{"id":"F2006B05057","name":"AD/CESSNA 180/44 - Wing Flap Actuator Ball Nut Assemblies","slug":"ad-cessna-180-44-wing-flap-actuator-ball-nut-assemblies","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44967,"registerId":"commonwealth-F2006B05057-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 180/44 - 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 180, 182 and Wren 460 Series Aeroplanes\n\nAD/CESSNA 180/44 Wing Flap Actuator Ball Nut Assemblies 3/77\n\nApplicability: Model 182 with S/Nos. as detailed in Cessna SL SE76-25.\n\nRequirement: 1. Inspect P/N C301002-0101 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: Paras. 1 and 2 \\- Before further flight after 28 January 1977.\n\nPara. 3 \\- Within 100 hours time in service after 28 January 1977.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The supplied directive sets out inspection, placarding and replacement obligations for specified Cessna 182 actuators identified by serial number and date-stamp codes, with deadlines. The document does not indicate any change to that scope from an earlier instrument; it states the applicability, required actions and compliance timings without showing an alteration of scope."},"complexity_factors":["Narrow applicability defined by aircraft serial numbers listed only in an external document (Cessna SL SE76-25) (Applicability)","Action depends on identifying specific date-stamp codes on a specific part number (Requirement ¶1–2)","Immediate operational restriction (placard prohibiting flap extension) that applies before further flight where codes match (Requirement ¶2; Compliance)","Replacement procedure and technical details are delegated to the manufacturer’s service letter, creating a dependency on an external document for execution (Requirement ¶3)","Two-stage compliance timetable: immediate inspection/placard before next flight and replacement within 100 hours, which imposes both urgent and short-term scheduling demands (Compliance)"],"plain_english_summary":"What this directive does (mechanically)\n\n- It applies to certain Cessna 182 aeroplanes listed by serial number in Cessna Service Letter SE76-25 (Applicability). \n- It requires an inspection of the wing flap actuator part number C301002-0101 to read the date-stamp code on the actuator (Requirement ¶1).\n- If the actuator’s date-stamp code is one of OH, HH, WH or ZH, the operator must install a placard near the flap control that reads “FLAP EXTENSION PROHIBITED” (Requirement ¶2). The placard can be removed once the affected ball nut assemblies are replaced (Note).\n- It requires replacement of the affected wing flap actuator ball nut assemblies in accordance with Cessna Service Letter SE76-25 (Requirement ¶3).\n- Timing: the inspection and, where required, placard installation must be done before the next flight after 28 January 1977; the replacement must occur within 100 hours time in service after 28 January 1977 (Compliance).\n\nWho is affected and who decides\n\n- Aircraft owners/operators of Cessna 182s identified by serial number in the referenced service letter are responsible for compliance (Applicability; Requirement).\n- The Civil Aviation Safety Authority issued the directive under the Schedule of Airworthiness Directives (header information). The detailed procedures and serial-number lists are in Cessna SL SE76-25, which the operator must consult (Applicability; Requirement ¶3).\n\nWhy the directive exists (stated or implied purpose)\n\n- The directive targets a specific flap-actuator part and specific date-stamp codes and directs removal of the ability to extend flaps where those codes are present, then replacement of the ball nut assemblies. That pattern of requirements indicates the ostensible purpose is to identify and remove from service actuators that may present a risk in flap operation (Requirements ¶1–3; placard rule ¶2). This description attributes the safety purpose to the instrument’s text rather than asserting external motives.\n\nPractical effects, incentives and trade-offs\n\n- Who pays: owners/operators must pay for the inspection, placard, and any replacement parts and labour (Requirement ¶1–3; Compliance). The directive does not specify funding or compensation arrangements.\n- Operational effect: where an affected actuator is found, the aircraft must operate with a placard prohibiting flap extension until the ball nut assemblies are replaced (Requirement ¶2; Note). That is an immediate operational restriction applied before further flight (Compliance).\n- Timing and compliance burden: the inspection and placard must be done before the next flight after 28 January 1977, creating an immediate pre-flight compliance obligation; replacement must follow within 100 hours’ time in service, creating a short-term maintenance deadline (Compliance).\n- Implementation dependency and information burden: operators must consult Cessna SL SE76-25 to determine which serial numbers are affected and to follow the replacement procedure; the directive delegates technical details to that service letter (Applicability; Requirement ¶3). Access to and correct interpretation of that external document is necessary to comply.\n- Incentives for operators: the placard and flight restriction create an incentive to replace affected ball nut assemblies promptly to restore normal flap operation. The near-term inspection requirement also concentrates immediate inspection costs on affected aircraft owners.\n- Discretion and enforcement: the directive is prescriptive about required actions and deadlines (Requirement; Compliance). The text does not describe any discretionary exemption process or alternative compliance method within the directive itself.\n\nCosts vs benefits and implementation risks (mechanically framed)\n\n- Benefit claimed by the instrument: removing or grounding actuators with specified date-stamp codes and replacing ball nut assemblies aims to reduce the operational risk associated with those components (Requirements ¶1–3).\n- Costs and trade-offs: owners bear the direct costs of inspection and replacement and face a temporary operational limitation (placard prohibiting flap extension) until replacements are completed (Requirement ¶2; Note; Compliance). The directive requires use of Cessna’s service letter for technical actions, which may create logistical delay if parts, skilled labour, or the service letter are not immediately available (Applicability; Requirement ¶3).\n\nConcrete mechanics for operators to follow\n\n1. Check whether your Cessna 182 serial number is listed in Cessna SL SE76-25 (Applicability).\n2. Inspect P/N C301002-0101 wing flap actuator for the date-stamp code per SE76-25 (Requirement ¶1). Do this before the next flight after 28 January 1977 (Compliance).\n3. If the code is OH, HH, WH or ZH, install the placard “FLAP EXTENSION PROHIBITED” at the flap control (Requirement ¶2). The placard can be removed once the ball nut assemblies have been replaced (Note).\n4. Replace affected wing flap actuator ball nut assemblies following Cessna SL SE76-25 within 100 hours time in service after 28 January 1977 (Requirement ¶3; Compliance).\n\nKey source citations: Applicability; Requirement ¶1–3; Note; Compliance."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue airworthiness directive targeting a specific mechanical defect in specific aircraft. It has not expanded beyond its original purpose of addressing the wing flap actuator ball nut assembly safety issue."},"complexity_factors":["Very short document (under 300 words)","Only 3 operative requirements with clear sequential numbering","Single applicability criterion (specific model and serial numbers)","No defined terms section — all terms are standard aviation maintenance terminology","No cross-references to other legislation beyond the enabling regulations (CAR 1998 Part 39)","Simple conditional logic (if date stamp matches specific codes, then install placard)","Clear compliance deadlines with no exceptions or extensions mentioned"],"plain_english_summary":"This is an **Airworthiness Directive** (a mandatory safety order) issued by Australia's Civil Aviation Safety Authority for specific Cessna aeroplanes.\n\n**What it does:**\nOrders owners and operators of certain Cessna 182 model aeroplanes to inspect and potentially replace faulty wing flap actuator ball nut assemblies. These are mechanical parts that control the wing flaps — the movable surfaces on the back of wings that help planes slow down for landing.\n\n**Who it affects:**\nOwners and operators of Cessna 182 aeroplanes with specific serial numbers listed in Cessna Service Letter SE76-25.\n\n**What must be done:**\n1. **Check the part** — Inspect the wing flap actuator for a date stamp code (OH, HH, WH, or ZH)\n2. **If affected, ground the flaps** — Install a warning placard saying \"FLAP EXTENSION PROHIBITED\" near the flap control\n3. **Replace the faulty part** — Swap out the defective ball nut assemblies following Cessna's instructions\n\n**Deadlines:**\n- The inspection and placard must happen **before the next flight** after 28 January 1977\n- The replacement must happen within **100 hours of flying time** after that date\n\n**Why it matters:**\nFaulty ball nut assemblies could cause wing flaps to fail during flight, creating serious safety risks during takeoff and landing. This directive forces immediate action to prevent accidents."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-180-44-wing-flap-actuator-ball-nut-assemblies","history":"/api/acts/ad-cessna-180-44-wing-flap-actuator-ball-nut-assemblies/history","analysis":"/api/acts/ad-cessna-180-44-wing-flap-actuator-ball-nut-assemblies/analysis","conflicts":"/api/acts/ad-cessna-180-44-wing-flap-actuator-ball-nut-assemblies/conflicts","importantCases":"/api/acts/ad-cessna-180-44-wing-flap-actuator-ball-nut-assemblies/important-cases","documents":"/api/acts/ad-cessna-180-44-wing-flap-actuator-ball-nut-assemblies/documents"}}