Hydraulics

Question 1

When armed the PTU activates when

Answer 1

L HYD pressure drops below 1500 psi

Question 2

Operation of the PTU assumes loss of the

Answer 2

Left hydraulic system

Question 3

When armed, the AUX pump comes on when

Answer 3

L HYD and PTU pressure is <1500 PSI, and

Brake pedals are depressed 10°

Question 4

What is the Brake Accumulator precharge

Answer 4

1200 psi

Question 5

If L HYD System fluid is depleted, but AUX fluid remains in the L HYD reservoir, what system can provide braking?

Answer 5

AUX Pump

Question 6

What is the GEAR EMERGENCY BLOWDOWN accumulator pressure charge

Answer 6

3100 PSI (at 70°F)

Question 7

What are the hydraulic fluid quantities of the L/R reservoirs

Answer 7

L - 4.8 Gal

R - 1.6 Gal

Question 8

What is lost if you lose L HYD System?

Answer 8

L Thrust Reverser

Question 9

If L HYD Pump and PTU are not working, the AUX pump can provide power to…

Answer 9

Flaps, Brakes and Nose Wheel Steering

Question 10

Can the pilots change Yaw Damper from left to right inflight?

Answer 10

Yes, switch FGCs from 1 to 2, or 2 to 1

Question 11

What is lost if you lose Right Hydraulic system?

Answer 11

R Thrust Reverser

Question 12

What will prevent PTU from automatically coming on?

Answer 12

L HYD system fluid <1.5 Gal

R Hyd system hot, temp >104.4­°C

Question 13

The AUX system reservoir is located…

Answer 13

in the left system reservoir

Question 14

Which hyd system can operate the HMG?

Answer 14

Left or PTU

Question 15

How is hyd fluid used during the opening of the main entrance door?

Answer 15

hydraulic fluid flowing out of the door system at a controlled rate slows opening of the door.

Question 16

What activates the PTU?

Answer 16

If the left hydraulic system pressure drops below 1500 psi with more than 1 gallon of fluid in the left system and pressure in the right system.

Question 17

When will PTU automatically shut off?

Answer 17

Left system pressure >1500 PSI, or
Left or Right system fluid loss, or
Right “HYDRAULIC RESERVOIR HOT” CAS (temp >104° C)

Question 18

What does the PTU Power?

Answer 18

All left side mechanics except the T/R, left yaw damp and flight controls

Question 19

Will the AUX PUMP turn OFF with an amber “Aux Hydraulic HOT” CAS?

Answer 19

NO

Question 20

What components are lost with a loss of the left hyd system fluid?

Answer 20

Left T/R and Landing gear

Question 21

If landing using only the AUX hydraulic pump, will nose wheel steering be available after landing?

Answer 21

Yes, once WOW is activated

Question 22

If a hardover is detected, can the system be reset and how?

Answer 22

Yes by pulling and resetting the appropriate CB - IAW the QRH

Question 23

What components are lost with both the Left and AUX systems inoperative?

Answer 23

Left Yaw damp
Left T/R
Normal Brakes
Flaps
NWS
Landing Gear
Auto Ground Spoilers

Question 24

How many DPIs on the a/c?

Answer 24

10
In the hell hole
5 on left
3 on right
One on PTU
One on AUX pump
One in the wheel well

Question 25

What automatically activates the AUX Pump

Answer 25

Switch armed
L and PTU system below 1500PSI
Brake pedals depressed >10°

Question 26

Aux Hydraulic Boost Pump turns on…

Does Pilot have any control of this?

Answer 26

ON - Hyd pressure in the line drops 20 PSI
OFF- pressure rises > 25 PSI

No. Pilot has no control. It’s fully automatic. Designed to boost AUX pump pressure in the tail compartment.