{"id":"F2006B02387","name":"AD/AMD 50/20 Amdt 1 - Fuel Feeder Tanks Double Skin","slug":"ad-amd-50-20-amdt-1-fuel-feeder-tanks-double-skin","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41617,"registerId":"commonwealth-F2006B02387-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/AMD 50/20 Amdt 1 - Fuel Feeder Tanks Double Skin","content":"![](image.001.png)![](image.001.png)AIRWORTHINESS DIRECTIVE\n\n![](image.001.png)For the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/AMD 50/20 and issues the following AD under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.\n\nAMD Falcon 50 and 900 Series Aeroplanes\n\nAD/AMD 50/20\n\nAmdt 1\n\n  \nFuel Feeder Tanks Double Skin 6/2002\n\nApplicability: Dassault Aviation Mystere Falcon 50 Aircraft, serial numbers 222 through 286, 288,\n\n290, and 291.\n\nRequirement: 1. Inspect in accordance with the procedure specified in Maintenance Manual procedure 686.3/1.\n\n2. Action in accordance with Dassault Aviation Service Bulletin F50-328 Revision 1.\n\nNote: DGAC AD 2001-604-038(B) R1 refers.\n\nCompliance: 1. Before 30 March 2001, and thereafter at intervals not to exceed thirteen months; until accomplishment of Requirement 2.\n\n2. a. For aircraft serial number 253 through 286, 288, 290, and 291, within 6 years and 6 months since new.\n\nb. For other applicable aircraft, at the next “C” check after 13 June 2002 or within 6 years and 6 months since new, whichever occurs later.\n\nThe compliance times remain unchanged for Requirement 1\\. This Amendment becomes effective on 13 June 2002.\n\nBackground: Inspections have revealed that the sealing of the double skins of the feeder tanks may be deficient and result in fuel fumes in the cabin.\n\nAmendment 1 is issued in response to a new DGAC AD which expands applicability and changes Requirement 2 compliance to account for additional applicable aircraft.\n\nAMD Falcon 50 and 900 Series Aeroplanes\n\nAD/AMD 50/20 Amdt 1 (Continued)\n\nThe original issue of this Airworthiness Directive became effective on 7 September 2000.\n\n![](image.002.png)  \n\nDavid Alan Villiers\n\nDelegate of the Civil Aviation Safety Authority 11 April 2002\n\n![](image.001.png)The above AD is notified in the Commonwealth of Australia Gazette on 22 May 2002.","sortOrder":0}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":true,"description":"The original AD (effective September 2000) was amended specifically to expand applicability to additional aircraft serial numbers and adjust compliance timing for the permanent fix. The amendment explicitly states it was issued 'in response to a new DGAC AD which expands applicability' — indicating the scope grew beyond the originally targeted aircraft population to cover more Falcon 50 jets."},"complexity_factors":["Multiple compliance pathways with date-dependent and serial number-dependent triggers (6 distinct aircraft groupings with different deadlines)","Cross-reference to external documents: Dassault Aviation Service Bulletin F50-328 Revision 1, Maintenance Manual procedure 686.3/1, and French DGAC AD 2001-604-038(B) R1","Nested temporal conditions: 'whichever occurs later' clauses and interval-based recurring inspections until condition-based termination","Regulatory layering: Amendment modifies original AD with changed applicability and compliance timing"],"plain_english_summary":"This AD from CASA mandates inspections and eventual replacement/modification of the fuel feeder tanks’ double-skin sealing on specified Dassault Falcon 50 jets (S/Ns 222–286, 288, 290, 291) to stop fuel fumes entering the cabin. Operators must perform recurring inspections until the permanent fix required by the manufacturer’s service bulletin is installed. It addresses fire, explosion and health risks from fuel vapour and expands coverage from the original 2000 directive."},"flash_summary":{"complexity_score":5,"scope_assessment":{"changed":true,"description":"Amendment 1 expands the AD's applicability to additional Falcon 50 aircraft and adjusts the compliance timing for Requirement 2 to account for those additional aircraft; Requirement 1 inspection intervals remain unchanged. This change is stated to respond to a new DGAC AD that broadened applicability (Background; Compliance)."},"complexity_factors":["Serial-number-limited applicability creates non-uniform obligations across the fleet (Applicability).","Two-step compliance structure: recurring inspections (Requirement 1) that continue until a one-time modification/corrective action (Requirement 2) is done (Requirement; Compliance).","Staggered and conditional compliance deadlines: fixed dates, intervals (13 months), ‘since new’ periods, and linkage to the next “C” check (Compliance).","Dependence on external technical documents for procedure and corrective action: Maintenance Manual procedure 686.3/1 and Dassault Service Bulletin F50-328 Revision 1 (Requirement).","Cross-reference to a foreign regulator’s AD (DGAC AD 2001-604-038(B) R1) and prior AD revocation increases traceability and audit requirements (Note; Background).","Effective-dating and prior-AD revocation require operators to reconcile legacy compliance records with the amended schedule (front matter; Background)."],"plain_english_summary":"This Airworthiness Directive requires operators of certain Dassault Aviation Mystere Falcon 50 aircraft (serial nos. 222–286, 288, 290, 291) to inspect the double-skin fuel feeder tank seals per the maintenance manual and to carry out corrective work following Dassault Service Bulletin F50-328 R1. CASA revoked the earlier AD and reissued this version.\n\nInspections must be done before 30 March 2001 and then every 13 months until the modification is completed; the deadline for the corrective action varies by serial number or next “C” check. The measure addresses possible fuel fumes entering the cabin."}},"importantCases":[],"_links":{"self":"/api/acts/ad-amd-50-20-amdt-1-fuel-feeder-tanks-double-skin","history":"/api/acts/ad-amd-50-20-amdt-1-fuel-feeder-tanks-double-skin/history","analysis":"/api/acts/ad-amd-50-20-amdt-1-fuel-feeder-tanks-double-skin/analysis","conflicts":"/api/acts/ad-amd-50-20-amdt-1-fuel-feeder-tanks-double-skin/conflicts","importantCases":"/api/acts/ad-amd-50-20-amdt-1-fuel-feeder-tanks-double-skin/important-cases","documents":"/api/acts/ad-amd-50-20-amdt-1-fuel-feeder-tanks-double-skin/documents"}}