{"id":"F2006B09978","name":"AD/FU24/15 - Main Landing Gear Axle Socket - Inspection","slug":"ad-fu24-15-main-landing-gear-axle-socket-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":55275,"registerId":"commonwealth-F2006B09978-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/FU24/15 - Main Landing Gear Axle Socket - 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)  Airparts (NZ) Ltd. FU 24 Series Aeroplanes\n\n \n\nAD/FU24/15 Main Landing Gear Axle Socket - Inspection 6/68\n\nApplicability: All models except those fitted with disc brakes.\n\n \n\nRequirement: Inspect visually, the Main Landing Gear Axle Sockets, P/N 245101, for cracks across the lugs containing the lower links.\n\n \n\nCompliance: At intervals not exceeding 100 hours time in service.\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\n \n\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The AD applies to all FU 24 series aeroplanes except those fitted with disc brakes and requires recurring visual inspection of a specific axle-socket part (Applicability; Requirement; Compliance). The text contains no indication that the instrument's scope has been altered from an earlier version within this excerpt."},"complexity_factors":["Narrow, specific applicability (all FU 24 models except those with disc brakes) (Applicability)","Single, clearly identified component and part number to inspect (Main Landing Gear Axle Socket, P/N 245101) (Requirement)","Single inspection method specified (visual) — lowers technical complexity but may leave technical discretion to maintenance organisations (Requirement)","Fixed, short recurring interval (every ≤100 hours time in service) creates operational scheduling requirements (Compliance)","No remedial actions or acceptance criteria stated in the text excerpt — leaves follow-up decisions to operators/maintenance providers (Requirement)"],"plain_english_summary":"What this instrument does, mechanically\n\n- This Airworthiness Directive (AD/FU24/15) requires operators of Airparts (NZ) Ltd. FU 24 series aeroplanes, except those fitted with disc brakes, to carry out a visual inspection of the Main Landing Gear Axle Sockets, part number 245101, specifically checking for cracks across the lugs that contain the lower links (Applicability; Requirement).\n- The inspections must be repeated at intervals not exceeding 100 hours time in service (Compliance).\n\nStated purpose and immediate effect\n\n- The directive's requirement is aimed at detecting cracks in a specific landing-gear component by mandating regular visual inspections (Requirement). Mechanically, it imposes a recurring inspection task on aircraft that fall within the applicability clause (Applicability; Compliance).\n\nWho pays, who decides, and what behaviour changes\n\n- Who pays: The aircraft owner/operator will incur the direct costs of performing the inspections and arranging any follow-up maintenance. The AD itself prescribes the inspection duty; it does not allocate funding or state who pays (Requirement; Compliance).\n- Who decides: The operator or their maintenance organisation must schedule and perform the inspections to meet the AD's timing (Compliance). If an inspection identifies a crack, the AD does not set out remedial steps in this text; the operator/maintenance provider will need to decide and carry out appropriate repairs or component replacement under applicable maintenance standards (Requirement).\n- Behaviour change: Operators must add a recurring visual-inspection task to their maintenance programme for affected aeroplanes, ensuring inspections occur at intervals of 100 hours TIS or less (Compliance).\n\nCosts, incentives and trade-offs (mechanical effects and implementation risk)\n\n- Recurring compliance cost: The 100-hour inspection interval creates an ongoing maintenance cost and scheduling obligation (Compliance). Those costs are borne by the aircraft owner/operator (Requirement; Compliance).\n- Operational trade-off: Regular inspections may require aircraft downtime and use of maintenance resources; the AD sets only the inspection obligation and interval, not the specific inspection technique beyond \"visual\" (Requirement; Compliance).\n- Administrative discretion and implementation: Because the AD specifies a visual inspection of a named part number and lugs, the scope of the work is narrowly defined (Applicability; Requirement). The AD does not describe follow-up repair instructions or acceptance criteria in this text, leaving follow-up actions to the operator’s maintenance procedures or to further instructions from the regulator or manufacturer (Requirement).\n\nEffects on private enterprise and market participants\n\n- Scope for maintenance providers: The requirement creates predictable, recurring work for maintenance organisations servicing affected FU 24 aircraft (Applicability; Compliance).\n- Competition and contract freedom: The AD prescribes what must be done (inspection at set intervals) but does not prescribe who must perform it; operators may use any certified maintenance provider consistent with airworthiness rules (Applicability; Requirement).\n\nConcrete limits of this text\n\n- The AD applies only to FU 24 series aeroplanes not fitted with disc brakes and only to the specified axle-socket part number (Applicability; Requirement).\n- The AD text supplied sets an inspection requirement and interval but does not set out remedies, acceptance criteria, or reporting obligations within the excerpt provided (Requirement; Compliance)."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue airworthiness directive focused on one specific mechanical inspection. It has not expanded beyond its original purpose of ensuring the structural integrity of FU 24 landing gear axle sockets."},"complexity_factors":["Extremely short document (under 150 words)","Only 4 operative provisions: applicability, requirement, compliance, and the specific part number","Single condition (disc brake exemption)","No defined terms section, no cross-references to other legislation","Simple temporal trigger (100 hours time in service)","No nested exceptions or conditional logic"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety notice issued by Australia's Civil Aviation Safety Authority (CASA) for specific aircraft.\n\n**What it does:**\nOrders owners and operators of certain Airparts (NZ) Ltd FU 24 series aeroplanes to regularly inspect a specific part — the Main Landing Gear Axle Socket (part number 245101) — for cracks where the lower links attach.\n\n**Who it affects:**\nAnyone who owns or operates an Airparts FU 24 series aircraft **that does NOT have disc brakes** (those with disc brakes are exempt).\n\n**What must be done:**\n- **Visual inspection** of the axle sockets for cracks across the lugs that hold the lower links\n- **How often:** Every 100 hours of flight time (\"time in service\")\n\n**Why it matters:**\nCracks in landing gear components can lead to catastrophic failure during takeoff or landing. This directive prevents accidents by catching fatigue damage before it causes structural collapse. The 100-hour interval reflects the critical safety nature of this component.\n\nThis directive dates back to 1968 (hence \"6/68\" in the reference), showing it's a long-standing safety requirement for this aircraft type."}},"importantCases":[],"_links":{"self":"/api/acts/ad-fu24-15-main-landing-gear-axle-socket-inspection","history":"/api/acts/ad-fu24-15-main-landing-gear-axle-socket-inspection/history","analysis":"/api/acts/ad-fu24-15-main-landing-gear-axle-socket-inspection/analysis","conflicts":"/api/acts/ad-fu24-15-main-landing-gear-axle-socket-inspection/conflicts","importantCases":"/api/acts/ad-fu24-15-main-landing-gear-axle-socket-inspection/important-cases","documents":"/api/acts/ad-fu24-15-main-landing-gear-axle-socket-inspection/documents"}}