{"id":"F2006B08336","name":"AD/CESSNA 400/5 - Fuel Crossover Line - Inspection and Modification","slug":"ad-cessna-400-5-fuel-crossover-line-inspection-and-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115743,"registerId":"commonwealth-F2006B08336-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 400/5 - Fuel Crossover Line - Inspection and 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\nAD/CESSNA 400/5 Fuel Crossover Line - Inspection\n\nand Modification\n\n\n6/68\n\n \n\nApplicability: All models 401 and 402 with S/Nos. below 401-0226 and 402-0226 except 401-0189,\n\n401-0197, 401-0212 and 401-0214 to 401-0225 and 402-0171, 401-0172, 402-0191,\n\n402-0209, 402-0210 and 402-0214 to 402-0225.\n\n \n\nDocument: Cessna SL No. ME68-6.\n\n \n\nCompliance: Within 100 hours time in service after 11 July 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","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive focused on a specific mechanical defect in specific aircraft. It has not expanded beyond its original purpose of addressing the fuel crossover line issue in early-model Cessna 401/402 aircraft."},"complexity_factors":["Very short document (approximately 150 words of substantive content)","Only 4 defined elements: applicability (aircraft models/serial numbers), reference document (Cessna SL No. ME68-6), compliance deadline, and the specific modification required","Single condition: serial number-based applicability with explicit exceptions list","No cross-references to other legislation or regulations beyond the enabling authority (Civil Aviation Regulations 1998, Part 39)","No nested exceptions or conditional logic — the serial number exceptions are a simple flat list","Clear, unambiguous compliance deadline (100 hours time in service after fixed date)"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for specific aircraft.\n\n**What it does:**\n- Requires owners and operators of certain **Cessna 401 and 402 aircraft** to inspect and modify the **fuel crossover line** — a pipe that allows fuel to flow between the plane's fuel tanks.\n\n**Who it affects:**\n- Owners and operators of Cessna 401 and 402 models with **serial numbers below 401-0226 and 402-0226**, with several specific exceptions listed (certain individual serial numbers are excluded from the requirement).\n\n**Why it matters:**\n- Fuel crossover lines can develop faults that could lead to fuel leaks or engine fuel starvation — both serious safety risks in flight. This directive ensures potentially defective components are identified and fixed before they cause accidents.\n\n**What must be done:**\n- The inspection and modification must be completed **within 100 hours of flight time** after 11 July 1968.\n- The technical details of how to do this are contained in **Cessna Service Letter No. ME68-6** (the manufacturer’s official instructions).\n\n**Key point:** This is a **time-critical safety mandate**. Non-compliance means the aircraft cannot legally fly."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The document itself defines a specific applicability (serial-number range with listed exceptions), cites a single manufacturer's service letter for technical action, and sets a clear compliance window. The text supplied contains no indication that it amends or narrows a prior directive or that its scope was changed from an earlier version."},"complexity_factors":["Serial-number-based applicability with multiple explicit exceptions increases administrative complexity for owners/operators determining whether their aircraft are affected (Applicability).","The AD delegates technical steps to an external document (Cessna SL No. ME68-6), requiring operators to obtain and follow that service letter (Document).","Compliance is measured as a finite flight-time window (100 hours time in service) counted from a historical date, which requires accurate time-in-service records (Compliance).","The AD is concise and leaves procedural details (parts, inspection criteria, certification of modification) to the referenced service letter, producing some operational ambiguity until that document is consulted (Document).","Issued under regulatory authority (Civil Aviation Regulations 1998 Part 39), so legal mandatory status is clear, but the AD text itself is short and does not spell out enforcement or reporting mechanics."],"plain_english_summary":"This AD mandates inspection and, if required, modification of the fuel crossover line on certain Cessna 401 and 402 aeroplanes (serials below 401‑0226 and 402‑0226, with some serials excluded), to be performed per Cessna SL No. ME68‑6. Work must be completed within 100 hours TIS after 11 July 1968. Owners/operators must arrange and pay for the work; maintenance must follow the referenced service letter."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-400-5-fuel-crossover-line-inspection-and-modification","history":"/api/acts/ad-cessna-400-5-fuel-crossover-line-inspection-and-modification/history","analysis":"/api/acts/ad-cessna-400-5-fuel-crossover-line-inspection-and-modification/analysis","conflicts":"/api/acts/ad-cessna-400-5-fuel-crossover-line-inspection-and-modification/conflicts","importantCases":"/api/acts/ad-cessna-400-5-fuel-crossover-line-inspection-and-modification/important-cases","documents":"/api/acts/ad-cessna-400-5-fuel-crossover-line-inspection-and-modification/documents"}}