{"id":"F2006B03458","name":"AD/BAe 146/104 Amdt 1 - APU and IDG In-Line Splices","slug":"ad-bae-146-104-amdt-1-apu-and-idg-in-line-splices","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":43012,"registerId":"commonwealth-F2006B03458-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BAe 146/104 Amdt 1 - APU and IDG In-Line Splices","content":"![](image.001.png)\n\n![](image.001.png)  \nAIRWORTHINESS DIRECTIVE\n\nFor the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/BAe 146/104 and issues the following 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\nBritish Aerospace BAe 146 Series Aeroplanes\n\nAD/BAe 146/104\n\nAmdt 1\n\n  \nAPU and IDG In-Line Splices 12/2004\n\nApplicability: All BAe 146 100, 200, and 300 series aeroplanes with Erma/Sunleigh Splice part number 12197/2 (BAe Systems standard part S1212-106) installed in the auxiliary power unit (APU) generator feeder cables or the main engine integrated drive generator (IDG) feeder cables.\n\nNote 1: This Directive is not applicable to aeroplanes with any of the following modifications incorporated:\n\nCable Type APU Feeder\n\n  \nModification Number\n\nHCM36097A, HCM36097B, HCM36089A, or HCM36089B.\n\nIDG Feeder HCM01253A, HCM01253B, HCM01203A, or HCM01203C.\n\nRequirement: Inspect all the APU generator feeder cable and the main engine IDG feeder cable in- line splices in accordance with BAe Systems (Operations) Limited Mandatory Inspection Bulletin ISB.24-139 dated 2 April 2003.\n\nNote 2: CAA(UK) AD 005-04-2003 refers.\n\nCompliance: Within twelve months after the last inspection of the in-line splices in accordance with AD/BAe 146/104 and thereafter at intervals of twelve months until each cable is modified in accordance with one of optional modification listed at Note 1.\n\nThis Amendment becomes effective on 25 November 2004.\n\nBackground: The original issue of this Directive superseded AD/BAe 146/23 Amdt 2 and AD/BAe 146/24 Amdt 2, which were cancelled. The Directive continued the repetitive inspection of the in-line splices and introduced optional terminating action.\n\nBritish Aerospace BAe 146 Series Aeroplanes\n\nAD/BAe 146/104 Amdt 1 (continued)\n\nThis Amendment changes Note 1 and the Compliance Statement to ensure that it is clear that any one of the listed modifications terminates the repetitive inspection of each cable in-line splices.\n\nThe original issue of this Airworthiness Directive became effective on 12 June 2003.\n\n![Signature of James Coyne, Delegate of the Civil Aviation Safety Authority.](image.002.png)  \n\nJames Coyne\n\nDelegate of the Civil Aviation Safety Authority 15 October 2004\n\n![](image.001.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 3 November 2004.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This amendment does not expand the scope beyond the original 2003 directive. It remains focused on the same safety issue (electrical splice inspections) for the same aircraft type. The amendment is purely clarifying: it specifies that modifications terminate repetitive inspections on a per-cable basis (APU vs IDG) rather than implying termination for the entire aircraft. This is a technical refinement, not scope creep."},"complexity_factors":["Short, single-purpose document (2 pages) with clear applicability and requirement sections","Only 1 defined term requiring industry knowledge ('IDG' - Integrated Drive Generator)","Simple conditional logic: if modification X is installed → exempt; if inspected → re-inspect in 12 months; if modified per Note 1 → terminate repetitive action","Cross-reference to one external technical document (BAe Systems Inspection Bulletin ISB.24-139) and one UK aviation directive (CAA(UK) AD 005-04-2003)","Minimal nested conditions: the amendment clarifies a single ambiguity about whether modifications terminate inspections per-cable or per-aircraft"],"plain_english_summary":"This CASA Airworthiness Directive mandates annual inspections of Erma/Sunleigh 12197/2 splices in BAe 146 APU and IDG generator feeder cables to catch defects that could cause power loss or electrical fire. It affects operators of BAe 146-100/200/300 aircraft with those splices.\n\nThe directive allows terminating inspections for a specific cable once that cable is modified using any approved kit. The amendment clarifies the repair relief applies per cable (APU or IDG), not both."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"This Amendment clarifies the original Directive rather than expanding its substantive scope. It modifies Note 1 and the Compliance statement to make explicit that incorporation of any one of the listed modification numbers for a given cable terminates the requirement for the repetitive inspections of that cable's in-line splices. The AD therefore keeps the same population of affected aircraft and the same inspection requirement, but reduces ambiguity about when inspections may stop; it does not add new types of work, new affected aircraft, or new compliance obligations beyond clarification."},"complexity_factors":["Limited applicability: only BAe 146 series 100/200/300 fitted with one specific splice part number (12197/2 / S1212-106)","Short directive with a single mandated action (inspection) and optional terminating modifications","Multiple listed modification numbers (4 for APU feeder, 4 for IDG feeder) that affect termination of inspections","Reference to an external mandatory inspection bulletin (BAe ISB.24-139) rather than containing procedural detail in the AD","Cross-reference to a prior AD (AD/BAe 146/104) for timing of the first required inspection","Two notes and a compliance timing rule (initial 12 months after last inspection under prior AD, then recurring 12-month intervals) introduce basic conditionality"],"plain_english_summary":"**What this instrument does (mechanics)\n\n- This is an Airworthiness Directive (AD) that requires inspections and sets an optional fix for particular electrical splices on certain BAe 146 aeroplanes.\n- It applies to BAe 146 series 100, 200 and 300 aeroplanes that have a specific splice fitted: Erma/Sunleigh splice part number 12197/2 (BAe Systems standard part S1212-106) used in either the auxiliary power unit (APU) generator feeder cables or the main engine integrated drive generator (IDG) feeder cables (\"Applicability\").\n- Operators must inspect every in-line splice in those APU and IDG feeder cables following BAe Systems Mandatory Inspection Bulletin ISB.24-139 dated 2 April 2003 (\"Requirement\").\n- Inspections must be done within 12 months after the last inspection done under the earlier AD/BAe 146/104 and then every 12 months thereafter until the cable is modified by one of the listed modifications (\"Compliance\").\n- If any one of the listed modification numbers for the APU or IDG feeder cable is incorporated into the aeroplane, that modification stops (terminates) the need for the yearly inspections for the cable it modifies (Note 1).\n\n**Who it affects\n\n- Aircraft operators and maintenance organisations that own, operate, maintain or certify BAe 146-100/200/300 aeroplanes with the specified Erma/Sunleigh splice installed in the APU or IDG feeder cables.\n- Maintenance personnel who perform the mandated inspections (they must follow the BAe Systems ISB). \n- Suppliers or shops that carry out the optional cable modification work if operators choose to incorporate the terminating modification.\n\n**Why it matters (stated purpose and practical implications)\n\n- Stated purpose: the AD addresses a potential unsafe condition in APU and IDG feeder cable in-line splices by requiring recurring inspections and offering an optional terminating modification. The background explains the AD continues previously required repetitive inspections and introduces optional terminating action.\n\n- Practical implications for operators:\n  - Ongoing cost and labour: operators must schedule and pay for the required inspections at least annually until the cable is modified by an approved modification.\n  - One-off cost vs recurring cost decision: an operator can avoid future annual inspections for a cable by installing any one of the listed modifications for that cable; that creates a trade-off between paying now for modification work or paying repeatedly for inspections.\n  - Compliance depends on an external document: inspections must be carried out in accordance with BAe Systems Mandatory Inspection Bulletin ISB.24-139, so operators must obtain and follow that bulletin.\n\n**Who pays and who decides\n\n- Who pays: the aircraft operator (or their maintenance provider) pays for the inspections and any optional modification work.\n- Who decides: the Civil Aviation Safety Authority (CASA) delegate issued the AD and sets the requirement and compliance timing. Operators decide whether to continue annual inspections or to incorporate a terminating modification for each cable.\n\n**Implementation, trade-offs and risks\n\n- Implementation burden: annual inspections impose predictable recurring maintenance labour and possible aircraft downtime; installing a terminating modification requires parts and maintenance resources and may have one-off costs and lead times.\n- Trade-offs: operators will weigh the present cost and availability of the listed modification(s) against the ongoing cost and operational impact of repeated inspections.\n- Reliance on external material: compliance requires following BAe Systems ISB.24-139; any ambiguity or delay in obtaining or interpreting that ISB could affect implementation timing and conformity.\n- Concentrated vs diffuse effects: the direct financial burden is on the relatively small group of operators of affected BAe 146 types; suppliers who provide the modification work or parts receive concentrated demand if many operators choose the terminating modification.\n- Compliance clarity: this Amendment clarifies that any one of the listed modifications terminates the repetitive inspections for the cable it modifies (see Note 1 and the revised Compliance statement), which reduces ambiguity about when inspections may cease.\n\n**Source citations (where key instructions appear in the AD)\n\n- Applicability: identifies aeroplane models and the specific splice part number.\n- Note 1: lists the modifications that, if incorporated, terminate the repetitive inspections (separately for APU and IDG feeders).\n- Requirement: directs inspections to be performed in accordance with BAe Systems Mandatory Inspection Bulletin ISB.24-139 (2 April 2003).\n- Compliance: sets inspection timing (within 12 months after the last inspection under AD/BAe 146/104, then every 12 months until modification).\n\n(Technical terms: APU = auxiliary power unit (a small engine that provides electrical power on the ground and in some situations in flight); IDG = integrated drive generator (a device driven by the main engine that generates electrical power); in-line splice = an electrical connector joining two sections of cable inline.)"},"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"}},"importantCases":[],"_links":{"self":"/api/acts/ad-bae-146-104-amdt-1-apu-and-idg-in-line-splices","history":"/api/acts/ad-bae-146-104-amdt-1-apu-and-idg-in-line-splices/history","analysis":"/api/acts/ad-bae-146-104-amdt-1-apu-and-idg-in-line-splices/analysis","conflicts":"/api/acts/ad-bae-146-104-amdt-1-apu-and-idg-in-line-splices/conflicts","importantCases":"/api/acts/ad-bae-146-104-amdt-1-apu-and-idg-in-line-splices/important-cases","documents":"/api/acts/ad-bae-146-104-amdt-1-apu-and-idg-in-line-splices/documents"}}