{"id":"F2006B10822","name":"AD/INST/20 - Sep 2 Automatic Pilot Trim Servomotor Venting - Modification","slug":"ad-inst-20-sep-2-automatic-pilot-trim-servomotor-venting-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":56300,"registerId":"commonwealth-F2006B10822-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/INST/20 - Sep 2 Automatic Pilot Trim Servomotor Venting - Modification","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 - 107 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Instruments and Automatic Pilots\n\n \n\nAD/INST/20  Sep 2 Automatic Pilot Trim Servomotor Venting - Modification\n\n\n7/76\n\n \n\nApplicability: Code 233 EAP, 234 EAP, 234 EAP/1, 234 EAP/2, 259 EAP, 259 EAP/1, 272 EAP,\n\n272 EAP/1 and 280 EAP SEP 2 trim servomotors.\n\n \n\nDocument: Smiths SB No. 22-918.\n\n \n\nCompliance: Before installation in an aircraft following the next reconditioning or repair performed after 30July 1976, whichever occurs first.\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\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":1646},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive maintains its original narrow scope from 1976, targeting only specific Smiths SEP 2 trim servomotor models for a single venting modification requirement without expansion into broader systems or aircraft types."},"complexity_factors":["Single, time-based compliance trigger (post-30 July 1976 reconditioning/repair)","Finite list of only 9 specific part number codes in applicability section","No conditional exceptions, nested definitions, or cross-references to other legislation","References only one external technical document (Smiths SB No. 22-918)","Extremely short directive with no interpretive provisions"],"plain_english_summary":"This Airworthiness Directive (AD) orders a mandatory modification for specific Smiths Industries automatic pilot trim servomotors (the SEP 2 models with part codes like 233 EAP, 234 EAP, and seven others). **The issue**: These units require venting modifications to prevent moisture or pressure buildup that could impair the autopilot's trim function. **Who it affects**: Aircraft operators and maintenance organisations handling these nine specific servomotor models. **What you must do**: Before installing one of these servomotors in an aircraft—following its next reconditioning or repair after 30 July 1976, whichever comes first—you must complete the venting modification per Smiths Service Bulletin No. 22-918. **Why it matters**: Prevents autopilot trim system failures that could compromise aircraft control and safety."}},"importantCases":[],"_links":{"self":"/api/acts/ad-inst-20-sep-2-automatic-pilot-trim-servomotor-venting-modification","history":"/api/acts/ad-inst-20-sep-2-automatic-pilot-trim-servomotor-venting-modification/history","analysis":"/api/acts/ad-inst-20-sep-2-automatic-pilot-trim-servomotor-venting-modification/analysis","conflicts":"/api/acts/ad-inst-20-sep-2-automatic-pilot-trim-servomotor-venting-modification/conflicts","importantCases":"/api/acts/ad-inst-20-sep-2-automatic-pilot-trim-servomotor-venting-modification/important-cases","documents":"/api/acts/ad-inst-20-sep-2-automatic-pilot-trim-servomotor-venting-modification/documents"}}