners/operators, with procedural and acceptance details in the referenced bulletin."}},"importantCases":[],"_links":{"self":"/api/acts/ad-g159-25-aileron-and-elevator-tabs-inspection","history":"/api/acts/ad-g159-25-aileron-and-elevator-tabs-inspection/history","analysis":"/api/acts/ad-g159-25-aileron-and-elevator-tabs-inspection/analysis","conflicts":"/api/acts/ad-g159-25-aileron-and-elevator-tabs-inspection/conflicts","importantCases":"/api/acts/ad-g159-25-aileron-and-elevator-tabs-inspection/important-cases","documents":"/api/acts/ad-g159-25-aileron-and-elevator-tabs-inspection/documents"}}