{"id":"F2006B08166","name":"AD/CESSNA 310/39 - Main Landing Gear Attachment - Inspection","slug":"ad-cessna-310-39-main-landing-gear-attachment-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115347,"registerId":"commonwealth-F2006B08166-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 310/39 - Main Landing Gear Attachment - Inspection","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nCessna 310 Series Aeroplanes\n\nAD/CESSNA 310/39 Main Landing Gear Attachment \\- Inspection 9/75\n\nApplicability: All models 310 to 310K inclusive. Requirement: With aeroplane on jacks:\n\n    Remove Main Landing Gear Attaching “U” Bolts and Shafts.\n\n    2. Visually inspect the “U” Bolts, with the aid of a 10X glass, in the area of the thread root ends for cracks.\n\n    3. Visually inspect the Attaching Shafts, with the aid of a 10X glass, in the area of the roll pin hole for cracks.\n\nCompliance: 1. For MLG attachment shafts and “U” bolts which have achieved 2500 hours time in service at 12 August 1975; within 100 hours time in service and thereafter at intervals not exceeding 200 hours time in service.\n\n2. All other MLG attachment shafts and “U” bolts; before achieving 2500 hours time in service and thereafter at intervals not exceeding 200 hours time in service.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive applies to all Cessna 310 models through 310K as stated (Applicability) and imposes inspection requirements for the specified components with the stated time-in-service triggers and recurring 200-hour intervals (Compliance). There is no indication in the text provided that the applicability or subject-matter scope has been expanded or narrowed from an earlier stated intent; the AD sets specific mechanical inspection actions and a time-based compliance regime for those models and parts."},"complexity_factors":["Clear and narrow applicability to Cessna 310–310K models (limited population). (Applicability)","Simple, prescriptive tasks: remove specified parts and visually inspect with 10X magnification. (Requirement 1–3)","Two-tier compliance schedule depending on whether parts had reached 2,500 hours as at a fixed historical date, then a uniform 200-hour recurrence interval. (Compliance paras 1–2)","Operational complexity from jacking the aircraft and removing/refitting load-bearing hardware (requires facilities and qualified personnel). (Requirement)","Recurring administrative burden of tracking time-in-service hours to trigger inspections. (Compliance)"],"plain_english_summary":"What this instrument does, mechanically:\n\n- It requires owners/operators of Cessna 310 series aeroplanes (models 310 through 310K) to jacked-up the aircraft, remove the main landing gear (MLG) attaching “U” bolts and shafts, and inspect them visually for cracks using a 10X magnifying glass. (Applicability; Requirement 1–3)\n- The inspection focuses on the thread root ends of the “U” bolts and the area around the roll-pin hole of the attaching shafts. (Requirement 2–3)\n- It prescribes when to do those inspections: parts that already had at least 2,500 hours time in service as at 12 August 1975 must be inspected within 100 hours time in service and then every 200 hours thereafter; all other such parts must be inspected before they reach 2,500 hours and then every 200 hours thereafter. (Compliance paras 1–2)\n\nWho is directly affected and who decides:\n\n- Owners and operators of Cessna 310–310K aircraft must carry out the physical actions and bear the costs of the inspections and any follow-up maintenance. (Applicability; Requirement)\n- Maintenance personnel perform the removals and visual inspections and must use a 10X glass as specified. (Requirement)\n- The Civil Aviation Safety Authority issued the directive and sets the intervals and thresholds; compliance is measured by time-in-service hours. (Compliance)\n\nWhy it matters (stated aim and practical trade-offs):\n\n- The stated aim of the directive is to detect cracks in the main landing gear attaching components (the U-bolts and shafts) before they lead to failure. (Requirement)\n- Mechanistically, earlier detection changes operator behaviour: regular removal and close visual inspection of those parts at prescribed intervals rather than waiting for symptoms or for scheduled major overhauls. (Requirement; Compliance)\n\nCosts, incentives and implementation considerations:\n\n- Who pays: the aircraft owner/operator pays for jacking the aircraft, labour to remove and re-fit the U-bolts and shafts, the time spent performing inspections with a magnifier, and any replacement parts if cracks are found. (Requirement; Compliance)\n- Operational impact: jacking an aircraft and removing MLG attachments creates aircraft downtime and requires appropriate facilities and qualified maintenance staff. (Requirement)\n- Inspection burden and repeat frequency: inspections occur at fixed service-hour intervals (every 200 hours after the initial trigger), which creates recurring maintenance tasks and record-keeping obligations tied to time-in-service tracking. (Compliance)\n- Incentives and substitution effects: operators may choose to replace suspect components early rather than repeat inspections, or to adjust maintenance scheduling to consolidate downtime; both choices shift costs between inspection labour and parts expenditure. (Requirement; Compliance)\n- Implementation risk and detection limits: the directive relies on visual inspection with 10X magnification. Cracks that are subsurface or not visible to this method may remain undetected; detection quality depends on inspector skill and inspection conditions. (Requirement)\n\nDistribution of benefits and costs:\n\n- The benefit of reduced risk from MLG attachment failure accrues to pilots, passengers and the aircraft owner in the event a crack would otherwise have led to a failure. This is a concentrated operational safety benefit for those using the aircraft. (Requirement)\n- The costs—inspection labour, downtime, and potential part replacement—are borne by the operators. These are recurring costs while the aircraft remain in service and subject to the stated inspection intervals. (Requirement; Compliance)\n\nDiscretion and administrative detail:\n\n- The directive specifies the inspection method (visual with 10X glass) and the service-hour triggers and intervals; it leaves practical execution (scheduling, who does the work, replacement decisions) to the owner/operator and maintenance personnel. (Requirement; Compliance)\n\nKey references in the text: Applicability; Requirement paragraphs 1–3; Compliance paragraphs 1–2."},"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 mechanical inspection. It has not expanded beyond its original safety purpose."},"complexity_factors":["Single, specific technical requirement with clear procedural steps","Only 2 defined compliance pathways based on flight hours","No cross-references to other legislation or regulations","Minimal conditional logic (simple binary split: parts at/above 2,500 hours vs below)","Short document (approximately 150 words)","Straightforward applicability statement (specific aircraft models by name)"],"plain_english_summary":"This is an **Airworthiness Directive** (a mandatory safety order) issued by Australia's Civil Aviation Safety Authority for **Cessna 310 series aircraft**.\n\n**What it does:**\n- Requires owners/operators to inspect the main landing gear attachment hardware on specific Cessna 310 models (310 through 310K)\n- Mandates removal and visual inspection of \"U\" bolts and attaching shafts using a 10x magnifying glass to check for cracks in specific areas\n\n**Who it affects:**\n- Owners and operators of Cessna 310, 310A, 310B, 310C, 310D, 310E, 310F, 310G, 310H, 310I, 310J, and 310K aircraft\n- Maintenance personnel responsible for airworthiness compliance\n\n**Why it matters:**\nCracks in landing gear attachment hardware can lead to **catastrophic failure during takeoff or landing**. This directive prevents accidents by catching fatigue cracks before they cause structural failure.\n\n**Compliance deadlines:**\n- **High-time parts** (already at 2,500+ flight hours as of August 1975): Inspect within next 100 flight hours, then every 200 hours\n- **Lower-time parts** (under 2,500 hours): Inspect before hitting 2,500 hours, then every 200 hours"}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-310-39-main-landing-gear-attachment-inspection","history":"/api/acts/ad-cessna-310-39-main-landing-gear-attachment-inspection/history","analysis":"/api/acts/ad-cessna-310-39-main-landing-gear-attachment-inspection/analysis","conflicts":"/api/acts/ad-cessna-310-39-main-landing-gear-attachment-inspection/conflicts","importantCases":"/api/acts/ad-cessna-310-39-main-landing-gear-attachment-inspection/important-cases","documents":"/api/acts/ad-cessna-310-39-main-landing-gear-attachment-inspection/documents"}}