{"id":"F2006B02131","name":"AD/AC/71 - Aft Engine Mount Attachment - Inspection","slug":"ad-ac-71-aft-engine-mount-attachment-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41361,"registerId":"commonwealth-F2006B02131-current","compilationNumber":null,"startDate":"2026-04-01","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/AC/71 - Aft Engine Mount Attachment - Inspection","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-description: CASA Airworthiness Directive\nmeta-generator: Aspose.Words for .NET 22.10.0\nmeta-keywords: Issue 10/1980,Aircraft below 5700 kg,Twin Commander (Gulfstream/Rockwell/ Aerocommander 500, 600 and 700) Series Aeroplanes,Aft Engine Mount Attachment - Inspection,71\ntitle: Airworthiness Directive - AD/AC/71 - Aft Engine Mount Attachment - Inspection\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)  Twin Commander (Gulfstream/Rockwell/ Aerocommander 500, 600 and 700) Series Aeroplanes\n\n \n\nAD/AC/71 Aft Engine Mount Attachment - Inspection 10/80\n\nApplicability: All models 690B with S/Nos. 11535 to 11566. Document:  Rockwell International SB No. 173.\n\nCompliance: Within 100 hours’ time in service after 31 October 1980.\n\n \n\nBackground: The manufacturer advises that the aft engine mount fitting may not be properly mounted to the firewall.\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":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":1551},"content_quality":"ok","complexity_score":1,"scope_assessment":{"changed":false,"description":"This directive remains narrowly targeted at the specific safety defect identified in the 1980 manufacturer bulletin. The scope has not expanded beyond the original intent: requiring a one-time inspection of engine mount attachments on affected Twin Commander aircraft."},"complexity_factors":["Single, specific aircraft model and limited serial number range (32 aircraft)","One discrete compliance action (inspection only)","No defined terms or interpretation sections","Simple temporal trigger (100 hours after fixed date)","No exceptions, exemptions, or conditional logic","Approximately 80 words of substantive content"],"plain_english_summary":"**What this requires:**\n\nOwners and operators of specific Twin Commander 690B aircraft (serial numbers 11535 to 11566) must inspect the rear engine mount attachment within 100 flight hours after 31 October 1980.\n\n**Why it matters:**\n\nThe manufacturer (Rockwell International) identified that the aft engine mount fitting might not be properly attached to the firewall during manufacturing. A loose engine mount could cause the engine to shift or detach in flight, creating a serious safety risk.\n\n**What you need to do:**\n\nFollow the inspection procedures outlined in Rockwell International Service Bulletin No. 173 to check that the engine mount is properly secured."}},"importantCases":[],"_links":{"self":"/api/acts/ad-ac-71-aft-engine-mount-attachment-inspection","history":"/api/acts/ad-ac-71-aft-engine-mount-attachment-inspection/history","analysis":"/api/acts/ad-ac-71-aft-engine-mount-attachment-inspection/analysis","conflicts":"/api/acts/ad-ac-71-aft-engine-mount-attachment-inspection/conflicts","importantCases":"/api/acts/ad-ac-71-aft-engine-mount-attachment-inspection/important-cases","documents":"/api/acts/ad-ac-71-aft-engine-mount-attachment-inspection/documents"}}