Flashcards in EMB-120 Hydraulic System Deck (47):
What redundancy exists across the two hydraulic systems if one system fails?
• Both systems power the rudder
• Brakes- inboard (blue) and outboard (green)
• Flaps- inboard (blue) and outboard (green)
Where is the Green Hydraulic Accumulator located and what is its function?
• Right nose compartment
• Raises the main cabin door
Where is the Blue Hydraulic Accumulator located and what is its function?
• Left wing root
• Emergency brakes
How is a mechanical hydraulic pump failure identified?
• MAIN PUMP LOW PRESS light
• ELEC PUMP light will come on if in AUTO
Will the hydraulic system lose pressure when the main pump fails?
Not if electric pump in AUTO or ON.
What does the FILTER light on the overhead hydraulic panel indicate?
1 of 3 filters is blocked (main, electric or return).
When the Blue system is inop, can a normal gear extension be accomplished?
Yes, landing gear on green system.
During Electrical Emergency Mode operation with the left engine failed, which normal hydraulic functions will not be available?
• Anti skid
• Green System failure
o Outboard brakes
o Outboard flaps
o Landing gear
The right engine has been shut down per the QRC with the fire handle pulled. How will the hydraulic system be affected?
System unaffected, electric pump still available.
Blue system main pump inop.
With the left engine shut down with the fire handle, will we expect to see a LOW PRESS light for that hydraulic system?
No, electric pump (in AUTO) will provide hydraulic reservoir pressure.
Where is the electric hydraulic pump physically located?
The rear portion of the engine nacelle in the hydraulic bay.
Can the APU pressurize the hydraulic reservoirs?
The APU can pressurize the hydraulic reservoirs but the APU bleed valve must be opened to do so.
Where are the CABIN DOOR SOLENOID VALVE PRESSURE RELIEF valves?
One in cockpit, one in hydraulic bay.
Which hydraulic pump filters trigger a FILTER light when necessary?
The MAIN PUMP, ELECTRIC PUMP, and RETURN LINE FILTERS have differential pressure sensors that illuminate the FILTER light when necessary, but, unlike the fuel system filters, these do not have a bypass function.
The MAIN PUMP, ELECTRIC PUMP, and RETURN LINE FILTERS have differential pressure sensors that illuminate the FILTER light when necessary. Do they have a bypass function?
Unlike the fuel system filters, these do not have a bypass function. On the other hand, the BACKUP RETURN FILTER does have a true bypass function, but does not illuminate the FILTER light because it would have already been illuminated.
While in Emergency Mode will you have hydraulic power?
The main pumps will continue to provide for all hydraulic services.
The Filter Bypass function is provided on which hydraulic pump filters?
On the Back-up Return filter only.
Is there Hydraulic FLUID OVERHEAT detection on both pumps?
There is no FLUID OVERHEAT detection on the electric hydraulic pump.
During emergency mode operation with the left engine failed, which normal hydraulic function will not be available?
Normal extension of the landing gear.
Which items are on the BLUE hydraulic system?
Which items are on the GREEN hydraulic system?
Is the cabin door on the Green or Blue Hydraulic system?
Are the Outboard Brakes on the Green or Blue Hydraulic system?
Are the Outboard Flaps on the Green or Blue Hydraulic system?
Is the Landing Gear on the Green or Blue Hydraulic system?
Are the Inboard Brakes on the Green or Blue Hydraulic system?
Are the Inboard Flaps on the Green or Blue Hydraulic system?
Are the Nacelle Flaps on the Green or Blue Hydraulic system?
Is the Emergency Brake on the Green or Blue Hydraulic system?
If a main system hydraulic pump fails what indications will you see and what happens?
A MAIN PUMP LOW PRESS Light Illuminates, And The Electric Pump Operates Automatically.
Low Hydraulic level light at:
<0.8 liters in reservoir
Low Hydraulic pressure light at:
<12 psi reservoir pressure
Hydraulic Main Pumps located on respective:
Main hydraulic pump low pressure light:
< 1500 psi
Hydraulic electric pumps powered by:
Normal DC Bus powered from the opposite engines DC bus
In “AUTO” electric hydraulic pumps will automatically turn on if main pressure drops below:
There is no Hydraulic FLUID OVERHEAT detection on the:
Electric hydraulic pump
Rudder green system disabled when?
Normal hydraulic pressure:
2700 to 3100 psi
Overpressure hydraulic relief:
Hydraulic Filter light:
Hydraulic overheat light:
Anti-skid disabled below:
Braking not possible on landing until:
Wheel speed of 50 knots or 3 sec
After T/O landing gear warning inhibited for:
After T/O pusher inhibited for:
5 sec and again above 173