{"id":"F2006L01111","name":"AD/B737/40 Amdt 3 - Structural Modification and Inspection Program","slug":"ad-b737-40-amdt-3-structural-modification-and-inspection-program","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":58469,"registerId":"commonwealth-F2006L01111-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Boeing 737 Series Aeroplanes","sectionType":"division","heading":"Boeing 737 Series Aeroplanes","content":"### Boeing 737 Series Aeroplanes\n\n| AD/B737/40 Amdt 3 | Structural Modification and Inspection Program | 5/2006 |\n| ----------------- | ---------------------------------------------- | ------ |\n\n| Applicability: | For Requirement 1: Model 737-100, -200, and -200C series aircraft.For Requirement 2: Model 737-100, -200, and -200C series aircraft, as listed in Section 4 and Appendices A.4 and B.4 of Boeing Document D6-38505, “Ageing Airplane Service Bulletin Structural Modification Program and Inspection Program,” Revision F.For Requirement 3: Model 737-100, -200, and -200C series aircraft, as listed in Boeing Document D6-38505, Revision F. |\n| -------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | 1. Incorporate structural modifications in accordance with the requirements of FAA AD 93-17-08 Amdt 39-8679.2. Accomplish structural inspections in accordance with the requirements of FAA AD 93-08-04 Amdt 39-8551.3. Incorporate structural modifications in accordance with the requirements of FAA AD 90-06-02 Amdt 39-6489.Note: Boeing Document No. D6-38505 Revision F, dated 23 April 1992, refers.                                    |\n| Compliance:    | For Requirements 1 and 2:As specified in the Requirement document, with a revised effective date of16 February 2006.For Requirement 3:As specified in the Requirement document, with a revised effective date of13 April 2006.The compliance times remain unchanged by this issue of the Directive.                                                                                                                                             |\n|                | This Amendment becomes effective on 11 May 2006.                                                                                                                                                                                                                                                                                                                                                                                                |\n\n| Background: | The Model 737 Structures Working Group evaluated Boeing service bulletins that must be included as part of the “Ageing Airplane Structural Modification Program”; and the Airworthiness Assurance Task Force assigned to review Model 737 series aircraft indicated that, to assure long term continued operational safety, various structural inspections should be accomplished. The actions specified by this Directive are intended to prevent degradation in the structural capabilities of the affected aircraft.Amendment 2 included FAA AD 90-06-02 as an additional Requirement document of this Directive.Amendment 3 is issued to clarify Requirement 3 applicability. |\n| ----------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n\n![](image.001.png)  \nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n31 March 2006","sortOrder":0},{"sectionNumber":"AD/B737/40 Amdt 3","sectionType":"part","heading":"AD/B737/40 Amdt 3","content":"## AD/B737/40 Amdt 3","sortOrder":1},{"sectionNumber":"Structural Modification and Inspection P","sectionType":"part","heading":"Structural Modification and Inspection Program","content":"## Structural Modification and Inspection Program","sortOrder":2},{"sectionNumber":"5/2006","sectionType":"part","heading":"5/2006","content":"## 5/2006","sortOrder":3}],"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"},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"This Amendment 3 does not materially expand the directive's underlying purpose (to require ageing-airframe structural modifications and inspections for specified 737-100/-200/-200C aircraft). Amendment 3 primarily clarifies the applicability of Requirement 3 and restates effective dates. (Background; Compliance). An earlier amendment (Amendment 2) did add an additional FAA AD as a requirement document, which was a prior scope extension, but Amendment 3 itself does not grow the scope beyond the original ageing-aircraft structural program—it refines which aircraft Requirement 3 covers and confirms effective dates."},"complexity_factors":["Cross-references to three FAA Airworthiness Directives (FAA AD 93-17-08, FAA AD 93-08-04, FAA AD 90-06-02) which supply the substantive technical requirements","Reference to Boeing Document D6-38505 Revision F and its Appendices A.4 and B.4 as the list of affected aircraft and as the inspection/modification program","Different applicability groupings for Requirements 1, 2 and 3 (not all requirements apply to the same list of aircraft)","Separate effective dates for the amendment and for different requirements (effective 11 May 2006; revised effective dates 16 Feb 2006 and 13 Apr 2006)","Amendment history (Amendment 2 added an FAA AD; Amendment 3 clarifies applicability) creating a need to track versions","Dependence on external documents for compliance times (the AD asserts compliance times remain unchanged but those times are set outside the instrument)"],"plain_english_summary":"**What this directive does (mechanics)\n\n- Requires owners/operators of certain older Boeing 737 models (737-100, -200, and -200C series) to carry out specific structural modifications and recurring inspections. (Applicability; Requirement)\n- Mandates that those modifications and inspections be done in accordance with three referenced FAA Airworthiness Directives and the Boeing service document D6-38505 Revision F (the Boeing \"Ageing Airplane\" structural modification and inspection program). (Requirement)\n- Sets effective dates for this amendment (11 May 2006) and gives revised effective dates for specific requirements (16 February 2006 and 13 April 2006). It states that the original compliance times required by the referenced documents remain unchanged. (Compliance)\n\nWho is affected\n\n- Aircraft owners/operators of Boeing 737-100, -200 and -200C series aeroplanes that are listed in the Boeing document and the FAA ADs cited. (Applicability)\n- Maintenance organisations or engineers performing the work must do so to the standards and procedures set out in the referenced FAA ADs and Boeing service bulletin. (Requirement)\n- The Civil Aviation Safety Authority (through its delegate) enforces the directive. (cover sheet and signature)\n\nWhy it matters (official purpose and how that maps to costs and choices)\n\n- The stated purpose is to prevent deterioration of the aircraft structure on ageing 737s by requiring certain modifications and inspections identified by Boeing and reviewed by industry working groups. (Background)\n- Who pays: operators pay for the inspection and modification work, parts, labour and any associated aircraft downtime. (Requirement; Compliance)\n- Who decides the technical method: the FAA ADs and the Boeing document define the specific technical steps to be followed; CASA has adopted those documents as the mandatory means of compliance. (Requirement)\n\nPractical trade-offs, implementation risk and incentives\n\n- Compliance burden: operators must allocate maintenance resources and schedule aircraft out of service to complete the mandated inspections/modifications. This creates direct costs and opportunity costs (lost revenue while an aircraft is unavailable). (Requirement; Compliance)\n- Concentrated vs diffuse impacts: the costs fall directly on individual operators of the affected models (a concentrated group). The safety benefit is meant to be general (diffuse) across passengers and other airspace users. (Background)\n- Reliance on external technical documents: the Directive cross‑references FAA ADs and a Boeing service document as the required means of compliance. That centralises technical specification with the manufacturer and the FAA, which reduces the local regulator's need to re-specify methods but also makes compliance dependent on those documents being available and followed. (Requirement)\n- Effects on private enterprise and competition: approved maintenance organisations (including independent MROs) can perform the work if authorised; however, the need to follow specific Boeing/FAA procedures can limit how operators choose to perform repairs (less discretion over method and approved parts). This may favour providers already set up to comply with those procedures. (Requirement)\n\nWhat changed in this amendment (mechanical change before rationale)\n\n- This Amendment 3 clarifies the applicability of Requirement 3 and re-states the effective dates for Requirements 1–3 while leaving the original compliance times unchanged. It also records that Amendment 2 previously added FAA AD 90-06-02 as an additional required document. (Background; Compliance)\n\nSource statements vs practical effects\n\n- The directive says the actions are intended to \"prevent degradation in structural capabilities\" of affected aircraft (Background). Practically, that means owners must incur inspection/repair costs and accept aircraft downtime; the trade-off is reduced risk of structural failure at the expense of those costs. The directive does not itself set new inspection techniques — it mandates compliance with the referenced FAA ADs and Boeing service bulletin, so the detailed technical and economic effects depend on those documents. (Requirement)\n\nKey reference points in the directive: Applicability; Requirement; Compliance; Background."},"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"This amendment represents a minor clarification rather than scope expansion. Amendment 3 specifically narrows/clarifies the applicability of Requirement 3 without adding new substantive obligations. The original intent — mandating structural modifications and inspections for ageing 737 aircraft — remains unchanged since the initial directive."},"complexity_factors":["Multiple nested applicability conditions — three separate requirements each apply to slightly different subsets of aircraft based on Boeing document references","Heavy reliance on external documents — requires cross-referencing three separate FAA Airworthiness Directives and one Boeing service bulletin (D6-38505 Revision F)","Amendment structure creates version confusion — this is Amendment 3, which only clarifies Requirement 3 applicability without changing compliance times, requiring readers to track prior amendments","Technical aviation terminology throughout (e.g., \"Ageing Airplane Service Bulletin Structural Modification Program\")","Dual regulatory framework — Australian directive that imports and defers to US FAA requirements, creating jurisdictional complexity"],"plain_english_summary":"This CASA Airworthiness Directive mandates structural modifications and inspections on older Boeing 737-100/‑200/‑200C aircraft to address ageing airframe fatigue and corrosion, following three referenced FAA ADs. It affects operators of the original “Classic” 737s listed in Boeing D6-38505 Rev F and is intended to prevent structural failure. Amendment 3 clarifies which aircraft Requirement 3 covers, without changing existing compliance dates; the AD takes effect 11 May 2006."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b737-40-amdt-3-structural-modification-and-inspection-program","history":"/api/acts/ad-b737-40-amdt-3-structural-modification-and-inspection-program/history","analysis":"/api/acts/ad-b737-40-amdt-3-structural-modification-and-inspection-program/analysis","conflicts":"/api/acts/ad-b737-40-amdt-3-structural-modification-and-inspection-program/conflicts","importantCases":"/api/acts/ad-b737-40-amdt-3-structural-modification-and-inspection-program/important-cases","documents":"/api/acts/ad-b737-40-amdt-3-structural-modification-and-inspection-program/documents"}}