Hydraulic System

Question 1

How many hydraulic pumps does the CL300/350 have?

Answer 1

6 total
2 EDPs
2 DCMPs
PTU
AUX Pump

Question 2

What is powered using the Hydraulic System?

Answer 2

Brakes
Thrust Reversers
Flaps
Elevators
Rudder
Multi-Function/Ground Spoilers
NWS

Question 3

What is the normal hydraulic system pressure?

Answer 3

3000 PSI

Question 4

What does the left hydraulic system power?

Answer 4

Gear
Inboard MFS
Inboard Brakes
Left (Upper) PCU
Alt Flaps
Inboard Ground Spoilers
Left TR
Nosewheel Steering
Inboard Elevator PCUs

Question 5

What does the right hydraulic system power?

Answer 5

Flaps
Outboard MFS
Outboard Brakes
Outboard Ground Spoilers
Lower PCU
Outboard elevator PCUs
Right TR
PTU
Main Landing Gear Assist Actuator

Question 6

What is the purpose of the PTU?

Answer 6

It is a hydraulic motor driven from the right system to provide pressure to the left system primarily to retract the gear after takeoff with a left engine failure. It also pressurizes the left hydraulic reservoir

Question 7

When does the PTU operate in AUTO?

Answer 7

Left EDP failed
Right EDP providing pressure
Weight OFF Wheels
Gear not in the selected position

Question 8

How is hydraulic fluid cooled?

Answer 8

Via fuel/hydraulic heat exchanger in each wing tank

Question 9

Hydraulic SOV can be closed in what 3 ways?

Answer 9

Hydraulic PBA
FIRE PBA
Hydraulic temp exceeds 135*C for more than 3 seconds

Question 10

What is the purpose of the AUX HYD system?

Answer 10

To provide hydraulic pressure to the lower rudder PCU if the right hydraulic system loses pressure (<1800psi) - via a switching valve

Question 11

In the event generator power fails and both EDPs fail, which DCMP is not load shed and can be powered?

Answer 11

Right DCMP if switch is selected to ON

Question 12

When should we use alternate flaps?

Answer 12

When directed by the checklist for Right Hydraulic pressure low conditions or Flap Fault CAS

Question 13

After loss of the left and right hydraulic systems, what flight control is powered by the AUX HYD system?

Answer 13

Rudder through the lower rudder PCU

Question 14

What accumulators are on the hydraulic system?

Answer 14

4 total:
Inboard/Outboard Brakes
Aux system
Main Gear down lock assist

Question 15

Why does flap extension using only the Right DCMP or alternate flaps take much longer than normal?

Answer 15

EDP pumps approximately 20 gpm, while the DCMPs only pump around 3 gpm

Question 16

When does the AUX HYD pump automatically turn on?

Answer 16

Aux system pressure less than 2500psi (off at 3350psi), right hydraulic system pressure less than 1800psi

Question 17

When do the DCMPs operate in the auto position?

Answer 17

• Low hydraulic system pressure
• Flaps are selected out of 0 (zero)
• On the ground with NWS ON (Left)

Question 18

From which electrical buses are the Right and Left DCMPs powered?

Answer 18

Right DCMP = L ESS BUS

Left DCMP = R MAIN BUS

Question 19

A/C without the brushless DCMP mod, what position do we place the DCMP switch after takeoff?

Answer 19

OFF - to prevent short circuits in a high temp environment that could lead to a cascade electrical failure

Question 20

CL350 and A/C with the brushless DCMP mod, what position do we place the DCMP switch after takeoff?

Answer 20

Remains in AUTO position