{"id":"F2006B08351","name":"AD/CESSNA 400/66 - Aileron and Elevator Control Surfaces - Modification","slug":"ad-cessna-400-66-aileron-and-elevator-control-surfaces-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115758,"registerId":"commonwealth-F2006B08351-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 400/66 - Aileron and Elevator Control Surfaces - 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 400 Series Aeroplanes\n\n \n\n# AD/CESSNA 400/66 Aileron and Elevator Control\n\nSurfaces - Modification\n\nApplicability: All model 441 with S/Nos. 441-0001 to 441-0090. Document:  Cessna Customer Care Owner Advisory No. PJ 79-3A.\n\n(FAA AD 79- 09-02 Amdt. 39-3453 refers).\n\n \n\nCompliance: Within 100 hours time in service after 30 June 1979.\n\n# 6/79\n\n \n\nBackground:  An inflight aileron vibration/flutter incident was caused by an accumulation of water in one of the aileron control surfaces.\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":3,"scope_assessment":{"changed":false,"description":"There is no indication in the text that the scope has been changed from its original intent. The directive targets a specific fleet segment (S/Nos 441-0001 to 441-0090) and prescribes a modification to address a vibration/flutter event caused by water accumulation in an aileron control surface (Applicability; Background). The required action and timeframe are explicit (Compliance), and the AD points to the Cessna advisory for technical instructions (Document)."},"complexity_factors":["Narrow numeric applicability — only Model 441 with S/Nos 441-0001 to 441-0090 (Applicability).","Mandatory compliance window tied to hours-in-service and a calendar reference (100 hours after 30 June 1979) (Compliance).","Technical modification details are not contained in the AD but are delegated to an external Cessna advisory (Document), requiring users to obtain and follow another source.","Reference to an FAA AD (FAA AD 79-09-02 Amdt. 39-3453) increases cross‑document checks required (Document).","Safety-critical nature: the subject (aileron vibration/flutter) requires correct technical execution and verification (Background), raising implementation and inspection burden."],"plain_english_summary":"# What this directive does\n\nThis airworthiness directive requires a specific physical modification to the aileron and elevator control surfaces on a set of Cessna 441 (Model 441) aeroplanes. It applies only to aircraft with serial numbers 441-0001 through 441-0090 and points operators to a Cessna advisory for the modification work (Applicability; Document). The modification must be carried out within 100 hours time in service after 30 June 1979 (Compliance).\n\n# Why it was issued\n\nThe directive was issued because one inflight incident of aileron vibration/flutter was traced to water accumulating inside an aileron control surface (Background). The directive implements a mandated mechanical change to address that failure mode.\n\n# Who must act and who pays\n\n- Owners/operators of the affected serial-numbered aircraft must arrange and pay for the required modification (Applicability; Compliance).  \n- The Civil Aviation Safety Authority (CASA) issues and enforces the directive as part of the Schedule of Airworthiness Directives under Part 39 (header information).\n\n# What the action requires, mechanically\n\n- Locate whether the aircraft is within the affected serial-number range (Applicability).  \n- Perform the specified modification to the aileron and elevator control surfaces following the instructions in Cessna Customer Care Owner Advisory No. PJ 79-3A (Document).  \n- Complete the work within the stated compliance window of 100 hours time in service after 30 June 1979 (Compliance).\n\n# Implementation, costs and incentives\n\n- Compliance is mandatory for affected operators; failure to comply risks continued exposure to the same vibration/flutter hazard and regulatory non‑compliance (Compliance; Background).  \n- The immediate costs are borne by owners/operators and include parts, labour, aircraft downtime and any record-keeping or inspection work needed to show compliance (Compliance; Document).  \n- Maintenance and repair organisations that can perform the modification may receive additional business from affected operators; operators may face local differences in availability and price for the work (Document).\n\n# Where to get the technical instructions and enforcement note\n\n- The AD refers operators to Cessna Customer Care Owner Advisory No. PJ 79-3A for the detailed modification procedure (Document).  \n- The AD also cross-references FAA AD 79-09-02 Amdt. 39-3453 (Document); those external documents contain the specific technical steps, parts and inspection criteria that implement the AD.\n\n# Implementation risks and practical trade-offs to consider\n\n- The directive is safety-driven and narrow in scope (specific serial numbers). To implement it operators must identify affected aircraft and schedule modification work within the compliance window, which can cause short-term operational disruption (Applicability; Compliance).  \n- Because the AD points to external technical documents for the exact modification method, operators and maintenance organisations must obtain and follow those documents; failure to follow the referenced advisory properly would leave the aircraft non‑compliant (Document).  \n- The directive concentrates costs on the relatively small set of affected owners while producing operational safety benefits for those aircraft (Applicability; Background)."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, time-bound safety directive addressing a specific mechanical defect in a limited aircraft population. It has not expanded beyond its original purpose of mandating a modification to prevent aileron flutter caused by water accumulation."},"complexity_factors":["Very short document (approximately 150 words of substantive content)","Only 2 defined applicability criteria (model 441 + specific serial number range)","Single compliance requirement with clear deadline","No nested exceptions or conditional logic","No cross-references to other legislation or regulations beyond a single referenced technical document","Straightforward cause-and-effect: identified safety problem → mandatory fix"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for aircraft.\n\n**What it does:**\nRequires owners and operators of specific Cessna 400 series aircraft (specifically model 441 with serial numbers 441-0001 through 441-0090) to modify their **aileron and elevator control surfaces**. These are the moving parts on the wings and tail that control the aircraft's roll and pitch.\n\n**Why it matters:**\nAn aircraft experienced dangerous **flutter** (rapid, uncontrolled vibration) in flight because water had accumulated inside an aileron. This vibration can cause structural failure and potentially crash the aircraft. The modification prevents water from getting trapped in these control surfaces.\n\n**Who must comply:**\nAnyone operating the affected Cessna 441 aircraft (serial numbers 0001 to 0090).\n\n**When:**\nThe work had to be completed within 100 hours of flight time after 30 June 1979.\n\n**How to comply:**\nFollow the instructions in **Cessna Customer Care Owner Advisory No. PJ 79-3A** (the technical document referenced). This directive also references a corresponding US Federal Aviation Administration (FAA) directive (AD 79-09-02)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-400-66-aileron-and-elevator-control-surfaces-modification","history":"/api/acts/ad-cessna-400-66-aileron-and-elevator-control-surfaces-modification/history","analysis":"/api/acts/ad-cessna-400-66-aileron-and-elevator-control-surfaces-modification/analysis","conflicts":"/api/acts/ad-cessna-400-66-aileron-and-elevator-control-surfaces-modification/conflicts","importantCases":"/api/acts/ad-cessna-400-66-aileron-and-elevator-control-surfaces-modification/important-cases","documents":"/api/acts/ad-cessna-400-66-aileron-and-elevator-control-surfaces-modification/documents"}}