{"id":"F2006B11037","name":"AD/JT9D/8 - Fan Blade - Inspection and Blending","slug":"ad-jt9d-8-fan-blade-inspection-and-blending","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":56649,"registerId":"commonwealth-F2006B11037-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/JT9D/8 - Fan Blade - Inspection and Blending","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 106 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Pratt and Whitney Turbine Engines - JT9D Series\n\n \n\nAD/JT9D/8 Fan Blade - Inspection and Blending 12/76\n\nApplicability: All JT9D engines containing fan blades, P/Nos. 658931, 718431, 726221, 734721,\n\n735831, 735841, 740421, 740431, 740441, 740521, 741131, 741141, 748231,\n\n748321, 748931, 750621, 750631, 758031, 758181, 758191, 758221, 760631,\n\n760641, 760721, 760731, 760831, 760841, 760941, 761041, 761121, 761131 and\n\n761141.\n\n \n\nDocument: 1. FAA AD 76-24-03 : Amendment 39-2776; or\n\n \n\n2. AD/PW-T/39.\n\n \n\nCompliance: As detailed in the Requirement Document.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard Airworthiness Directive implementing a specific safety requirement for a particular engine type. It has not expanded beyond its original purpose of mandating fan blade inspections and repairs for JT9D engines. The scope remains tightly focused on the specific safety issue identified in the referenced FAA directive from 1976."},"complexity_factors":["Very short document (approximately 250 words)","Only 4 operative sections: Applicability, Document reference, Compliance, and the title","No defined terms section — all language is technical but self-explanatory to intended audience","No conditional logic or nested exceptions — straightforward mandatory compliance structure","Single cross-reference to external FAA document and one alternative Australian document","Simple applicability test: engine model + specific part numbers (binary yes/no determination)"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) under the Civil Aviation Regulations 1998.\n\n**What it does:**\nThis directive (AD/JT9D/8) requires specific **inspection and repair procedures** for **fan blades** on Pratt & Whitney JT9D jet engines. The \"blending\" mentioned refers to a repair technique where damaged areas of a blade are carefully smoothed and reshaped to maintain safe aerodynamic performance.\n\n**Who it affects:**\n- **Aircraft operators** using Pratt & Whitney JT9D engines with specific fan blade part numbers (listed in the applicability section — 32 different part numbers in total)\n- **Maintenance organisations** responsible for servicing these engines\n- **Owners** of aircraft powered by these engines (including Boeing 747s and other wide-body aircraft from that era)\n\n**Why it matters:**\nFan blade failures can cause catastrophic engine damage and potentially endanger the aircraft. This directive mandates compliance with an original US Federal Aviation Administration (FAA) safety order (AD 76-24-03) from 1976, ensuring Australian-registered aircraft meet the same critical safety standards. The directive requires operators to follow specific inspection timelines and repair procedures detailed in the referenced documents.\n\n**Key point:** This is not optional — compliance is legally mandatory, and failure to follow an Airworthiness Directive can ground an aircraft."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The text supplied does not indicate any change in scope from the directive's stated applicability. The AD applies to all JT9D engines containing the listed fan blade part numbers and requires compliance with the procedures set out in the referenced Requirement Document(s) (Applicability; Document; Compliance)."},"complexity_factors":["Reliance on external Requirement Documents (FAA AD 76-24-03 or AD/PW-T/39) for the actual procedures rather than stating steps in the AD text (Document; Compliance).","Long list of specific fan blade part numbers to check against component records and physical parts (Applicability).","No timing, intervals or explicit thresholds are reproduced in the AD text; those details are in the referenced documents, increasing cognitive and administrative load (Compliance).","Operational impact: required inspections/blending can produce aviation downtime, labour and parts costs borne by operators (Compliance).","Delegated technical detail concentrates discretion and implementation risk in the maintenance execution and the referenced documents rather than this AD (Document)."],"plain_english_summary":"This AD requires operators of Pratt & Whitney JT9D engines with the listed fan blade part numbers to carry out inspections and any blending work specified in one of two external Requirement Documents (FAA AD 76-24-03 or AD/PW-T/39). It affects engine owners and maintenance organisations, shifts compliance costs to operators, and compels them to obtain and follow the referenced procedures."}},"importantCases":[],"_links":{"self":"/api/acts/ad-jt9d-8-fan-blade-inspection-and-blending","history":"/api/acts/ad-jt9d-8-fan-blade-inspection-and-blending/history","analysis":"/api/acts/ad-jt9d-8-fan-blade-inspection-and-blending/analysis","conflicts":"/api/acts/ad-jt9d-8-fan-blade-inspection-and-blending/conflicts","importantCases":"/api/acts/ad-jt9d-8-fan-blade-inspection-and-blending/important-cases","documents":"/api/acts/ad-jt9d-8-fan-blade-inspection-and-blending/documents"}}