{"id":"F2006B04265","name":"AD/BEECH 90/81 - Stabiliser and Fin Moisture Sealing","slug":"ad-beech-90-81-stabiliser-and-fin-moisture-sealing","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44066,"registerId":"commonwealth-F2006B04265-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BEECH 90/81 - Stabiliser and Fin Moisture Sealing","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)  Beechcraft 90 and 65-90 (King Air) Series Aeroplanes\n\n \n\nAD/BEECH 90/81 Stabiliser and Fin Moisture Sealing 8/89\n\nApplicability: Model F90 S/N LA-1 to LA-236.\n\n \n\nRequirement: Action in accordance with Beechcraft SB 2254.\n\n \n\nCompliance: Prior to the next inspection for Maintenance Release issue after 10 August 1989 or within 100 hours’ time in service after 10 August 1989 whichever is later.\n\n \n\nBackground: The Authority is aware of control cable freezing occurring in local 100 and 200 series aircraft. This was addressed by Australian mandatory action. The manufacturer has now indicated that the F90 series are also susceptible.\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":1480},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This directive maintains its original narrow scope addressing a specific safety defect (moisture ingress causing control cable freezing) in a specific aircraft model. There is no evidence of scope expansion beyond the original intent to mandate moisture sealing for the Beechcraft F90 series."},"complexity_factors":["Single applicability criterion (one model series with specific serial number range)","Only one substantive requirement (compliance with external service bulletin)","Simple alternative compliance deadline (inspection OR flight hours, whichever is later)","No defined terms or interpretation section","No nested exceptions, provisos, or conditional logic"],"plain_english_summary":"This directive requires owners/operators of Beechcraft Model F90 aircraft (serials LA-1 through LA-236) to follow Beechcraft Service Bulletin 2254 to seal the stabiliser and fin, preventing moisture ingress that can freeze and jam control cables.\n\nComplete the work by the later of: your next scheduled maintenance release inspection after 10 August 1989, or within 100 flight hours after that date. Frozen cables can cause loss of control; similar fixes were done on King Air 100/200 series."}},"importantCases":[],"_links":{"self":"/api/acts/ad-beech-90-81-stabiliser-and-fin-moisture-sealing","history":"/api/acts/ad-beech-90-81-stabiliser-and-fin-moisture-sealing/history","analysis":"/api/acts/ad-beech-90-81-stabiliser-and-fin-moisture-sealing/analysis","conflicts":"/api/acts/ad-beech-90-81-stabiliser-and-fin-moisture-sealing/conflicts","importantCases":"/api/acts/ad-beech-90-81-stabiliser-and-fin-moisture-sealing/important-cases","documents":"/api/acts/ad-beech-90-81-stabiliser-and-fin-moisture-sealing/documents"}}