{"id":"F2006B03095","name":"AD/B747/193 Amdt 1 - Fuel Leaks","slug":"ad-b747-193-amdt-1-fuel-leaks","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42467,"registerId":"commonwealth-F2006B03095-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B747/193 Amdt 1 - Fuel Leaks","content":"![](image.001.png)  \n![](image.002.png)  \nBoeing 747 Series Aeroplanes\n\nAIRWORTHINESS DIRECTIVE\n\n![](image.002.png)\n\n![](image.002.png)  \nFor the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/B747/193 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\nAD/B747/193\n\nAmdt 1\n\n  \nFuel Leaks 12/2000\n\nApplicability: Model 747 series aeroplanes, with line number 1 through 1006 inclusive and certificated in any category.\n\nRequirement: 1. For aeroplanes with line number 629 through 1006 inclusive and powered by General Electric or Rolls Royce engines; perform a one-time inspection to determine the part number of the fuel shutoff spar valve installed for the left- and right-hand outboard engines in accordance with Boeing Alert Service Bulletin 747-28A2199 dated August 1, 1996; Boeing Service Bulletin 747-28A2199, Revision 1, dated October 1, 1998; or Boeing Service Bulletin 747-28A2199, Revision 2, dated July 8, 1999.\n\n    (a) If a valve having part number (P/N) S343T003-40 (ITT P/N 125334D-1) is installed, no further action is required by this AD.\n\n    (b) If a valve P/N S343T003-40 (ITT P/N 125334D-1) is not installed then either:\n\n    (i) replace the valve in accordance with the requirements of the service bulletin, or\n\n    (ii) modify the valve in accordance with the requirements of the service bulletin.\n\n    2. For aeroplanes with line number 629 through 1006 inclusive and powered by General Electric or Rolls Royce engines: Except as provided for in requirement 3, below, perform a one-time general visual inspection to detect fuel leaks of the components between the fuel shutoff spar valve and the engine fuel shutoff valve on all four engines, in accordance with the applicable section of Chapter 71 of the Boeing 747 Airplane Maintenance Manual (AMM) that pertains to the engines fitted to the aeroplane, or Boeing Service Bulletin 747-28A2199, Revision 2, dated July 8, 1999. If any leak is detected, replace the part with a serviceable part. No further action is required by this AD.\n\n    3. For aeroplanes with line number 629 through 1006 inclusive and powered by General Electric or Rolls Royce engines, and having maintenance records that positively demonstrate that the inboard engines have never been located in the outboard position, perform a one-time general visual inspection to detect fuel leaks of the components between the fuel shutoff spar valve and the engine fuel shutoff valve on the outboard engines only, in accordance with the applicable section of Chapter 71 of the Boeing 747 Airplane Maintenance Manual (AMM) that pertains to the engines fitted to the aeroplane, or Boeing Service Bulletin 747-28A2199, Revision 2, dated July 8 1999. If any leak is detected, replace the part with a serviceable part. No further action is required by this AD.\n\n    4. For aeroplanes with line number 1 through 628 inclusive, irrespective of engine type fitted; perform a one-time inspection of the maintenance records of the aeroplane to determine if the fuel shutoff spar valve for the left- and right-hand outboard engines has ever been replaced, in accordance with Boeing Service Bulletin 747-28A2199, Revision 2, dated July 8, 1999.\n\n    (a) If the maintenance record inspection establishes that neither valve has been replaced, no further action is required by this AD.\n\n    (b) If either valve has been replaced, or if the maintenance record inspection does not clearly establish that neither valve has been replaced, accomplish paragraph 5(a), 5(b), or 5(c), as applicable.\n\n    5. For aeroplanes with line number 629 through 1006 inclusive and powered by Pratt and Whitney engines, or for aeroplanes having line number 1 through 628 inclusive on which a fuel shutoff spar valve has been, or may have been, replaced; perform a one-time inspection to determine the part number of the fuel shutoff spar valve for the left-and right-hand outboard engines, as applicable, in accordance with Boeing Alert Service Bulletin 747-28A2199, dated August 1, 1996; Boeing Service Bulletin 747-28A2199, Revision 1, dated October 1, 1998; or Boeing Service Bulletin 747-28A2199, Revision 2, dated July 8, 1999.\n\n    (a) If a valve having P/N S343T003-40 (ITT P/N 125334D-1) is installed, no further action is required by this AD.\n\n(b) If a valve having P/N 60B92406-161 (ITT P/N 125334-1), P/N 60B92406-81 (ITT P/N 125120-1), or P/N 60B92406-201 (ITT P/N 107970-1) is installed,\n\naccomplish either paragraph 6. or 7. of this AD, as applicable.\n\n(c) If a valve having P/N S343T003-40 (ITT P/N 125334D-1), P/N 60B92406- 161 (ITT P/N 125334-1), P/N 60B92406-81 (ITT P/N 125120-1), or P/N\n\n60B92406-201 (ITT P/N 107970-1) is not installed, accomplish either paragraph 5.(c)(i) or 5.(c)(ii), and either paragraph 6. or 7. of this AD, as applicable.\n\n    (i) Replace the valve with a new valve in accordance with the requirements of the service bulletin, or\n\n    (ii) Modify the valve body assembly of the fuel system in accordance with the service bulletin.\n\n    6. Except as provided in paragraph 7. of this AD, perform a one-time general visual inspection to detect fuel leaks of the components between the fuel shutoff spar valve and the engine fuel shutoff valve on all four engines, in accordance with Boeing Service Bulletin 747-28A2199, Revision 2, dated July 8, 1999. If any leak is detected, replace the part with a serviceable part.\n\n    7. For aeroplanes having maintenance records that positively demonstrate that the inboard engines have never been located in the outboard positions; perform a one- time general visual inspection to detect fuel leaks of the components between the fuel shutoff spar valve on the outboard engines only, in accordance with Boeing Service Bulletin 747-28A2199, Revision 2, dated July 8, 1999. If any leak is detected, replace the part with a serviceable part.\n\nNote 1: For the purposes of this AD, a general visual inspection is defined as : “ A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made under normally available lighting conditions such as daylight, hanger lighting, flashlight, or droplight, and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked.”\n\nNote2: Accomplishment of the actions specified in AMM 71-00-00/501, Test No.2, “ Fuel and Oil Leak Check, “ for Rolls Royce RB211 series engines, and AMM 71-00- 00/501, Test No. 3 “Ground Test - Idle Leak Check (or Idle Power)”, for General Electric CF6-80C and CF6-43/50 series engines, is acceptable for compliance with the actions specified by paragraphs 2 and 3 of this AD.\n\nNote3: FAA airworthiness directives AD 98-21-29 amendment 39-10837 and 2000- 14-06 amendment 39-11815 refer.\n\nCompliance: 1. Within 18 months of 28 January 1999 (unchanged).\n\n    (b). Before further flight after accomplishment of Requirement 1.\n\n    2. Before further flight after accomplishment of requirement 1(b).\n\n    3. Before further flight after accomplishment of requirement 1(b).\n\n    4. Within 18 months of the effective date of this amended Directive.\n\n    4. (b). Before further flight after accomplishment of requirement 4.\n\n    5. Within 18 months of the effective date of this amended Directive.\n\n5. (b). Before further flight after accomplishment of requirement 5.\n\n    5. (c). Before further flight after accomplishment of requirement 5.\n\n    6. Before further flight after accomplishment of requirement 5.\n\n    7. Before further flight after accomplishment of requirement 5\\. This amendment becomes effective on 30 November 2000.\n\nBackground: Reports indicate that, due to high fuel pressure, certain fuel components of the outboard engines have failed on in-service aircraft. This Directive introduces measures to prevent such high fuel pressure which could lead to the failure of the fuel system components and the possibility of an engine fire.\n\nAmendment 1 has been issued to include additional aeroplanes to the AD applicability, the requirements and compliance periods for the additional aeroplanes and to reference FAA airworthiness directive 2000-14-06 amendment 39-11815.\n\nAeroplanes in compliance with the original issue of the AD are not affected by this AD amendment.\n\nThe original issue of this airworthiness directive became effective on 28 January 1999.\n\n![Signature of Eugene Paul Holzapfel, Delegate of the Civil Aviation Safety Authority.](image.003.png)  \n\nEugene Paul Holzapfel\n\nDelegate of the Civil Aviation Safety Authority 24 October 2000\n\n![](image.002.png)\n\nThe above AD is notified in the Commonwealth of Australia Gazette on 1 November 2000.","sortOrder":0}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"kimi_summary":{"content_quality":"ok","complexity_score":6,"scope_assessment":{"changed":true,"description":"The original directive (effective January 1999) applied to a narrower subset of aircraft. Amendment 1 significantly expanded the scope to include additional Boeing 747 line numbers (originally excluded aircraft with line numbers 1-628) and added new requirements for Pratt & Whitney engines. The amendment also introduced new compliance pathways and record-checking requirements for older aircraft, transforming what was originally a targeted fix for newer aircraft into a comprehensive safety program covering the entire production range of the 747 series up to line 1006."},"complexity_factors":["Multiple overlapping applicability criteria based on aircraft line numbers (1-628 vs 629-1006) and engine types (General Electric/Rolls Royce vs Pratt & Whitney)","Nested conditional logic with 7 main requirements and multiple sub-paragraphs (a, b, c, i, ii) creating decision trees","Cross-references to external Boeing Service Bulletins and Airplane Maintenance Manual chapters that are not reproduced in the text","Specific part number identification required (e.g., P/N S343T003-40, ITT P/N 125334D-1) with multiple alternative acceptable references","Exception to exception structure (e.g., Requirement 3 provides an exception to Requirement 2; Requirement 7 provides an exception to Requirement 6)","Multiple compliance deadlines that vary by requirement and reference different baseline dates (28 January 1999 vs effective date of amended Directive)","Technical aviation terminology requiring specialized knowledge (spar valves, line numbers, serviceable parts, general visual inspection)","Interaction with prior version of same directive requiring tracking of which aircraft are already compliant"],"plain_english_summary":"This Airworthiness Directive requires operators of specified Boeing 747s to inspect outer-engine fuel shutoff valves (and some records), and to replace or modify valves and remediate any fuel leaks where unsafe parts or failures are found. It targets certain line-numbered aircraft with different engine types, responding to in-service fuel-component failures that could lead to engine fires. The amendment widens the fleet covered and imposes short-term compliance deadlines to mitigate the risk."},"flash_summary":{"complexity_score":6,"scope_assessment":{"changed":true,"description":"This Amendment (Amdt 1) expanded the AD’s applicability and imposed additional requirements and compliance periods for aircraft not covered, relative to the original AD. The Background of the amendment states it \"include[s] additional aeroplanes to the AD applicability, the requirements and compliance periods for the additional aeroplanes and to reference FAA AD 2000-14-06\". Practically this means more line-number ranges and engine-type permutations became subject to inspections, and new compliance deadlines were introduced for those additional aircraft (see Requirements 4 and 5 and the Compliance section). Aeroplanes already in compliance with the original AD are not required to repeat the work under this amendment (Background)."},"complexity_factors":["Applicability split by line-number ranges (1–628 vs 629–1006) and by engine manufacturer (GE, Rolls Royce, Pratt & Whitney)","Multiple conditional branches depending on part numbers (explicit P/N S343T003-40 vs other listed P/Ns) and on maintenance-record evidence (nesting of Requirements 2–3 and 4–7)","Cross-references to three versions of a Boeing service bulletin (747-28A2199, Alert + Revision 1 + Revision 2) and to specific AMM chapters and AMM tests (Notes 1–2)","Several distinct compliance deadlines and ‘before further flight’ triggers (Compliance section includes different deadlines for different requirements)","Definition of inspection type (“general visual inspection”) plus acceptance of alternative AMM leak tests (Note 1–2)","Nested options for remediation: replace the valve, modify the valve body assembly, or perform leak inspections (e.g. requirement 5(c)(i)/(ii) combined with 6/7)","References to external regulatory material (FAA ADs) and service documents increases interpretive steps","Multiple part numbers explicitly listed (at least 5 distinct P/Ns referenced)"],"plain_english_summary":"**What this directive does (mechanics first)**\n\n- Applies to Boeing 747 series aeroplanes, line numbers 1–1006 (all categories). (Applicability)\n- Requires one-time inspections and, where necessary, replacement or modification of certain fuel shutoff spar valves and a one-time visual check for fuel leaks in the fuel supply components between the shutoff spar valve and the engine fuel shutoff valve. (Requirements 1–7)\n- Uses Boeing service bulletins (747-28A2199 and its revisions) and sections of the Boeing 747 Airplane Maintenance Manual (AMM) as the instructions for how to inspect, replace or modify parts and how to do the leak checks. (Requirements and Notes)\n\n**Who is affected**\n\n- Aircraft operators, maintenance organisations and licensed engineers responsible for Boeing 747s with the listed line numbers and engine types (General Electric, Rolls Royce or Pratt & Whitney, as specified). (Applicability; Requirements 1 and 5)\n- Parts suppliers and maintenance providers who supply or install fuel shutoff spar valves and carry out modifications or inspections.\n\n**What you must do (plain steps)**\n\n- For 747s line numbers 629–1006 with GE or Rolls Royce engines: inspect the part number of the outboard engines’ fuel shutoff spar valve. If it is the approved part P/N S343T003-40 (ITT P/N 125334D-1), no further action. If not, either replace or modify the valve as directed in the Boeing service bulletin. (Requirement 1)\n- For the same group (629–1006 GE/RR): do a one-time general visual leak inspection of the components between the spar valve and the engine shutoff valve on all four engines, unless maintenance records positively show the inboard engines were never moved to outboard positions — in that case inspect outboard engines only. Replace any leaking part. (Requirements 2–3)\n- For line numbers 1–628 (any engine): inspect maintenance records to see whether the outboard spar valves have ever been replaced. If records show they have not been replaced, no further action. If they have been replaced or records are unclear, follow the parts-number inspection or replacement/modification path described in Requirement 5. (Requirement 4)\n- For 629–1006 with Pratt & Whitney engines, and for any 1–628 aircraft where the valve may have been replaced: inspect the valve part number. If the valve is the approved P/N S343T003-40, no further action. If other specific P/Ns are found (listed in Requirement 5(b)) you must follow either the leak inspection requirements (Requirement 6 or 7) or replace/modify the valve as directed in the service bulletin. If a different/unknown valve is present, you must either replace it with a new valve or modify the valve body assembly as the service bulletin requires, and then do the leak inspection. (Requirement 5)\n- Leak inspections required by Requirements 2, 3, 6 or 7 are defined as a “general visual inspection” as described in Note 1; certain AMM leak-check tests are acceptable alternatives for some engines. (Notes 1–2)\n\n**When it must be done (timing summary)**\n\n- Some inspections were required within 18 months of 28 January 1999 (Requirement 1 — unchanged). (Compliance)\n- For other inspectors/replacements added by this amendment (Requirements 4 and 5), the compliance period is within 18 months of the effective date of the amended directive (the amendment’s effective date is stated in the AD). Some subsequent actions (e.g. leak checks after replacing/modifying a valve) must be completed before further flight. (Compliance)\n\n**Why the rule exists (stated rationale)**\n\n- The Background states that high fuel pressure caused certain outboard-engine fuel components to fail on in-service aircraft, which could lead to fuel system failures and the possibility of an engine fire. The AD’s measures are intended to prevent the high fuel pressure condition and resulting failures. (Background)\n\n**Practical effects, incentives and trade-offs**\n\n- Who pays: aircraft operators bear direct costs — worker-hours for inspections, potential parts purchases, engineering/modification work and aircraft downtime for replacements or tests (Requirements 1–7; Compliance). Maintenance organisations will incur labour costs but may also gain billable work.\n- Who decides: operators and their approved maintenance organisations decide how and when to schedule the inspections and any replacements/modifications, subject to the specified deadlines and the service bulletin procedures. CASA enforces compliance through the AD mechanism (preamble and Compliance). \n- Behaviour changes: operators must (a) search maintenance records (Requirement 4), (b) inspect part numbers on valves (Requirements 1 and 5), (c) perform specified visual or AMM leak checks (Requirements 2, 3, 6, 7 and Notes), and (d) replace or modify valves when required. Some operators with incomplete records will have to treat that uncertainty as if a replacement may have occurred (Requirement 4(b)).\n- Deadlines and operational impact: several tests must be completed before further flight after certain actions; this creates immediate operational constraints if valve replacement or modification is required (Compliance; Requirements 1(b), 2–3, 5(b)–(c), 6–7). \n- Market effects: maintenance providers and valve suppliers that can supply compliant parts or carry out the Boeing-recommended modification are likely to obtain concentrated business from affected operators. Operators with better records or already-installed compliant parts avoid replacement costs (Requirement 4(a)).\n- Substitution and ordering effects: operators may prefer to install the specified P/N S343T003-40 where compatible, to avoid repeated inspections; this shifts demand toward that part and its suppliers (Requirement 1 and 5).\n- Compliance risk and verification: the AD relies on accurate maintenance records to reduce inspection scope (Requirement 3 and 4); where records are incomplete, operators must take the conservative path (more inspections/replacements), increasing cost and workload. The AD also cross-references manufacturer service information, so access to those documents and parts availability is an implementation constraint.\n\n**Implementation and enforcement notes**\n\n- The AD mandates compliance with Boeing Service Bulletin 747-28A2199 (original and two revisions) and cross-references specific AMM leak-check procedures; following those documents precisely determines lawful compliance. (Requirements; Notes)\n- The AD references related FAA ADs for background and technical correspondence. (Note 3)\n\n"}},"importantCases":[],"_links":{"self":"/api/acts/ad-b747-193-amdt-1-fuel-leaks","history":"/api/acts/ad-b747-193-amdt-1-fuel-leaks/history","analysis":"/api/acts/ad-b747-193-amdt-1-fuel-leaks/analysis","conflicts":"/api/acts/ad-b747-193-amdt-1-fuel-leaks/conflicts","importantCases":"/api/acts/ad-b747-193-amdt-1-fuel-leaks/important-cases","documents":"/api/acts/ad-b747-193-amdt-1-fuel-leaks/documents"}}