Hydraulic System DREAMLINER Architecture(cont New controlled system operating temperature to approximately:100°-160°F Temperature control maintained by a bypass valve and fuel tank heat exchanger in each system Bypass valve is a mechanical thermostat type device located on the case drain filter module Bypass valve is designed for two positions Closed: flow through the heat exchanger(only Open a percentage of flow bypassing the heat exchanger Boeing Propriet
Boeing Proprietary Hydraulic System Architecture (cont.) ◼ New controlled system operating temperature to approximately: 100 – 160F ◼ Temperature control maintained by a bypass valve and fuel tank heat exchanger in each system ◼Bypass valve is a mechanical thermostat type device located on the case drain filter module ◼Bypass valve is designed for two positions: • Closed: flow through the heat exchanger (only) • Open: a percentage of flow bypassing the heat exchanger
Hydraulic System DREAMLINER Architecture(cont No bleed air used for hydraulic power ■ Bootstrap Reservoir Chosen because bleed air not available for reservoir pressurization Change from traditional air-over-oil configuration Bootstrap system utilizes hydraulic system pressure to pressurize reservoIr Proven design on Douglas model airplanes DC-10,MD-11 717.DC-8,DC-9.MD-80.MD-90 Boeing Propriet
Boeing Proprietary Hydraulic System Architecture (cont.) ◼ No bleed air used for hydraulic power ◼ Bootstrap Reservoir ◼Chosen because bleed air not available for reservoir pressurization ◼Change from traditional air-over-oil configuration ◼Bootstrap system utilizes hydraulic system pressure to pressurize reservoir ◼Proven design on Douglas model airplanes • DC-10, MD-11 • 717, DC-8, DC-9, MD-80, MD-90
Hydraulic Systems DREAMLINER Bootstrap Reservoir Schematic Pressure AutoBleed Transduc Valve ATm Return High pressure(Red) Am PressReli ef 5000psi Samplevalve ■ Low pressure High Pressure (Blue) Cty ransduc AltExtend MLG Te Transd EMP 1 EMP 2 Boeing Propriet
Boeing Proprietary Hydraulic Systems Bootstrap Reservoir Schematic ◼ High pressure (Red) 5000psi ◼ Low pressure (Blue)
Hydraulic System DREAMLINER Architecture(cont Ground test that require 5000 psi pressure Landing gear retraction RAT functional tests(GsE) High pressure hydraulic leakage checks Flaps/slats operation(hydraulic mode-priority valve Primary flight controls actuation confidence test Hydraulic Power Options for Ground Tests ■ APU generator Three or Four external ground power sources TWo external ground power sources can provide limited hydraulic power in maintenance mode ■5000 psi ground cart Boeing Proprieta
Boeing Proprietary Hydraulic System Architecture (cont.) ◼ Ground test that require 5000 psi pressure: ◼Landing gear retraction ◼RAT functional tests (GSE) ◼High pressure hydraulic leakage checks ◼Flaps/slats operation (hydraulic mode – priority valve) ◼Primary flight controls actuation confidence test ◼ Hydraulic Power Options for Ground Tests: ◼APU generator ◼Three or Four external ground power sources ◼Two external ground power sources can provide limited hydraulic power in maintenance mode ◼5000 psi ground cart
Hydraulic System DREAMLINER Transport Elements System Pressure Tubing ■ Titanium,T-3-2.5 Requires thicker wall tubing Qualification to 5080 psi for industry commonality Threat zones will use 21-6-9 CRES tubing ( thrown tread area, pressure dome, etc.) Return Pressure tubing Thin wall titanium. Ti-3-25 Aluminum inside the fuel tanks Boeing Propriet
Boeing Proprietary Hydraulic System Transport Elements ◼ System Pressure Tubing ◼Titanium, Ti-3-2.5 • Requires thicker wall tubing • Qualification to 5080 psi for industry commonality ◼Threat zones will use 21-6-9 CRES tubing (thrown tread area, pressure dome, etc.) ◼ Return Pressure Tubing ◼Thin wall titanium, Ti-3-2.5 ◼Aluminum inside the fuel tanks