{"id":"F2006B06140","name":"AD/PC-6/36 - Engine Fuel Line - Replacement","slug":"ad-pc-6-36-engine-fuel-line-replacement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":46928,"registerId":"commonwealth-F2006B06140-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PC-6/36 - Engine Fuel Line - Replacement","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)  Pilatus Porter PC-6 Series Aeroplanes\n\n \n\nAD/PC-6/36 Engine Fuel Line - Replacement 4/76\n\nApplicability: Model PC-6 with S/Nos. 1 to 685, fitted with Lycoming GSO-480-B1A6 engines. Requirement:               1. Replace aluminium fuel line P/N 6238.94. Pos. 80 with a stain- less steel fuel line\n\nP/N 6238.94.Pos.80C or with an equivalent fuel line approved by the Secretary.\n\n \n\n2. Replace aluminium fittings AN822-8D and AN823-8D with stainless steel fittings MS 20822-BC and MS 20823-8C or with equivalent fittings approved by the Secretary.\n\n \n\n3. FAA AD 75-27-06, Amdt. 39-2478.\n\n \n\nCompliance: Before 1 June 1976.\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":"The document sets a targeted maintenance requirement limited to Pilatus PC-6 aircraft S/N 1–685 with Lycoming GSO-480-B1A6 engines and mandates replacement of specified fuel line and fittings by a stated date. It does not expand the set of affected aircraft or add additional obligations beyond specified replacements and the Secretary’s approval of equivalents; therefore the scope remains the same as stated in the instrument (Applicability; Requirements 1–2; Compliance; Requirement 3)."},"complexity_factors":["Technical specificity: exact aircraft models, serial numbers and engine model are specified (Applicability).","Part‑level prescription: replacement requires specific part numbers for fuel line and fittings (Requirements 1–2).","Regulatory discretion: Secretary may approve equivalent parts, introducing administrative approval steps (Requirements 1–2).","Cross‑reference to foreign AD: incorporates FAA AD 75-27-06, requiring cross‑consultation (Requirement 3).","Fixed compliance deadline creates scheduling pressure and potential downtime (Compliance)."],"plain_english_summary":"What this instrument does (mechanics):\n\n- It requires owners/operators of certain Pilatus PC-6 aeroplanes (serial numbers 1–685) fitted with Lycoming GSO-480-B1A6 engines to replace a specific aluminium fuel line (part number 6238.94, position 80) with a stainless steel fuel line (part number 6238.94.Pos.80C) or with an equivalent fuel line that the Secretary approves (Requirement 1).\n- It requires replacement of two aluminium fittings (AN822-8D and AN823-8D) with specified stainless steel fittings (MS 20822-8C and MS 20823-8C) or with Secretary‑approved equivalent fittings (Requirement 2).\n- It incorporates by reference FAA Airworthiness Directive 75-27-06 (Requirement 3).\n- It imposes a mandatory compliance deadline: the replacements must be done before 1 June 1976 (Compliance).\n\nWho is affected and who decides:\n\n- Affected parties are the registered owners and operators of the specified Pilatus PC-6 aeroplanes with the listed serial numbers and engine type (Applicability). These parties must arrange and pay for the parts and labour to perform the replacements (Requirements 1–2; Compliance).\n- The Secretary (an authorised regulator in this instrument) has the delegated discretion to approve equivalent replacement parts in place of the exact part numbers listed (Requirements 1–2). This creates an approval gate for substitutes.\n\nWhy it matters (stated basis and practical consequences):\n\n- The directive sets a prescriptive maintenance action to change specified fuel plumbing components from aluminium to stainless steel for the listed aircraft. The document references an FAA airworthiness directive (Requirement 3), which provides the regulatory precedent or parallel action.\n- Practically, operators must schedule the work, source the required stainless steel parts (or obtain Secretary approval for alternatives), and record compliance before the stated date (Compliance). Maintenance organisations and parts suppliers will be the immediate suppliers of labour and materials.\n\nCosts, incentives, trade-offs and implementation points (source‑grounded):\n\n- Who pays: Owners/operators pay for parts, installation and any associated downtime (Requirements 1–2; Compliance).\n- Incentives and behaviour change: Operators are incentivised to replace the listed aluminium components with stainless steel to meet the directive and maintain legal airworthiness. They may seek approved equivalents if exact part numbers are unavailable, which requires administrative interaction with the Secretary (Requirements 1–2).\n- Compliance burden: The directive prescribes specific part numbers, which narrows purchasing choices and may impose search or stocking costs if parts are scarce. The approval process for equivalents imposes an administrative step that may delay substitution (Requirements 1–2).\n- Bureaucratic discretion: The Secretary’s authority to approve equivalents gives the regulator a role in deciding acceptable substitutes; that discretion translates into time and administrative cost for operators seeking approvals (Requirements 1–2).\n- Cross‑jurisdiction reference: The inclusion of FAA AD 75-27-06 (Requirement 3) signals reliance on another regulator’s findings; operators may need to consult the FAA AD for technical justification or additional details.\n\nOpportunity costs and competitive effects (limited to source evidence):\n\n- The instrument narrows component supply choices to specified stainless steel parts or Secretary‑approved equivalents, which may advantage suppliers of those particular parts and maintenance providers familiar with the replacement. Operators who already stock compatible stainless steel fittings will face lower immediate costs than those who must source new suppliers (Requirements 1–2).\n\nRisks and unintended practical effects (mechanism‑focused):\n\n- If stainless steel parts are in short supply, operators may incur aircraft downtime while awaiting parts or approvals. The Secretary approval route mitigates absolute delays only if approvals are granted promptly (Requirements 1–2; Compliance).\n- The prescriptive part‑number approach reduces flexibility for operators to choose alternative remediation methods unless they obtain approval (Requirements 1–2).\n\nSource citations: Applicability and the three numbered Requirements and the Compliance date are taken verbatim from the instrument (Applicability; Requirements 1–3; Compliance)."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific mechanical defect in a limited population of aircraft. It has not expanded beyond its original purpose of mandating fuel system component replacement."},"complexity_factors":["Very short document (approximately 150 words of substantive content)","Only 4 defined elements: specific aircraft model, serial number range, engine type, and part numbers","No cross-references to other legislation beyond a single citation to a US FAA directive","Simple conditional structure: if you operate this specific aircraft, you must do these three things by this date","No nested exceptions or complex definitional sections","Straightforward part-number-based compliance requirements"],"plain_english_summary":"This is an **Airworthiness Directive** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). It requires owners and operators of specific Pilatus Porter aircraft to replace certain fuel system components before a deadline.\n\n**What it does:**\n- **Targets:** Pilatus PC-6 aircraft (serial numbers 1 to 685) powered by Lycoming GSO-480-B1A6 engines\n- **Requires three specific actions:**\n  1. Swap out an aluminium fuel line for a stainless steel version (or an approved equivalent)\n  2. Replace two types of aluminium fittings with stainless steel alternatives (or approved equivalents)\n  3. Follow the related US Federal Aviation Administration directive (FAA AD 75-27-06)\n\n**Why it matters:**\nAluminium fuel lines and fittings can corrode or fail under certain conditions. This directive prevents potential fuel leaks and engine failures that could lead to accidents. The switch to stainless steel improves durability and safety.\n\n**Who must comply:**\nAnyone operating the affected aircraft in Australia must complete these replacements **before 1 June 1976** (the compliance deadline)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pc-6-36-engine-fuel-line-replacement","history":"/api/acts/ad-pc-6-36-engine-fuel-line-replacement/history","analysis":"/api/acts/ad-pc-6-36-engine-fuel-line-replacement/analysis","conflicts":"/api/acts/ad-pc-6-36-engine-fuel-line-replacement/conflicts","importantCases":"/api/acts/ad-pc-6-36-engine-fuel-line-replacement/important-cases","documents":"/api/acts/ad-pc-6-36-engine-fuel-line-replacement/documents"}}