{"id":"F2006B10102","name":"AD/G164/17 - Lower Wing Attachment Fittings - Inspection","slug":"ad-g164-17-lower-wing-attachment-fittings-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":55604,"registerId":"commonwealth-F2006B10102-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/G164/17 - Lower Wing Attachment Fittings - 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 Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Schweizer (Grumman) G-164 (Ag-Cat) Series Aeroplanes\n\n \n\nAD/G164/17 Lower Wing Attachment Fittings - Inspection 12/78\n\nApplicability: All models G-164, G-164A and G-164B which have achieved 500 flying hours or 6 months time in service.\n\n \n\nDocument: Gulfstream American AG-CAT (G164) SB No. 65.\n\n \n\nCompliance: Within 25 hours time in service after 6 November 1978 and there- after at intervals not exceeding 500 hours time in service or 6 months whichever occurs first.\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":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, time-limited safety directive issued in 1978 for a specific aircraft type. It has not expanded beyond its original purpose of mandating wing fitting inspections on Ag-Cat aircraft."},"complexity_factors":["Very short document (approximately 150 words)","Only 4 operative provisions: applicability, reference document, compliance deadline, and recurring interval","No defined terms section — uses plain aviation terminology","No cross-references to other legislation or regulations","Simple conditional logic: '500 hours OR 6 months' trigger, then '500 hours OR 6 months' recurring interval","Single technical reference to external service bulletin"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). It requires owners and operators of specific agricultural aircraft to inspect a critical part of the plane's wing structure.\n\n**What it does:**\n- **Targets:** Schweizer (formerly Grumman) G-164 \"Ag-Cat\" series aeroplanes — these are crop-dusting aircraft used in agriculture.\n- **The problem:** The \"lower wing attachment fittings\" — the metal brackets that connect the wings to the fuselage — need checking for cracks or wear that could cause wing failure.\n- **Who must comply:** All G-164, G-164A, and G-164B models that have flown 500 hours or been in service for 6 months.\n- **When:** First inspection due within 25 flying hours after 6 November 1978, then repeated every 500 flying hours or 6 months (whichever comes first).\n- **How:** Follow the procedures in Gulfstream American Service Bulletin No. 65.\n\n**Why it matters:** Wing attachment failures can cause catastrophic crashes. This AD prevents accidents by forcing regular inspections of a high-stress component on workhorse aircraft that operate in harsh, dusty conditions."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive does not expand or contract the class of aircraft beyond the models and service thresholds stated in the Applicability clause. It imposes an inspection requirement and sets the timing for initial and recurring inspections, but does not change certification, operating privileges, or the aircraft definition: it only mandates inspection intervals for the specified models. (See: Applicability; Compliance; Document.)"},"complexity_factors":["Narrow scope limited to specific aircraft models and a clear hours/age threshold (Applicability clause).","Clear, simple compliance timing (initial short window and recurring 500‑hour/6‑month interval).","Procedural details are not included in the AD text but are delegated to an external document (Gulfstream American AG-CAT (G164) SB No. 65), requiring operators to obtain and follow that bulletin.","No repair, enforcement, or acceptable-alternative-methods language in the AD text, which may create practical uncertainty for implementers.","Historical compliance date referenced (25 hours after 6 November 1978) — relevant to operators who met thresholds at that time, but the dated language may complicate interpretation for later record-keeping or retrospective compliance checks."],"plain_english_summary":"What this direction does, in plain terms:\n\n- This is an airworthiness directive titled “AD/G164/17 Lower Wing Attachment Fittings - Inspection.” It applies to Schweizer (Grumman) G-164, G-164A and G-164B aeroplanes (identified in the text) and requires inspections of the lower wing attachment fittings. (See: “Applicability: All models G-164, G-164A and G-164B…” and the AD title.)\n\n- Who is affected: Owners and operators of the listed G-164 series aeroplanes that have reached 500 flying hours or six months time in service. (See: “which have achieved 500 flying hours or 6 months time in service.”)\n\n- What must be done and when: Each affected aeroplane must have the prescribed inspection performed within 25 hours time in service after 6 November 1978, and then repeatedly at intervals not exceeding 500 hours time in service or six months, whichever comes first. (See: “Compliance: Within 25 hours time in service after 6 November 1978 and thereafter at intervals not exceeding 500 hours time in service or 6 months whichever occurs first.”)\n\n- Where the detailed inspection procedure comes from: The directive references Gulfstream American AG‑CAT (G164) Service Bulletin No. 65 as the document containing the inspection instructions. Operators must use that document to carry out the inspections. (See: “Document: Gulfstream American AG-CAT (G164) SB No. 65.”)\n\nWhy this matters (as stated and as implemented):\n\n- The instrument mechanically imposes a recurring inspection obligation on a defined set of aircraft (specified models and age/hours threshold). The AD itself sets the compliance windows and points to a manufacturer service bulletin for the inspection method. (See: AD title, Applicability, Compliance, Document.)\n\n- Purpose-claim: The title and placement in the Schedule of Airworthiness Directives indicate the directive’s purpose is to require inspection of lower wing attachment fittings for the listed aeroplanes. That claim is carried by the directive text which (a) identifies the fittings to be inspected and (b) prescribes inspection timing. (See: AD title; Applicability; Compliance.)\n\nTesting that purpose against practical effects and trade-offs:\n\n- Who pays: Owners/operators pay the costs of obtaining Service Bulletin No. 65 (if not already on hand), performing the inspections, and any follow-up work (repairs, part replacement, or additional inspections). The AD text requires compliance but does not allocate costs or fund the work. (See: Document; Compliance.)\n\n- Implementation dependence: The AD gives the timing and the target (lower wing attachment fittings) but does not set out the step‑by‑step inspection procedure in the text. Instead it references Service Bulletin No. 65; therefore, operators must obtain and follow that bulletin for actionable instructions. This delegates procedural detail outside the AD itself. (See: Document.)\n\n- Compliance burden and frequency: The recurring interval—every 500 hours or six months, whichever is first—creates regular maintenance workload and record‑keeping for affected aircraft. The initial short window (within 25 hours after 6 November 1978) requires prompt action from operators who meet the applicability threshold. (See: Compliance; Applicability.)\n\n- Discretion and enforcement: The AD prescribes what must be done (inspect at specified intervals) but does not describe enforcement steps, tolerances, or acceptable follow-up actions in its text. Enforcement discretion and any approval of alternative methods would rest with the civil aviation authority or be determined by the referenced Service Bulletin, neither of which is detailed in the AD text itself. (See: Compliance; Document.)\n\n- Effects on private choices and business operations: The directive reduces operator discretion by mandating inspection timing and by pointing to a specific Service Bulletin for the inspection method. Independent maintenance providers can perform the inspections only to the extent they follow the referenced documentation and any applicable approval processes. The directive may increase operating costs (inspection time, possible repairs) and affects scheduling for aircraft that meet the applicability criteria. (See: Applicability; Compliance; Document.)\n\n- Concentration of benefits and costs: The immediate, concentrated cost-bearers are the owners/operators of the specified G-164 series aeroplanes. Any safety or airworthiness benefits claimed by the directive (implicit in the AD title) would accrue to operators, passengers, and the aviation system generally, but the AD text itself only prescribes inspections and does not quantify benefits or costs. (See: AD title; Applicability; Compliance.)\n\n- Implementation risks and practical gaps: Because the AD text does not contain procedural inspection steps, practitioners must locate and rely on Service Bulletin No. 65. If the bulletin lacks clarity, or if parts/repair instructions are needed but absent, operators may face uncertainty about acceptable corrective actions; that uncertainty is not resolved within the AD text. (See: Document.)\n\nRelevant text citations: “AD/G164/17 Lower Wing Attachment Fittings - Inspection” (title); “Applicability: All models G-164, G-164A and G-164B which have achieved 500 flying hours or 6 months time in service.” (applicability); “Document: Gulfstream American AG-CAT (G164) SB No. 65.” (procedure reference); “Compliance: Within 25 hours time in service after 6 November 1978 and thereafter at intervals not exceeding 500 hours time in service or 6 months whichever occurs first.” (timing)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-g164-17-lower-wing-attachment-fittings-inspection","history":"/api/acts/ad-g164-17-lower-wing-attachment-fittings-inspection/history","analysis":"/api/acts/ad-g164-17-lower-wing-attachment-fittings-inspection/analysis","conflicts":"/api/acts/ad-g164-17-lower-wing-attachment-fittings-inspection/conflicts","importantCases":"/api/acts/ad-g164-17-lower-wing-attachment-fittings-inspection/important-cases","documents":"/api/acts/ad-g164-17-lower-wing-attachment-fittings-inspection/documents"}}