{"id":"F2006B09317","name":"AD/EC 135/3 - Tail Boom Bearing Supports","slug":"ad-ec-135-3-tail-boom-bearing-supports","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":53451,"registerId":"commonwealth-F2006B09317-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# AIRWORTHINESS DIRECTIVE\n\n![](image.002.png)\n\n![](image.002.png)  \nFor the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CAR 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 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.","sortOrder":0},{"sectionNumber":"AD/EC 135/3 Tail Boom Bearing Supports 2","sectionType":"part","heading":"AD/EC 135/3 Tail Boom Bearing Supports 2/2000","content":"# AD/EC 135/3 Tail Boom Bearing Supports 2/2000\n\nApplicability: All Model EC 135 helicopters, serial numbers 0001 through 0074.\n\nRequirement: Initial and repeat inspections of the tail boom supports in accordance with Eurocopter Deutschland Alert Service Bulletin EC 135-53A-004.\n\nNote: LBA AD 1998-389 refers.\n\nCompliance: Accomplish the replacement before 29 February 2000, unless already accomplished. As specified in the Requirement document for the repetitive inspection requirement.\n\nThis Airworthiness Directive becomes effective on 24 February 2000.\n\nBackground: Some of the bearing supports on the tailboom were found to be out of alignment and/or not perpendicular to the drive shaft axis. In addition, a number of the current bearing supports have proved to be susceptible to corrosion and cracking.\n\n![Signature of Eugene Paul Holzapfel, Delegate of the Civil Aviation Safety Authority.](image.003.png)  \n\nEugene Paul Holzapfel\n\nDelegate of the Civil Aviation Safety Authority 13 January 2000\n\n![](image.002.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 27 January 2000.","sortOrder":1}],"analysis":{"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 AD maintains its original narrow scope — addressing a specific mechanical defect in a limited production run of helicopters (serial numbers 0001-0074). The document remains focused on the single safety issue of tail boom bearing support alignment and corrosion."},"complexity_factors":["Very short document (approximately 250 words)","Only 3 defined elements: applicability (specific serial numbers), requirement (reference to external service bulletin), and compliance deadline","No nested conditional logic or exceptions","Single cross-reference to external document (Eurocopter service bulletin EC 135-53A-004)","Simple linear structure: Background → Applicability → Requirement → Compliance","No interpretation section or defined terms glossary"],"plain_english_summary":"This CASA Airworthiness Directive orders owners/operators of Eurocopter EC135 helicopters (S/N 0001–0074) to inspect and replace tail‑boom bearing supports because misalignment and corrosion/cracking were found. The defects risk tail‑boom failure, so replacements must be completed by 29 February 2000 and ongoing inspections continued per the Eurocopter service bulletin. This is a mandatory safety requirement before the helicopters may be flown."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The instrument's scope is confined to EC 135 helicopters serial nos. 0001–0074 and to the inspection/replacement work specified in the referenced Eurocopter service bulletin. The text contains no indication that the applicability or substantive requirements have been altered from the Directive as issued."},"complexity_factors":["Narrow applicability: applies only to EC 135 serial numbers 0001–0074 (Applicability).","Mandates actions by reference to an external document (Eurocopter Deutschland Alert Service Bulletin EC 135‑53A‑004), creating dependency on that bulletin for technical steps (Requirement).","Combines one‑off replacement deadline with ongoing repetitive inspections (Requirement; Compliance).","Fixed statutory deadline for initial compliance (Compliance: before 29 February 2000), which creates a time pressure for operators.","Regulatory provenance and enforceability via CASA delegate under CAR 1998 subregulation 39.1(1) (preamble), tying administrative discretion to a statutory provision.","Cross‑reference to another authority’s AD (LBA AD 1998‑389) that may affect interpretation or related requirements (Note)."],"plain_english_summary":"This Airworthiness Directive requires operators of Eurocopter EC 135 helicopters (serial numbers 0001–0074) to carry out initial and repeat inspections of the tail‑boom bearing supports and to replace parts as directed by Eurocopter Deutschland Alert Service Bulletin EC 135‑53A‑004. The CASA delegate set a compliance deadline of 29 February 2000. Operators are responsible for performing and funding the inspections and replacements and must follow the bulletin's instructions to correct reported misalignment, corrosion and cracking."}},"importantCases":[],"_links":{"self":"/api/acts/ad-ec-135-3-tail-boom-bearing-supports","history":"/api/acts/ad-ec-135-3-tail-boom-bearing-supports/history","analysis":"/api/acts/ad-ec-135-3-tail-boom-bearing-supports/analysis","conflicts":"/api/acts/ad-ec-135-3-tail-boom-bearing-supports/conflicts","importantCases":"/api/acts/ad-ec-135-3-tail-boom-bearing-supports/important-cases","documents":"/api/acts/ad-ec-135-3-tail-boom-bearing-supports/documents"}}