Hydraulics

Question 0

What components are on the #1 hydraulic system?

Answer 0

Brakes 
Anti-Skid
Rudder (lower)
Flaps
PTU
Inboard spoilers
Elevator (outboard PCU)

Question 1

How many hydraulic systems are there on the airplane?

Answer 1

Four. The two main hydraulic systems, the backup hydraulic system and the auxiliary system.

Question 2

What components are on the #2 hydraulic system?

Answer 2

Landing gear
Outboard spoilers
Steering
Elevator (center PCU)
Rudder (upper PCU)
Emergency brake

Question 3

What are the max quantities for each hydraulic system?

Answer 3

System 1: 8 quarts
System 2: 12 quarts
System 3: 2 quarts
Auxiliary: 1 quart

Question 4

What is the minimum quantity for dispatch?

Answer 4

40%

Question 5

How many pumps are on the #1 system?

Answer 5

Two, an engine driven pump mounted on the prop reduction gearbox and an AC powered standby pump.

Question 6

What is the primary power source for the standby hydraulic pump?

Answer 6

The right 115vAC BUS serves as the primary power source and the left 115vAC bus serves as the backup.

Question 7

What is the backup for the #2 hydraulic system?

Answer 7

The PTU. If the #2 engine driven pump fails the PTU will serve as the backup. The PTU uses power from the #1 system to create hydraulic pressure on the #2 side.

Question 8

What is the purpose of the #3 system?

Answer 8

Operates the inboard elevator PCUs in case both the number 1 and 2 systems both fail

Question 9

What is the purpose of the Auxiliary Hydraulic System?

Answer 9

Provides hydraulic pressure to manually extend the landing gear to ensure they are locked in position after an alternate gear extension.

Question 10

When will the standby hydraulic pump automatically activate?

Answer 10

If the number one engine fails OR the flaps are greater than 0° and the parking brake is released. The ON portion of the STBY HYD pushbutton will only illuminate if it is manually selected on. Pressure can be confirmed on the co-pilot’s MFD.

Question 11

When will the PTU automatically activate on the ground?

Answer 11

If the number two engine fails OR the flaps are greater than 0° with the parking brake released.

Question 12

What is the minimum parking brake pressure for starting the #1 engine? The #2 engine?

Answer 12

#1 engine: 1000 psi
#2 engine: 500 psi

Question 13

When will the PTU automatically activate in the air?

Answer 13

#1 Engine driven pump is operating normally
System #2 quantity is available AND

Flaps are greater than 0° OR
#2 hydraulic pressure is low OR
#2 engine oil pressure is low

Question 14

What do the ///// mean on the PTU pushbutton?

Answer 14

PTU is operating normally in either automatic or manual mode

Amber //// means that the PTU has failed to achieve normal pressure 5 seconds after being commanded on.

Question 15

Explain how the #3 HYD ISO VALVE works

Answer 15

Pushing the #3 HYD ISO VALVE button will manually open the isolation valve allowing the #3 system to power the inboard elevator PCUs. If the number 1 and 2 systems have failed the valve will open automatically but the Amber light will not illuminate unless the button is pushed in.

Question 16

The #1 system isolation valve is normally open but will close if fluid loss is detected in order to power:

Answer 16

PTU
Rudder (lower)
Elevator (outboard)
Flaps

Question 17

The #1 system priority valve will close at 2100psi. This will cut off hydraulic pressure to:

Answer 17

PTU
Flaps

You will still have the:
Brakes
Anti skid
Rudder
Inboard spoilers
Elevator

Question 18

If either of the EDPs fail will the Standby Pump or PTU automatically activate?

Answer 18

No, they only activate in the case of ENGINE failure. If the EDP fails the standby pump or PTU need to be manually activated.

Question 19

Like the #1 isolation valve, the #2 system also normally operates with an isolation valve in the open position. If this detects a fluid loss the isolation valve will close but you will still have power to:

Answer 19

The rudder and elevator

Question 20

The #3 system is powered by a gas accumulator, with its pressure maintained by?

Answer 20

A DC motor pump which will keep pressure between 2600-3250psi

Question 21

What does the #3 STBY HYD PUMP caution light mean?

Answer 21

3 system pressure has fallen below 900psi or the DCMP has been running for over 60 seconds on the ground.

Question 22

When will the ELEVATOR PRESS caution light illuminate?

Answer 22

If the #3 HYD ISO valve fails open or is manually selected open. All 3 systems will be powering the elevator at the same time.

Question 23

Where is the Auxiliary system located and how do we tell the reservoir quantity?

Answer 23

The reservoir for the #4 system is located in the lower right nose behind the crew O2 bottle. There is no quantity indication for the system.