{"id":"F2006B07441","name":"AD/TPE 331/31 Amdt 1 - Fuel Control and Pump Mating Splines","slug":"ad-tpe-331-31-amdt-1-fuel-control-and-pump-mating-splines","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":49742,"registerId":"commonwealth-F2006B07441-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/TPE 331/31 Amdt 1 - Fuel Control and Pump Mating Splines","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 - 106 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  AlliedSignal (Garrett/AiResearch) Turbine Engines - TPE 331 Series\n\n \n\nAD/TPE 331/31\n\nAmdt 1\n\n\nFuel Control and Pump Mating Splines 3/95\n\n \n\nCANCELLED.\n\n \n\nBackground: The requirements of this Directive are now contained in the AlliedSignal TPE331-11 Maintenance Manual.\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":1,"scope_assessment":{"changed":false,"description":"This is a cancellation instrument that explicitly narrows the regulatory footprint to zero. The scope has not expanded; it has been eliminated entirely, with functions transferred to manufacturer documentation."},"complexity_factors":["Document is only 3 substantive lines long","No defined terms section","No conditional logic or cross-references to other legislation","Single straightforward administrative action (cancellation)","No operative provisions remaining — purely archival/notification purpose"],"plain_english_summary":"**What this is:** This is an **Airworthiness Directive (AD)** — a mandatory safety instruction issued by the Civil Aviation Safety Authority (CASA) that tells aircraft owners and operators they must fix or check specific problems to keep their planes safe to fly.\n\n**What it says:** This particular directive (AD/TPE 331/31, Amendment 1) has been **CANCELLED**. It originally dealt with **fuel control and pump mating splines** on **AlliedSignal TPE 331 series turbine engines** (commonly used in small turboprop aircraft). \"Mating splines\" are the interlocking teeth that connect rotating parts — if they wear out or fail, fuel pumps can stop working, which is obviously bad when you're flying.\n\n**Why it was cancelled:** The safety requirements that used to be in this directive are now covered in the official **AlliedSignal TPE331-11 Maintenance Manual**. So operators don't need to follow this separate CASA directive anymore — they just follow the manufacturer's manual instead.\n\n**Who it affects:** Owners and operators of aircraft with AlliedSignal (formerly Garrett/AiResearch) TPE 331 engines — typically used in planes like the Beechcraft King Air, Cessna Conquest, and various commuter aircraft.\n\n**Why it matters:** Even though cancelled, this document matters because it shows the paper trail of safety regulation. If you're maintaining one of these engines, you need to know that this specific AD no longer applies, and you should check the current maintenance manual instead."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":true,"description":"The scope of the statutory instrument has been narrowed in form: the standalone airworthiness directive (AD/TPE 331/31 Amdt 1) is cancelled and its technical requirements are stated to reside in the AlliedSignal TPE331-11 Maintenance Manual. In effect, the Schedule entry no longer contains the operative maintenance prescriptions; instead the manufacturer manual is identified as the source of those requirements (AD/TPE 331/31 Amdt 1: \"CANCELLED\"; Background)."},"complexity_factors":["Directive has been cancelled — single, discrete action (low legal complexity).","Requirements relocated to an external document (AlliedSignal TPE331-11 Maintenance Manual), increasing operational/document-control complexity for operators.","Absence of reproduced technical detail in the Schedule forces reliance on the manufacturer manual for substantive obligations.","Potential for version-control issues (editions/updates of the manual) creates ongoing compliance attention.","Limited text and few cross-references in the source reduce statutory interpretive complexity but increase practical dependency on non-statutory material."],"plain_english_summary":"- What this instrument does mechanically:\n  - AD/TPE 331/31 Amdt 1 (Fuel Control and Pump Mating Splines) has been cancelled. (AD/TPE 331/31 Amdt 1: \"CANCELLED\")\n  - The background statement says the requirements that were in the Directive are now contained in the AlliedSignal TPE331-11 Maintenance Manual. (Background: \"The requirements of this Directive are now contained in the AlliedSignal TPE331-11 Maintenance Manual.\")\n\n- Who this affects:\n  - Operators and owners of aircraft fitted with AlliedSignal (Garrett/AiResearch) TPE331 series turbine engines.\n  - Maintenance organisations, licensed engineers and any party responsible for complying with airworthiness directives or following the engine maintenance manual.\n  - The Civil Aviation Safety Authority (CASA) and its inspectors who enforce compliance with airworthiness requirements.\n\n- Why this matters and how it works in practice:\n  - Mechanically, a standalone airworthiness directive (AD) has been removed from the Schedule of Airworthiness Directives and its technical requirements are now stated to be in a manufacturer maintenance manual. This changes where operators look for the mandatory maintenance requirements: from the AD text to the AlliedSignal TPE331-11 Maintenance Manual. (AD/TPE 331/31 Amdt 1: \"CANCELLED\"; Background: maintenance manual statement.)\n\n- Practical implications, stated without value judgements:\n  - Who pays: operators and maintenance providers bear the cost of implementing and documenting compliance with whichever document (AD or manual) contains the requirements. With the AD cancelled, any time and administrative cost of switching references or updating procedures falls to those operators and maintainers. (Background: requirements moved to manual.)\n  - Who decides and where discretion sits: CASA cancelled the AD (the Schedule entry records the cancellation). Enforcement and interpretation may now rely on the content of the AlliedSignal manual; CASA retains regulatory authority to require compliance but the immediate source of the technical requirements is the manufacturer's manual as stated in the background. (AD/TPE 331/31 Amdt 1: \"CANCELLED\"; Background.)\n  - Behaviour changes required: maintenance programmes, logbooks, checklists and internal procedures that previously referenced AD/TPE 331/31 must be checked and, if necessary, updated to reference and follow the TPE331-11 Maintenance Manual instead. Maintenance personnel must ensure they are using the current edition of that manual. (Background.)\n  - Compliance burden and information access: relying on an external manufacturer manual concentrates the authoritative technical specification outside the consolidated statutory AD text. Operators must obtain and track the correct edition of the TPE331-11 manual to be sure they meet the stated requirements. This introduces a potential administrative burden of document control and version checking. (Background.)\n  - Implementation and enforcement risks: if there is any discrepancy between the cancelled AD and the manual, or if the manual is updated, operators and regulators will need to reconcile the differences. The Schedule entry explicitly cancels the AD and points to the manual as the source of requirements; the Schedule does not itself reproduce those requirements. (AD/TPE 331/31 Amdt 1: \"CANCELLED\"; Background.)\n\n- Market and operational effects to consider (mechanics only):\n  - Shifting the stated requirements into a manufacturer maintenance manual changes the locus of the technical detail from a regulatory schedule document to a commercial technical manual. This may affect how maintenance providers compete on service offerings (they must demonstrate knowledge of the manual) and how costs are internalised by operators, because compliance relies on access to and implementation of the manual's procedures. (Background.)\n\n- Source citation:\n  - AD/TPE 331/31 Amdt 1 — Fuel Control and Pump Mating Splines — entry in the Schedule of Airworthiness Directives marked \"CANCELLED\" and background note that requirements are contained in the AlliedSignal TPE331-11 Maintenance Manual. (AD/TPE 331/31 Amdt 1: \"CANCELLED\"; Background: \"The requirements of this Directive are now contained in the AlliedSignal TPE331-11 Maintenance Manual.\")"}},"importantCases":[],"_links":{"self":"/api/acts/ad-tpe-331-31-amdt-1-fuel-control-and-pump-mating-splines","history":"/api/acts/ad-tpe-331-31-amdt-1-fuel-control-and-pump-mating-splines/history","analysis":"/api/acts/ad-tpe-331-31-amdt-1-fuel-control-and-pump-mating-splines/analysis","conflicts":"/api/acts/ad-tpe-331-31-amdt-1-fuel-control-and-pump-mating-splines/conflicts","importantCases":"/api/acts/ad-tpe-331-31-amdt-1-fuel-control-and-pump-mating-splines/important-cases","documents":"/api/acts/ad-tpe-331-31-amdt-1-fuel-control-and-pump-mating-splines/documents"}}