Hydraulics Flashcards
What does the left hydraulic system power?
- Flight controls
- Right yaw damper
- Rudder ratio changer
- Stabiliser trim control
- Left reverser
What does the right hydraulic system power?
- Flight controls
- Normal brakes
- Pitch enhancement system
- Right reverser
What does the center hydraulic system power?
- Flight controls
- Nose wheel steering
- Flaps and Slats
- Alternate brakes
- Landing gear
- Hydraulic driven generator (when power is lost to both AC buses
- Tail skid
- Left yaw damper
- Stabiliser trim control (1/2)
- RAT ( provides power to the flight controls portion of the centre system)
What is the Pitch Enhancement System (PES)?
If left and centre hydraulic systems are lost the right system drives a pump that uses trapped left system fluid to operate the stabiliser.
When the PES is activated the trim works at 1/4 the normal rate. only electric trim.
Explain reserve brake and steering system?
Center 1 electric hyd pump is automatically isolated if the system quantity is sensed low to provide hid pressure to the reserve brakes and steering system.
“ISLN” light on rear panel illuminates
Explain Hydraulic Driven Generator?
- Automatically powered by the centre hydraulic system when power is lost from both AC busses.
- The centre air driven demand pump will then operate continuously to ensure sufficient hydraulic pressure to drive the generator.
Explain the Ram Air Turbine
Provides hud power to the flight controls portion of the centre hid system
- Works above 130kts
- Deploys automatically when both engines fail
- Auto deployment is inhibited on the ground
- Can not be stowed without engineer
- PRESS light next to RAT switch when it is producing power
How are the three hydraulic systems powered?
Left an Right = engine driven primary pumps
= electric motor driven demand pumps that can be selected to auto
operate or can be selected to operate continuously.
Center system = Two electric motor driven primary pump
= Air driven demand pump
Hydraulic stytem pannel
When would you see the below light?
Illuminated (white) – the center number one electric primary hydraulic pump is
isolated to provide hydraulic pressure to the reserve brakes and steering system.
- located on the aft control pannel
What does the following picture show?
Hydraulic Fluid Quantities (HYD QTY)
• displays system reservoir quantity (1.00 is the normal service level)
• RF (magenta) – displayed when the reservoir requires refilling
What are 1, 2 and 3?
1 RAM AIR Turbine (TURB) Switch Push – deploys the RAT.
2 Ram Air Turbine Pressure (PRESS) Light
Illuminated (green) –
• the RAT is deployed
• the RAT is producing hydraulic pressure
3 Ram Air Turbine Unlocked (UNLKD) Light Illuminated (amber) – the RAT is not stowed and locked.
