{"id":"F2006B10950","name":"AD/JETSTREAM/8 - Engine Mounting Structure Attachment Bolts","slug":"ad-jetstream-8-engine-mounting-structure-attachment-bolts","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":56517,"registerId":"commonwealth-F2006B10950-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/JETSTREAM/8 - Engine Mounting Structure Attachment Bolts","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 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  British Aerospace BAe 3100 (Jetstream) Series Aeroplanes\n\n \n\nAD/JETSTREAM/8 Engine Mounting Structure Attachment Bolts\n\n\n10/85\n\n \n\nApplicability: All Jetstream Series 3100 with S/Nos. 601 to 607, 609 to 633, 635 to 640 and 649. Requirement:               Action in accordance with British Aerospace S.B. 71-JA850625.\n\nCompliance: As per Requirement Document.\n\n \n\nBackground: Each engine mounting structure incorporates two special bolts. It has been found that some batches have been insufficiently heat treated during manufacture.\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\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific manufacturing defect in specific aircraft. It has not expanded beyond its original narrow technical purpose."},"complexity_factors":["Extremely short document (under 200 words)","Only one substantive requirement: comply with an external technical document (Service Bulletin 71-JA850625)","No defined terms section","No conditional logic or nested exceptions","Simple applicability clause listing specific serial numbers","Single cross-reference to external technical standard rather than legislative cross-referencing"],"plain_english_summary":"This is an **Airworthiness Directive** — essentially a mandatory safety notice issued by Australia's Civil Aviation Safety Authority (CASA) for specific aircraft.\n\n**What it does:**\nOrders owners and operators of certain British Aerospace Jetstream 3100 aeroplanes to inspect or replace bolts that attach the engines to the aircraft's mounting structure. The bolts in question may have been poorly heat-treated during manufacturing, making them potentially weak or prone to failure.\n\n**Who it affects:**\nOwners and operators of Jetstream Series 3100 aircraft with specific serial numbers: 601–607, 609–633, 635–640, and 649.\n\n**Why it matters:**\nIf these bolts fail, an engine could detach from the wing during flight — obviously catastrophic. The directive references a British Aerospace Service Bulletin (S.B. 71-JA850625) which contains the detailed technical instructions for the fix. Operators must follow that document to remain compliant with Australian aviation law.\n\n**Key point:** This isn't optional — it's a legal requirement under the Civil Aviation Regulations 1998."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive’s scope, as stated in the instrument, is limited to Jetstream Series 3100 aeroplanes with the listed serial numbers and to carrying out the actions in British Aerospace S.B. 71-JA850625 (Applicability; Requirement). The instrument does not indicate any expansion or narrowing of that scope beyond the listed applicability and the referenced service bulletin."},"complexity_factors":["Narrow, specific applicability to a defined set of serial numbers (Applicability).","Dependence on an external technical document (British Aerospace S.B. 71-JA850625) for required action (Requirement; Compliance).","Technical nature of the defect (insufficient heat treatment of special bolts) requiring specialist inspection/repair (Background).","The AD mandates a particular manufacturer-prescribed corrective method rather than specifying alternative remedies (Requirement).","Practical compliance depends on availability of the service bulletin and approved replacement parts or repair resources (Requirement; Background)."],"plain_english_summary":"What this instrument does, mechanically:\n\n- It is an airworthiness directive issued under the Civil Aviation Regulations (Part 39) applying to certain British Aerospace Jetstream Series 3100 aeroplanes. The directive requires operators of the listed aircraft to take the actions set out in British Aerospace Service Bulletin 71-JA850625 (Requirement; Compliance).\n\nWho it affects and who pays:\n\n- It applies only to Jetstream Series 3100 aeroplanes with serial numbers 601–607, 609–633, 635–640 and 649 (Applicability).\n- Inspection and repair costs fall on the operators of those affected aircraft (Applicability; Requirement).\n\nWhy it matters and the technical trigger:\n\n- The Background states that the engine mounting structure uses two special bolts and some manufacturing batches were found to have been insufficiently heat treated. The directive implements the manufacturer’s corrective instructions to address that defect (Background; Requirement).\n\nHow compliance works in practice:\n\n- Operators must carry out the action “in accordance with British Aerospace S.B. 71-JA850625” (Requirement).\n- The AD requires compliance within the timeframes and by the methods specified in that service bulletin (Compliance). The AD prescribes the manufacturer’s service bulletin as the mandated corrective method rather than permitting operator-selected alternatives (Requirement).\n\nImplementation dependencies and operational effects:\n\n- The directive’s practical effect depends on availability of the referenced British Aerospace service bulletin and any required replacement parts or approved repair components. Compliance therefore depends on obtaining and following S.B. 71-JA850625 and on access to approved parts or repair facilities (Requirement; Background).\n\nSource citations (for each factual claim above): Applicability; Requirement; Compliance; Background."}},"importantCases":[],"_links":{"self":"/api/acts/ad-jetstream-8-engine-mounting-structure-attachment-bolts","history":"/api/acts/ad-jetstream-8-engine-mounting-structure-attachment-bolts/history","analysis":"/api/acts/ad-jetstream-8-engine-mounting-structure-attachment-bolts/analysis","conflicts":"/api/acts/ad-jetstream-8-engine-mounting-structure-attachment-bolts/conflicts","importantCases":"/api/acts/ad-jetstream-8-engine-mounting-structure-attachment-bolts/important-cases","documents":"/api/acts/ad-jetstream-8-engine-mounting-structure-attachment-bolts/documents"}}