{"id":"F2006B05722","name":"AD/PA-31/16 Amdt 1 - Pitch Trim Switch - Modification","slug":"ad-pa-31-16-amdt-1-pitch-trim-switch-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":135521,"registerId":"commonwealth-F2006B05722-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PA-31/16 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-31 Series Aeroplanes\n\n \n\nAD/PA-31/16\n\nAmdt 1\n\n\nPitch Trim Switch - Modification 9/77\n\n \n\nApplicability: Model PA-31 and PA-31-300 S/Nos. 31-2 to 31-797; PA-31-350 S/Nos. 31-5001 to 31-5004; and PA-31P S/Nos 31P-1 to 31P-109; fitted with Rocker Type switch on pilot’s control wheel.\n\n \n\nDocument: 1. Piper SB No. 527; or\n\n \n\n2. FAA AD 77-09-10.\n\n \n\nCompliance: Within 100 hours time in service after 28 February 1977.\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":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The AD is labelled as an amendment (Amdt 1), but the text provided does not state or document any change in scope from a prior version. The instrument itself sets out the operative requirement (Applicability, Document, Compliance) without comparing or contrasting with an earlier issuance, so no change of scope can be identified from this text alone."},"complexity_factors":["Narrow applicability defined by specific model types and serial-number ranges (Applicability).","Requirement to follow one of two external technical references (Piper SB No. 527 or FAA AD 77-09-10) rather than describing the work in full within the AD (Document).","Technical nature of the mandated work (modification of pitch-trim switch) which requires technical documents and hands-on maintenance.","Single fixed compliance window tied to a historical reference date (100 hours TIS after 28 February 1977) which requires operators to calculate remaining allowable time in service (Compliance)."],"plain_english_summary":"This Airworthiness Directive (AD/PA-31/16 Amdt 1) requires a specific modification to the pitch-trim switch on certain Piper PA-31 series aeroplanes. Mechanically, the AD obliges operators to carry out the modification described in one of two external technical documents: Piper Service Bulletin No. 527 or FAA AD 77-09-10 (Document). The requirement applies only to the listed serial-number ranges and only to aeroplanes that are fitted with a rocker-type switch on the pilot’s control wheel (Applicability).\n\nTechnical Scope and Implementation\n\n- What the AD changes: It mandates that the pitch-trim switch modification be performed in accordance with either Piper SB No. 527 or FAA AD 77-09-10 (Document).\n- Which aeroplanes are affected: Model PA-31 and PA-31-300 with S/N 31-2 to 31-797; PA-31-350 with S/N 31-5001 to 31-5004; and PA-31P with S/N 31P-1 to 31P-109, but only if fitted with a rocker-type switch on the pilot’s control wheel (Applicability).\n- Deadline for compliance: The modification must be completed within 100 hours time in service after 28 February 1977 (Compliance).\n\nAffected Parties and Compliance Responsibility\n\n- Responsible parties: Owners/operators of the listed aeroplanes that have the rocker-type switch are responsible for ensuring the modification is carried out (Applicability). The AD requires following one of the two specified documents; it does not allow substituting other procedures in place of those documents (Document).\n\nPractical implementation steps an operator would follow (as derived from the AD text)\n\n1. Identify whether the aircraft model and serial number are within the listed ranges and confirm the aircraft is fitted with the rocker-type switch (Applicability).\n2. Obtain the required technical reference: Piper SB No. 527 or FAA AD 77-09-10 (Document).\n3. Schedule and complete the modification per the chosen document within the stated compliance window of 100 hours TIS after 28 February 1977 (Compliance).\n\nSource citations in this summary refer to the AD text sections labelled Applicability, Document, and Compliance."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard, narrow airworthiness directive focused on a specific technical modification to a specific aircraft type. The scope remains tightly constrained to the pitch trim switch modification as originally intended. Amendment 1 appears to be a minor update to the original AD/PA-31/16 without expanding the scope beyond the original safety purpose."},"complexity_factors":["Very short document (approximately 250 words)","Only 4 defined applicability criteria (specific aircraft models and serial numbers)","Simple conditional logic: applies only if rocker-type switch is fitted","Single compliance requirement with clear deadline","Only 2 reference documents cited","No nested exceptions or cross-references to other legislation sections"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** issued by Australia's Civil Aviation Safety Authority (CASA) that mandates a safety modification to specific Piper PA-31 series aircraft.\n\n**What it does:**\n- Requires owners/operators to modify the **pitch trim switch** (a control on the pilot's control wheel that adjusts the aircraft's nose-up or nose-down attitude) on certain Piper PA-31 aeroplanes\n- The modification addresses a specific type of switch — the \"rocker type\" switch on the pilot's control wheel\n\n**Who it affects:**\n- Owners and operators of specific Piper aircraft models:\n  - PA-31 and PA-31-300 (serial numbers 31-2 to 31-797)\n  - PA-31-350 (serial numbers 31-5001 to 31-5004)\n  - PA-31P (serial numbers 31P-1 to 31P-109)\n- Only applies if the aircraft has the rocker-type pitch trim switch installed\n\n**Why it matters:**\n- Airworthiness Directives are legally binding safety orders — compliance is mandatory\n- Pitch trim switch failures or malfunctions can cause dangerous flight conditions, including loss of control\n- The directive references **Piper Service Bulletin No. 527** and **FAA AD 77-09-10**, indicating this addresses a known safety issue identified by the manufacturer and US regulators\n\n**Compliance deadline:**\n- The modification must be completed within **100 hours of flight time** after 28 February 1977 (note: this is a historical directive from 1977, though Amendment 1 may be a later update to the original AD)"}},"importantCases":[],"_links":{"self":"/api/acts/ad-pa-31-16-amdt-1-pitch-trim-switch-modification","history":"/api/acts/ad-pa-31-16-amdt-1-pitch-trim-switch-modification/history","analysis":"/api/acts/ad-pa-31-16-amdt-1-pitch-trim-switch-modification/analysis","conflicts":"/api/acts/ad-pa-31-16-amdt-1-pitch-trim-switch-modification/conflicts","importantCases":"/api/acts/ad-pa-31-16-amdt-1-pitch-trim-switch-modification/important-cases","documents":"/api/acts/ad-pa-31-16-amdt-1-pitch-trim-switch-modification/documents"}}