{"id":"F2006B07024","name":"AD/SF340/93 - Engine Bottom Mounts","slug":"ad-sf340-93-engine-bottom-mounts","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":48695,"registerId":"commonwealth-F2006B07024-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# AIRWORTHINESS DIRECTIVE\n\n![](image.001.png)\n\nFor the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CASR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.\n\n![](image.001.png)  \n\nSAAB SF340 Series Aeroplanes","sortOrder":0},{"sectionNumber":"AD/SF340/93 Engine Bottom Mounts 7/2003","sectionType":"part","heading":"AD/SF340/93 Engine Bottom Mounts 7/2003","content":"# AD/SF340/93 Engine Bottom Mounts 7/2003\n\nApplicability: Model SF340A aircraft, serial numbers 004 through 159.\n\nModel 340B aircraft, serial numbers 160 through 459.\n\nRequirement: Action in accordance with Saab Aircraft Mandatory Service Bulletin 340-71-059, dated 16 May 2003.\n\nNote: LFV AD 1-192 refers.\n\nCompliance: Within 500 flight hours after 10 July 2003.\n\nThis Airworthiness Directive becomes effective on 10 July 2003.\n\nBackground: The engine bottom mounts molded assembly part number 00-13226-03 with certain cure dates, have exhibited de-bonding of the elastomer from the metal inner core and shim after a few hundred hours of operation. This de-bonding will reduce the redundancy and change the stiffness and damping characteristics of the engine support system, causing heavy chafing on the nacelle structure and chafing of the fire sensor loop.\n\n![Signature of David Villiers Delegate of the Civil Aviation Safety Authority](image.002.jpeg)  \n\nDavid Villiers\n\nDelegate of the Civil Aviation Safety Authority 30 May 2003\n\n![](image.001.png)","sortOrder":1}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope — addressing a specific manufacturing defect in engine mounts for a particular aircraft type. There is no evidence of scope creep; it targets exactly the unsafe condition described in the background."},"complexity_factors":["Single, clearly defined applicability (two specific aircraft models with serial number ranges)","Single requirement referencing an external technical document (Saab Service Bulletin)","Simple compliance deadline (500 flight hours from effective date)","No defined terms section, no nested exceptions, no conditional logic","Background section provides clear technical rationale in plain language","Total length: approximately 200 words of substantive text"],"plain_english_summary":"This AD requires owners/operators of Saab SF340A (s/n 004–159) and SF340B (s/n 160–459) to inspect and repair engine bottom mounts with certain manufacture dates because the elastomer can separate from the metal core. Follow Saab Mandatory Service Bulletin 340-71-059 (16 May 2003) and complete repairs within 500 flight hours after 10 July 2003 to prevent excessive engine movement, structural damage, or fire-detection failures."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD implements corrective action limited to the identified Saab SF340 serial numbers and the specified engine mount part; it does not broaden applicability or alter the remedial measure beyond mandating the Saab service bulletin within the stated compliance period."},"complexity_factors":["Narrow applicability by aircraft model and serial number (Applicability: SF340A s/n 004–159; 340B s/n 160–459) increases administrative tracking but limits operational scope.","Dependence on an external technical document for the corrective action (Requirement: Saab Mandatory Service Bulletin 340‑71‑059, dated 16 May 2003) creates interpretive and implementation reliance.","Single, short compliance window (within 500 flight hours after 10 July 2003) requires scheduling and potential out‑of‑service time.","Technical specificity tied to a particular part number and cure dates (Background: p/n 00‑13226‑03) demands inspection/identification work and possible parts replacement.","Safety‑critical nature of the defect (reduced redundancy, changed stiffness/damping, chafing of nacelle and fire sensor loop) raises urgency but follows standard AD processes.","Regulatory decision is delegated to a CASA official (signature by CASA delegate) rather than requiring further legislative action."],"plain_english_summary":"This Airworthiness Directive requires operators of Saab SF340A (s/n 004–159) and 340B (s/n 160–459) to carry out the work specified in Saab Mandatory Service Bulletin 340‑71‑059 (16 May 2003) on engine bottom mounts within 500 flight hours of 10 July 2003. It responds to de‑bonding of the elastomer from the metal core on part no. 00‑13226‑03 that alters support stiffness and causes nacelle and fire‑sensor chafing. The CASA delegate issues the requirement; operators/owners bear the cost and compliance burden."}},"importantCases":[],"_links":{"self":"/api/acts/ad-sf340-93-engine-bottom-mounts","history":"/api/acts/ad-sf340-93-engine-bottom-mounts/history","analysis":"/api/acts/ad-sf340-93-engine-bottom-mounts/analysis","conflicts":"/api/acts/ad-sf340-93-engine-bottom-mounts/conflicts","importantCases":"/api/acts/ad-sf340-93-engine-bottom-mounts/important-cases","documents":"/api/acts/ad-sf340-93-engine-bottom-mounts/documents"}}