{"id":"F2006B05470","name":"AD/PA-23/44 Amdt 1 - Pitch Trim Switch - Modification","slug":"ad-pa-23-44-amdt-1-pitch-trim-switch-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":46256,"registerId":"commonwealth-F2006B05470-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PA-23/44 Amdt 1 - Pitch Trim Switch - 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 - 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\nAD/PA-23/44\n\nAmdt 1\n\n\nPitch Trim Switch - Modification 9/77\n\n \n\nApplicability: Models PA-23-250 and PA-E23-250 with S/Nos. 27-3837 27-4796, fitted with Rocker Type Trim Switch on Pilot’s Control Wheel.\n\n \n\nDocument: 1. Piper SB No. 527; or 2. FAA AD 77-09-10.\n\nCompliance: Within 100 hours time in service after 28 February 1977.\n\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":true,"description":"The entry is presented as \"Amdt 1\" to AD/PA-23/44, indicating it amends a prior directive. This amendment specifies (1) the exact applicability (models, serial numbers, and the presence of a rocker-type pilot trim switch), (2) the acceptable compliance methods (Piper SB No. 527 or FAA AD 77-09-10), and (3) a firm compliance period (within 100 hours TIS after 28 February 1977). These elements define the current scope of obligation for affected operators."},"complexity_factors":["Very narrow applicability: specific models and a limited range of serial numbers (Applicability).","Equipment-specific condition: applies only if fitted with a rocker-type trim switch on the pilot's control wheel (Applicability).","Compliance requires consulting external technical documents (Piper SB No. 527 or FAA AD 77-09-10), which adds a step outside the AD text (Document).","Short and firm compliance window (100 hours TIS after 28 February 1977) creates scheduling constraints (Compliance).","Labelled as an amendment (Amdt 1), requiring operators to track which version applies to their aircraft (Header)."],"plain_english_summary":"What this instrument does (mechanically)\n\n- This is an airworthiness directive (AD) that requires a specific modification to the pitch trim switch on certain Piper PA-23 aeroplanes. (See \"Applicability\".)\n- It applies only to PA-23-250 and PA-E23-250 aeroplanes with the listed serial numbers and only where the aircraft is fitted with a rocker-type trim switch on the pilot's control wheel. (Applicability: \"Models PA-23-250 and PA-E23-250 with S/Nos. 27-3837 27-4796, fitted with Rocker Type Trim Switch on Pilot’s Control Wheel.\")\n- The AD directs operators to carry out the modification in accordance with one of two documents: Piper Service Bulletin No. 527 or FAA AD 77-09-10. (Document: \"1. Piper SB No. 527; or 2. FAA AD 77-09-10.\")\n- The work must be done within 100 hours time-in-service after 28 February 1977. (Compliance: \"Within 100 hours time in service after 28 February 1977.\")\n\nWhy it matters (stated purpose and practical consequences)\n\n- The title and requirement of the AD identify the action: a pitch trim switch modification. The AD therefore imposes a mandatory maintenance/modification task on a narrow group of aircraft; the text itself does not set out a narrative explanation of the underlying technical failure mode or accident history.\n\n- Who pays: operators/owners of the affected aeroplanes must arrange and pay for the modification. (Applicability + Compliance.)\n\n- Who decides and how: the Civil Aviation Safety Authority issued the AD as the prescriptive instrument. The AD prescribes the acceptable means of compliance by reference to Piper SB No. 527 or FAA AD 77-09-10; operators must follow one of those documents to meet the AD requirement. (Document.)\n\n- Compliance burden and implementation mechanics: operators must first identify whether an aircraft is within the serial-number range and whether it has the specified rocker-type trim switch (Applicability). If so, they must obtain and follow one of the referenced documents to perform the modification and schedule the work within the stated 100 hours TIS window (Compliance; Document). This imposes direct maintenance cost, downtime and administrative record-keeping for the affected aircraft.\n\n- Effects on private enterprise and markets: the AD creates a small, immediate demand for maintenance work and for use of the methods in the cited service/airworthiness documents. Independent maintenance providers or the operator's own maintenance organisation will perform the work. The AD does not itself require use of a particular maintenance provider or parts supplier; it requires adherence to the referenced technical instructions. (Document.)\n\n- Trade-offs, incentives and risk allocation: the AD concentrates obligations and direct costs on owners/operators of the specified aircraft and reduces the operator's discretion to defer or ignore the modification beyond the set time window (Compliance). The mechanism transfers the decision of how to meet the requirement to the operator, constrained to the two referenced documents. Implementation risk arises from obtaining and correctly applying the referenced documents and from scheduling the work inside the stated compliance period. (Document; Compliance.)\n\nNotes on scope and tracking\n\n- This entry is labelled as Amendment 1 to AD/PA-23/44 (Amdt 1), which indicates it modifies a prior directive. The instrument itself specifies applicability, documentary means of compliance, and a firm compliance period; those are the concrete changes operators must track. (Header: \"AD/PA-23/44 Amdt 1\"; Applicability; Document; Compliance.)"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive. It has not expanded beyond its original purpose of addressing a specific trim switch defect in specific aircraft. Airworthiness directives are inherently narrow in scope by design."},"complexity_factors":["Single, specific technical requirement with clear applicability criteria","Only 2 reference documents cited","Simple compliance deadline (100 hours time in service after fixed date)","Narrow scope — limited to specific aircraft models, serial number range, and switch type","No nested exceptions, conditional logic, or defined terms section","Total length under 200 words"],"plain_english_summary":"This is an **Airworthiness Directive** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). It requires owners of specific Piper Apache and Aztec aircraft to modify the pitch trim switch on the pilot's control wheel.\n\n**What it does:**\n- Mandates a safety modification to prevent potential trim switch failures\n- Applies only to specific aircraft models (PA-23-250 and PA-E23-250) with serial numbers between 27-3837 and 27-4796\n- Only affects planes with \"rocker type\" trim switches on the pilot's control wheel\n\n**Who must comply:**\n- Owners and operators of the affected Piper aircraft\n- Must be completed within 100 hours of flight time after 28 February 1977\n\n**Why it matters:**\nPitch trim controls help keep the aircraft level during flight. A faulty trim switch could cause sudden, unexpected nose-up or nose-down movements, potentially leading to loss of control. This directive ensures a known defect is fixed before it causes an accident.\n\n**How to comply:**\nFollow either Piper Service Bulletin No. 527 or the equivalent US Federal Aviation Administration directive (FAA AD 77-09-10)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pa-23-44-amdt-1-pitch-trim-switch-modification","history":"/api/acts/ad-pa-23-44-amdt-1-pitch-trim-switch-modification/history","analysis":"/api/acts/ad-pa-23-44-amdt-1-pitch-trim-switch-modification/analysis","conflicts":"/api/acts/ad-pa-23-44-amdt-1-pitch-trim-switch-modification/conflicts","importantCases":"/api/acts/ad-pa-23-44-amdt-1-pitch-trim-switch-modification/important-cases","documents":"/api/acts/ad-pa-23-44-amdt-1-pitch-trim-switch-modification/documents"}}