{"id":"F2006B03387","name":"AD/B767/31 - EEC System Electromagnetic Shielding","slug":"ad-b767-31-eec-system-electromagnetic-shielding","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42889,"registerId":"commonwealth-F2006B03387-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B767/31 - EEC System Electromagnetic Shielding","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Boeing 767 Series Aeroplanes\n\n \n\nAD/B767/31 EEC System Electromagnetic Shielding 1/90\n\nApplicability: As detailed in the Requirement Document.\n\n \n\nRequirement: Action in accordance with Boeing SB 767-71-0041 R2 or later revision.\n\n \n\nNote: FAA AD 89-21-04 refers.\n\n \n\nCompliance: Prior to 25 April 1991.\n\n \n\nBackground: Boeing have advised that at the maximum probable lightning threat level, lightning induced voltage transients in excess of the EEC qualification requirement may result. A lightning strike at take-off could therefore adversely affect EEC operation and could result in uncommanded thrust loss greater than the loss of one engine.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, time-limited safety directive addressing a specific technical defect in a specific aircraft type. It has not expanded beyond its original purpose of mandating electromagnetic shielding for lightning protection."},"complexity_factors":["Very short document (under 200 words)","Only 1 substantive requirement (comply with referenced Boeing Service Bulletin)","No defined terms section — relies entirely on external technical document","Single compliance date with no conditional exceptions or alternative methods","No cross-references to other legislation beyond the parent Civil Aviation Regulations 1998 and the external Boeing/FAA documents"],"plain_english_summary":"**What this is:** This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) that requires specific fixes or inspections on aircraft.\n\n**What it does:** It orders owners and operators of **Boeing 767 aeroplanes** to install improved electromagnetic shielding on the **EEC (Electronic Engine Control)** system. This is the computer that manages engine thrust.\n\n**Why it matters:** Without this fix, a **lightning strike during take-off** could cause electrical interference strong enough to make the engine control system malfunction. This could lead to **sudden, unplanned loss of engine power** — worse than losing one engine — creating a serious safety risk during the most critical phase of flight.\n\n**What must be done:** Aircraft operators must follow the instructions in **Boeing Service Bulletin 767-71-0041 Revision 2** (or a later updated version) to install the shielding.\n\n**Who it affects:** Anyone operating Boeing 767 aircraft in Australia under the Civil Aviation Regulations 1998.\n\n**Deadline:** The work had to be completed **before 25 April 1991**.\n\n**Note:** This aligns with a similar US safety order (FAA AD 89-21-04)."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The document sets a single, specific mandatory modification (EEC electromagnetic shielding) with a compliance date and does not indicate any alteration to that scope. No indication in the text that the directive's scope has been expanded or narrowed from an earlier or original intent; applicability remains governed by the referenced Requirement Document (Requirement, Applicability)."},"complexity_factors":["Reference to external technical document (Boeing SB 767-71-0041 R2) rather than listing technical steps directly (Requirement).","Applicability is delegated to a separate Requirement Document, creating an external dependency and potential ambiguity (Applicability).","Permission to comply with 'or later revision' of the Service Bulletin allows technical requirements to change after issue (Requirement).","Technical nature of the work (electromagnetic shielding of EEC) requires specialised maintenance skills and verification, increasing implementation complexity (Requirement, Background).","Cross-reference to an FAA AD introduces an international regulatory linkage (Note)."],"plain_english_summary":"This directive requires operators of Boeing 767 series aeroplanes to modify the Electronic Engine Control (EEC) electromagnetic shielding per Boeing Service Bulletin SB 767‑71‑0041 (or later revision) by 25 April 1991. It affects airlines and maintenance providers, aims to reduce the risk of lightning‑induced EEC malfunction and uncommanded thrust loss, and is enforced by CASA; operators bear the costs and downtime for compliance."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b767-31-eec-system-electromagnetic-shielding","history":"/api/acts/ad-b767-31-eec-system-electromagnetic-shielding/history","analysis":"/api/acts/ad-b767-31-eec-system-electromagnetic-shielding/analysis","conflicts":"/api/acts/ad-b767-31-eec-system-electromagnetic-shielding/conflicts","importantCases":"/api/acts/ad-b767-31-eec-system-electromagnetic-shielding/important-cases","documents":"/api/acts/ad-b767-31-eec-system-electromagnetic-shielding/documents"}}