{"id":"F2006B03774","name":"AD/BEECH 300/3 - Engine Mount Assembly Attachment Bolts","slug":"ad-beech-300-3-engine-mount-assembly-attachment-bolts","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":43370,"registerId":"commonwealth-F2006B03774-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BEECH 300/3 - Engine Mount Assembly Attachment Bolts","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)  \nBeechcraft 300 Series Aeroplanes\n\nAD/BEECH 300/3 Engine Mount Assembly Attachment Bolts 10/92\n\nApplicability: Models and serial numbers as listed in Beech SB 2432.\n\nRequirement: 1. Individually remove each engine truss-to-firewall bolt and determine whether the bolt is manufactured by Dumont Aviation as specified by Figure 2 of, and in accordance with paragraphs 1 and 2 of the ACCOMPLISHMENT INSTRUCTIONS section of Beech SB 2432. Only one engine truss-to-firewall bolt shall be removed at any given time.\n\n2. Replace any bolt manufactured by Dumont Aviation as identified in Requirement 1 of this Directive with a new bolt part number MS20006-20 /M/.\n\nNote: FAA AD 92-15-01 Amdt 39-8294 refers.\n\nCompliance: 1. Within 150 hours time in service after 17 September 1992.\n\n2. Prior to further flight.\n\nBackground: This Directive requires a one-time visual inspection of all engine mount assembly attachment bolts to determine whether bolts that could have been improperly heat treated are installed, and replacement of any such bolts.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, time-limited safety directive addressing a specific manufacturing defect in a specific aircraft type. It has not expanded beyond its original purpose of inspecting and replacing potentially defective engine mount bolts."},"complexity_factors":["Very short document (under 300 words)","Only 2 substantive requirements with clear sequential steps","Single defined reference (Beech SB 2432) — external technical standard, not legislative cross-referencing","Simple conditional logic: 'If Dumont bolt found → replace'","No nested exceptions or complex temporal provisions","Plain language throughout with minimal aviation jargon"],"plain_english_summary":"This CASA Airworthiness Directive requires owners/operators of specified Beechcraft 300 series aeroplanes to inspect the engine-to-firewall mounting bolts and replace any Dumont Aviation bolts (suspected of improper heat treatment) with MS20006-20 bolts. Action must be taken within the specified compliance window. It targets aircraft in Beechcraft Service Bulletin 2432 and prevents potentially catastrophic engine-mount failures."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"Scope remains a targeted, one-time inspection and replacement requirement for the specific Beech 300 serials listed in SB 2432. The directive does not broaden applicability beyond those aircraft or impose recurring inspections; it directs a corrective action where bolts potentially received improper heat treatment (Background; Applicability; Requirement 1–2)."},"complexity_factors":["Narrow applicability: applies only to models/serial numbers listed in Beech SB 2432 (Applicability).","Technical identification: requires verifying bolt manufacturer per Figure 2 and Beech SB 2432 instructions (Requirement 1).","One-at-a-time removal constraint increases task sequencing and downtime risk for maintenance (Requirement 1).","Immediate replacement requirement: any identified Dumont bolt must be replaced before further flight, creating potential grounding until parts fitted (Requirement 2; Compliance).","Fixed compliance window (150 hours TIS) creates scheduling pressure for operators (Compliance 1).","Dependency on external documents (Beech SB 2432 and referenced FAA AD) for execution and interpretation (Note; Background).","Requires qualified maintenance personnel and access to specific replacement part MS20006-20/M (Requirement 2)."],"plain_english_summary":"This airworthiness directive requires owners/operators of the Beechcraft 300 series listed in Beech Service Bulletin 2432 to remove and inspect each engine truss‑to‑firewall bolt to see if it was manufactured by Dumont Aviation, and to replace any such bolt with part MS20006-20/M (Requirement 1–2). Costs, parts sourcing and labour fall to the operator; only one bolt may be removed at a time and the inspection must be done within 150 hours TIS (Compliance) with any identified bolt replaced before further flight."}},"importantCases":[],"_links":{"self":"/api/acts/ad-beech-300-3-engine-mount-assembly-attachment-bolts","history":"/api/acts/ad-beech-300-3-engine-mount-assembly-attachment-bolts/history","analysis":"/api/acts/ad-beech-300-3-engine-mount-assembly-attachment-bolts/analysis","conflicts":"/api/acts/ad-beech-300-3-engine-mount-assembly-attachment-bolts/conflicts","importantCases":"/api/acts/ad-beech-300-3-engine-mount-assembly-attachment-bolts/important-cases","documents":"/api/acts/ad-beech-300-3-engine-mount-assembly-attachment-bolts/documents"}}