{"id":"F2006B06997","name":"AD/SF340/68 - Power Plant - Engine Mount Inspection","slug":"ad-sf340-68-power-plant-engine-mount-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":48614,"registerId":"commonwealth-F2006B06997-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/SF340/68 - Power Plant - Engine Mount Inspection","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)  \nSAAB SF340 Series Aeroplanes\n\nAD/SF340/68 Power Plant \\- Engine Mount Inspection 2/99\n\nDM\n\nApplicability: SAAB Model SF340A, serial numbers \\-004 through \\-159 and SAAB Model 340B aeroplanes, serial numbers -160 through -459.\n\nRequirement: 1. Perform engine mount inspection in accordance with SAAB Aircraft Mandatory Service Bulletin No. SAAB 340-71-057 Rev 01 dated 18 December 1998, or later revision.\n\n2. Repeat inspection at 1. Above.\n\nNote: LFV Airworthiness Directive 1-135 R1 dated 18 December 1998 refers.\n\nCompliance: 1. Unless already accomplished, within 400 flight hours of the effective date of this Directive.\n\n2. Every 250 flight hours if required in para 2.B(6) of SAAB Aircraft AB Mandatory Service Bulletin SAAB 340-71-057 R01, dated 18 December 1998.\n\nInitial compliance against SAAB 340-71-057, dated 20 November 1998 is an acceptable means of compliance with requirement 1) and 2) above if achieved before the effective date of this Directive.\n\nThis Airworthiness Directive becomes effective on 13 January 1999.\n\nBackground: Certain bottom forward engine mounts have been found to be degraded after a short period in service. This degradation reduces the redundancy and damping effects of the engine support system and can lead to heavy chafing of the nacelle structure and fire sensor loop with consequent reduction in safety of the structure and sensor system. This Directive mandates a Country of Origin inspection to locate degraded mounts and replace as necessary.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a discrete, time-limited safety directive addressing a specific identified defect in a particular aircraft type. It has not expanded beyond its original purpose of mandating engine mount inspections."},"complexity_factors":["Short, single-purpose directive focused on one specific mechanical issue","Only 2 substantive requirements with clear compliance timeframes","Cross-references to external technical document (SAAB service bulletin) rather than internal legislative complexity","Simple conditional logic (repeat inspection only 'if required' by referenced bulletin)","Single defined applicability range (specific serial numbers)","No nested exceptions or layered conditional provisions"],"plain_english_summary":"CASA issued an Airworthiness Directive for SAAB SF340A and SF340B aircraft (serials -004 to -459) requiring inspection and replacement of bottom forward engine mounts per a SAAB service bulletin. Inspections must begin within 400 flight hours, with follow-ups every 250 hours if defects are found.\n\nThe AD prevents engine chafing that could damage fire-detection equipment and lead to engine-related fires. Australia adopted this as the country-of-origin action from Sweden’s LFV AD 1-135 R1."},"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The Directive implements a focused corrective requirement for specified SAAB SF340 serials to inspect and replace degraded bottom‑forward engine mounts. The text does not expand applicability beyond the stated serial ranges or add new categories of affected aircraft; it merely prescribes inspection timing, methods (by reference to the SAAB Service Bulletin), and acceptance of prior compliance. No material change from the instrument's original corrective intent is evident in the provided text."},"complexity_factors":["Narrow applicability by serial-number ranges (SAAB SF340A -004 to -159; 340B -160 to -459) — requires precise aircraft identification.","Reliance on an external document: SAAB Mandatory Service Bulletin SAAB 340-71-057 (including later revisions) as the compliance standard, creating dependency on manufacturer documentation.","Specific timing requirements: initial compliance within 400 flight hours and conditional repeat intervals (250 flight hours if para 2.B(6) applies) — operational scheduling impact.","Conditionality/interpretation risk: repeat inspection depends on a paragraph in the Service Bulletin (para 2.B(6)), which may require interpretation by maintenance personnel/regulator.","Acceptable means clause: earlier compliance via SAAB 340-71-057 dated 20 Nov 1998 can satisfy obligations if completed before the effective date — introduces retroactive compliance recognition.","Technical and logistical burden: inspections and potential part replacements impose maintenance cost, parts procurement and downtime on operators.","Regulatory coordination: mandates a 'Country of Origin' inspection and references an LFV AD, implying cross-jurisdictional alignment requirements."],"plain_english_summary":"Mandates inspection and, where necessary, replacement of bottom‑forward engine mounts on specified SAAB SF340A/B serial numbers, carried out in accordance with SAAB Mandatory Service Bulletin SAAB 340-71-057 (or later revision). Operators must complete an initial inspection within 400 flight hours and repeat inspections as specified (250 flight‑hour interval where paragraph 2.B(6) applies). The measure targets degraded mounts that can cause structural chafing and fire‑sensor damage. Operators pay for inspections and repairs and must adjust maintenance schedules accordingly."}},"importantCases":[],"_links":{"self":"/api/acts/ad-sf340-68-power-plant-engine-mount-inspection","history":"/api/acts/ad-sf340-68-power-plant-engine-mount-inspection/history","analysis":"/api/acts/ad-sf340-68-power-plant-engine-mount-inspection/analysis","conflicts":"/api/acts/ad-sf340-68-power-plant-engine-mount-inspection/conflicts","importantCases":"/api/acts/ad-sf340-68-power-plant-engine-mount-inspection/important-cases","documents":"/api/acts/ad-sf340-68-power-plant-engine-mount-inspection/documents"}}