{"id":"F2006B03376","name":"AD/B767/200 - Primary Nacelle Strut Structure","slug":"ad-b767-200-primary-nacelle-strut-structure","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42839,"registerId":"commonwealth-F2006B03376-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# ![](image.001.png)  \nAIRWORTHINESS DIRECTIVE\n\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 CASR 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\n![](image.001.png)  \n\nBoeing 767 Series Aeroplanes","sortOrder":0},{"sectionNumber":"AD/B767/200 Primary Nacelle Strut Struct","sectionType":"part","heading":"AD/B767/200 Primary Nacelle Strut Structure 11/2004","content":"# AD/B767/200 Primary Nacelle Strut Structure 11/2004\n\nApplicability: Model 767-200, \\-300, and \\-300F series aircraft, line numbers 1 through 663; powered by Pratt & Whitney or General Electric engines.\n\nRequirement: Action in accordance with the technical requirements of FAA AD 2004-16-12 Amdt 39-13768.\n\nCompliance: For the requirements of FAA AD 2001-02-07 (previously reflected in CASA AD/B767/134) the revised effective date of 19 April 2001 applies.\n\nFor the requirements of FAA AD 2001-06-12 (previously reflected in CASA AD/B767/137) the revised effective date of 12 July 2001 applies.\n\nFor the requirements of FAA AD 2001-08-23 (previously reflected in CASA AD/B767/135 Amdt 1) the revised effective date of 10 April 2001 applies.\n\nFor the new requirements of FAA AD 2004-16-12, as specified in the Requirement document, with a revised effective date of 28 October 2004.\n\nThis Airworthiness Directive becomes effective on 28 October 2004.\n\nBackground: This Directive requires, for aircraft subject to FAA AD 2001-02-07 and AD 2001-06- 12 on which certain modifications have been accomplished previously, reworking the aft pitch load fitting, and installing a new diagonal brace fuse pin. This Directive also requires, for aircraft subject to FAA AD 2001-08-23, replacing the outboard pitch load fitting of the wing front spar with a new, improved fitting.\n\nThe actions specified by this Directive are intended to prevent fatigue cracking in primary strut structure, which could result in separation of the strut and engine from the aircraft.","sortOrder":1}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"This version expands and consolidates earlier AD requirements. It incorporates the new technical requirements of FAA AD 2004-16-12 and at the same time revises the effective dates of three earlier FAA ADs previously reflected in CASA ADs. Concretely, the AD adds explicit rework and new hardware-installation requirements (aft pitch load fitting rework; diagonal brace fuse pin installation; replacement of outboard pitch load fitting) beyond simply restating earlier ADs. That materially increases the scope of mandated physical work for affected aircraft compared with the earlier CASA ADs that adopted the previous FAA ADs."},"complexity_factors":["Short, single-aircraft-type applicability (Boeing 767-200/-300/-300F, line numbers 1–663).","Primary instruction is a direct reference to an external FAA AD (FAA AD 2004-16-12) rather than many internal technical conditions.","Three earlier FAA ADs are referenced with revised effective dates (cross-references to ADs 2001-02-07, 2001-06-12, 2001-08-23).","Limited number of actions described (rework aft pitch load fitting; install diagonal brace fuse pin; replace outboard pitch load fitting).","No extensive definitions, schedules, or multiple nested exceptions within the text provided.","Some conditionality based on whether certain prior modifications were already accomplished (adds a small layer of complexity)."],"plain_english_summary":"**What this instrument does (mechanically):**\n\n- Applies to Boeing 767-200, -300 and -300F aeroplanes, line numbers 1–663, fitted with Pratt & Whitney or General Electric engines (see \"Applicability\").\n- Requires operators to carry out the technical actions set out in FAA Airworthiness Directive (AD) 2004-16-12 (see \"Requirement\").\n- Re-sets the effective dates for three earlier FAA ADs as adopted previously in CASA ADs (see \"Compliance\").\n- Becomes effective 28 October 2004 (see \"Compliance\").\n\n**What you must physically do (from the Background/Requirement):**\n\n- For aeroplanes already subject to earlier FAA ADs but having had certain earlier modifications, you must rework the aft pitch load fitting and install a new diagonal brace fuse pin.\n- For aeroplanes subject to a different FAA AD, you must replace the outboard pitch load fitting on the wing front spar with a new, improved fitting.\n\nThese actions follow the technical instructions in FAA AD 2004-16-12; the Directive points operators to that document for procedural detail (see \"Requirement\").\n\n**Why it matters (stated safety concern):**\n\n- The Directive aims to prevent fatigue cracking in primary nacelle-strut structure. Fatigue cracking in these components could cause separation of the strut and engine from the aircraft (see \"Background\").\n\nWho is affected and who pays\n\n- Aircraft operators/owners of affected 767s must comply. That means arranging inspections, rework and part replacement, hiring certified maintenance organisations or authorised personnel, and keeping compliance records.\n- Direct costs are borne by the operators: parts, labour, and aircraft downtime. Maintenance organisations and parts suppliers incur implementation work and may receive payment for services and parts.\n\nWho decides and how compliance is implemented\n\n- The CASA delegate issues the Australian AD; compliance is achieved by following the FAA AD’s technical instructions (the FAA AD is the Requirement document cited).\n- Licensed maintenance organisations perform the work to the FAA AD/mfg service bulletin instructions; operators must schedule and certify the work per regulatory maintenance records.\n\nOperational effects, incentives and trade-offs\n\n- Behavioural change: operators must inspect and modify structural fittings rather than defer repairs; aircraft may be temporarily grounded for the work.\n- Concentrated benefits: the safety benefit concentrates on passengers, crew and insurers of the particular aircraft. The cost burden is concentrated on owners/operators of older 767s.\n- Compliance cost vs. retirement option: for higher-cost or low-utilisation aircraft, operators may choose to retire or sell rather than fund modifications — a substitution effect.\n- Market impact: increased demand for certified maintenance labour and approved replacement fittings; potential short-term part supply bottlenecks and downtime-driven scheduling pressure.\n\nImplementation risks and administrative burden\n\n- Risks include parts availability, scheduling downtime, and ensuring all earlier modifications have been correctly identified (the AD targets aircraft with some prior modifications differently).\n- Administrative requirements include tracking applicability by line number and engine type, performing and recording mandated work, and meeting the revised effective dates for earlier ADs.\n\nCosts, incentives and compliance burden (concise):\n\n- Who pays: aircraft operators.\n- What they do differently: schedule inspections, rework or replace fittings, install a new diagonal brace fuse pin as specified.\n- Likely short-term costs: parts, certified labour, and lost flying time; possible longer-term effects on fleet composition (older aircraft retirement or sale).\n\nSource mechanics cited: Applicability; Requirement (references FAA AD 2004-16-12); Compliance (revised effective dates and effective date 28 October 2004); Background (lists rework, fuse pin installation, and fitting replacement and states the safety rationale)."},"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":false,"description":"This AD maintains its original narrow scope: addressing a specific structural fatigue issue in Boeing 767 engine mounts. It incorporates updated FAA requirements and revises effective dates for previously mandated actions, but does not expand beyond the original safety purpose of preventing strut failure."},"complexity_factors":["Short, single-purpose document (approximately 300 words)","Only 4 defined applicability criteria (aircraft model, line numbers, engine types)","Simple conditional structure: if aircraft subject to prior FAA AD X, do action Y","Heavy reliance on external technical documents (FAA ADs) rather than spelling out procedures in full","No nested exceptions or complex cross-referencing within the document itself","Clear, sequential compliance dates with explicit effective date"],"plain_english_summary":"This CASA Airworthiness Directive makes mandatory certain repairs and modifications to Boeing 767-200/-300/-300F aircraft (line numbers 1–663) with Pratt & Whitney or General Electric engines to address fatigue cracking in the primary nacelle strut. \n\nOperators must complete the required rework or part replacements by the specified deadlines (final actions due 28 October 2004) to prevent possible engine separation; the AD adopts equivalent FAA safety measures into Australian law."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b767-200-primary-nacelle-strut-structure","history":"/api/acts/ad-b767-200-primary-nacelle-strut-structure/history","analysis":"/api/acts/ad-b767-200-primary-nacelle-strut-structure/analysis","conflicts":"/api/acts/ad-b767-200-primary-nacelle-strut-structure/conflicts","importantCases":"/api/acts/ad-b767-200-primary-nacelle-strut-structure/important-cases","documents":"/api/acts/ad-b767-200-primary-nacelle-strut-structure/documents"}}