{"id":"F2006B05752","name":"AD/PA-31/48 - Alternator Switch Bus Bar Link Insulation - Modification","slug":"ad-pa-31-48-alternator-switch-bus-bar-link-insulation-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":135597,"registerId":"commonwealth-F2006B05752-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PA-31/48 - Alternator Switch Bus Bar Link Insulation - 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-31/48 Alternator Switch Bus Bar Link Insulation - Modification\n\nApplicability: Model 31P Serials 31P-1 to 31P-7630001 inclusive and 31P-7630003. Document:  1. Piper SB No. 473; or\n\n2. FAA AD 76-11-06.\n\n \n\nCompliance: Within 100 hours time in service after 31 August 1976.\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\n \n\n \n\n\n8/76\n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The source text defines a narrowly targeted modification for identified serial numbers, with a single compliance deadline and specified external documents for the procedure (Applicability; Document; Compliance). There is no indication in the provided text that the scope has been altered from the instrument's original stated action."},"complexity_factors":["Narrow applicability to a single model and specific serial number range (Applicability).","Single, clearly defined required action (modification of alternator switch bus bar link insulation) described in the title.","Mandatory compliance timeframe specified (within 100 hours TIS after 31 August 1976) (Compliance).","Dependence on external technical documents for the detailed procedure (Piper SB No. 473 or FAA AD 76-11-06) increases procedural dependence but not conceptual complexity (Document).","Historical/dated compliance window makes the directive a past-action mandate rather than an ongoing inspection regime (Compliance).","Little procedural discretion or multiple compliance options provided in the text itself—one must follow the referenced documents (Document)."],"plain_english_summary":"What this instrument requires, mechanically\n\n- The directive requires a physical modification: insulation of the alternator switch bus bar link on certain Piper PA-31 (Model 31P) aeroplanes. The required work is to be carried out following one of the two referenced technical documents: Piper Service Bulletin No. 473 or FAA AD 76-11-06 (see \"Document\").\n\nWho it affects\n\n- This applies only to Piper PA-31 Model 31P aeroplanes with the serial numbers listed: 31P-1 through 31P-7630001 inclusive, and 31P-7630003 (see \"Applicability\"). Owners, operators and maintenance organisations responsible for those specific aircraft are the parties required to act.\n\nWhen it must be done\n\n- The modification had to be completed within 100 hours time in service after 31 August 1976 (see \"Compliance\").\n\nWhy the rule is in place (how the source frames the purpose)\n\n- The title of the directive identifies the subject as \"Alternator Switch Bus Bar Link Insulation - Modification.\" From that title and the use of an airworthiness directive, the source frames the action as addressing a condition with the alternator switch bus bar link that requires modification. The instrument itself does not set out a detailed explanation or background in this text; it refers users to the specified service/airworthiness documents for the technical procedures (see \"Document\").\n\nWho pays, who decides and what behaviour changes\n\n- Who pays: The aircraft owner/operator pays for parts, labour and any downtime needed to perform the modification. This follows from the directive placing an obligation on those responsible for the listed aircraft (see \"Applicability\" and \"Compliance\").\n- Who decides: The Civil Aviation Safety Authority issued the directive as part of the Schedule of Airworthiness Directives; the technical method of compliance is decided by following the referenced Piper SB or FAA AD (see header and \"Document\").\n- Behaviour changes required: For affected aircraft, maintenance personnel must perform the specified insulation modification within the prescribed time window and in accordance with one of the referenced documents.\n\nPractical costs, incentives and implementation trade-offs (mechanical and economic)\n\n- Direct costs and burdens: The operator bears the direct costs of the modification—parts, certified maintenance labour and aircraft downtime—because the AD imposes the modification on specified serials (see \"Applicability\" and \"Compliance\").\n- Compliance burden: The AD's instruction to follow an external Piper service bulletin or FAA AD means operators must obtain and follow those documents; this adds a small administrative step and ties the required procedure to those documents (see \"Document\").\n- Incentives: Operators are incentivised to comply within the time window to meet the regulatory requirement for those aircraft; the directive defines the required action and the timeframe (see \"Compliance\").\n- Trade-offs and opportunity cost: Time and money spent performing the retrofit are foregone uses of the aircraft during downtime; conversely, the measure replaces whatever residual risk the referenced documents are intended to address with an immediate maintenance cost.\n- Implementation risk and discretion: The AD prescribes the modification by reference to a service bulletin or foreign AD rather than embedding the full procedure in the directive text. That concentrates implementation detail in the external documents; maintenance organisations will need to interpret and apply those documents. The directive itself leaves no elaboration on alternative methods of compliance in this text (see \"Document\").\n\nScope and reach\n\n- The instrument is narrow in scope: it applies only to a specific model and a narrowly defined set of serial numbers, and it mandates a single modification to be completed within a defined historical time window (see \"Applicability\" and \"Compliance\")."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue airworthiness directive from 1976 addressing a specific electrical insulation defect. It has not expanded beyond its original narrow technical scope."},"complexity_factors":["Extremely short document (approximately 150 words)","Only 2 defined applicability criteria (model and serial numbers)","Simple binary compliance path (follow either of 2 referenced documents)","Single unambiguous deadline (100 hours time in service after fixed date)","No nested conditions, exceptions, or cross-references to other legislation","No interpretive provisions or defined terms section"],"plain_english_summary":"**What this is:** This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) that requires aircraft owners to fix a specific mechanical problem.\n\n**What it does:** It orders owners of certain **Piper PA-31 aeroplanes** (specifically Model 31P with serial numbers from 31P-1 up to 31P-7630001, plus 31P-7630003) to carry out a **modification to the alternator switch bus bar link insulation**. In plain terms: there's a problem with the electrical wiring insulation around the alternator switch that could cause a safety issue, and this directive mandates a fix.\n\n**Who must comply:** Anyone who owns or operates one of these specific Piper aircraft models in Australia.\n\n**How to comply:** Follow either:\n- **Piper Service Bulletin No. 473** (the manufacturer's official repair instructions), OR\n- **FAA AD 76-11-06** (the equivalent American safety order)\n\n**Deadline:** The work must be done **within 100 hours of flight time** after 31 August 1976.\n\n**Why it matters:** Airworthiness Directives are legally binding. Flying an aircraft without complying with an AD can ground the plane and expose the operator to penalties. This particular AD addresses an electrical insulation defect that could potentially cause electrical failure or fire."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pa-31-48-alternator-switch-bus-bar-link-insulation-modification","history":"/api/acts/ad-pa-31-48-alternator-switch-bus-bar-link-insulation-modification/history","analysis":"/api/acts/ad-pa-31-48-alternator-switch-bus-bar-link-insulation-modification/analysis","conflicts":"/api/acts/ad-pa-31-48-alternator-switch-bus-bar-link-insulation-modification/conflicts","importantCases":"/api/acts/ad-pa-31-48-alternator-switch-bus-bar-link-insulation-modification/important-cases","documents":"/api/acts/ad-pa-31-48-alternator-switch-bus-bar-link-insulation-modification/documents"}}