{"id":"F2006B05439","name":"AD/PA-22/34 - Shimmy Damper","slug":"ad-pa-22-34-shimmy-damper","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":46157,"registerId":"commonwealth-F2006B05439-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PA-22/34 - Shimmy Damper","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-22 (Tri-Pacer and Colt) Series Aeroplanes\n\n \n\nAD/PA-22/34 Shimmy Damper 2/90\n\nApplicability: Models PA 22-125/135/150/160 Tri-Pacer with serial numbers 22-1 through 22-7642 and model PA 22-108 Colt with serial numbers 22-8000 through 22-9848; and equipped with shimmy damper, Piper part number 13086-00, or 21701-02, or 21701- 04.\n\n \n\nRequirement: Action in accordance with Piper Service Bulletin No. 924. Compliance:  Prior to the issue of the next Maintenance Release after 30 April 1990.\n\nBackground: The shimmy damper currently installed in applicable aircraft may be defective and could jam during a maximum left turn, resulting in partial or total loss of rudder control. This AD requires replacement of the early model damper and a serviceability check of later model dampers.\n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":1540},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive remains focused on its original purpose: addressing the specific safety defect in shimmy dampers for Piper PA-22 aircraft. There is no evidence of scope creep or expansion beyond the initial safety concern regarding rudder control loss."},"complexity_factors":["Narrow applicability limited to specific aircraft models and serial number ranges","Single, clear compliance requirement referencing an external technical standard (Piper Service Bulletin No. 924)","No nested exceptions or conditional logic—just a straightforward replacement and inspection mandate","Specific but simple deadline tied to Maintenance Release cycle"],"plain_english_summary":"This safety rule applies to owners of specific **Piper PA-22 aircraft** (Tri-Pacer and Colt models with particular serial numbers) that have a **shimmy damper** installed—a device that prevents the nose wheel from shaking during takeoff or landing.\n\n**What you must do:**\n- If your aircraft is listed in the applicability section, you must follow **Piper Service Bulletin No. 924** before your next Maintenance Release (a safety check document) is issued after 30 April 1990.\n- Early model dampers must be replaced entirely.\n- Later model dampers must undergo a serviceability check.\n\n**Why this matters:**\nThe shimmy damper can jam when the rudder is turned fully to the left, which could cause **partial or total loss of rudder control**—a serious safety risk during flight. This directive ensures the defective part is identified and fixed before the aircraft returns to service."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pa-22-34-shimmy-damper","history":"/api/acts/ad-pa-22-34-shimmy-damper/history","analysis":"/api/acts/ad-pa-22-34-shimmy-damper/analysis","conflicts":"/api/acts/ad-pa-22-34-shimmy-damper/conflicts","importantCases":"/api/acts/ad-pa-22-34-shimmy-damper/important-cases","documents":"/api/acts/ad-pa-22-34-shimmy-damper/documents"}}