{"id":"F2006B02122","name":"AD/AC/63 - Electric Elevator Trim Speed - Modification","slug":"ad-ac-63-electric-elevator-trim-speed-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41352,"registerId":"commonwealth-F2006B02122-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/AC/63 - Electric Elevator Trim Speed - Modification","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 4/1977,Aircraft below 5700 kg,Twin Commander (Gulfstream/Rockwell/ Aerocommander 500, 600 and 700) Series Aeroplanes,Electric Elevator Trim Speed - Modification,63\ntitle: Airworthiness Directive - AD/AC/63 - Electric Elevator Trim Speed - Modification\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/63 Electric Elevator Trim Speed - Modification 4/77\n\nApplicability:  Model 690A S/Nos. 11143 thru 11344 equipped with a Rockwell international installed Collins Radio Company AP 106 auto pilot (this AD does not apply to installations made in accordance with STC SA 1876 SW).\n\n \n\nDocument: 1. Rockwell International SB No. 162, Rev. 1 or 2. FAA AD 77-04-01.\n\nCompliance: Part I - Before 30 April 1977.\n\n \n\nPart II - Must be accomplished prior to re-activation of manual electric trim.\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":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a narrow, targeted safety directive focused on a specific technical modification for a specific aircraft type. It has not expanded beyond its original purpose of addressing the electric elevator trim speed issue in Twin Commander 690A aircraft."},"complexity_factors":["Very short document (approximately 200 words)","Only 1 defined term implicitly used (STC — Supplemental Type Certificate, a certification for aircraft modifications)","No cross-references to other legislation sections","Simple two-part compliance structure with clear deadlines","Narrow applicability — only one specific aircraft model range with specific serial numbers and specific equipment","Single exemption clearly stated","No nested conditions or exceptions beyond the basic applicability clause"],"plain_english_summary":"This mandatory CASA Airworthiness Directive requires owners/operators of Twin Commander 690A aircraft (S/N 11143–11344) fitted with Rockwell‑installed Collins AP‑106 autopilots to modify the electric elevator trim system to prevent excessive/overspeed trim movement. Aircraft with the autopilot installed under STC SA 1876 SW are exempt. The modification must be completed by 30 April 1977, and before any deactivated/disconnected manual electric trim is reactivated. Compliance follows Rockwell Service Bulletin No.162 (Rev 1/2) or FAA AD 77‑04‑01."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive as drafted applies narrowly to the listed Model 690A serials with the specified autopilot and references a particular service bulletin and FAA AD. The text shows no expansion or contraction of scope from its stated corrective purpose; obligations are limited to the named aircraft and installations (Applicability; Document; Compliance)."},"complexity_factors":["Narrow applicability: targets a single model and serial number range and a specific autopilot installation (Applicability).","Exclusion clause: does not apply where STC SA 1876 SW was used (Applicability).","External references: mandates compliance with Rockwell SB No.162 (Rev 1 or 2) and FAA AD 77‑04‑01, requiring operators to obtain and follow external documents (Document).","Two-stage compliance timing: Part I has a calendar deadline (before 30 April 1977) and Part II is conditional on operational action (must be done before re‑activation of manual electric trim) (Compliance).","Operational/maintenance impact: requires physical modification and recordation by operators, creating direct cost and maintenance scheduling obligations (Applicability; Compliance)."],"plain_english_summary":"This Airworthiness Directive requires a physical modification to the electric elevator trim system on certain Twin Commander Model 690A aeroplanes (S/N 11143–11344) fitted with a Collins AP‑106 autopilot (excludes installations under STC SA 1876 SW). It directs operators to follow Rockwell Service Bulletin No.162 (Rev 1 or 2) and FAA AD 77‑04‑01, with Part I done by 30 April 1977 and Part II completed before re‑activating manual electric trim. It affects owners/operators who must arrange and pay for the modification to comply."}},"importantCases":[],"_links":{"self":"/api/acts/ad-ac-63-electric-elevator-trim-speed-modification","history":"/api/acts/ad-ac-63-electric-elevator-trim-speed-modification/history","analysis":"/api/acts/ad-ac-63-electric-elevator-trim-speed-modification/analysis","conflicts":"/api/acts/ad-ac-63-electric-elevator-trim-speed-modification/conflicts","importantCases":"/api/acts/ad-ac-63-electric-elevator-trim-speed-modification/important-cases","documents":"/api/acts/ad-ac-63-electric-elevator-trim-speed-modification/documents"}}