{"id":"F2006B10860","name":"AD/JBK 117/1 Amdt 1 - Tail Rotor Blade Bonding","slug":"ad-jbk-117-1-amdt-1-tail-rotor-blade-bonding","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":56356,"registerId":"commonwealth-F2006B10860-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/JBK 117/1 Amdt 1 - Tail Rotor Blade Bonding","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)  \nKawasaki BK 117 Series Helicopters\n\nAD/BK 117/1\n\nAmdt 1\n\n  \nTail Rotor Blade Bonding 2/94\n\nApplicability: All models fitted with tail rotor blades P/n 117-31742 serial numbers 63 to 82\\. Requirement: Action in accordance with Japan Civil Aviation Bureau AD TCD 2589-2-90. Compliance: For Tail Rotor Blades with:\n\n    less than five hours time in service prior to 23 July 1990, replace prior to further flight, and\n\n    2. more than five hours time in service prior to 23 July 1990, inspect prior to each flight in accordance with the requirement document.\n\n    3. this amendment is effective 3 February 1994.\n\nNote: The previous effective date of this Directive was 24 August 1987.\n\nBackground: Some blades may have had inadequate bonding. Amendment 1 is to reflect the latest issue of the requirement document.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"Amendment 1 updates the directive to reflect the latest issue of the referenced Japan Civil Aviation Bureau requirement document and sets a new effective date (Background; Compliance 3; Requirement). The applicability (part number and serial-number range) and the compliance conditions (replace if <5 hours before 23 July 1990; inspect prior to each flight if >5 hours before that date) are retained in this amendment (Applicability; Compliance 1–2)."},"complexity_factors":["Narrow applicability defined by specific part number and serial-number range (Applicability).","Conditional compliance rules that depend on blade hours in service before a fixed historical cutoff date (Compliance 1–2).","Mandatory per-flight inspection requirement for one class of affected blades, increasing operational detail and burden (Compliance 2).","Mandatory replacement requirement for another class of affected blades, creating a one-off parts-and-labour obligation (Compliance 1).","Dependency on an external foreign technical document (Japan Civil Aviation Bureau AD TCD 2589-2-90) for the detailed procedures and standards to be followed (Requirement).","Amendment updates and effective-dates history that operators must track for compliance timing (Compliance 3; Note; Background)."],"plain_english_summary":"This AD covers Kawasaki BK117 helicopters fitted with tail rotor blades P/N 117-31742, S/N 63–82, requiring either immediate replacement (if those blades had <5 hours service before 23 July 1990) or a pre-flight inspection regime (if >5 hours), to be carried out “in accordance with” Japan JCAA AD TCD 2589-2-90. It affects owners/operators and maintenance organisations (who bear costs and operational downtime), and was issued after findings of potentially inadequate blade bonding."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a routine amendment to an existing Airworthiness Directive. Amendment 1 simply updates the reference to the latest version of the Japanese requirement document (JCAB AD TCD 2589-2-90). The scope remains tightly focused on the specific tail rotor blade bonding issue for the identified serial number range. No expansion of applicability or purpose has occurred."},"complexity_factors":["Very short document (under 200 words)","Only 4 defined elements: specific part number, serial number range, two time-in-service thresholds, and one reference document","Simple binary conditional logic (less than 5 hours vs more than 5 hours)","No cross-references to other Australian legislation beyond the enabling regulations (CAR 1998 Part 39)","Single external reference to Japanese aviation document (JCAB AD TCD 2589-2-90) — the actual technical requirements are contained there, not in this instrument","No nested exceptions or sub-delegations"],"plain_english_summary":"This is an **Airworthiness Directive** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for aircraft.\n\n**What it does:**\nOrders owners and operators of **Kawasaki BK 117 series helicopters** to take specific safety actions regarding certain tail rotor blades.\n\n**Who it affects:**\n- All BK 117 helicopter models fitted with tail rotor blades part number **117-31742** with serial numbers **63 to 82**\n- This covers a specific batch of blades suspected of having manufacturing defects\n\n**What must be done:**\n- **New blades** (less than 5 hours flight time before 23 July 1990): **Replace immediately** before flying again\n- **Used blades** (more than 5 hours flight time before that date): **Inspect before every single flight** following the procedures in a Japanese aviation safety document (JCAB AD TCD 2589-2-90)\n\n**Why it matters:**\nSome tail rotor blades may have had **inadequate bonding** (the glue or adhesive holding parts together was faulty). A tail rotor failure can cause catastrophic loss of control. This directive prevents crashes by forcing immediate replacement or constant inspection of suspect blades.\n\n**Key update:**\nThis version (Amendment 1, effective 3 February 1994) updates the directive to match the latest Japanese safety requirements."}},"importantCases":[],"_links":{"self":"/api/acts/ad-jbk-117-1-amdt-1-tail-rotor-blade-bonding","history":"/api/acts/ad-jbk-117-1-amdt-1-tail-rotor-blade-bonding/history","analysis":"/api/acts/ad-jbk-117-1-amdt-1-tail-rotor-blade-bonding/analysis","conflicts":"/api/acts/ad-jbk-117-1-amdt-1-tail-rotor-blade-bonding/conflicts","importantCases":"/api/acts/ad-jbk-117-1-amdt-1-tail-rotor-blade-bonding/important-cases","documents":"/api/acts/ad-jbk-117-1-amdt-1-tail-rotor-blade-bonding/documents"}}