{"id":"F2006B07432","name":"AD/TPE 331/23 - Fuel Control and Fuel Pump Mating Splines - Inspection","slug":"ad-tpe-331-23-fuel-control-and-fuel-pump-mating-splines-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":49711,"registerId":"commonwealth-F2006B07432-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/TPE 331/23 - Fuel Control and Fuel Pump Mating Splines - Inspection","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 331/23 Fuel Control and Fuel Pump Mating Splines - Inspection\n\n\n3/95\n\n \n\nCANCELLED.\n\n \n\nBackground: The requirements of this Directive are now reflected in the AlliedSignal TPE331-1/2 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":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":true,"description":"The Directive itself is cancelled. The inspection requirements are located in the AlliedSignal TPE331-1/2 maintenance manual rather than in the Directive text itself. The substantive inspection requirements are incorporated into the AlliedSignal TPE331-1/2 maintenance manual. The cancellation notice does not provide transitional timing or detail on how the manual's requirements supersede the AD."},"complexity_factors":["Very short cancellation notice with minimal operational content","Substantive inspection requirements are referenced in an external manufacturer maintenance manual rather than included in the AD text","No inspection procedures, intervals or technical detail in the notice itself","No transitional timing or enforcement detail provided in the cancellation notice","Requires users to obtain and read the AlliedSignal TPE331-1/2 maintenance manual to determine obligations"],"plain_english_summary":"The directive cancels Airworthiness Directive AD/TPE 331/23 because its inspection requirements for TPE331-1/2 fuel control and fuel pump mating splines are now reflected in the AlliedSignal TPE331-1/2 maintenance manual. Issued by the Civil Aviation Safety Authority, the change means operators and maintenance organisations must consult that manufacturer manual for inspection obligations— the cancelled AD itself contains no procedures or intervals."},"kimi_summary":{"content_quality":"ok","complexity_score":1,"scope_assessment":{"changed":false,"description":"This is a cancellation instrument with no active regulatory scope. The original directive's scope (fuel control spline inspections) has been transferred to manufacturer documentation, but this document itself does not expand or alter scope — it simply terminates the regulatory instrument."},"complexity_factors":["Document is only 3 substantive lines long","No defined terms section","No conditional logic or cross-references to other legislation","Single operative word: 'CANCELLED'","Background explanation is purely informational, not regulatory"],"plain_english_summary":"**What this is:** This is a cancelled Airworthiness Directive (AD) for a specific type of aircraft engine — the AlliedSignal TPE 331 series (also known as Garrett or AiResearch engines).\n\n**What it used to do:** The directive required inspections of the **fuel control and fuel pump mating splines** — essentially, the interlocking teeth that connect the fuel control unit to the fuel pump. These splines transfer power to drive the pump, and wear or damage here could cause engine fuel system failures.\n\n**Why it's cancelled:** The safety requirements from this directive have been permanently incorporated into the engine manufacturer's official **maintenance manual** (the TPE331-1/2 maintenance manual). This means mechanics now follow the manual instead of this separate government directive.\n\n**Who it affects:** Aircraft operators and maintenance engineers using TPE 331 engines — commonly found on turboprop aircraft like the Beechcraft King Air, Cessna Conquest, and various commuter aircraft.\n\n**Why it matters:** This shows how aviation safety regulation evolves. Rather than maintaining a separate mandatory inspection rule, CASA (the Civil Aviation Safety Authority) has allowed the manufacturer’s documentation to carry the safety requirement. This is common in aviation — when manufacturer procedures become sufficiently robust, standalone directives can be retired."}},"importantCases":[],"_links":{"self":"/api/acts/ad-tpe-331-23-fuel-control-and-fuel-pump-mating-splines-inspection","history":"/api/acts/ad-tpe-331-23-fuel-control-and-fuel-pump-mating-splines-inspection/history","analysis":"/api/acts/ad-tpe-331-23-fuel-control-and-fuel-pump-mating-splines-inspection/analysis","conflicts":"/api/acts/ad-tpe-331-23-fuel-control-and-fuel-pump-mating-splines-inspection/conflicts","importantCases":"/api/acts/ad-tpe-331-23-fuel-control-and-fuel-pump-mating-splines-inspection/important-cases","documents":"/api/acts/ad-tpe-331-23-fuel-control-and-fuel-pump-mating-splines-inspection/documents"}}