Hydraulics

Question 1

What does the hydraulic PBIT do and when will it automatically run?

Answer 1

Provides functional test of the flight control actuators and will turn on only when hydraulic systems 3A, 1 and 2 are pressurized in the correct order

Question 2

What will interrupt the Hydraulic PBIT? How long will it take to complete?

Answer 2

Movement of the flight controls. 1 minute

Question 3

What does it mean if a hydraulic quantity indication is Cyan?

Answer 3

Reservoir requires refilling

Question 4

What type of hydraulic pumps are in system 1?

Answer 4

(Engine Driven Pump) EDP 1 and (AC Motor Pump) ACMP 1, accumulator stores power

Question 5

When will EDP1 begin pumping hydraulic fluid? Is this automatic?

Answer 5

When the respective engine turns on and if switch is in AUTO then it is automatic

Question 6

When will ACMP1 turn on automatically?

Answer 6

Takeoff: Flaps greater than 0 AND 50 Knots GS OR Thrust Levers at TO/GA

In Flight: Flaps greater than 0, or EDP/Engine Failure

Question 7

What type of hydraulic pumps are in system 2?

Answer 7

(Engine Driven Pump) EDP 1, (AC Motor Pump) ACMP 1, and Power Transfer Unit (PTU), accumulator stores power

Question 8

What does the accumulator do?

Answer 8

Stores hydraulic pressure from system 1 and 2 to provide 6 uses of the parking brake

Question 9

When will EDP2 begin pumping hydraulic fluid? Is this automatic?

Answer 9

When the respective engine turns on and if switch is in AUTO then it is automatic

Question 10

When will ACMP2 turn on automatically?

Answer 10

Taxi: Engine 1 running AND parking brake released (Will automatically turn off 6m after the park. brake has been set)

Takeoff: Flaps greater than 0 AND 50 Knots GS OR Thrust Levers at TO/GA

In Flight: Flaps greater than 0, or EDP/Engine Failure

Question 11

Which hydraulic system controls nosewheel steering? Landing gear?

Answer 11

System 2

Question 12

What type of hydraulic pumps are in system 3?

Answer 12

AC Motor Pumps 3a and 3b with a reservoir

Question 13

When will ACMP 3A begin pumping hydraulic fluid? Is this automatic?

Answer 13

When the 3A switch is turned to ON and this switch is not automatic.

Question 14

When will ACMP 3B turn on automatically?

Answer 14

If ACMP 3A fails in flight ONLY

Question 15

What is the primary purpose of the PTU?

Answer 15

Assists the retraction or extension of the landing gear if EDP 2 or right engine has failed. ACMP2 is too weak to operate landing gear. PTU moves hydraulic force from system 1 and moves it to system 2 (does not move fluid) 100% mechanical does not require AC Power

Question 16

Will the PTU run on the ground in AUTO?

Answer 16

No because it will not run with weight on wheels

Question 17

When will the PTU automatically activate?

Answer 17

When flaps not set to 0
OR Gear not up and locked

Weight not on wheels

EDP 1 has not failed

Reservoir 2 quantity is above 12%

When the EDP 2 or right engine has failed

Question 18

What happens when the Hydraulic overheats 100, 125 and 145 degrees

Answer 18

100 degrees, yellow caution EICAS

125 degrees, system automatically shutdowns respective EDP

145 degrees,red warning on EICAS

Question 19

What does the hydraulic eng pump shutoff button do?

Answer 19

Closes the hydraulic SOV, isolating the EDP from the system