{"id":"F2006B08330","name":"AD/CESSNA 400/44 - Tip Tank Fuel Seepage - Inspection","slug":"ad-cessna-400-44-tip-tank-fuel-seepage-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115737,"registerId":"commonwealth-F2006B08330-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 400/44 - Tip Tank Fuel Seepage - Inspection","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 400/44 Tip Tank Fuel Seepage - Inspection 3/75\n\nApplicability: All models fitted with Strobe Lights in the wing tip fuel tank nose cap. Document:  1. Cessna SL ME73-4; or\n\n2. FAA AD 75-05-08.\n\n \n\nCompliance: Within 100 hours time in service after 30 April 1975 and thereafter at intervals not exceeding 100 hours time in service.\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 directive as provided sets a narrow, time-based inspection requirement for a specific configuration of Cessna 400 series aeroplanes. The text contains no indication that the scope has been expanded or altered from an original intent; it defines applicability (models fitted with strobe lights in the wing tip fuel tank nose cap), references the technical procedures to follow, and prescribes the inspection interval. (Applicability; Documents; Compliance)"},"complexity_factors":["Narrow applicability (only Cessna 400 series with strobe lights in the wing tip fuel tank nose cap) (Applicability)","Single, simple compliance prescription (initial inspection within 100 hours after 30 April 1975 and repeating at intervals not exceeding 100 hours) (Compliance)","Dependence on external technical documents for procedural detail (Cessna SL ME73-4 or FAA AD 75-05-08) (Documents)","No detailed procedural, reporting, or remediation rules in the directive text (Compliance)","No stated allocation of costs or enforcement mechanics within the text"],"plain_english_summary":"What this directive does, mechanically\n\n- Requires periodic inspections of the wing tip fuel tank nose cap area of Cessna 400 series aeroplanes that have strobe lights fitted in the wing tip fuel tank nose cap. The inspections must follow the procedures in the referenced documents (Cessna SL ME73-4 or FAA AD 75-05-08). (Documents; Applicability)\n- Sets the inspection timing: each affected aeroplane must be inspected within 100 hours time in service after 30 April 1975 and then at intervals not exceeding 100 hours time in service. (Compliance)\n\nStated purpose\n\n- The title of the directive indicates the safety concern addressed: detection of tip tank fuel seepage. The instrument implements inspections to find and deal with that condition (title and required inspection procedures in the referenced documents). (Documents; Applicability)\n\nWho is affected and who issues it\n\n- Affected: owners/operators and maintainers of Cessna 400 series aeroplanes that are fitted with strobe lights in the wing tip fuel tank nose cap. (Applicability)\n- Issued by: the instrument is published under the Commonwealth Civil Aviation Safety Authority framework (header). The directive references Cessna and FAA documents as the procedural sources. (header; Documents)\n\nWho pays, who decides, and what changes in behaviour\n\n- The directive mandates inspections but does not allocate payment responsibility or describe funding arrangements in the text. (Compliance)\n- Decision-making: the Civil Aviation Safety Authority (as the issuing authority shown in the header) requires compliance; the directive also directs adherence to the referenced Cessna/FAA procedures. (header; Documents)\n- Behaviour change required: affected aircraft must undergo the prescribed inspection within the initial 100-hour window after 30 April 1975 and then be inspected at least every 100 hours time in service thereafter. This creates a recurring maintenance action for operators and maintainers. (Compliance)\n\nCosts, incentives, and trade-offs (source-grounded testing of the directive)\n\n- Compliance burden: the recurring 100-hour inspection interval creates a recurring maintenance task. The text prescribes the timing but does not detail the labour, parts, or downtime costs. Operators and maintenance providers will need to schedule inspections to meet the periodicity. (Compliance)\n- Procedural dependence: the directive points to external technical documents (Cessna SL ME73-4 or FAA AD 75-05-08) for the inspection method. This concentrates procedural authority in the referenced documents rather than in the directive text itself. Operators must obtain and follow those documents to know the exact tasks required. (Documents)\n- Implementation risk and discretion: the directive sets a fixed inspection schedule but does not, in its text, describe permissible alternative actions, levels of acceptable findings, or reporting requirements. Where interpretation is needed (for example, scope of inspection details or remedial steps), implementers must look to the referenced documents or to regulator guidance. That reliance creates a dependency on those documents for operational detail. (Documents; Compliance)\n- Effects on private enterprise and markets: the directive applies narrowly to a specific aircraft family fitted in a specific way (strobe lights in the wing tip fuel tank nose cap). The imposed inspections increase maintenance activity for affected aircraft and thereby impose ongoing operating costs and scheduling constraints on their owners/operators. The text does not address price effects, competition, or certification beyond requiring inspection compliance. (Applicability; Compliance)\n\nConcentrated benefits, diffuse costs, and substitution effects (source-grounded)\n\n- Benefits of the inspection (detection of tip tank fuel seepage) are concentrated on the safety of the specific aeroplanes covered; the text does not quantify benefits. (title; Applicability)\n- Costs are borne by the set of affected operators/maintainers through the need for recurring inspections; the directive text does not allocate costs or exemptions. (Compliance)\n- Substitution effects: the directive does not specify alternative compliance methods or allow substitution in the text itself; any substitution would depend on guidance or allowance in the referenced documents. (Documents)\n\nSummary statement\n\n- Mechanically, the directive requires owners/operators of Cessna 400 series aeroplanes fitted with strobe lights in the wing tip fuel tank nose cap to have those areas inspected according to Cessna or FAA procedures, starting within 100 hours after 30 April 1975 and every 100 hours thereafter. (Applicability; Documents; Compliance)\n- The text mandates the inspection periodicity but is silent on cost allocation, remedial actions, reporting, or alternative compliance; those operational details must be obtained from the referenced documents or regulator guidance. (Documents; Compliance)"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue safety directive from 1975 addressing a specific mechanical defect. It has not expanded beyond its original purpose of ensuring fuel tank integrity near electrical installations."},"complexity_factors":["Extremely short document (under 200 words)","Only 4 operative provisions: applicability, document reference, compliance deadline, and repeat interval","No defined terms section — uses plain language ('time in service', 'tip tank')","No cross-references to other legislation or regulations beyond naming the enabling regulation (CAR 1998 Part 39)","Single condition: applicability limited to aircraft with strobe lights in wing tip tank nose caps","Simple temporal trigger (date + flight hours) with fixed repeat interval"],"plain_english_summary":"**What this is:** This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). Think of it as a \"recall notice\" for aircraft, but legally binding.\n\n**What it requires:** Owners and operators of **Cessna 400 series aeroplanes** (like the Cessna 401, 402, 411, 414, 421) must inspect the **wing tip fuel tanks** for fuel leaks (\"seepage\"). This only applies to planes that have **strobe lights installed in the nose cap** of those tip tanks.\n\n**When to do it:**\n- **First inspection:** Within 100 hours of flying time after 30 April 1975\n- **Repeat inspections:** Every 100 hours of flying time thereafter\n\n**Why it matters:** Fuel leaking near electrical equipment (strobe lights) creates a **fire and explosion risk**. This AD was issued after Cessna and the US FAA identified this hazard.\n\n**Who must follow this:** Anyone operating these aircraft in Australia — private owners, charter companies, flying schools. Non-compliance means the aircraft is not legally airworthy."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-400-44-tip-tank-fuel-seepage-inspection","history":"/api/acts/ad-cessna-400-44-tip-tank-fuel-seepage-inspection/history","analysis":"/api/acts/ad-cessna-400-44-tip-tank-fuel-seepage-inspection/analysis","conflicts":"/api/acts/ad-cessna-400-44-tip-tank-fuel-seepage-inspection/conflicts","importantCases":"/api/acts/ad-cessna-400-44-tip-tank-fuel-seepage-inspection/important-cases","documents":"/api/acts/ad-cessna-400-44-tip-tank-fuel-seepage-inspection/documents"}}