{"id":"F2006B05461","name":"AD/PA-23/31 - Rudder Trim Tab Control Rod - Modification and Inspection","slug":"ad-pa-23-31-rudder-trim-tab-control-rod-modification-and-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":46226,"registerId":"commonwealth-F2006B05461-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PA-23/31 - Rudder Trim Tab Control Rod - Modification and Inspection","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)  Piper PA-23 (Apache and Aztec) Series Aeroplanes\n\n \n\n# AD/PA-23/31 Rudder Trim Tab Control Rod - Modification\n\nand Inspection\n\nApplicability: Models PA-23 and PA-23-160 with S/Nos. 23-1 to 23-2046.\n\n# 12/63\n\n \n\nRequirement: 1. Modify the forward end of the rudder trim tab control rod by replacing the existing cotter pin with a steel roll pin P/N 480-728 in accordance with Piper SL No. 407.\n\n \n\n2.     Inspect the rudder trim tab control rod in accordance with Piper SL No. 407.\n\n \n\n3.     Piper SL No. 407. Compliance: For para. 1 - Forthwith.\n\nFor para. 2 - At intervals not exceeding 100 hours time in service.\n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":1267},"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This airworthiness directive maintains its original targeted scope addressing a specific mechanical safety defect in defined Piper aircraft models. It has not expanded beyond its initial purpose of mandating a hardware modification and recurring inspection protocol for the rudder trim tab control rod assembly."},"complexity_factors":["References external technical document (Piper Service Letter No. 407) without reproducing its contents, creating dependency on outside material","Narrow applicability limited to specific aircraft models and serial number range (23-1 to 23-2046)","Dual compliance timelines with different triggers (immediate vs recurring 100-hour intervals)","Technical aviation terminology requiring specialized knowledge (cotter pin, roll pin, time in service, rudder trim tab)"],"plain_english_summary":"This directive requires owners/operators of specific Piper Apache and Aztec airplanes (PA‑23 and PA‑23‑160, S/N 23‑1 through 23‑2046) to immediately replace the cotter pin at the forward end of the rudder trim tab control rod with a steel roll pin (per Piper Service Letter No. 407) and thereafter inspect that control rod every 100 flight hours.  \n\nIt prevents possible trim‑tab control‑rod failure and loss of rudder trim control, which could make the airplane difficult or unsafe to handle."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pa-23-31-rudder-trim-tab-control-rod-modification-and-inspection","history":"/api/acts/ad-pa-23-31-rudder-trim-tab-control-rod-modification-and-inspection/history","analysis":"/api/acts/ad-pa-23-31-rudder-trim-tab-control-rod-modification-and-inspection/analysis","conflicts":"/api/acts/ad-pa-23-31-rudder-trim-tab-control-rod-modification-and-inspection/conflicts","importantCases":"/api/acts/ad-pa-23-31-rudder-trim-tab-control-rod-modification-and-inspection/important-cases","documents":"/api/acts/ad-pa-23-31-rudder-trim-tab-control-rod-modification-and-inspection/documents"}}