Hydraulics

Question 1

What is the operating pressure of the hydraulic systems?

Answer 1

3000psi

Question 2

What are the possible pressure sources for the hydraulic systems?

Answer 2

Engine Driven Pumps

Electric Pumps

Ram Air Turbine (RAT)

Power Transfer Unit (PTU)

Question 3

How is the system pressurized?

Answer 3

By bleed air from Engine 1 or through the cross bleed duct.

Question 4

What powers the Green System?

Answer 4

Engine 1 hydraulic pump

Question 5

What does the Power Transfer Unit (PTU) do?

Answer 5

Compares the Yellow and Green systems and pressurizes the lower with the higher if the differential is >500psi.

Question 6

What backup system does the yellow system have that the green does not?

Answer 6

A backup electric pump and hand pump.

Question 7

What does the yellow system power?

Answer 7

2 Thrust Reverser

Brakes

Cargo doors

Question 8

How is the BLUE system powered?

Answer 8

Electric pump ONLY

PTU can not pressurize

There are no engine pumps

RAT

Question 9

During engine failure or fire, the hydraulic valve closes on the ECAM. What is unique about the Yellow and Green systems when the valve is closed?

Answer 9

Although not depicted, the electric (yellow) or PTU can still pressurize the system without the engine operating.

Question 10

When is the PTU monitored and what does an amber indication mean?

Answer 10

The PTU is only tested during second engine startup. It is not monitored at any other time.

The amber PTU line on the ECAM means that the PTU has been selected OFF.

Question 11

What happens when the cargo doors are operated with the engines off?

Answer 11

The yellow electric pump engages when the cargo door is operated.

Question 12

When will the RAT deploy?

Answer 12

When power is lost to both AC BUS 1 & 2.

Question 13

When is the hydraulic pressure displayed in amber?

Answer 13

<1450psi

Question 14

Beside a pump failure, why else would you see a FAULT light on the hyd system?

Answer 14

Reservoir overheat

Reservoir low air pressure

Low Fluid Level

Question 15

Why would you manually deploy the RAT?

Answer 15

To pressurize the system without activating the emergency generator.

Only required if electric pump is lost and one of the other hyd systems has also failed.

Question 16

Name the 3 ways the RAT will be deployed?

Answer 16

Auto with loss of AC BUS 1&2

RAT MAN ON pb (no emer gen)

MAN ON on EMER ELEC PWR1

Question 17

What does it mean when you have all FAULT lights on during pre-flight?

Answer 17

The pneumatic reservoir pressure has bled overnight. APU bleed air will re-pressurize and extinguish the FAULTs

Question 18

When is the PTU inhibited?

Answer 18

Split Engine Master Switches
\+
Nosewheel disconnected or Parking brake ON
\+
On the ground
OR
40 seconds after cargo door operation

Question 19

Why should you delay second engine start 1 minute after cargo door ops?

Answer 19

The PTU is inhibited 40 seconds after cargo door ops to prevent inadvertent pressurizing the green side. When inhibited, the PTU will fail its self-test after 2nd engine start.

Question 20

What are the 3 types of reservoir problems?

Answer 20

Low Fluid Level

Low Air Pressure

Overheat