{"id":"F2006B10969","name":"AD/JT15D/6 Amdt 1 - Fan Blades","slug":"ad-jt15d-6-amdt-1-fan-blades","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":56545,"registerId":"commonwealth-F2006B10969-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/JT15D/6 Amdt 1 - Fan Blades","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 106 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nPratt and Whitney Canada Turbine Engines \\- JT15D Series\n\nAD/JT15D/6\n\nAmdt 1\n\n  \nFan Blades 11/87\n\nApplicability: JT15D-1,-1A,-1B,-4,-4B,-4C and -4D. Requirement: Action in accordance with PWC SB No 7257 Rev 2.\n\nNote: Transport Canada AD CF-87-05R1 refers to SB 7257.\n\nCompliance: Unless already accomplished:\n\n    Within 25 flight hours or 15 days after 1 May 1987.\n\n    2. Prior to installation in an aircraft.\n\nBackground: This Directive was issued to reflect the requirements of Transport Canada Emergency Airworthiness Directive CF-87-05R1. The Canadian Directive was issued following a JT15D fan blade event which apparently resulted from machine marks on the blade root fillet radius.\n\nThis Directive is now amended to reflect SB 7257 Rev 2 which further identifies specific engine models affected.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":true,"description":"The directive was amended to reflect Pratt & Whitney Canada Service Bulletin No. 7257 Revision 2, which \"further identifies specific engine models affected.\" This amendment refines which JT15D engine variants are covered (Applicability; Background)."},"complexity_factors":["Narrow technical scope — applies only to specified JT15D engine models (Applicability).","Single external normative reference — compliance requires following one manufacturer service bulletin (PWC SB No 7257 Rev 2) rather than multiple complex rules (Requirement).","Short, fixed compliance window creates operational timing pressure but does not create multi-step procedural complexity (Compliance).","Pre-installation prohibition adds a straightforward inventory/maintenance constraint but not layered procedural discretion (Compliance).","Dependence on external document (the SB) means technical complexity is offloaded to the manufacturer document rather than the AD text itself (Requirement)."],"plain_english_summary":"What the directive changes mechanically:\n\n- It requires operators and maintenance organisations that work on certain Pratt & Whitney Canada JT15D turbofan engines to carry out the specific inspection/repair actions set out in Pratt & Whitney Canada Service Bulletin No. 7257 Revision 2. (Requirement)\n- Those actions must be completed either within 25 flight hours or 15 days after 1 May 1987, unless they have already been done, and must be completed before any affected fan blade is installed in an aircraft. (Compliance)\n\nWho this affects and why it matters:\n\n- Affected parties: owners, operators and maintenance organisations for aircraft fitted with JT15D-1, -1A, -1B, -4, -4B, -4C and -4D engines. (Applicability)\n- Why it matters: the directive is intended to address a fan blade failure mode that was traced to machine marks at the blade root fillet radius; it implements the technical steps in SB 7257 Rev 2 to reduce the risk of the same failure happening. (Background)\n- The directive mirrors an earlier Transport Canada emergency airworthiness directive and expressly directs compliance with the manufacturer service bulletin. (Note)\n\nWho pays, who decides, and what changes in behaviour:\n\n- Who pays: aircraft owners/operators and their maintenance providers must bear the cost of reading and implementing SB 7257 Rev 2, performing inspections, repairs or replacements, and any associated aircraft downtime. (Requirement, Compliance)\n- Who decides: the Civil Aviation Safety Authority imposes the mandatory requirement by issuing this airworthiness directive; the manufacturer’s service bulletin specifies the technical actions to be performed. Operators choose how to schedule the required work, subject to the compliance deadlines. (Requirement, Compliance)\n- Behaviour changes required: operators must obtain and follow SB 7257 Rev 2, schedule and perform the prescribed work within the specified short timeframe (or before installing affected parts), and record compliance. (Requirement, Compliance)\n\nCosts, incentives, trade-offs and implementation issues to note:\n\n- Costs and timing pressure: the compliance window (25 flight hours or 15 days after the stated date) creates pressure to reallocate maintenance capacity quickly; that can increase short-term labour and logistic costs and may cause aircraft scheduling disruption. (Compliance)\n- Dependence on manufacturer documentation: the AD mandates action “in accordance with PWC SB No 7257 Rev 2,” so the technical scope and any parts, tools or procedures required are determined by that service bulletin rather than by the AD text itself. Operators must obtain and follow the SB. (Requirement)\n- Pre-installation restriction: the directive prohibits installation of affected fan blades unless the SB actions have been accomplished, which can affect spares provisioning and maintenance flow. (Compliance)\n- Regulatory alignment and scope refinement: the AD implements an action that tracks a Transport Canada emergency AD and has been amended to reflect the manufacturer’s revision that further identifies which engine models are subject to the requirement. That narrows or clarifies which operators must act. (Note, Background)\n- Compliance risk: failure to obtain or apply the SB, or to meet the tight deadlines, creates airworthiness non-compliance for operators; logistical constraints (parts, workshop availability) are practical risks to timely compliance. (Requirement, Compliance)\n\nSource citations: applicability and affected models are stated under “Applicability”; required action is under “Requirement” (PWC SB No 7257 Rev 2); timing and pre-installation rule are under “Compliance”; the reason for the directive and the amendment are explained under “Background.”"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This amendment narrows and clarifies the original scope rather than expanding it. The original directive applied broadly; Amendment 1 specifically identifies which engine models are affected based on revised manufacturer data. This is a precision refinement consistent with the original safety purpose."},"complexity_factors":["Very short document (under 200 words)","Only 1 defined term implicitly referenced (the Service Bulletin)","No nested conditional logic — simple 'unless already accomplished' trigger","Single cross-reference to Canadian aviation authority (Transport Canada) and manufacturer service bulletin","Clear, unambiguous compliance deadlines","No exceptions or exemptions listed"],"plain_english_summary":"This is an **Airworthiness Directive** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) that requires aircraft owners and operators to take specific action to fix a known safety problem.\n\n**What it does:**\nOrders inspection or replacement of **fan blades** on specific Pratt & Whitney Canada JT15D jet engines (models -1, -1A, -1B, -4, -4B, -4C, and -4D).\n\n**Why it matters:**\nA fan blade failure can cause catastrophic engine damage and potentially bring down an aircraft. This directive was triggered after a Canadian investigation found that **machine marks** (tiny scratches or grooves from manufacturing) on the blade root were causing blades to crack and fail.\n\n**Who must comply:**\nAnyone operating aircraft with these specific engine models.\n\n**What they must do:**\nFollow the instructions in **Pratt & Whitney Canada Service Bulletin 7257 Revision 2** — a technical document from the engine manufacturer detailing the required inspections or replacements.\n\n**When:**\n- Within **25 flight hours or 15 days** after 1 May 1987 (whichever comes first), OR\n- **Before installing** any affected engine in an aircraft\n\n**Key change in this version (Amendment 1):**\nThe original directive has been updated to specify exactly which engine models are affected, based on revised manufacturer guidance."}},"importantCases":[],"_links":{"self":"/api/acts/ad-jt15d-6-amdt-1-fan-blades","history":"/api/acts/ad-jt15d-6-amdt-1-fan-blades/history","analysis":"/api/acts/ad-jt15d-6-amdt-1-fan-blades/analysis","conflicts":"/api/acts/ad-jt15d-6-amdt-1-fan-blades/conflicts","importantCases":"/api/acts/ad-jt15d-6-amdt-1-fan-blades/important-cases","documents":"/api/acts/ad-jt15d-6-amdt-1-fan-blades/documents"}}