A320 Lounge Hydraulics 1

Question 1

Which hydraulic systems have their own reservoir?

Answer 1

All of them

Question 2

Which hydraulic reservoir is biggest?

Answer 2

Green 14.5 litres
Yellow 12.5 litres
Blue 6.5 litres

Question 3

Which hydraulic systems are powered by engine driven pumps?

Answer 3

Green and Yellow

Question 4

What is the normal pressure in the hydraulic system?

Answer 4

3000psi

Question 5

Which hydraulic systems are normally powered by electric pumps?

Answer 5

Blue

The yellow system also has an electric pump if selected by pilots or if cargo door opened

Question 6

Which hydraulic systems are supplied with pressure by the RAT?

Answer 6

Blue

Question 7

How much pressure is supplied by the RAT?

Answer 7

2500psi

Question 8

What is the function of the PTU?

Answer 8

Allows green system to pressurise yellow system, or the opposite, if there is a pressure deficit.

Fluid is not transferred

Question 9

Which hydraulic systems have fire shutoff valves?

Answer 9

The green and the yellow systems.

They’re fitted close to the accessory gearbox in the engine, so if there is an engine fire, it prevents the hydraulic fluid, which is flammable, being sent into the engine fire

Question 10

How are the hydraulic fire shutoff valves activated?

Answer 10

By the engine fire push button

Question 11

Which part of the engine is the engine driven pump connected to?

Answer 11

N2

Question 12

When does the blue electric pump start?

Answer 12

When the first engine is started

Question 13

When is the yellow electric driven pump activated?

Answer 13

Manually, when we press the yellow hydraulic push button, or when ground crew operate cargo doors

Question 14

Which hydraulic system has a hand pump?

Answer 14

Yellow

Question 15

When is the hand pump used?

Answer 15

When the yellow electric pump is inop, enabling ground crew to manually pump in order to open cargo doors

Question 16

When does the blue electric pump turn off?

Answer 16

When the last engine is turned off

Question 17

When will the engine driven pump sensor get triggered?

Answer 17

Below 1750psi

Question 18

When will the electrically driven pump sensor get triggered?

Answer 18

Below 1450psi

(For blue or for yellow)

Question 19

What does the accumulator do?

Answer 19

Store fluid and store pressure, so that when the pressure isn’t quite 3000psi, the energy in the fluid helps to regulate the natural peaks and troughs and keep system at 3000psi

Question 20

When is PTU active?

Answer 20

If difference in pressure is greater than 500psi

Question 21

When is PTU tested?

Answer 21

Second engine start

Question 22

When is PTU inhibited?

Answer 22

On ground during 1st engine start
NWS DISC amber
On ground, if parking brake off if engine masters alt position (on/off) - if the master switches are in the same position, it is only active with the difference of 500psi. If the masters are in opposite positions (eg single engine taxi), the PTU inhibited only if the parking brake is on

Question 23

Why is PTU inhibited when NWS DISC amber present?

Answer 23

We don’t want to accidentally pressurise the NWS and potentially damage towing equipment

Question 24

Why do the pump outlet pressure sensor and system pressure sensor trigger at different times?

Answer 24

Because pressure sensor is downstream of the PTU, helping identify if the system is still pressurised via the PTU when a pump failure occurs

Question 25

Which triggers at a higher psi, pump outlet pressure sensor or system pressure sensor?

Answer 25

Engine driven pumps looking for 1750psi, whereas system pump looking for 1450psi