{"id":"F2005L02072","name":"AD/BAe 146/66 Amdt 3 - Wing Top Skin Panels","slug":"ad-bae-146-66-amdt-3-wing-top-skin-panels","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":36269,"registerId":"commonwealth-F2005L02072-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"British Aerospace BAe 146 Series Aeropla","sectionType":"division","heading":"British Aerospace BAe 146 Series Aeroplanes","content":"### British Aerospace BAe 146 Series Aeroplanes\n\n| AD/BAe 146/66 Amdt 3 | Wing Top Skin Panels | 9/2005 |\n| -------------------- | -------------------- | ------ |\n\n| Applicability: | All BAe 146 Series aircraft.Avro 146-RJ70 aircraft from E1223 through E1260.Avro 146-RJ85 aircraft from E2208 through E2266.Avro 146-RJ100 aircraft from E3221 through E3265.                                                                                                                                                                                                                                                                                                                                                                                                                                                               |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Action in accordance with BAE Systems Mandatory Service Bulletin (MSB) 57-057 Revision 2.Note: UK CAA AD 009-02-2000 refers.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |\n| Compliance:    | As specified in the Requirement document.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |\n|                | This Amendment becomes effective on 1 September 2005.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |\n| Background:    | The manufacturer found on a number of production aircraft, that during assembly of the Stringer Crown Dagger fittings at Rib 0 and Rib 2, “drill marks“ have been produced on the underside of the wing top skin. These small marks have impaired the protective treatment.Amendment 1 was prompted by the discovery, that, following the closing action in accordance with R.I.L. HC573H9014, paint debris had been found within the fuel tanks.Amendment 2 is issued to introduce the latest revision of the Requirement document, which does not require rework of the modification(s) embodied by previous Requirement document issues. |\n\n![](image.001.png)  \nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n21 July 2005","sortOrder":0},{"sectionNumber":"AD/BAe 146/66 Amdt 3","sectionType":"part","heading":"AD/BAe 146/66 Amdt 3","content":"## AD/BAe 146/66 Amdt 3","sortOrder":1},{"sectionNumber":"Wing Top Skin Panels","sectionType":"part","heading":"Wing Top Skin Panels","content":"## Wing Top Skin Panels","sortOrder":2},{"sectionNumber":"9/2005","sectionType":"part","heading":"9/2005","content":"## 9/2005","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"This amendment does not broaden the AD’s original safety focus (repairing/mitigating drill-mark damage to wing top skin protective treatment). Instead it updates the required technical document to MSB 57-057 Revision 2 and removes the need to rework modifications completed under earlier MSB issues. That change narrows operator burden relative to earlier versions rather than expanding the AD beyond its initial purpose (See: Background; Requirement)."},"complexity_factors":["Short, single-issue instrument","Relies on one external technical document: BAE Systems MSB 57-057 Rev 2 (primary procedural content not reproduced in the AD)","Specific serial-number applicability for some RJ variants (three serial ranges listed)","Cross-reference to prior amendments and to UK CAA AD (external cross-references increase navigation cost)","Amendment history affects whether rework is required (conditional on which MSB revision applied)"],"plain_english_summary":"**What this instrument does (mechanically)**\n\n- It requires operators of BAe 146 family aeroplanes (including Avro/146-RJ variants listed by serial number) to carry out the actions specified in BAE Systems Mandatory Service Bulletin (MSB) 57-057 Revision 2. (See: Requirement.)\n- The Civil Aviation Safety Authority (CASA) delegate made this airworthiness directive effective from 1 September 2005. (See: Compliance / Effective date.)\n\n**Who it affects**\n\n- Owners and operators of all BAe 146 series aircraft, and specifically Avro 146-RJ70 aircraft with serials E1223–E1260, Avro 146-RJ85 with serials E2208–E2266, and Avro 146-RJ100 with serials E3221–E3265. (See: Applicability.)\n- Maintenance organisations and engineers who carry out the mandated inspections and corrective work required by the referenced BAE MSB.\n\n**Why it matters (stated purpose and practical effect)**\n\n- The manufacturer discovered ‘‘drill marks’’ on the underside of wing top skin near stringer/fitment assembly points (Rib 0 and Rib 2) that damaged protective treatment (paint/anti-corrosion treatments). This can reduce protection against corrosion or create debris risks. (See: Background.)\n- A previous action revealed paint debris in fuel tanks after earlier corrective work; this AD updates the required work to the latest MSB revision to address that problem and clarifies that the latest revision does not require reworking modifications done under earlier MSB issues. (See: Background.)\n\n**What operators must do in practice**\n\n- Examine the aircraft and carry out whatever inspections, removals, repairs or treatments are specified in BAE Systems MSB 57-057 Rev 2. The AD does not reproduce step-by-step technical procedures; it makes compliance with the MSB mandatory. (See: Requirement / Compliance.)\n\n**Costs, incentives and trade-offs — tested against the instrument’s mechanics**\n\n- Who pays: aircraft operators pay directly for inspections, any repairs, and associated aircraft downtime. Maintenance providers charge labour and parts costs under normal commercial terms. (See: Applicability; Requirement.)\n- Who decides the technical detail: the manufacturer’s MSB contains the technical instructions; CASA’s directive makes those instructions mandatory for the specified fleet. That concentrates technical decision-making with the manufacturer (through the MSB) and regulatory enforcement with CASA (through the AD). (See: Requirement.)\n- Compliance burden and implementation risk: the AD is brief but binding; operators must obtain MSB 57-057 Rev 2, plan inspections and any corrective work, and manage aircraft availability. Risk includes discovery of more extensive corrosion or damage than expected, which increases cost and downtime. (See: Requirement / Background.)\n- Trade-offs and opportunity cost: the AD imposes maintenance costs and possible schedule disruption in return for reduced risk from compromised protective treatment and paint debris. The amendment explicitly removes a previous rework requirement, which reduces rework costs for operators who already implemented earlier MSB revisions. (See: Background.)\n- Effects on market and private choice: mandating the MSB limits operator discretion to accept risk or choose alternative repair methods unless those alternatives are approved by the regulator. It may increase demand for approved maintenance work on the affected type, benefitting certified maintenance providers. (See: Requirement.)\n\n**Implementation and enforcement mechanics**\n\n- The AD enforces compliance by reference to an external technical document (MSB 57-057 Rev 2); CASA enforces the AD under its airworthiness regulatory powers. The AD also notes the related UK CAA AD (informational cross-reference). (See: Requirement; Note.)\n\n**Short summary sentence**\n\n- This AD obliges operators of specified BAe 146/Avro 146-RJ aircraft to follow BAE Systems MSB 57-057 Revision 2 to inspect and, if necessary, repair/restore wing top skin protective treatment where drill marks were found, and it clarifies that the latest MSB revision does not require reworking earlier modifications."},"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 Airworthiness Directive maintains its original scope — addressing a specific manufacturing defect in wing top skin panels on BAe 146 series aircraft. The amendments (1, 2, and now 3) have refined the technical requirements and compliance methods but have not expanded beyond the original safety purpose of addressing drill mark damage and fuel tank contamination in these specific aircraft types."},"complexity_factors":["Very short document (approximately 200 words of substantive content)","Only 4 defined applicability ranges (specific aircraft serial numbers)","Single requirement referencing an external technical document (MSB 57-057 Rev 2)","No nested conditional logic or exceptions within the instrument itself","Simple amendment structure (Amendment 3) with brief background explaining evolution from Amendments 1 and 2","No cross-references to other legislation or complex legal definitions"],"plain_english_summary":"This AD requires operators of BAe 146 and specified Avro 146‑RJ aircraft to carry out inspections and repairs per Manufacturer Service Bulletin 57‑057 Revision 2 to fix drill‑mark damage to wing top skin panels and remove paint debris in fuel tanks. It updates earlier directives by adopting the latest SB revision and avoids reworking work already done under prior mandates. The aim is to prevent corrosion, fuel contamination, and related safety risks."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bae-146-66-amdt-3-wing-top-skin-panels","history":"/api/acts/ad-bae-146-66-amdt-3-wing-top-skin-panels/history","analysis":"/api/acts/ad-bae-146-66-amdt-3-wing-top-skin-panels/analysis","conflicts":"/api/acts/ad-bae-146-66-amdt-3-wing-top-skin-panels/conflicts","importantCases":"/api/acts/ad-bae-146-66-amdt-3-wing-top-skin-panels/important-cases","documents":"/api/acts/ad-bae-146-66-amdt-3-wing-top-skin-panels/documents"}}