{"id":"F2006B03315","name":"AD/B767/139 - Potable Water Fill Line","slug":"ad-b767-139-potable-water-fill-line","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42752,"registerId":"commonwealth-F2006B03315-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# AIRWORTHINESS DIRECTIVE\n\n![](image.001.png)\n\n![](image.001.png)  \nFor the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (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\nBoeing 767 Series Aeroplanes","sortOrder":0},{"sectionNumber":"AD/B767/139 Potable Water Fill Line 7/20","sectionType":"part","heading":"AD/B767/139 Potable Water Fill Line 7/2001","content":"# AD/B767/139 Potable Water Fill Line 7/2001\n\nApplicability: All Boeing 767-200 and \\-300 series aircraft.\n\nRequirement: 1. Replace the existing potable water fill line tube with a flexible hose in accordance with Boeing Alert Service Bulletin 767-38A0057.\n\n2. No person shall install a potable water fill tube, part number 417T2021-179, on an Australian registered Boeing 767-200 or -300 series aircraft.\n\nNote: FAA AD 2001-08-22 refers.\n\nCompliance: 1. No later than 1 June 2002.\n\n2. As of the effective date of this Airworthiness Directive.\n\nThis Airworthiness Directive becomes effective on 12 July 2001.\n\nBackground: This Airworthiness Directive is prompted by advice that fracture of the clamshell coupling can result in a large amount of water entering the aft cargo compartment. If this occurs, the aircraft’s centre of gravity could shift aft to the extent that controllability of the aircraft is adversely affected.\n\n![Signature of Eugene Paul Holzapfel, Delegate of the Civil Aviation Safety Authority.](image.002.png)  \n\nEugene Paul Holzapfel\n\nDelegate of the Civil Aviation Safety Authority 18 May 2001\n\n![](image.001.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 13 June 2001.","sortOrder":1}],"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":2,"scope_assessment":{"changed":false,"description":"This AD remains tightly focused on its original purpose: addressing a specific mechanical failure mode (clamshell coupling fracture) in a specific aircraft system (potable water fill line) on specific aircraft models. There is no evidence of scope creep or expansion beyond the original safety issue identified."},"complexity_factors":["Single, clearly defined applicability (two specific aircraft models)","Only two straightforward requirements with no conditional logic or exceptions","Single compliance date with no phased implementation or hour-based thresholds","No defined terms section or interpretation provisions","No cross-references to other legislation (only a non-binding note referencing a related US FAA directive)","Background section provides clear safety rationale without technical engineering specifications"],"plain_english_summary":"This CASA safety order mandates Australian-registered Boeing 767-200/300s replace a rigid water fill tube with a flexible hose and immediately bans fitting part 417T2021-179. The replacement must be completed by 1 June 2002. It addresses a failure mode where a broken tube could flood the rear cargo hold, shift the aircraft’s weight aft and risk loss of control."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The AD stays within the original safety-correction purpose: it addresses a specific identified unsafe condition (fracture of the clamshell coupling and potential aft cargo flooding) by mandating a single retrofit and banning a specific part. It does not broaden regulatory scope beyond correcting that condition, add unrelated obligations, or create ongoing regulatory regimes beyond the one-off modification and installation prohibition."},"complexity_factors":["Short single-aircraft-type applicability (all Boeing 767-200 and -300 series).","One primary mandated action (replace rigid tube with flexible hose) plus one simple prohibition (do not install part number 417T2021-179).","Single external technical reference: Boeing Alert Service Bulletin 767-38A0057.","One compliance date for the modification and immediate prohibition effective date — minimal conditional logic.","Cross-reference to FAA AD 2001-08-22 noted but not relied on for additional complex requirements."],"plain_english_summary":"**What this instrument does**\n\n- This Airworthiness Directive (AD) orders owners/operators of certain Boeing 767 aircraft to replace a rigid potable (drinking) water fill tube with a flexible hose, and bans the installation of a particular rigid tube part on Australian-registered aircraft. (See Requirement and Applicability.)\n\n**Who it affects**\n\n- All operators and maintainers of Boeing 767-200 and 767-300 series aeroplanes registered in Australia. (Applicability.)\n- Maintenance organisations and parts suppliers who install or supply potable water fill system components for these aircraft. (Requirement, Note.)\n\n**What must be done and when**\n\n- Replace the existing potable water fill line tube with a flexible hose following Boeing Alert Service Bulletin 767-38A0057. This replacement must be completed by 1 June 2002. (Requirement, Compliance 1.)\n- From the AD's effective date (12 July 2001), no person may install the potable water fill tube part number 417T2021-179 on an Australian-registered Boeing 767-200 or -300. (Requirement 2, Compliance 2.)\n\n**Why the regulator issued it**\n\n- The AD states that the clamshell coupling on the rigid fill tube can fracture, allowing a large volume of water into the aft cargo compartment. That water transfer could shift the aircraft's centre of gravity aft and adversely affect controllability. The AD's measures are presented as necessary to correct that unsafe condition. (Background.)\n\n**Who bears the costs and who decides**\n\n- Aircraft operators bear the direct costs: purchasing the replacement flexible hose parts, labour for the modification, and any aircraft downtime while the work is fitted by maintenance. (Requirement; Compliance.)\n- CASA (through its delegate) determines the mandatory action, timing and prohibition under the CAR 1998 delegation cited on the AD cover page; operators must follow the Boeing Alert Service Bulletin for the technical procedure. (Covering text; Requirement.)\n\n**Practical effects, trade-offs and implementation risks**\n\n- Safety trade-off: Replacing a rigid tube with a flexible hose reduces the specific fracture/flooding risk described in the Background; the AD relies on the Boeing service bulletin for the technical fix. (Requirement; Background.)\n- Compliance cost and logistics: Operators must schedule work and secure parts and qualified maintenance, which creates short-term expense and potential aircraft downtime. (Requirement; Compliance.)\n- Market/industry effect: Parts suppliers and maintenance organisations cannot fit or supply the banned rigid tube (part number 417T2021-179) for Australian-registered 767-200/-300s after the effective date, limiting some replacement-options and affecting spare-parts inventory management. (Requirement 2.)\n- Enforcement/verification: The AD does not itself specify inspection or record-keeping procedures beyond compliance timing; verifying compliance will typically occur through maintenance records, air operator procedures or regulatory surveillance. (Compliance.)\n\n**Source claims and testing them against costs and incentives**\n\n- The AD's stated purpose is to remove an unsafe condition (clamshell coupling fracture leading to aft cargo flooding and CG shift). Treating that as the objective, the remedy (hose replacement and installation prohibition) directly targets the mechanical failure mode cited. (Background; Requirement.)\n- Cost incentives: Operators face a one-off retrofit cost and supply-chain impact; the benefit is reduced likelihood of the specific failure and its safety consequences. The AD imposes no compensating funding; private operators pay the cost of compliance. (Requirement; Compliance.)\n\n**Key references inside the AD**\n\n- Applicability: all Boeing 767-200 and -300 series aircraft.\n- Requirement: replacement action (per Boeing Alert Service Bulletin 767-38A0057) and prohibition on installing part number 417T2021-179.\n- Compliance dates: replacement by 1 June 2002; installation ban effective from 12 July 2001.\n- Background: explains the unsafe condition (clamshell coupling fracture, water ingress, aft CG shift).\n\n(Sections cited above are those headed Applicability, Requirement, Compliance and Background in the AD.)"}},"importantCases":[],"_links":{"self":"/api/acts/ad-b767-139-potable-water-fill-line","history":"/api/acts/ad-b767-139-potable-water-fill-line/history","analysis":"/api/acts/ad-b767-139-potable-water-fill-line/analysis","conflicts":"/api/acts/ad-b767-139-potable-water-fill-line/conflicts","importantCases":"/api/acts/ad-b767-139-potable-water-fill-line/important-cases","documents":"/api/acts/ad-b767-139-potable-water-fill-line/documents"}}