{"product_id":"aeroshell-390-turbine-oil","title":"AeroShell Turbine Oil 390 Synthetic APU Oil (DEF STAN 91-94)","description":"\u003ch3\u003eCold-Soak Synthetic APU Oil\u003c\/h3\u003e\n\u003cp\u003eAeroShell Turbine Oil 390 (ASTO 390) is a 3 mm²\/s (cSt) synthetic diester turbine oil engineered with a specialized additive matrix for high thermal-oxidative stability and superior load-carrying capacity. Formulated specifically to overcome viscous drag during high-altitude cruising, ASTO 390 ensures rapid, reliable auxiliary power unit (APU) cold-soak starting in temperatures down to **-40°C**.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eETOPS \u0026amp; Aviation Maintenance Advantage:\u003c\/strong\u003e Fully qualified to British Specification \u003cstrong\u003eDEF STAN 91-94\u003c\/strong\u003e (Joint Service Designation OX-7), ASTO 390 maintains a significantly lower viscosity at extreme sub-zero temperatures (typically 2,000 cSt at -40°C versus 10,000 cSt for standard 5 cSt oils). This dramatically reduces hung-start risks on extended twin-engine operations (ETOPS) and holds active OEM approvals across Honeywell, Pratt \u0026amp; Whitney Canada, and Hamilton Sundstrand APUs.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eOrdering Information:\u003c\/strong\u003e\u003cbr\u003e• \u003cstrong\u003ePackaging Unit:\u003c\/strong\u003e Individual 1 US Quart Can | \u003cstrong\u003eMFG #: 550049742\u003c\/strong\u003e\u003cbr\u003e• Please verify specific APU model compatibility and required case quantities with our aviation supply specialists before ordering.\u003c\/p\u003e\n\u003ch3\u003eKey Characteristics \u0026amp; Performance Benefits\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eOptimized ETOPS Cold-Soak Starting:\u003c\/strong\u003e Lowers viscous drag under sub-zero in-flight shutdown conditions (-40°C), ensuring immediate APU startup during emergency electrical power demands.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e3 cSt Synthetic Diester Chemistry:\u003c\/strong\u003e High-purity diester base matrix provides exceptional fluid circulation and thermal stability under severe flight envelopes.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eExtensive OEM Engine Approvals:\u003c\/strong\u003e Approved for Honeywell GTCP series, Hamilton Sundstrand APS series, and Pratt \u0026amp; Whitney Canada PW901A APUs.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHigh Load-Carrying Capacity:\u003c\/strong\u003e Protects high-speed APU starter-generators, turbocompressors, and gearboxes against surface scoring and wear.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThermal-Oxidative Defense:\u003c\/strong\u003e Inhibits carbon varnish and sludge formation in high-temperature bearing chambers and oil galleries.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eTypical Aviation Applications \u0026amp; Approved Engine Lines\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eHoneywell APUs \u0026amp; Starters:\u003c\/strong\u003e Approved for GTCP 30, 36, 70, 85, 331, and 660 APUs, starters, and turbocompressors.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHamilton Sundstrand APUs:\u003c\/strong\u003e Fully qualified for APS 500, 1000, 2000, and 3000 series auxiliary power systems.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePratt \u0026amp; Whitney Canada APUs:\u003c\/strong\u003e Primary lubricant for PW901A APU equipment on commercial airliners.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTurbomeca \u0026amp; Rolls-Royce Engines:\u003c\/strong\u003e Approved for Turbomeca (Astazou, Artouste, Makila) and Rolls-Royce (Conway, Spey, Tay, M45H) powerplants.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eTechnical Specifications \u0026amp; OEM Approvals\u003c\/h3\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eManufacturer \/ Product Line\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eShell Aviation \/ AeroShell® Turbine Oil 390 (ASTO 390)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMilitary Specifications \u0026amp; Codes\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eDEF STAN 91-94 (British) | Joint Service Designation OX-7\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eViscosity \u0026amp; Operating Capability\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e3 cSt (mm²\/s) at 100°C | Engineered for -40°C APU Cold-Soak Starts\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eCore OEM Approvals\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eHoneywell GTCP | Hamilton Sundstrand APS | Pratt \u0026amp; Whitney Canada PW901A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eManufacturer Part Number\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eQuart Can (1 US Qt): MFG # 550049742\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003ePrimary Operational Focus\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eETOPS compliance, APU cold-soak starting, and high-altitude restart reliability\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Aeroshell","offers":[{"title":"Quart Can","offer_id":51651127214452,"sku":"AST0390","price":28.0,"currency_code":"USD","in_stock":true},{"title":"Case of 24 QT - FREE GROUND SHIPPING","offer_id":52370434457972,"sku":"AST0390-CS","price":626.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0888\/2991\/9604\/files\/aeroshell-390-turbine-oil-def-stan-91-94-550049742-quart.png?v=1787759091","url":"https:\/\/145.aero\/products\/aeroshell-390-turbine-oil","provider":"Aircraft Shop Supply","version":"1.0","type":"link"}