Hydraulics

Question 1

What is the normal hydraulic pressure

Answer 1

3,000 psi (2,500 from the RAT)

Question 2

Which systems has engine driven pumps

Answer 2

Green and yellow

Question 3

When does the PTU activate

Answer 3

If the difference between green and yellow system is >500 psi

Question 4

When is the PTU automatically tested

Answer 4

During 2nd engine start

Question 5

How many electric hyd pumps are there

Answer 5

2. Blue and yellow

Question 6

With no electric power, can the cargo door be opened

Answer 6

Yes, by a hydraulic hand pump

Question 7

Which fault will not be extinguished when turning the pump push button off

Answer 7

Any overheat will only be extinguished when the temperature drops below a threshold

Question 8

Which important systems are lost with the loss of the green system

Answer 8

Reverser 1, landing gear, autobrakes

Question 9

Which important systems are lost with the loss of the yellow system

Answer 9

Nose wheel steering, Reverser 2

Question 10

When does the RAT drop

Answer 10

If both AC bus 1&2 are lost

Question 11

What usually pressurizes the hyd reservoirs

Answer 11

Eng1 bleed (2 as backup)

Question 12

When does the blue elec pump start operating

Answer 12

After first engine start

Question 13

What hydraulic system(s) power the THS

Answer 13

Via 3 electric motors (based on which ELAC/SEC is in control), they are then moved by the green or yellow hyd system.