{"id":"F2006B05778","name":"AD/PA-31/73 - Elevator Cable - Inspection and Modification","slug":"ad-pa-31-73-elevator-cable-inspection-and-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":135647,"registerId":"commonwealth-F2006B05778-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PA-31/73 - Elevator Cable - Inspection and 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-31/73 Elevator Cable - Inspection and Modification 12/78\n\nApplicability: All models PA-31-350 with S/Nos 31-5001 to 31-7852151. Document:  Piper SB No. 621.\n\nCompliance: Within the next 25 hours time in service after 15 November 1978.\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 \n\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific mechanical defect in a specific aircraft model. It has not expanded beyond its original purpose of mandating elevator cable inspection and modification."},"complexity_factors":["Very short document (single page directive)","Only 3 substantive requirements: applicability, reference document, and compliance deadline","No defined terms section","No cross-references to other legislation beyond the parent Civil Aviation Regulations 1998","Simple conditional logic: if you own this specific aircraft model with these serial numbers, you must comply","Single compliance trigger (time-in-service hours) with clear deadline"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for specific aircraft.\n\n**What it does:**\n- Requires owners/operators of certain Piper PA-31-350 aeroplanes (twin-engine Navajo/Chieftain aircraft) to inspect and modify the elevator control cables.\n- The directive references a specific Piper Service Bulletin (SB No. 621) which contains the technical details of what needs to be done.\n\n**Who it affects:**\n- Owners and operators of Piper PA-31-350 aircraft with serial numbers between 31-5001 and 31-7852151.\n\n**When it must be done:**\n- Within 25 hours of flying time after 15 November 1978.\n\n**Why it matters:**\n- Elevator cables control the aircraft's pitch (nose up/down movement). A failure here could cause loss of control and crash. This AD addresses a known safety defect before it causes an accident.\n\n**Key point:** This is not optional. Airworthiness Directives are legally binding safety requirements. Non-compliance means the aircraft cannot legally fly."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive's scope is stated explicitly: it applies to PA-31-350 aircraft with serial numbers 31-5001 through 31-7852151 (Applicability). The AD prescribes a one-time inspection/modification to be completed within the stated 25-hour window (Compliance). There is no information in the text indicating the scope was broadened or narrowed from an earlier or original intent."},"complexity_factors":["Narrow applicability limited to a single model and a defined serial number range (Applicability).","Clear, short compliance timeframe (25 hours TIS after 15 November 1978) reduces procedural complexity but increases scheduling pressure (Compliance).","Technical details are externalised to a manufacturer service bulletin (Piper SB No. 621), creating dependency on an external document for implementation (Document).","Directive is short and prescriptive; it does not create layered procedural requirements or multiple compliance options."],"plain_english_summary":"This AD mandates inspection and modification of the elevator control cable on Piper PA-31-350 aeroplanes within a specified serial number range, to be done per Piper Service Bulletin No. 621. It applies to owners/operators and maintenance organisations, must be completed within 25 hours TIS after 15 November 1978, and costs and scheduling impacts fall to aircraft owners/operators."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pa-31-73-elevator-cable-inspection-and-modification","history":"/api/acts/ad-pa-31-73-elevator-cable-inspection-and-modification/history","analysis":"/api/acts/ad-pa-31-73-elevator-cable-inspection-and-modification/analysis","conflicts":"/api/acts/ad-pa-31-73-elevator-cable-inspection-and-modification/conflicts","importantCases":"/api/acts/ad-pa-31-73-elevator-cable-inspection-and-modification/important-cases","documents":"/api/acts/ad-pa-31-73-elevator-cable-inspection-and-modification/documents"}}