Hydraulics Flashcards
(49 cards)
How many hydraulic systems does the ERJ175 have?
3 independent systems
fluid cannot be transferred from one system to another
Type of hydraulic fluid and pressure?
Skydrol Hydraulic fluid; 3000 psi
What do the three hydraulic systems provide pressure for?
6 items
Flight Controls Spoilers Thrust Reversers Landing Gear Nose Wheel Steering Wheel Brakes
What items does Hydraulic System 1 provide pressure to?
7 Items
-Elevator
{Left hand outboard actuator)
-Rudder
(Upper Actuator)
-Thrust Reverser
(Engine 1)
-Multifunction spoilers
(left and right panels 3 & 4)
-Ground spoilers
(Left and right panels 2)
-Outboard Brakes
-Emergency parking brakeHydraulic System 1 is comprised of?
4 items
1 Engine driven pump (EDP 1)
1 A/C motor pump (ACMP 1)
1 Reservoir
1 Accumulator
What is the primary power source for hydraulic system 1?
Engine driven pump 1 (EDP 1)
It is connected to the engine 1 accessory gearbox
Normal operation requires no pilot action
What serves as a backup for the Engine Driven Pump 1 (EDP 1)? And how is it powered?
The ACMP 1, and it is electrically powered by AC BUS 2
What is the normal position for the ACMP 1 knob
- ON
- AUTO
- OFF
Auto
On the ground ACMP 1 will turn on as a back up for EDP 1 if?
Flap position is greater than 0 AND
- Thrust levers set to Takeoff Thrust, OR
- Ground speed greater than 50kts
In flight the ACMP 1 will turn on for 2 reasons?
- EDP 1 or Engine 1 failure
- Flaps selected to any position greater than 0
What items does Hydraulic system 2 provide pressure for?
9 items
-Elevator (Left and right hand inboard actuator) -Ailerons (Left and right hand inboard actuator) -Thrust Reverser (Engine 2) -Multifunction Spoilers (Left and right panel 5) -Ground Spoilers (Left and right panel 1) -Nose wheel steering -Inboard Brakes -Landing Gear (Retraction and extension) -Emergency Parking Brake
Hydraulic system 2 is comprised of?
1 Engine driven pump (EDP 2) 1 A/C motor pump (ACMP 2) 1 Reservoir 1 Accumulator 1 Power Transfer Unit (PTU)
What is the primary power source for hydraulic system 2?
Engine driven pump 2 (EDP 2)
It is connected to the engine 2 accessory gearbox
Normal operation requires no pilot action
What serves as a backup for the Engine Driven Pump 2 (EDP 2)? And how is it powered?
The ACMP 2, and it is electrically powered by AC BUS 1
What is the normal position for the ACMP 2 knob
- ON
- AUTO
- OFF
Auto
On the ground ACMP 2 will turn on as a back up for EDP 2 if?
Flap position is greater than 0 AND
- Thrust levers set to Takeoff Thrust, OR
- Ground speed greater than 50k
- *ALSO**
- If engine 1 is running and the parking brake is released
- During Engine 1 start (once N2 reaches 40%) if the parking brake has been applied within the last 6 minutes. (it turns off after 6 minutes have elapsed)
In flight the ACMP 2 will turn on for 2 reasons?
- EDP 2 or Engine 2 failure
- Flaps selected to any position greater than 0
What is the purpose of the PTU?
To assist with landing gear retraction or extension should a right engine or right EDP failure occur
What pilot action is required to activate the PTU?
None:
During takeoff and landing, with the selector knob in the Auto position the hydraulic system logic activates the PTU if engine 2 or the EDP 2 fails
What condition have to be met for the PTU to turn on?
4 items
-Flaps not set to 0 (e.g. Flaps 1 callout)
OR
-Landing gear not up and locked (after takeoff)
AND
-EDP 1 must not be failed
-Hydraulic reservoir 2 quantity above 12%
What happens when hydraulic fluid temperature reaches 100 degrees Celsius?
The HYD 1/2 HI TEMP (yellow) EICAS caution message is displayed
What happens when hydraulic fluid temperature reaches 125 degrees Celsius?
Hydraulic system 1 and 2 are equipped with an automatic overheat protection system.
When the temp reaches 125 Celsius, the shutoff valve (SOV) automatically actuates thus isolating the EDP 1 or EDP2 from the respective hydraulic flow line.
What happens when hydraulic fluid temperature reaches 145 degrees Celsius?
The HYD 1/2 OVERHEAT (red) EICAS warning message is displayed.
In this case the SOV can be manually commanded though a guarded pushbutton on the hydraulic system control panel.
If the aircraft is experiencing sever problems and you have lost more than one hydraulic system… what do you do?
You must complete the Combined Failure Procedure found in the NON-Annunciated Procedures
(Loss of hydraulic system 1 and 2) ( NAP 1-30, 1-31, 1-31)
