{"id":"F2006B02386","name":"AD/AMD 50/2 - Booster Pump Crossfeed Valve Actuators","slug":"ad-amd-50-2-booster-pump-crossfeed-valve-actuators","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41616,"registerId":"commonwealth-F2006B02386-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/AMD 50/2 - Booster Pump Crossfeed Valve Actuators","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)  AMD Falcon 50 and 900 Series Aeroplanes\n\n \n\nAD/AMD 50/2 Booster Pump Crossfeed Valve Actuators 6/86 Applicability:              1. All model AMD Falcon 50 aeroplanes S/Nos 2 to 146, 148 to 158, 160 to 162. Requirement:               Action in accordance with Service Bulletin AMD/BA F50-182.\n\nBureau Veritas AD 86-55-4 (B) refers. Compliance: Before further flight after 30 June 1986.\n\nBackground: Water entrapment in the Aviac actuators P/No.2773 has resulted in a dormant failure of the booster crossfeed valve. The engine which had its feed system fail could not be supplied from the feed system of one of the other engines.\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":3,"scope_assessment":{"changed":false,"description":"The instrument limits its scope to the listed Falcon 50 serial numbers and requires implementation of Service Bulletin AMD/BA F50-182 before further flight after 30 June 1986. The directive’s stated objective (addressing water entrapment in Aviac actuators P/No.2773 causing booster crossfeed valve failure) matches the mechanical requirement; the scope is narrowly targeted and does not expand beyond the specified aeroplanes or the prescribed corrective action. (Applicability, Requirement, Compliance, Background)"},"complexity_factors":["Narrow and specific applicability limited to particular serial-number ranges (Applicability).","Prescriptive requirement to follow an external technical document (Service Bulletin AMD/BA F50-182) rather than listing technical steps in the AD itself (Requirement).","Hard compliance deadline that grounds affected aircraft until work is completed (Compliance).","Reference to another authority's AD (Bureau Veritas AD 86-55-4 (B)), creating a cross-jurisdictional/document dependency (Requirement).","Technical subject-matter (actuator water entrapment and valve failure) that requires specialised maintenance capability not described in the AD (Background, Requirement)."],"plain_english_summary":"### What this instrument requires\n\n- This is an airworthiness directive (AD/AMD 50/2) issued under the Civil Aviation Regulations Part 39 by the Civil Aviation Safety Authority (header). (Applicability)\n- It applies to specified AMD Falcon 50 aeroplanes (serial numbers 2–146, 148–158, 160–162). (Applicability)\n- Owners/operators of those aeroplanes must carry out the actions set out in Service Bulletin AMD/BA F50-182. (Requirement)\n- Compliance is mandatory before any further flight after 30 June 1986. (Compliance)\n- The directive refers to Bureau Veritas AD 86-55-4 (B). (Requirement)\n\n### Why the directive was issued (stated reason)\n\n- The document states that water has become entrapped in Aviac actuators, part number 2773, causing a dormant failure of the booster crossfeed valve. On at least one occasion, that failure prevented one engine from being fed from another engine's feed system. (Background)\n\n### How it works mechanically\n\n- The AD does not itself list technical steps; instead it mandates adherence to Service Bulletin AMD/BA F50-182. The Service Bulletin is the technical prescription that operators must follow to remedy the actuator problem. (Requirement)\n- Because the AD requires compliance before further flight after a specific date, affected aircraft effectively may not be flown after that date until the Service Bulletin work has been completed. (Compliance)\n\n### Who pays and who decides\n\n- The legal obligation to act falls on the owners/operators of the listed aeroplanes: they must arrange and fund the work required by the Service Bulletin. (Applicability, Requirement, Compliance)\n- The Civil Aviation Safety Authority is the issuing authority under Part 39. The AD also cross-references a Bureau Veritas AD, indicating another regulator/authority’s advisory content is being relied on. (header, Requirement)\n\n### Incentives, trade-offs and compliance burden (source-grounded)\n\n- Incentives: Operators are incentivised to perform the Service Bulletin work because the AD prohibits further flight of affected aircraft after the compliance date. (Requirement, Compliance)\n- Direct costs: The source requires maintenance/action per the Service Bulletin; the document does not allocate funding, so those costs fall to operators. (Requirement)\n- Operational trade-off: Completing the mandated work imposes maintenance downtime before the aircraft may fly again. The AD does not state how long the work takes; the Service Bulletin will specify that. (Requirement, Compliance)\n- Implementation dependency: The AD is prescriptive in referring to an external technical document (the Service Bulletin) and to another authority’s AD; obtaining and following those documents is necessary to meet the directive. (Requirement)\n\n### Discretion and enforcement\n\n- The AD is prescriptive rather than discretionary: it requires a defined action (follow the Service Bulletin) and sets a hard compliance deadline. (Requirement, Compliance)\n- The notice does not describe enforcement mechanisms, exemptions, or alternative means of compliance within the text supplied. (Requirement)\n\n### Effects on private choice and third parties (limited to what the text shows)\n\n- The AD constrains the operational choice of affected aircraft operators by requiring specified maintenance before flight after the deadline. (Applicability, Requirement, Compliance)\n- Independent maintenance organisations can perform the work if they implement the Service Bulletin, but the AD itself does not address approval processes or limits on who may carry out the work. (Requirement)\n\nSummary of source-cited sections: the applicability clause defines which aeroplanes are covered; the requirement clause mandates action per Service Bulletin AMD/BA F50-182 and references Bureau Veritas AD 86-55-4 (B); the compliance clause sets the deadline of before further flight after 30 June 1986; the background clause states the safety problem (water entrapment in Aviac actuators P/No.2773 leading to dormant crossfeed valve failure)."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted airworthiness directive addressing a specific mechanical defect in specific aircraft. It has not expanded beyond its original purpose of mandating a safety fix for water ingress in booster pump crossfeed valve actuators."},"complexity_factors":["Very short document (approximately 150 words of substantive content)","Only 1 defined applicability criterion (specific serial number ranges)","Single, unambiguous compliance requirement (follow Service Bulletin AMD/BA F50-182)","No nested exceptions or conditional logic","No cross-references to other legislation beyond a single reference to Bureau Veritas AD 86-55-4 (B) for information purposes","Clear, fixed deadline (before further flight after 30 June 1986)"],"plain_english_summary":"This is an **Airworthiness Directive** (a mandatory safety order) issued by Australia's Civil Aviation Safety Authority for specific AMD Falcon 50 and 900 series aircraft.\n\n**What it does:**\n- Requires owners/operators of certain Falcon 50 aeroplanes (serial numbers 2-146, 148-158, and 160-162) to take specific maintenance action\n- The action involves following **Service Bulletin AMD/BA F50-182** (a manufacturer-issued repair instruction)\n\n**Why it matters:**\n- **The safety problem:** Water was getting trapped inside \"Aviac actuators\" (hydraulic/mechanical devices that control valves) with part number 2773\n- **The risk:** This water caused a \"dormant failure\" — meaning the booster crossfeed valve could fail without anyone knowing until it was needed\n- **The danger:** If one engine's fuel feed system failed, the pilots couldn't switch to draw fuel from another engine's system. This could lead to engine failure in flight\n\n**Who must comply:**\n- Operators of the specified Falcon 50 aircraft\n- **Deadline:** Before flying the aircraft after 30 June 1986\n\n**Key point:** This is a **mandatory** safety fix — the aircraft cannot legally fly until this maintenance is completed."}},"importantCases":[],"_links":{"self":"/api/acts/ad-amd-50-2-booster-pump-crossfeed-valve-actuators","history":"/api/acts/ad-amd-50-2-booster-pump-crossfeed-valve-actuators/history","analysis":"/api/acts/ad-amd-50-2-booster-pump-crossfeed-valve-actuators/analysis","conflicts":"/api/acts/ad-amd-50-2-booster-pump-crossfeed-valve-actuators/conflicts","importantCases":"/api/acts/ad-amd-50-2-booster-pump-crossfeed-valve-actuators/important-cases","documents":"/api/acts/ad-amd-50-2-booster-pump-crossfeed-valve-actuators/documents"}}