{"id":"F2006B03487","name":"AD/BAe 146/37 - Landing Gear","slug":"ad-bae-146-37-landing-gear","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":43041,"registerId":"commonwealth-F2006B03487-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BAe 146/37 - Landing Gear","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 146/37 Landing Gear 12/91\n\nApplicability: BAe 146 All Series 100, 100A, 200, 200A, 300 and 300A equipped with hydraulic fuses P/N ACM29100 (Mod states 1 or 2).\n\nRequirements: Action in accordance with technical requirements of British Aerospace Service Bulletin, CAA(UK) Mandatory, 32-130-70295C dated 27 September 1991.\n\nCompliance: Compliance required by 31 January 1992 on all aircraft equipped with hydraulic fuses, as defined in para 1 A (1) of the requirement document, that will have completed 4 000 flights on, or before 26 December 1991 since the introduction of these fuses. All other remaining affected hydraulic fuses must be modified by\n\n29 February 1992.\n\nBackground: Two cases have occurred of failure of the fork end fitting to the hydraulic fuses in the yellow hydraulic system. The same fuses are also fitted in the green hydraulic system. Due to mode of failure , there is a possibility of a double hydraulic system failure if a fuse fails in one system, followed by fuse failure in the other system.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, time-bound safety directive addressing a specific mechanical defect. It has not expanded beyond its original purpose of mandating inspection/modification of hydraulic fuses on affected BAe 146 aircraft."},"complexity_factors":["Single, specific technical requirement referencing an external service bulletin","Only two compliance deadlines based on flight hours since installation","Limited applicability (one aircraft type, one specific part number)","No nested definitions, cross-references to other legislation, or conditional exceptions","Straightforward cause-and-effect safety rationale"],"plain_english_summary":"This Airworthiness Directive requires owners/operators of BAe 146 Series 100/100A/200/200A/300/300A aircraft fitted with ACM29100 hydraulic fuses to inspect and modify those fuses per British Aerospace Service Bulletin 32-130-70295C by set deadlines. \n\nIt responds to fork-end failures in the yellow-system fuses (used in green system too); uncorrected, a second fuse failure could cause a simultaneous loss of both hydraulic systems, risking landing-gear and flight safety."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The directive enforces modification of the specified hydraulic fuses on the identified BAe 146 models and sets compliance deadlines tied to flight counts. It does not broaden applicability beyond the stated parts/models or introduce new regulatory powers; the scope aligns with the stated safety rationale and the technical service bulletin reference."},"complexity_factors":["Precise applicability: specific aircraft family (BAe 146 All Series 100–300A) and a single part number P/N ACM29100 with mod states 1 or 2.","Two-tier compliance schedule: early deadline for aircraft with ≥4,000 flights since fuse introduction (compliance by 31 Jan 1992) and a later universal deadline (29 Feb 1992).","Requirement to follow an external technical document: British Aerospace Service Bulletin CAA(UK) Mandatory 32-130-70295C dated 27 Sep 1991.","Safety-critical system work: modification of hydraulic fuses (yellow and green systems) addressing a failure mode that risks dual hydraulic loss.","Record-keeping burden: operators must establish flight counts since fuse introduction to determine applicable deadline.","Operational disruption potential: scheduling maintenance windows and parts/technical resources to meet mandated dates."],"plain_english_summary":"This airworthiness directive requires operators of BAe 146 series aeroplanes fitted with hydraulic fuses P/N ACM29100 (mod 1 or 2) to modify those fuses in accordance with a British Aerospace/CAA(UK) mandatory service bulletin, under staged deadlines tied to each aircraft’s flight count. It affects BAe 146 operators and maintenance organisations because the modification addresses a fork-end fitting failure mode that can cause loss of both hydraulic systems."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bae-146-37-landing-gear","history":"/api/acts/ad-bae-146-37-landing-gear/history","analysis":"/api/acts/ad-bae-146-37-landing-gear/analysis","conflicts":"/api/acts/ad-bae-146-37-landing-gear/conflicts","importantCases":"/api/acts/ad-bae-146-37-landing-gear/important-cases","documents":"/api/acts/ad-bae-146-37-landing-gear/documents"}}