{"id":"F2006B08229","name":"AD/CESSNA 336/9 - Flap Actuator - Inspection and Modification","slug":"ad-cessna-336-9-flap-actuator-inspection-and-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115475,"registerId":"commonwealth-F2006B08229-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 336/9 - Flap Actuator - Inspection and Modification","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)  Cessna 336 Series Aeroplanes\n\n \n\nAD/CESSNA 336/9 Flap Actuator - Inspection and Modification 2/73\n\nApplicability: All models with S/Nos. 336-0001 to 336-0195.\n\n \n\nRequirement: PART 1 - Inspect actuator jack screw and clean and relubricate in accordance with Cessna SL SE60-16.\n\n \n\nPART 2 - Modify the aircraft in accordance with Cessna SL ME72-19.\n\n \n\nCompliance: For Part 1 : At intervals not exceeding 100 hours time in service after 28 February 1973 until modified.\n\n \n\nFor Part 2 : Before 1st June 1973.\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 instrument's scope is explicit and confined to Cessna 336 aeroplanes with serial numbers 336-0001 to 336-0195 (\"Applicability\"). There is no text in the provided instrument indicating an expansion or narrowing of that applicability or of the two required actions; the AD requires the inspection routine and a one-off modification by the stated deadlines (\"Requirement\" and \"Compliance\")."},"complexity_factors":["Narrow applicability limited to a contiguous serial number range (336-0001 to 336-0195).","Two discrete, clearly referenced actions: a recurring inspection/lubrication (Service Letter SE60-16) and a specific modification (Service Letter ME72-19).","Clear compliance timing: inspection every 100 hours until modification; modification required before a fixed date.","Little regulatory discretion or conditionality in the text—the AD delegates technical detail to the named service letters.","No multiple cross-references to other regulations or exceptions within the provided text."],"plain_english_summary":"What this instrument does\n\n- This is an Airworthiness Directive (AD) issued under the Commonwealth Civil Aviation Regulations schedule of airworthiness directives (header). It applies to Cessna 336 aeroplanes with serial numbers 336-0001 to 336-0195 (\"Applicability: All models with S/Nos. 336-0001 to 336-0195\").\n\n- It requires two actions: an ongoing inspection and relubrication of the flap actuator jack screw, and a one‑off modification to the aircraft. These are set out as \"Requirement: PART 1\" and \"Requirement: PART 2\" in the instrument.\n\nWho this affects\n\n- Aircraft owners and operators of Cessna 336 airframes in the stated serial number range.\n- Maintenance organisations and technicians who carry out the required inspection, re‑lubrication and the modification.\n\nWhat exactly must be done and when\n\n- PART 1 (inspection and relubrication): Inspect the actuator jack screw and clean and relubricate it in accordance with Cessna Service Letter SE60‑16 (\"Requirement: PART 1 - Inspect actuator jack screw and clean and relubricate in accordance with Cessna SL SE60-16\").\n  - Frequency: repeat at intervals not exceeding 100 hours time in service after 28 February 1973 until the aircraft has been modified (\"Compliance: For Part 1 : At intervals not exceeding 100 hours time in service after 28 February 1973 until modified\").\n\n- PART 2 (modification): Modify the aircraft in accordance with Cessna Service Letter ME72‑19 (\"Requirement: PART 2 - Modify the aircraft in accordance with Cessna SL ME72-19\").\n  - Timing: the modification must be completed before 1 June 1973 (\"Compliance: For Part 2 : Before 1st June 1973\").\n\nWhy it matters (stated purpose and practical implications)\n\n- The title and required actions identify the flap actuator as the subject; the explicit text sets mandatory maintenance and a retrofit modification. The instrument does not include an extended policy discussion; its practical effect is to change operator behaviour: regular inspections and a mandated retrofit within the stated dates.\n\nWho pays and who decides\n\n- Owners/operators pay for the inspection, relubrication and the modification (costs of parts, labour and any downtime). The AD prescribes the required actions and compliance timing (see \"Requirement\" and \"Compliance\" entries).\n- Maintenance providers decide how to schedule the work and execute it, but must follow the specified Cessna service letters (SE60‑16 for the inspection/relubrication and ME72‑19 for the modification).\n\nCompliance burden and discretion\n\n- The AD prescribes the tasks and the service letters to be followed; it leaves little technical discretion about what to do (the work is to be performed \"in accordance with\" the named Cessna service letters) (Requirement: PART 1 and PART 2).\n- There is an operational burden of repeating the inspection every 100 hours until the modification is done; and there is a binding deadline to complete the one‑off modification (Compliance provisions).\n\nTrade‑offs, incentives and implementation risks\n\n- Incentives: operators have an incentive to complete the modification promptly to remove the recurring inspection requirement (the inspection repeats every 100 hours until modified) (Compliance for Part 1 and Part 2).\n- Costs: owners bear direct costs (inspection, lubricant, modification parts and labour) and indirect costs (aircraft downtime). The AD does not provide funding or exemptions.\n- Substitution effects: operators may choose different approved maintenance providers, or schedule the modification during other maintenance to reduce aircraft downtime; qualified independent maintenance organisations can perform the work provided they follow the specified service letters.\n- Implementation risk: if an operator fails to comply with the modification deadline, the AD requires continued inspections every 100 hours, increasing ongoing maintenance burden.\n\nNet operational effect (mechanics, not judgement)\n\n- The directive changes the maintenance regime for affected Cessna 336s by imposing regular inspection/relubrication until a mandated modification is installed by a specified date. The owner/operator decides when and where to have the work done (subject to the service letters), and pays for it. The regulator set the compliance interval and the final modification deadline."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue airworthiness directive focused specifically on flap actuator maintenance for a limited aircraft population. It has not expanded beyond its original safety purpose."},"complexity_factors":["Very short document (approximately 150 words of substantive content)","Only 2 defined applicability criteria (aircraft model and serial number range)","Simple two-part structure with clear sequential requirements","No cross-references to other legislation or regulations beyond the enabling Civil Aviation Regulations 1998","No nested conditions or exceptions — straightforward compliance deadlines and intervals","References to external technical documents (Cessna Service Letters) but does not reproduce their content"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for specific aircraft.\n\n**What it does:**\nThis directive requires owners and operators of certain **Cessna 336 series aeroplanes** (specifically serial numbers 336-0001 through 336-0195) to perform two safety actions on the **flap actuator** — the mechanical component that controls the aircraft's wing flaps (the movable surfaces on the wings that help with takeoff and landing).\n\n**The two required actions:**\n- **Part 1 — Regular inspection:** Check the actuator's jack screw (a threaded rod that converts rotational motion into linear movement), clean it, and re-lubricate it. This must be done every **100 hours of flight time** starting from 28 February 1973, and repeated until the modification in Part 2 is completed.\n- **Part 2 — Permanent modification:** Modify the aircraft according to Cessna Service Letter ME72-19. This must be done **before 1 June 1973**.\n\n**Who it affects:**\nOwners and operators of early-model Cessna 336 Skymaster aircraft (roughly the first 195 aircraft built).\n\n**Why it matters:**\nFlap actuators are critical for safe flight operations. This AD addresses a known safety issue — likely wear, corrosion, or potential failure of the jack screw mechanism — that could impair flap operation and jeopardise landing safety. The directive ensures aircraft either receive ongoing maintenance or a permanent fix."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-336-9-flap-actuator-inspection-and-modification","history":"/api/acts/ad-cessna-336-9-flap-actuator-inspection-and-modification/history","analysis":"/api/acts/ad-cessna-336-9-flap-actuator-inspection-and-modification/analysis","conflicts":"/api/acts/ad-cessna-336-9-flap-actuator-inspection-and-modification/conflicts","importantCases":"/api/acts/ad-cessna-336-9-flap-actuator-inspection-and-modification/important-cases","documents":"/api/acts/ad-cessna-336-9-flap-actuator-inspection-and-modification/documents"}}