Hydraulic Panel - MD-11.org

1 Hydraulic Panel SYS (1,2,3) PRESS Illuminates if hyd pressure is too high or too low (<2400 or >3500). Extinguishes when press is normal 1-3 & 2-3 RMP (Reversible Motor Pump)switch Switch Controls the RMP shutoff valves when Hydraulic system is in Manual mode RMP(s) On (ON illuminated) RMP(s) OFF (ON Extinguished) If in Manual Mode -Hyd reservoir quantity < 1 gal on either side of RMP -Switch pressed and Respective RMP has been commanded on -ADG deployed with ADG electric switch off If in Auto Mode -Cruise flight with two hyd systems pressurized -Any N2 falls below 45% during taxi, takeoff or landing -Engine start in flight -Eng driven pumps unable to maintain pressure during taxi.

2 T/O or landing -Auto slat extend DISAG -Loss of second engine or second hyd system during cruise phase of flight -Disagreement between valves and commanded position -When selecting Manual during Auto operation -RMP commanded OFF & pressure still exists in system SYSTEM SELECT / MANUAL switch Two channels pressing once selects manual. Pressing a second time selects second auto channel. SELECT (illuminated) System has automatically switched to manual. Pressing switch locks system in manual mode (SELECT no longer illuminated). MANUAL (illuminated) System operating in manual mode MANUAL flashes if switch has been pressed that has no effect in auto mode. HYD PRESS TEST Initiates hyd pressure test. Switch operates only in Auto mode. TEST (Illum.)

3 Indicates hyd test is in progress. Tests RMP s and Aux pumps If Aux Pump pressed while test is in progress, the test PUMP (1 & 2) Switches command AUX PUMP(S) on or off when operating in Auto or Manual mode. ON Illuminates when respective aux pump is on for the purpose of pressurizing Hydraulic system 3. The Aux pumps can be commanded on automatically by the HSC, or commanded on manually by the pilot. The #1 aux pump is also commanded on prior to engine start when the AUX HYD PUMP 1 switch on the Brake Control Panel is pressed - then automatically shuts down when the first fuel switch is turned on. L PUMP / R PUMP Switches (Systems 1,2,3) The L PUMP switch commands the respective engine hyd pump On/Off when operating in Manual mode. The R PUMP switch commands the respective engine hyd pump Armed/Off when operating in manual mode. Both switches for the respective engine are disabled in Auto mode.

4 With the engine running and Hydraulic systems operating normally, the respective engine driven L PUMP is ON, and the R PUMP is armed (ready to operate in the event of a L PUMP malfunction). Right pumps are tested at engine start. FAULT (illuminated) When low pressure (<2400) or high temperature (>245o in pump case drain) is detected. In auto mode, a failure of the primary (left) pump will cause the secondary (right) pump to start. OFF - Extinguished when pump is operating normally, and respective system is pressurized. Pumps are off (and OFF is illuminated) when pump or system pressure is too low or too high, when pump or system temperature is too high, when fluid qty is low (< gals), during engine start and when fire handle is pulled. When electrical power is lost, engine pumps fail to ON. OFF also illuminates when pump is manually commanded off (which only possible when operating in manual mode).

5 Min Hyd quantity for dispatch Sys 3 = 6 gals, sys 1 & 2 = ( desired) Loss of fluid in system 3 down to gals will close a one-way check valve, preventing total fluid loss from leak in the tail section. HYD QTY LOW alert when qty reaches on the ground, or in flight HYD SYS FAIL alert when hyd qty reaches 1 gallon Non-Reversible Motor Pumps 2-1 NRMP provides hyd power for the upper rudder and stab trim with a loss of Sys 1 hydraulics. 3-2 NRMP provides hyd power for the lower rudder with a loss of Sys 2 hydraulics. No fluid is exchanged through the NRMP s. Fluid is provided from alternate reservoir systems referred to as compensators. Hyd Sys 1..Hyd Sys 2..Hyd Sys 3. Spoilers Spoilers Spoilers Ailerons Ailerons Ailerons Flaps Flaps Landing Gear Elevator Elevator Elevator Rudder [UPR] Rudder [LWR] Reverser (P&W) Reverser (P&W) Reverser (P&W) Nose Steering Nose Steering Trim Trim Slats Slats Brakes Brakes Autopilot use with Hydraulic system loss: Lose 1 Use A/P 1 Lose 2 Use A/P 2 Lose 3 Use A/P 2 * - Autopilot 1 uses hyd sys 2 & 3 - Autopilot 2 uses hyd sys 1 * If using A/P 1 with a loss of Sys 3, A/P will not be able to control stab trim.

6 Enhancement Sioux City Valve Valve located near pressure bulkhead in HYD System 3 protects hyd fluid forward of the valve. Closes at gals Enough Sys 3 fluid will be retained to allow pitch & roll control through use of horizontal stab trim and lateral controls powered by Hyd system 3. Controls Avail.: Ailerons, Spoilers, Stab TrimM A/M M M A/M A M M 3-1 RMP, NRMP. NRMP. 3-2 RMP. ON