{"id":"F2006B08372","name":"AD/CESSNA 400/89 - Engine Truss","slug":"ad-cessna-400-89-engine-truss","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115791,"registerId":"commonwealth-F2006B08372-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 400/89 - Engine Truss","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\nAD/CESSNA 400/89 Engine Truss 7/86\n\nApplicability: All models 441 with S/Nos. 441-001 to 441-0362 Requirement:  Action in accordance with Cessna Service Bulletin CQB85-24 Compliance:               As per Requirement Document.\n\nBackground:  In service cracking may occur at the welded joints in the engine truss as described in the Service Bulletin.\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":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue airworthiness directive from 1986 addressing a specific structural defect in a specific aircraft type. It has not expanded beyond its original purpose of mandating inspection/repair of engine truss cracking."},"complexity_factors":["Extremely short document (under 150 words)","Only 4 operative provisions: applicability, requirement, compliance, and background","No defined terms section — relies entirely on external reference to Cessna Service Bulletin CQB85-24","No conditional logic, exceptions, or nested provisions","Single cross-reference only (to the Service Bulletin)","Clear, unambiguous applicability criteria (specific model and serial number range)"],"plain_english_summary":"**What this is:** An Airworthiness Directive (AD) — a mandatory safety order issued by the Civil Aviation Safety Authority (CASA) requiring specific maintenance action on certain aircraft.\n\n**What it does:** Orders owners and operators of Cessna 400 series aeroplanes (specifically Model 441 Conquest II aircraft with serial numbers 441-001 through 441-0362) to inspect and repair the **engine truss** — the metal framework that holds the engine to the wing.\n\n**Why it matters:** The welded joints in this framework can develop cracks during normal use. If left unchecked, these cracks could cause the engine to separate from the aircraft in flight — a catastrophic failure. This AD mandates compliance with Cessna Service Bulletin CQB85-24, which provides the technical instructions for finding and fixing these cracks.\n\n**Who must act:** Anyone who owns, operates, or maintains affected Cessna 441 aircraft.\n\n**When:** Compliance timing follows the schedule set out in the referenced Service Bulletin (not a fixed calendar date, but typically based on flight hours or cycles)."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD, as supplied, does not indicate any change in scope from its stated objective. It targets all Cessna 441 aircraft with serial numbers 441-001 to 441-0362 and mandates compliance with Cessna Service Bulletin CQB85-24 to address in-service cracking at engine-truss welded joints (Applicability; Requirement; Background). The instrument itself contains no wording that expands or narrows that defined applicability beyond what is explicitly listed."},"complexity_factors":["Narrow applicability (specific model and serial-number range) reduces breadth but concentrates effect (Applicability).","Substantive technical requirements are deferred to an external document (Cessna Service Bulletin CQB85-24), creating dependency on that document for details (Requirement).","Compliance language is brief and refers to the Requirement Document without reproducing inspection intervals, acceptance criteria or remedial steps in the AD text, creating interpretive work for operators and regulators (Compliance).","The subject matter (welded joints in an engine truss) is technical and requires specialised maintenance skills and parts, which raises practical complexity despite legal simplicity (Background).","Enforcement and demonstration of compliance depend on regulator practice and the Service Bulletin’s clarity, introducing administrative discretion and implementation risk (Requirement; Compliance)."],"plain_english_summary":"This AD makes compliance with Cessna Service Bulletin CQB85‑24 mandatory for Cessna 441 aircraft S/N 441‑001 to 441‑0362 to address reported in‑service cracking at engine‑truss welded joints. Operators/owners of the affected fleet must carry out the SB’s inspections/repairs and will bear the associated costs and downtime. The AD delegates technical detail, intervals and compliance demonstration to the external Service Bulletin, creating reliance on that document and on the regulator’s enforcement."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-400-89-engine-truss","history":"/api/acts/ad-cessna-400-89-engine-truss/history","analysis":"/api/acts/ad-cessna-400-89-engine-truss/analysis","conflicts":"/api/acts/ad-cessna-400-89-engine-truss/conflicts","importantCases":"/api/acts/ad-cessna-400-89-engine-truss/important-cases","documents":"/api/acts/ad-cessna-400-89-engine-truss/documents"}}