{"id":"F2006B10113","name":"AD/G164/8 Amdt 1 - Main Landing Gear Leg - Inspection","slug":"ad-g164-8-amdt-1-main-landing-gear-leg-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":55637,"registerId":"commonwealth-F2006B10113-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/G164/8 Amdt 1 - Main Landing Gear Leg - 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/G164/8\n\nAmdt 1\n\n\nMain Landing Gear Leg - Inspection 8/67\n\n \n\nApplicability: All models with landing gear legs which have exceeded 5000 landings.\n\n \n\nRequirement: 1. Inspect the main undercarriage spring legs by magnetic particle method for transverse cracking in the vicinity of the outboard clamp on the upper and lower surfaces.\n\n \n\n2. Replace cracked legs before further flight. Compliance: At intervals not exceeding 3000 landings.\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":true,"description":"The document is titled as an amendment (\"Amdt 1\") to AD/G164/8, which indicates it alters a prior airworthiness directive. The supplied text does not include the original version, so the nature and extent of the change from the original instrument cannot be determined from this document alone. The current instrument, as supplied, sets applicability (>5,000 landings), a mandated inspection method and location, replacement-before-flight for cracked legs, and a repeat interval (≤3,000 landings) (Applicability; Requirement 1–2; Compliance)."},"complexity_factors":["Narrow applicability threshold (applies only to aircraft with landing gear legs that have exceeded 5,000 landings) (Applicability).","Single, specific inspection method mandated (magnetic particle method) (Requirement 1).","Clear, narrowly defined inspection location (vicinity of the outboard clamp on upper and lower surfaces) (Requirement 1).","Binary corrective action required (replace cracked legs before further flight) (Requirement 2).","Compliance cadence stated in a single simple unit (intervals not exceeding 3,000 landings) rather than multiple overlapping requirements (Compliance)."],"plain_english_summary":"Owners/operators of Schweizer (Grumman) G‑164 (Ag‑Cat) aeroplanes whose main landing‑gear spring legs have exceeded 5,000 landings must carry out magnetic‑particle inspections for transverse cracking near the outboard clamp (upper and lower surfaces), remove and replace any cracked legs before further flight, and repeat inspections at intervals not exceeding 3,000 landings. Issued by the Civil Aviation Safety Authority, the directive targets safety of the main undercarriage and imposes inspection, replacement, recordkeeping, cost and downtime burdens on operators."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard, narrow Airworthiness Directive targeting a specific maintenance issue on a specific aircraft type. It has not expanded beyond its original safety purpose."},"complexity_factors":["Extremely short document (approximately 150 words)","Only 1 defined term implicitly understood ('transverse cracking' — explained by context)","No cross-references to other legislation or regulations","Simple conditional logic: if >5000 landings, then inspect every 3000 landings","Single technical requirement with straightforward compliance action","No exceptions, exemptions, or nested conditions","Clear applicability criteria (specific aircraft model + landing count threshold)"],"plain_english_summary":"This is an **Airworthiness Directive** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for specific aircraft.\n\n**What it does:**\n- Requires owners and operators of **Schweizer (Grumman) G-164 \"Ag-Cat\" agricultural aircraft** to inspect the main landing gear legs for dangerous cracks.\n- The inspection must use a **magnetic particle method** (a specialised technique that detects hidden cracks in metal using magnetic fields and iron particles).\n\n**Who it affects:**\n- Anyone operating these crop-dusting/agricultural planes **whose landing gear has done more than 5,000 landings**.\n\n**What must be done:**\n- **Inspect** the upper and lower surfaces of the main spring legs near the outboard clamp, looking specifically for cracks running across the metal (transverse cracking).\n- **Replace** any cracked legs immediately — the aircraft cannot fly again until this is done.\n- **How often:** Repeat this inspection every **3,000 landings**.\n\n**Why it matters:**\nLanding gear failures during takeoff or landing can be catastrophic. This directive prevents accidents by catching fatigue cracks in high-stress components before they cause structural failure. The Ag-Cat is a workhorse aircraft used in harsh agricultural conditions, making its landing gear particularly susceptible to wear."}},"importantCases":[],"_links":{"self":"/api/acts/ad-g164-8-amdt-1-main-landing-gear-leg-inspection","history":"/api/acts/ad-g164-8-amdt-1-main-landing-gear-leg-inspection/history","analysis":"/api/acts/ad-g164-8-amdt-1-main-landing-gear-leg-inspection/analysis","conflicts":"/api/acts/ad-g164-8-amdt-1-main-landing-gear-leg-inspection/conflicts","importantCases":"/api/acts/ad-g164-8-amdt-1-main-landing-gear-leg-inspection/important-cases","documents":"/api/acts/ad-g164-8-amdt-1-main-landing-gear-leg-inspection/documents"}}