{"id":"F2006B03520","name":"AD/BAe 146/72 - Fire Protection and Smoke Detection - Freight Compartment","slug":"ad-bae-146-72-fire-protection-and-smoke-detection-freight-compartment","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":43087,"registerId":"commonwealth-F2006B03520-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BAe 146/72 - Fire Protection and Smoke Detection - Freight Compartment","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nBritish Aerospace BAe 146 Series Aeroplanes\n\nAD/BAe 146/72 Fire Protection and Smoke Detection \\- Freight Compartment\n\n  \n1/99\n\nDM\n\nApplicability: All BAe 146 series aeroplanes fitted with L’Hotellier smoke detectors part number FR2113 or FR2121 and FR2213 or FR2226.\n\nNote: These smoke detectors are known to be fitted to, but not limited to, the following BAe 146 series aeroplanes:\n\nModel Constructor Numbers\n\nBAe 146-100 Series aircraft \\- E1002\n\nBAe 146-200 Series aircraft \\- E2056, E2067, E2078, E2086, E2089,\n\nE2100, E2102, E2105, E2109, E2112, E2113, E2114, E2117,\n\nBAe 146-300 Series aircraft \\- E3150, E3151, E3153, E3154, E3166,\n\nE3168, E3182, E3186, E3194, E3198.\n\nAnd\n\nAll BAe 146 Series 200 with Mod HCM50201C embodied. All BAe 146 Series 300 with Mod HCM50214C embodied.\n\nRequirement: 1. Test the smoke detectors for serviceability in accordance with British Aerospace, Regional Aircraft Limited, Service Bulletin SB.26-A38 Revision 1 dated\n\n20 October 1998.\n\nNote: This Inspection Service Bulletin has been classified Mandatory by the CAA(UK).\n\nCompliance: 1. Prior to the 18 December 1998 and thereafter at intervals not to exceed 48 hours.\n\nIncorporation of Mod No HCM56094A, B and C (SB 26-38-56094A, B and C) is terminating action for these repetitive inspections.\n\nThis Airworthiness Directive becomes effective on 16 December 1998.\n\nBackground: During in-service trouble shooting of the smoke detectors it was found that operation of the flight deck smoke detection test switch can give a serviceable indication, even though the detector light source filament is blown. This directive introduces terminating action and supersedes AD/BAe 146/62 which is cancelled.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a standard, narrow Airworthiness Directive addressing a specific technical fault in specific aircraft. It has not expanded beyond its original safety purpose."},"complexity_factors":["Single, specific technical requirement with clear compliance deadline","Limited applicability scope (one aircraft series, specific part numbers and serial numbers)","Contains one terminating action (modification installation) that ends the repetitive obligation","Cross-references external technical document (British Aerospace Service Bulletin SB.26-A38) but does not reproduce its contents","Minimal conditional logic — essentially 'if fitted with these parts, then test every 48 hours until modified'","Short length (approximately 300 words)","Only 4 defined part numbers and specific aircraft constructor numbers listed"],"plain_english_summary":"This Airworthiness Directive orders operators of BAe 146 freighter compartments fitted with certain L'Hotellier smoke detectors to perform cockpit tests every 48 hours until a mandated permanent modification is installed. It responds to a fault where a blown lamp can make a detector appear serviceable from the cockpit, risking undetected cargo fires. The AD replaces an earlier one and ends the repetitive testing requirement once the approved modification is fitted."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"This AD stays within the original safety-focused purpose (ensure freight-compartment smoke detectors are actually serviceable). It replaces and refines an earlier directive (AD/BAe 146/62) by specifying a 48‑hour inspection interval and naming a terminating modification. That is an adjustment of compliance method and timing rather than an expansion of the AD’s substantive scope."},"complexity_factors":["Narrow applicability to specific part numbers and a defined aircraft family (low scope breadth)","Single external normative reference (British Aerospace Service Bulletin SB.26-A38 Rev 1)","One repetitive action with a single fixed interval (every 48 hours) (simple conditional logic)","Clear terminating action via three Mod numbers (HCM56094A, B, C) referenced by Service Bulletin series","Supersedes and cancels a previous AD (AD/BAe 146/62) — cross-reference but limited effect","Some ambiguity in the applicability note: ‘known to be fitted to, but not limited to’ creates modest uncertainty about completeness of the aircraft list"],"plain_english_summary":"**What this directive does (mechanically)**\n\n- It requires operators of British Aerospace BAe 146 aeroplanes that have certain L’Hotellier smoke detector part numbers (FR2113 or FR2121 and FR2213 or FR2226) to perform a serviceability test on those freight-compartment smoke detectors.\n- The required test procedure is the one in British Aerospace Regional Aircraft Service Bulletin SB.26-A38 Revision 1 (dated 20 October 1998). The Service Bulletin has been classified Mandatory by the UK CAA.\n- The tests must be carried out before 18 December 1998 and then at intervals not exceeding 48 hours (i.e. every 48 hours while the aircraft remains in service) until a specified modification is incorporated.\n- Installing Mod HCM56094A, B or C (referenced as SB 26-38-56094A, B or C) is a terminating action: once that modification is embodied, the repetitive 48‑hour inspections are no longer required.\n\n**Who this affects**\n\n- Aircraft operators and maintenance organisations who operate BAe 146 series aeroplanes fitted with the listed L’Hotellier smoke detectors. The AD lists specific constructor numbers that are known to have the detectors, but it applies to all BAe 146 aircraft fitted with those part numbers (including others not listed).\n- Maintenance and engineering staff who must carry out the tests in accordance with the service bulletin, and any organisation contracted to perform the terminating modification.\n\n**Why it matters (stated purpose and practical implications)**\n\n- Stated purpose: In service troubleshooting showed that using the flight-deck smoke-detection test switch could indicate the detector was serviceable even though the detector’s light source filament had failed. The AD is intended to ensure detectors are actually serviceable until a modification fixes the underlying defect (Background section).\n\n- Practical effects and trade-offs:\n  - Who pays: operational costs fall on aircraft operators (labour/time to perform the tests every 48 hours; possible parts and downtime if detectors fail tests). If operators choose the terminating modification, they pay modification parts and installation costs but avoid ongoing inspection cost.\n  - Who decides and enforces: the Civil Aviation Safety Authority (via the Airworthiness Directive) requires compliance; maintenance records and inspections are the mechanism of enforcement.\n  - Behaviour change required: operators must add a frequent (every-48-hour) test to the maintenance/operational routine or incorporate the terminating mod. The latter is an investment decision that trades an up-front mod cost against ongoing inspection burden.\n  - Compliance burden and implementation risk: frequent checks increase maintenance workload and scheduling complexity; failure to comply could ground aircraft or trigger regulatory action. Independent maintenance organisations can perform the tests or modifications, so the rule does not appear to prevent use of third-party MROs.\n\n**Concrete legal hooks in the directive**\n\n- Requirement: perform the test per British Aerospace Service Bulletin SB.26-A38 Rev 1 (20 Oct 1998).\n- Compliance: test before 18 Dec 1998 and thereafter at intervals not exceeding 48 hours.\n- Terminating action: incorporate Mod HCM56094A, B or C (SB 26-38-56094A/B/C) to stop the repetitive inspection requirement.\n\n**Costs, incentives and likely responses**\n\n- Concentrated benefit: improved reliability of smoke detection for affected aircraft — a directly targeted safety outcome for operators and passengers on those aircraft.\n- Concentrated cost: the recurring labour/time cost is borne by operators of the relatively small, defined fleet of BAe 146 aircraft with the specified detectors. The fleet is limited, so the cost is concentrated on a small set of operators rather than spread widely.\n- Incentive to modify: because the inspections are frequent (every 48 hours), operators have a clear incentive to adopt the terminating modification if the mod cost is lower than the expected ongoing inspection cost (including aircraft downtime and labour). This creates a predictable substitution effect: inspections -> mod.\n- Administrative discretion: the AD delegates the technical content to the manufacturer’s Service Bulletin (external document). That creates reliance on the bulletin’s procedures for compliance and may require operators to purchase or obtain that document and any associated parts.\n\n**Net operational summary**\n\n- Short-term: start repeating a serviceability test every 48 hours to catch detectors whose filament has blown but still give a false serviceable indication via the flight-deck test.\n- Medium-term: most operators will likely evaluate the cost of the terminating mod and, if cost-effective, install Mod HCM56094A/B/C to remove the inspection burden.\n\n(Referenced portions: Requirement; Compliance; Incorporation of Mod No HCM56094A, B and C is terminating action; Background.)"},"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-146-72-fire-protection-and-smoke-detection-freight-compartment","history":"/api/acts/ad-bae-146-72-fire-protection-and-smoke-detection-freight-compartment/history","analysis":"/api/acts/ad-bae-146-72-fire-protection-and-smoke-detection-freight-compartment/analysis","conflicts":"/api/acts/ad-bae-146-72-fire-protection-and-smoke-detection-freight-compartment/conflicts","importantCases":"/api/acts/ad-bae-146-72-fire-protection-and-smoke-detection-freight-compartment/important-cases","documents":"/api/acts/ad-bae-146-72-fire-protection-and-smoke-detection-freight-compartment/documents"}}