{"id":"F2006B08062","name":"AD/CESSNA 210/10 Amdt 3 - Main Landing Gear Actuators - Modification","slug":"ad-cessna-210-10-amdt-3-main-landing-gear-actuators-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115152,"registerId":"commonwealth-F2006B08062-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 210/10 Amdt 3 - Main Landing Gear Actuators - Modification","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 210 Series Aeroplanes\n\nAD/CESSNA 210/10\n\nAmdt 3\n\n  \nMain Landing Gear Actuators \\- Modification 12/75\n\nApplicability: All 210 Series with S/Nos. 21058510 and below.\n\nRequirement: Unless previously accomplished, replace all integral flange and gear spindle assemblies, Cessna P/No. ED11935L and R, with modified splined shaft and sector listed in:\n\n    Cessna SL SE69-17 \\- for aircraft S/No. 21058460 and below;\n\n    2. Cessna SL SE75-21 \\- for aircraft S/Nos. 21058461 to 21058510.\n\nCompliance: For Sub-Para. 1 \\- Within 300 hours time in service after 29 June 1973 or at first major inspection after 1 September 1973, whichever occurs first.\n\nFor Sub-Para. 2 \\- Before 1 September 1976.\n\nNote: Aircraft complying with DCA/CESSNA 210/10A or 10B satisfy compliance with this issue of the Directive.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":true,"description":"This instrument is presented as Amendment 3 to AD/CESSNA 210/10 and therefore updates the prior directive. It narrows and specifies the required modification by naming the exact replacement parts (Cessna SL SE69-17 and SL SE75-21) for two serial-number ranges and sets distinct compliance windows for each group (Requirement; Compliance). The Note preserves compliance credit for aircraft already modified under DCA/CESSNA 210/10A or 10B, indicating the amendment refines requirements while recognising prior compliant work (Note)."},"complexity_factors":["Clear, single technical requirement: replace specific part assemblies with specified modified parts (Requirement).","Applicability limited by a single, simple serial-number cutoff: S/Nos. 21058510 and below (Applicability).","Two distinct service letters apply to two contiguous serial-number ranges, requiring owners to check serial number to pick the correct service letter (Requirement).","Two different compliance timeframes: one defined in service hours or at inspection, the other as a calendar date (Compliance), which adds a small scheduling interpretation step.","Note cross-reference to earlier directives that satisfy compliance creates a conditional exemption that operators must verify (Note)."],"plain_english_summary":"### What this instrument does\n\nThis Airworthiness Directive (AD/CESSNA 210/10 Amdt 3) requires specified Cessna 210 aeroplanes to have particular parts of their main landing gear replaced with modified components. The directive identifies which aircraft are affected, which replacement service documents to use for two serial-number groups, and sets deadlines for when the replacements must be done. (See Applicability; Requirement; Compliance.)\n\n### Who it affects\n\n- Owners and operators of Cessna 210 series aeroplanes with serial numbers 21058510 and below. (Applicability.)\n- Maintenance providers who will source and install the replacement parts listed in the Cessna service letters. (Requirement.)\n\n### What must be done, mechanically\n\n- Replace all integral flange and gear spindle assemblies, Cessna P/No. ED11935L and R, with the modified splined shaft and sector specified in the Cessna service letters. (Requirement.)\n- Use Cessna SL SE69-17 for aircraft with S/N 21058460 and below. (Requirement.)\n- Use Cessna SL SE75-21 for aircraft with S/N 21058461 to 21058510. (Requirement.)\n\n### When it must be done\n\n- For the aircraft covered by Cessna SL SE69-17 (Sub‑Para. 1): within 300 hours time in service after 29 June 1973 or at the first major inspection after 1 September 1973, whichever occurs first. (Compliance: Sub‑Para. 1.)\n- For the aircraft covered by Cessna SL SE75-21 (Sub‑Para. 2): before 1 September 1976. (Compliance: Sub‑Para. 2.)\n\n### Interaction with earlier work\n\n- If an aircraft already complies with DCA/CESSNA 210/10A or DCA/CESSNA 210/10B, it is treated as having complied with this amendment. (Note.)\n\n### Who pays and who decides (practical mechanics)\n\n- Owners/operators bear the cost of parts and labour to replace the listed assemblies because the directive requires replacement on the specified aircraft. (Applicability; Requirement; Compliance.)\n- The Civil Aviation Safety Authority (via the airworthiness directive) is the issuing authority that sets the requirement and deadlines; owners/operators decide scheduling within the given compliance windows. (Requirement; Compliance.)\n\n### Incentives, compliance burden and implementation points to watch\n\n- The directive creates a direct compliance cost for each affected aircraft in the form of parts procurement and installation. (Requirement.)\n- Two different service letters apply to two serial‑number ranges, so owners must check their aircraft serial number to determine which service letter and compliance timing applies. (Requirement.)\n- The staggered compliance windows (one expressed in hours or inspection timing, the other as a calendar date) impose different scheduling constraints on different groups of owners/operators. (Compliance.)\n- The Note provides an alternative compliance path for aircraft already modified under earlier related directives, reducing duplicate work where those earlier actions were done. (Note.)\n\n### Implementation risks and trade-offs (mechanical, scheduling, procurement)\n\n- Operators must source the specified modified parts and arrange maintenance within the stated windows; availability of parts and maintenance slots will determine how easily owners meet the deadlines. (Requirement; Compliance.)\n- The directive does not themselves state enforcement mechanisms or penalties in this text; it sets mandatory technical and timing requirements that owners/operators must follow. (Entire instrument.)"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is Amendment 3 of a long-standing airworthiness directive. The scope remains tightly focused on the original safety issue: replacing specific defective landing gear actuators in Cessna 210 aircraft. The amendment appears to consolidate or clarify compliance requirements without expanding the directive's reach to new aircraft types, systems, or operational contexts."},"complexity_factors":["Very short document (under 200 words)","Only 2 defined applicability ranges based on serial numbers","Simple conditional structure: 'Unless previously accomplished' plus two sub-paragraphs with distinct compliance dates","No cross-references to other legislation or regulations beyond naming two Cessna Service Letters (SL SE69-17 and SL SE75-21)","Single note providing exemption for prior compliance","No nested exceptions or recursive definitions"],"plain_english_summary":"This is an **Airworthiness Directive** — a mandatory safety order issued by Australia's aviation safety regulator (CASA) that requires specific repairs or modifications to aircraft.\n\n**What it does:**\nOrders owners and operators of certain **Cessna 210 series aeroplanes** (specifically those with serial numbers 21058510 and below) to replace faulty main landing gear components. The original parts (integral flange and gear spindle assemblies, part number ED11935L and R) must be swapped out for improved, modified versions.\n\n**Who it affects:**\n- Owners and operators of older Cessna 210 aircraft (roughly those manufactured before a certain point in the production line)\n- Maintenance organisations servicing these aircraft\n\n**Why it matters:**\nLanding gear failures can be catastrophic. This directive addresses a known design flaw in the main landing gear actuators — the mechanical parts that extend and retract the wheels. The original components were prone to failure, so this order mandates their replacement before a deadline to prevent accidents.\n\n**Key deadlines:**\n- For the oldest aircraft (serial 21058460 and below): within 300 flight hours after 29 June 1973, or at the first major inspection after 1 September 1973 — whichever comes first\n- For slightly newer aircraft (serials 21058461 to 21058510): before 1 September 1976\n\n**Good news if you already complied:** If you already followed earlier versions of this directive (DCA/CESSNA 210/10A or 10B), you're done — no need to do it again."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-210-10-amdt-3-main-landing-gear-actuators-modification","history":"/api/acts/ad-cessna-210-10-amdt-3-main-landing-gear-actuators-modification/history","analysis":"/api/acts/ad-cessna-210-10-amdt-3-main-landing-gear-actuators-modification/analysis","conflicts":"/api/acts/ad-cessna-210-10-amdt-3-main-landing-gear-actuators-modification/conflicts","importantCases":"/api/acts/ad-cessna-210-10-amdt-3-main-landing-gear-actuators-modification/important-cases","documents":"/api/acts/ad-cessna-210-10-amdt-3-main-landing-gear-actuators-modification/documents"}}