{"id":"F2006B05797","name":"AD/PA-31/92 - Elevator Balance Weight","slug":"ad-pa-31-92-elevator-balance-weight","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":135710,"registerId":"commonwealth-F2006B05797-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PA-31/92 - Elevator Balance Weight","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-31/92 Elevator Balance Weight 9/80\n\nApplicability: All models PA-31 & PA31-325 with S/Nos. 31-7401201 to 31-8012076; All models PA-31-350 with S/Nos. 31-7405401 to 31-8052172.\n\n \n\nRequirement: Action in accordance with Piper SB No. 690.\n\n \n\nCompliance: Unless already accomplished, within 100 hours time in service after 30 September 1980.\n\n \n\nBackground: The manufacturer has advised that some of the referenced aeroplanes may have been fitted with incorrect elevator balance weights.\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 manufacturing defect in a defined aircraft population. It has not expanded beyond its original purpose of correcting elevator balance weight installations."},"complexity_factors":["Very short document (under 200 words)","Only 4 substantive paragraphs (Applicability, Requirement, Compliance, Background)","No defined terms section","Single cross-reference to external document (Piper SB No. 690)","Simple conditional logic (unless already accomplished)","Clear, unambiguous compliance deadline"],"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) under the Civil Aviation Regulations 1988.\n\n**What it does:** It requires owners and operators of specific Piper PA-31 series aircraft to inspect and fix a problem with the **elevator balance weights** — small counterweights attached to the tail control surfaces that help keep the plane stable in flight.\n\n**Who it affects:** Owners and operators of:\n- Piper PA-31 and PA-31-325 aircraft with serial numbers between 31-7401201 and 31-8012076\n- Piper PA-31-350 aircraft with serial numbers between 31-7405401 and 31-8052172\n\n**What must be done:** Follow the instructions in **Piper Service Bulletin No. 690** (a technical notice from the manufacturer). This involves checking whether the wrong balance weights were installed and correcting them if necessary.\n\n**When it must be done:** Within 100 hours of flying time after 30 September 1980 — unless the fix was already completed.\n\n**Why it matters:** Incorrect balance weights can affect how the aircraft handles, potentially creating dangerous flight characteristics. This AD ensures affected planes are checked and corrected before they become unsafe."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The instrument’s stated purpose (remedying potentially incorrect elevator balance weights) is aligned with its operative content: it applies to specific PA-31 serial-number ranges, requires action in accordance with Piper SB No. 690, and sets a compliance deadline (Applicability; Requirement; Compliance; Background). The text contains no indication that the scope was broadened or narrowed from an earlier version, and there are no amendments or additional measures in the supplied text that would constitute a change in scope."},"complexity_factors":["Narrow, specific applicability limited to a small set of serial-number ranges (Applicability).","Single, clearly referenced corrective action (Piper SB No. 690) rather than multiple or novel regulatory requirements (Requirement).","A fixed and short compliance window (100 hours after 30 September 1980) reduces ongoing regulatory ambiguity but requires prompt action (Compliance).","Dependence on an external document (the Service Bulletin) for technical detail creates operational dependency and potential implementation complexity (Requirement).","No additional procedures, reporting regimes, or new certification tests are introduced in the text, limiting administrative complexity."],"plain_english_summary":"This Airworthiness Directive requires owners/operators of the Piper PA‑31 series aeroplanes listed by serial number to carry out Piper Service Bulletin No. 690 to correct potentially incorrect elevator balance weights. Compliance is mandatory within 100 hours TIS after 30 September 1980 (unless already done), imposing the maintenance cost, downtime and scheduling burden on affected operators."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pa-31-92-elevator-balance-weight","history":"/api/acts/ad-pa-31-92-elevator-balance-weight/history","analysis":"/api/acts/ad-pa-31-92-elevator-balance-weight/analysis","conflicts":"/api/acts/ad-pa-31-92-elevator-balance-weight/conflicts","importantCases":"/api/acts/ad-pa-31-92-elevator-balance-weight/important-cases","documents":"/api/acts/ad-pa-31-92-elevator-balance-weight/documents"}}