Hydraulic System

Question 1

How many hydraulic pumps does the CL-300/350 have?

Answer 1

6 total

2 EDP’s
2 DCMP’s
1 PTU
1 AUX

Question 2

What is powered using the hydraulic system?
(7)

Answer 2

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

Question 3

Normal hydraulic system pressure is psi?

Answer 3

3000

Question 4

What does the Left Hydraulic System power?
(9)

nail iill

Answer 4

Nose steering
Alternate flaps
Inboard Elevator
Landing Gear

Inboard Spoilers
Inboard Brakes
Left(upper)PCU
Left TR

Question 5

What does the Right Hydraulic System power?
(9)

floormop

Answer 5

Flaps
Lower PCU
Outboard spoilers
Outboard brakes
Right TR

Main landing gear assist actuator
Outboard Elevator.
PTU

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.

Also pressurizes the left hydraulic reservoir.

Question 7

When does the PTU operate in “AUTO” ?

Answer 7

• Left EDP failed
• Right EDP producing pressure.
• Weight off wheels(WOW in air)
• Gear not in the selected position (ie…gear is down with the handle “UP”)

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 3 ways?

Answer 9

Pushing the Hydraulic PBA
Pushing the FIRE PBA
hydraulic temperature exceeds 135C (275F) 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(less than 1800 psi)

Question 11

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

Answer 11

The right DCMP if switch is selected to ON

Question 12

When would we use the 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 hydraulic system?

Answer 13

The rudder thru the lower rudder pcu

Question 14

What accumulators are on the hydraulic system?

Answer 14

4 – 
Inboard brakes
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

DCMP pumps approximately 3 gpm.

Question 16

When does the Aux Hydraulic pump automatically turn ON?
(2)

Answer 16

Aux system pressure less than 2500 psi
(OFF at 3350 psi)

Right hydraulic system pressure is less than 1800 psi

Question 17

When do the DCMP’s operate in the auto position?
(3)

Answer 17

Low hydraulic system pressure
When 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 DCMP’s powered?

Answer 18

Right DCMP is powered from L ESS bus

Left DCMP is powered from R Main bus.

Question 19

A/C not modified SB 100-29-18 (Brushless DCMP’s), 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

On CL350’s and A/C with modified with SB 100-29-18 (Brushless DCMP’s) what position do we place the DCMP switch after takeoff??

Answer 20

Remain in the “AUTO” position.

Question 21

The Aux DCMP is powered by the?

Answer 21

LEFT essential bus

Question 22

If you loose all the hydraulic fluid on the left side will the gear still come up with the PTU?

Answer 22

No. The PTU is turned with the right side hydraulic system (so it will still turn) but it is powering the left side fluid, so if none of that remains the gear will not come up.