{"id":"F2006B05024","name":"AD/CESSNA 177/3 - Stabilator Slot","slug":"ad-cessna-177-3-stabilator-slot","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44934,"registerId":"commonwealth-F2006B05024-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 177/3 - Stabilator Slot","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 177 Series Aeroplanes\n\n \n\nAD/CESSNA 177/3 Stabilator Slot 6/68\n\nApplicability: Model 177 with S/Nos. 17700001 to 17701160.\n\n \n\nRequirement: Action in accordance with Cessna SL SE68-14 Operation 23 dated 22 April 1968. Compliance:              Before 27 June 1968.\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\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The instrument applies to Model 177 aircraft with serial numbers 17700001–17701160, requires action as set out in Cessna SL SE68-14 Operation 23 (dated 22 April 1968), and sets a compliance deadline of before 27 June 1968. The supplied text contains no amendment or extension of that applicability or requirement; therefore the scope in the document as supplied remains the same as stated within the AD (no change indicated). (See \"Applicability\", \"Requirement\", \"Compliance\".)"},"complexity_factors":["Narrow applicability limited to a specific model and serial-number range (reduces complexity). (Applicability).","Mandates compliance with an external technical document (Cessna SL SE68-14 Operation 23) but does not include the technical steps in the AD itself, which requires owners to obtain another document (increases practical complexity). (Requirement).","Fixed, short compliance deadline creates scheduling and logistics pressure for operators (increases implementation complexity). (Compliance).","No explanatory material or enforcement details included in the AD text — straightforward obligation but little procedural guidance (moderate effect on perceived complexity)."],"plain_english_summary":"What this instrument does (mechanically)\n\n- It requires owners/operators of certain Cessna 177 aeroplanes to carry out a specific maintenance/inspection action described in an external Cessna service document. (See \"Applicability\" and \"Requirement\".)\n- The action to be carried out is the procedure set out in \"Cessna SL SE68-14 Operation 23\" dated 22 April 1968; the AD itself does not reproduce the technical steps. (See \"Requirement\".)\n- The work must be completed by a fixed deadline: before 27 June 1968. (See \"Compliance\".)\n\nWho is affected and who pays\n\n- A narrow group of aircraft owners/operators are affected: Cessna Model 177 with serial numbers 17700001 through 17701160. (See \"Applicability\".)\n- The owners/operators of those specific aircraft bear the costs of obtaining and carrying out the work mandated by the service letter (labour, parts, downtime). (See \"Requirement\" and \"Compliance\").\n- The Civil Aviation Safety Authority (the issuer of the AD) is the decision-maker that set the mandatory requirement and the deadline. (Document header and structure.)\n\nWhat the AD’s stated rationale is, and how that plays against costs and incentives\n\n- The text of the AD as provided does not contain an explicit statement of the technical or safety reason for the required action. The instrument simply references the Cessna service letter and sets a compliance date. (No explanatory text appears in the supplied AD.)\n- If the requirement is read as a typical airworthiness directive claim (that the action is necessary to address an aircraft defect or unsafe condition), the practical effects are: owners must choose to fund and schedule the work by the deadline (direct cost and aircraft downtime), and compliance preserves the aircraft’s legal airworthiness status. These effects follow from the AD’s compulsory wording and the fixed deadline. (See \"Requirement\" and \"Compliance\".)\n\nCompliance mechanics and implementation risks\n\n- The AD makes compliance conditional on following an external document (Cessna SL SE68-14 Operation 23). That means the work to be done is defined outside the AD text; owners must obtain and correctly apply that service letter. (See \"Requirement\".)\n- If the service letter is unavailable, ambiguous, or requires parts not on hand, owners may face delays, additional costs, or need for approval from a maintenance authority to alter procedures. Those are practical implementation risks inherent in mandating an externally referenced procedure. (Implied by the AD referencing an external service letter in \"Requirement\".)\n\nDistribution of costs and benefits, and decision incentives\n\n- Costs are concentrated on the small, identifiable set of owners/operators of the listed serial-number aircraft. (See \"Applicability\".)\n- Any putative benefits (for example, reduced risk related to the stabilator slot) would accrue to users of those aircraft and the broader flying public, but the AD text supplied does not set out those benefits explicitly. The AD imposes a compliance cost and a deadline; it does not create a funding mechanism or compensation for owners. (See entire AD.)\n\nPractical takeaways for an affected operator\n\n- Check whether your aircraft serial number is within 17700001–17701160. (See \"Applicability\".)\n- Obtain Cessna SL SE68-14 Operation 23 (dated 22 April 1968) and arrange for the specified action to be carried out by qualified personnel. (See \"Requirement\".)\n- Ensure the work is completed before 27 June 1968 to meet the AD’s compliance date. (See \"Compliance\".)"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, time-bound safety directive issued in 1968. It has not grown beyond its original purpose — it addressed a specific technical defect in specific aircraft and required a one-time compliance action. The scope remains precisely as intended: limited to early Cessna 177 aircraft and the stabilator slot issue."},"complexity_factors":["Extremely short document (approximately 100 words of substantive content)","Only one defined applicability criterion (serial number range)","Single requirement referencing an external technical document (Cessna Service Letter)","No nested conditions, exceptions, or cross-references to other legislation","Straightforward compliance deadline with no alternative methods or conditional extensions","No interpretation section or defined terms"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). It applies to specific Cessna 177 aircraft (serial numbers 17700001 through 17701160).\n\n**What it requires:**\n- Owners and operators of these aircraft must carry out a specific maintenance action detailed in a Cessna Service Letter (SL SE68-14, Operation 23, dated 22 April 1968).\n- The work relates to the \"stabilator slot\" — a component of the aircraft's tail control surface (the stabilator is a combined horizontal stabilizer and elevator that moves as one piece; the \"slot\" refers to a gap or opening in this assembly).\n\n**Who it affects:**\n- Owners and operators of early-model Cessna 177 aircraft built between 1967-1968 (based on the serial number range).\n\n**Why it matters:**\n- Airworthiness Directives are legally binding safety instructions. Non-compliance means the aircraft cannot legally fly. This particular directive addressed a specific safety concern with the stabilator slot that required urgent correction before 27 June 1968.\n\n**Key deadline:**\n- The work had to be completed before 27 June 1968 (the compliance date)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-177-3-stabilator-slot","history":"/api/acts/ad-cessna-177-3-stabilator-slot/history","analysis":"/api/acts/ad-cessna-177-3-stabilator-slot/analysis","conflicts":"/api/acts/ad-cessna-177-3-stabilator-slot/conflicts","importantCases":"/api/acts/ad-cessna-177-3-stabilator-slot/important-cases","documents":"/api/acts/ad-cessna-177-3-stabilator-slot/documents"}}