# Hydraulic System Examples It can be complex to set up a [Modular Hydraulics System](hydraulics-info/), and so on this page we provide two examples to help you. These samples cover a simple aircraft (like the DA62) and a complex aircraft (like the Boeing 737), and provides both a visual schematic for the systems being created, and the resulting CFG settings.     ### Simple Aircraft The hydraulics system for small aircraft is a very simple one, as it only has a single actuator for the landing gear. For this actuator to work it requires the actuator itself as well as a single reservoir and an automatic electric pump provide the actuator with pressurized fluid, along with an accumulator (which allows the pilot to extend the landing gear even if the pump fails). The image below shows the schematic for the DA62 hydraulic system:   {{< image-center src="images/5_Content_Config/CFGs/hydraulics/hydraulics_1_da62.png" alt="Simple Hydraulic System Schematic" >}}   The CFG file contents for the components in this system would look like this: ``` cpp [HYDRAULICS_SYSTEM_EX1] Version = 1 Reservoir.1 = Name:Tank #Maxcapacity:10 #WearAndTearCollision:GlobalDamage Pump.1 = Name:ElectricPump #Type:Electric #Normalpressure:2000 #Nominaldisplacement:600 #Circuit:HydraulicPump #Mode:Auto #WearAndTearCollision:GlobalDamage Accumulator.1 = Name:Accumulator #Normalpressure:2000 #Initialpressure:1700 #Capacity:500 #WearAndTearCollision:GlobalDamage Actuator.1 = Name:LandingGear #Fluidvolume:300 #Minimalpressure:1300 #Type:LandingGear #WearAndTearCollision:GlobalDamage Line.1 = Name:TankToPump #Inputs:Tank #Outputs:ElectricPump #WearAndTearCollision:GlobalDamage Line.2 = Name:PumpToLdgGear #Inputs:ElectricPump #Outputs:LandingGear #Accumulator:Accumulator #WearAndTearCollision:GlobalDamage ```   In this simple system, the accumulator can hold 500ml of hydraulic fluid at pump pressure, and the actuator consumes 100ml/s. This means that the accumulator can sustain the actuator for 5 seconds, but as it depletes its pressure will decrease towards its pre-charged pressure, and so it may fall below the minimal pressure of the actuator if not set correctly.     ### Complex Aircraft The hydraulics system of a complex aircraft - like an airliner - is a more complex setup than the one used by the simple aircraft shown above. It has two separate hydraulics systems which are connected via a *non-reversible* PTU. The PTU itself is the most complex of the hydraulic components as it has multiple ports to deal with the various input and output lines. Notice that this one does not use the **Motor Relief** port. If it was *reversible* then this would be required as well. The way this system is setup means that the "A" system can provide the "B" system with hydraulic power if necessary. It is also worth noting that the number of hydraulic pumps has been doubled for the complex aircraft, as each system has an *electric* pump and an *engine* driven pump. This provides redundancy to the system, so that having a failure on any one of the pumps will not cause a catastrophic system failure.   {{< image-center src="images/5_Content_Config/CFGs/hydraulics/hydraulics_2_737.png" alt="Complex Hydraulic System Schematic" >}} The CFG file contents for the components in this system would look like this: ``` cpp [HYDRAULICS_SYSTEM_EX1] Version = 1 Reservoir.1 = Name:TANKA #MaxCapacity:10 Reservoir.2 = Name:TANKB #MaxCapacity:10 Valve.1 = Name:ValveSO_A #Type:ShutOff #Circuit:C_HYDRAULIC Valve.2 = Name:ValveSO_B #Type:ShutOff #Circuit:C_HYDRAULIC Valve.3 = Name:ValvePTU #Type:ShutOff #Index:3 Pump.1 = Name:Pump_ENG_1 #NormalPressure:3000 #NominalDisplacement:2400 #Type:EngineDriven #Index:1 Pump.2 = Name:Pump_ENG_2 #NormalPressure:3000 #NominalDisplacement:2400 #Type:EngineDriven #Index:2 Pump.3 = Name:Pump_ELEC_1 #NormalPressure:3000 #NominalDisplacement:800 #Type:Electric #Circuit:C_Hyd_PUMP_1 Pump.4 = Name:Pump_ELEC_2 #NormalPressure:3000 #NominalDisplacement:800 #Type:Electric #Circuit:C_Hyd_PUMP_2 Accumulator.1 = Name:AccumulatorBrakes #NormalPressure:3000 #InitialPressure:1080 #Capacity:3 Actuator.1 = Name:Rudder #MinimalPressure:1500 #FluidVolume:400 #Type:Rudder Actuator.2 = Name:Flaps #MinimalPressure:1500 #FluidVolume:400 #Type:Flaps#Index:1 Actuator.3 = Name:Brakes #MinimalPressure:1000 #FluidVolume:400 #Type:Brakes Actuator.4 = Name:LandingGear #MinimalPressure:1500 #FluidVolume:400 #Type:LandingGear Actuator.5 = Name:Spoilers #MinimalPressure:1500 #FluidVolume:400 #Type:Spoilers Actuator.6 = Name:Elevator #MinimalPressure:1500 #FluidVolume:400 #Type:Elevator Actuator.7 = Name:AileronsL #MinimalPressure:1500 #FluidVolume:400 #Type:LeftAilerons Actuator.8 = Name:AileronsR #MinimalPressure:1500 #FluidVolume:400 #Type:RightAilerons Actuator.9 = Name:FlapsTrail #MinimalPressure:1500 #FluidVolume:400 #Type:Flap #Index:2 Junction.1 = Name:JunctionA Junction.2 = Name:JunctionB PTU.1 = Name:PTU #NormalPressure:3000 #NominalDisplacement:1200 Line.1 = Name:TankAToPumpEng #Inputs:TANKA #Outputs:Pump_ENG_1 #Valves:ValveSO_A Line.2 = Name:TankAToPumpElec #Inputs:TANKA#Outputs:Pump_ELEC_1 Line.3 = Name:PumpsToJunctionA #Inputs:Pump_ENG_1,Pump_ELEC_1 #Outputs:JunctionA Line.4 = Name:JunctionAToActuators #Inputs:JunctionA #Outputs:LandingGear,Elevator,Rudder,AileronsL Line.5 = Name:JunctionAToPTUMotor #Inputs:JunctionA #Outputs:PTU.MotorInput #Valves:ValvePTU Line.6 = Name:TankBToPumpEng #Inputs:TankB #Outputs:Pump_ENG_2 #Valves:ValveSO_B Line.7 = Name:TankBToPumpElec_PTU #Inputs:TANKB #Outputs:Pump_ELEC_2,PTU.PumpInput Line.8 = Name:PumpsToPTUActuatorsB #Inputs:PTU.PumpOutput, Pump_ENG_2, Pump_ELEC_2 #Outputs:Flaps, Spoilers, AileronsR, FlapsTrail, JunctionB Line.9 = Name:JunctionBToBrakes #Inputs:JunctionB #Outputs:Brakes #Accumulator:AccumulatorBrakes #NonReturn ```