Hydraulic

Question 1

What is the normal pressure of the HYD system ?

Answer 1

3000PSI
2500PSI if powered by RAT

Question 2

What system can pressurizes the Yellow HYD system ?

Answer 2

ENG 2 pump
Can be ELECT Pump or hand pump

Question 3

What system can pressurizes the Blue HYD system ?

Answer 3

Elect pump
And RAT in an emergency

Question 4

Can any fluid be transferred with the PTU ? And when will it automatically start ?

Answer 4

No
Diff pressure of 500PSI

Question 5

When will the RAT automatically deploy ?

Answer 5

when AC BUS 1 & 2 are lost

Question 6

What system pressurises the HYD reservoirs

Answer 6

HP bleed from ENG 1, if too low can use the pressure from crossbleed duct
It’s avoid cavitation

Question 7

What are the main systems powered by the green HYD ?

Answer 7

Landing gear
Flaps/slats
Reverser 1
Normal brakes
flight controls

Question 8

What are the main systems powered by the Blue HYD ?

Answer 8

Emer gen
Slats
flight controls

Question 9

What are the main systems powered by the Yellow HYD ?

Answer 9

Flaps
Alternate braking
Parking brake
NWS
Flight controls
Reverser 2
Cargo door

Question 10

What are the main operational consequences of loosing Green HYD ?

Answer 10

-No landing gear retract => Gravity extension
-Loss of autobrakes and normal brakes
-landing distance due to 2 spoilers lost and 1 rev

Question 11

What are the main operational consequences of loosing Blue HYD ?

Answer 11

• Loss of emer gen if loss of fluid
• loss of redundancy
• slightly longer landing distance

Question 12

What are the main operational consequences of loosing Yellow HYD ?

Answer 12

• can’t vacate due to no NWS
• landing distance due to 2 spoilers and Rev 2 lost
• loss of alternate braking => Check pressure on stand for park brake

Question 13

For a dual HYD failure, how would you describe by few words the main consequences of loss of B+Y, G+B, G+Y ?

Answer 13

B+Y => Least detrimental
G+B => controllability
G+Y => Stopping

Question 14

What are the main operational consequences of dual HYD failure B+Y ?

Answer 14

• Normal law but no AP
• no NWS
• increased landing distance
• Landing gear gravity extension to protect remaining system
• no Speed brakes

Question 15

What are the commun consequences of any dual HYD failure ?

Answer 15

• CAT 1 landing capability due to AP1&2 Lost
• Landing gear by gravity so no gear retract
• increase landing distance

Question 16

What are the main operational consequences of dual HYD failure G+Y ?

Answer 16

• Alternate law so direct law landing
• landing distance massively increased due to loss of 4 spoilers, Rev 1&2, antiskid
• No flaps so use of QRH flaps/slats jammed
• No THS
• no NWS
• For landing Gear gravity extension
  For landing => All the way to config 3 THEN gear down to maintain some auto trim as long as possible

Question 17

In dual HYD failure G+Y, how should you configure the A/C for landing and why ?

Answer 17

Use flaps slat jammed QRH
Configure up to Flaps 3 then gear down.
Allow to maintain some auto trim with the elevator and provide sufficient elevator control for the flare.

Question 18

What are the main operational consequences of dual HYD failure G+B ?

Answer 18

• Alternate law so direct law landing
• Controllability issue due to loss of ailerons => Roll only with 2 spoilers and only one elevator
• loss of slats => So QRH flaps/slats jammed
• for landing gear gravity extension
• For better controllability => at 200kt gear down => Better elevator response in direct law

Question 19

Why in flight does the G reservoir level always show slight less than the other 2 ?

Answer 19

After gear retraction some fluid is still in the system and not back in the reservoir

Question 20

What is the purpose of priority valves ?

Answer 20

Disconnect heavy load user if HYD pressure gets low.

Question 21

What is the purpose of the accumulator ?

Answer 21

help maintain constant pressure by covering transient demands

Question 22

When does the HYD system PR becomes amber ?

Answer 22

pressure of less than 1450PSI

Question 23

On G+B SYS fault why do you extent the LDG gear at 200kt ?

Answer 23

Better pitch control in direct law

Question 24

On G+Y SYS fault, why do you select Flap 3 before gear down ?

Answer 24

once gear is extended you loose the autotrim via the elevators + it provide sufficient elevator control to flare A/C on landing

Question 25

What HYD service power the ailerons

Answer 25

G+B