Hydraulic System

Question 1

What are the 6 hydraulic pumps?

Answer 1

2 EDPs
2 DCMPs
1 PTU
1 AUX pump

Question 2

The hydraulic system provides power to (7) _____.

Answer 2

-brakes
-thrust reversers
-flaps
-elevators
-rudder
-multi-function/ground spoilers
-NWS

Question 3

Normal hydraulic system pressure is _____ PSI

Answer 3

3,000

Question 4

The Left Hydraulic System powers the (LUINGA) _____.

Answer 4

L - Left thrust reverser
U - Upper (Rudder - PCU)
I - Inboard (Spoilers, Ground/Multi Function, Elevator, EMER brakes
N - Nose wheel steering
G - Gear
A - Alt Flaps

Question 5

The Right (ROLF) + P Hydraulic System powers the _____.

Answer 5

R - Right thrust reverser
O - Outboard (Spoilers, Ground/Multi Function, elevator, brakes,
L - Lower (Rudder PCU)
F - Flaps (normal flaps)

-PTU

Question 6

What is the purpose of the PTU?

Answer 6

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

Question 7

The PTU operates in AUTO under the following 4 conditions: _____.

Answer 7

1) left EDP failed
2) right EDP producing pressure
3) weight off wheels (WOW in air)
4) gear not in the selected position (i.e., gear is down with the handle UP)

Question 8

Hydraulic fluid is cooled via _____.

Answer 8

a fuel/hydraulic heat exchanger in each wing
tank

Question 9

What are the 3 ways for the hydraulic SOV can be closed?

Answer 9

1 - By pushing the PBA
2 - By pushing the FIRE PBA
3 - Hydraulic temperature in excess of 275°F (135°C) for more than 3 sec

Question 10

The purpose of the Auxiliary Hydraulics System is to _____

Answer 10

provide hydraulic pressure to the lower rudder PCU—if the right hydraulic system loses pressure (less than 1,800 PSI)—via a switching valve

Question 11

If generator power fails and both EDPs fail, the _____ DCMP is not load shed and can be powered if _____.

Answer 11

-right
-the switch is selected to ON

Question 12

Alternate Flaps would be used when _____.

Answer 12

directed by the checklist for Right Hydraulic Pressure Low Conditions or the Flap Fault CAS message

Question 13

After loss of the left and right hydraulic systems, the _____ flight control is operated via the Auxiliary Hydraulic System.

Answer 13

rudder (through the lower rudder PCU)

Question 14

There are _____ total accumulators in the hydraulic systems, including _____.

Answer 14

-four

-inboard brakes
-outboard brakes
-aux system
-main gear downlock assist

Question 15

Flap extension using only the Right DCMP or Alternate Flaps takes much longer than normal because _____.

Answer 15

the EDP pumps approximately 20 gpm, the DCMP approximately 3 gpm

Question 16

The Aux Hydraulic Pump automatically turns ON when _____ (and OFF at _____).

Answer 16

aux system pressure is less than 2,500 PSI; 3,350 PSI

Question 17

DCMPs operate in the AUTO position _____.

Answer 17

under low hydraulic system pressure conditions, when flaps are selected out of 0 (zero), and on the ground with NWS ON (Left DCMP)

Question 18

Right DCMP is powered from the _____ bus; Left DCMP is powered from the _____ bus.

Answer 18

-Left ESS
-Right MAIN

Question 19

On aircraft not modified with SB 100-29-18 (Brushless DCMPs), the DCMP switches should be placed to the _____ position after takeoff, in order to _____.

Answer 19

-OFF

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

Question 20

On Challenger 350s and aircraft modified with SB 100-29-18 (Brushless DCMPs), the DCMP switch should _____ after takeoff.

Answer 20

remain in the AUTO position