{"id":"F2006B05272","name":"AD/CESSNA 207/12 - Wing Flap Actuator Ball Nut Assemblies","slug":"ad-cessna-207-12-wing-flap-actuator-ball-nut-assemblies","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":45635,"registerId":"commonwealth-F2006B05272-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 207/12 - Wing Flap Actuator Ball Nut Assemblies","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 207 Series Aeroplanes\n\nAD/CESSNA 207/12 Wing Flap Actuator Ball Nut Assemblies 3/77\n\nApplicability: Model 207 with S/Nos. as detailed in Cessna SL SE76-25.\n\nRequirement: 1. Inspect P/N C301002-0101 or P/N C301002-0102 wing flap actuator for date stamp code as detailed in Cessna SL SE76-25.\n\n    2. If the date stamp code on the actuator is OH, HH, WH or ZH, install a placard near the flap control which reads:\n\n“FLAP EXTENSION PROHIBITED”.\n\nNote: This placard may be removed when the Paragraph 3 requirement is satisfied.\n\n    3. Replace affected wing flap actuator ball nut assemblies in accordance with Cessna SL SE76-25.\n\nCompliance: Paragraphs 1 and 2 \\- Before further flight after 28 January 1977.\n\nParagraph 3 \\- Within 100 hours time in service after 28 January 1977.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific mechanical defect in a specific aircraft model. It has not expanded beyond its original purpose of addressing the wing flap actuator ball nut assembly issue."},"complexity_factors":["Very short document (under 200 words)","Only 2 defined part numbers (P/N C301002-0101 and P/N C301002-0102)","Simple conditional logic: if date stamp matches specific codes → install placard","Clear compliance deadlines with no nested exceptions","Single cross-reference to Cessna Service Letter SE76-25 for technical details","No interpretation section or defined terms"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order for aircraft owners and operators. It applies to specific **Cessna 207 series aeroplanes** (small utility aircraft) with particular serial numbers.\n\n**What it does:**\n- Requires inspection of the **wing flap actuator** (the mechanical device that moves the wing flaps) to check for specific date stamp codes (OH, HH, WH, or ZH)\n- If those codes are found, operators must **immediately install a warning placard** prohibiting use of the flaps until repairs are made\n- Requires **replacement of faulty ball nut assemblies** (a component inside the actuator that can fail) within 100 flight hours\n\n**Who it affects:**\n- Owners and operators of affected Cessna 207 aircraft\n- Maintenance engineers servicing these aircraft\n\n**Why it matters:**\nThe ball nut assemblies with these specific date codes were found to be defective and could fail, potentially causing **loss of flap control** — a serious safety hazard during takeoff and landing. This AD prevents accidents by grounding unsafe components and mandating repairs."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive, as drafted, does not indicate any change to scope from a prior stated intent within the text provided. It applies specifically to Model 207 aeroplanes listed by serial number in Cessna SL SE76-25 and to wing flap actuators with part numbers P/N C301002-0101 or P/N C301002-0102, requires inspection for certain date-stamp codes, a temporary placard if those codes are present, and eventual replacement of the affected ball nut assemblies per the Service Letter within 100 hours. No expansion or narrowing of applicability beyond those elements is stated in the text provided (Applicability; Paragraphs 1–3; Compliance)."},"complexity_factors":["Serial-number-specific applicability requiring cross-check against Cessna SL SE76-25 (Applicability).","Identification depends on physical inspection of date-stamp codes on specific part numbers P/N C301002-0101 and P/N C301002-0102 (Paragraph 1).","Immediate operational requirement (placard) must be satisfied before next flight if date codes match specified values (Paragraph 2; Compliance).","Replacement action must follow the manufacturer’s Service Letter procedures (Cessna SL SE76-25) and be completed within a 100-hour time window (Paragraph 3; Compliance).","Coordination between regulatory requirement and manufacturer service instructions introduces procedural dependency and potential logistical delay (Paragraph 3).","Temporary mitigation (placard) creates an operational constraint until a parts replacement is completed (Paragraph 2; Note)."],"plain_english_summary":"This instrument targets specific Cessna 207 airframes and requires inspection of wing flap actuator assemblies to read date-stamp codes. Actuators with codes OH, HH, WH or ZH must have a cockpit placard “FLAP EXTENSION PROHIBITED” installed before the next flight and the affected ball nut assemblies replaced per Cessna Service Letter SE76-25 within 100 hours time-in-service.\n\nIt affects owners/operators and maintenance organisations, who bear inspection, placarding and replacement costs and face a temporary operational restriction on flap use until parts are replaced."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-207-12-wing-flap-actuator-ball-nut-assemblies","history":"/api/acts/ad-cessna-207-12-wing-flap-actuator-ball-nut-assemblies/history","analysis":"/api/acts/ad-cessna-207-12-wing-flap-actuator-ball-nut-assemblies/analysis","conflicts":"/api/acts/ad-cessna-207-12-wing-flap-actuator-ball-nut-assemblies/conflicts","importantCases":"/api/acts/ad-cessna-207-12-wing-flap-actuator-ball-nut-assemblies/important-cases","documents":"/api/acts/ad-cessna-207-12-wing-flap-actuator-ball-nut-assemblies/documents"}}