Hydraulic - Flight Conrols - Landing Gear/Brakes -

Question 1

How many separate hydraulic systems are there on the CRJ 900?

Answer 1

3

Question 2

Hydraulic systems 1, 2, and 3 normal pressure is?

Answer 2

3000 psi

Question 3

Low pressure (Caution) occurs at what pressure?

Answer 3

< 1800 psi

Question 4

High pressure occurs at what pressure?

Answer 4

3200 psi

Question 5

What is the normal system quantity?

Answer 5

45% to 85%

Question 6

High temperature condition occurs at what temp?

Answer 6

≥ 96°C

Question 7

The HYD HI TEMP caution indicates that hydraulic fluid is hot in what part of system?

Answer 7

The reservoir

Question 8

How many hydraulics pumps are there?

Answer 8

6,

3 full-time (“A” pumps),
3 part-time (“B” pumps)

Question 9

When will the “B” pumps operate?

Answer 9

Switch ON or

with switches in AUTO at least one generator online
and flaps > 0

Question 10

When will hydraulic pump 3B operate?

Answer 10

Switch ON or

with the switch in AUTO,
at least one generator online and flaps >0

or ADG deployed

Question 11

What type of hydraulic fluid is used?

Answer 11

Skydrol

Question 12

What color is the hydraulic fluid?

Answer 12

Purple

Question 13

When will pressure relief occur?

Answer 13

≥ 3750 psi

Question 14

Which yoke is connected to the right aileron?

Answer 14

First officer’s

Question 15

Which yoke is connected to the left aileron?

Answer 15

Captain’s

Question 16

How are the ailerons, elevators and rudder actuated?

Answer 16

Yoke and pedals operate a
system of cables and pulleys
that connect to pull and push
rods at the flight control
which operate a hydraulic
PCU (power control unit)
which hydraulically actuates
the control surface

Question 17

Which yoke controls the right elevator?

Answer 17

First officer’s.

Question 18

Which yoke controls the left elevator?

Answer 18

Captain’s

Question 19

What is the purpose of the Multifunction Spoilers (MFS)?

Answer 19

To assist with roll control and serve as a spoiler

in flight and on landing.

Question 20

Are the Multifunction spoilers operational at any speed?

Answer 20

Yes

Question 21

How are the MFSs controlled when used for roll assistance?

Answer 21

The FO’s yoke position sends an electrical signal
to the left MFS panels which are hydraulically operated by PCUs.

The CA’s yoke position sends an electrical signal to the right MFS panels which are hydraulically operated by PCUs.

Question 22

What is the flight deck indication of a jammed aileron cable?

Answer 22

Both yokes will be jammed

Question 23

What happens after the ROLL DISC handle is pulled?

Answer 23

The aileron cable and pulley systems are disconnected
through torque tubes.

20 seconds later, if the operable side has not been selected, the amber ROL SEL switchlight illuminates

Question 24

How is the operable side selected?

Answer 24

By pushing the ROL SEL/PLT ROL switchlight on the unjammed side.

Question 25

What does pushing the ROL SEL/PLT ROL switchlight accomplish?

Answer 25

Allows the pilot with the operable aileron to control | the on-side MFS panels

Question 26

What is the flight deck indication of an aileron PCU runaway?

Answer 26

Aircraft begins an uncommanded roll and the PLT SEL switchlight on the side without the PCU runaway illuminates automatically because of the bungee break-out signal.

Question 27

What is occurring when the pilots trim the ailerons or rudder?

Answer 27

The control surface is being repositioned. | There are no trim tabs

Question 28

What panels are part of the GND LIFT dumping system?

Answer 28

Inboard and outboard ground spoilers, all 4 MFS panels.

Question 29

How are the flight controls gust locked?

Answer 29

Hydraulic fluid is trapped during shutdown

Question 30

How is the Yaw Damper engaged?

Answer 30

YD1 and YD2 engage switch lights on the | center pedestal

Question 31

How is the Yaw Damper disengaged?

Answer 31

DISC button on the center pedestal.

Question 32

What controls the yaw damper?

Answer 32

The flight control computer

Question 33

Is it necessary to disconnect the Yaw Damper on landing?

Answer 33

No

Question 34

How are the flaps operated?

Answer 34

Electrically.

Question 35

How many flap segments does the CRJ have?

Answer 35

4 total 2 on each wing

Question 36

Is there any asymmetrical protection within the flaps?

Answer 36

Yes, if the flap segments differ by > 5 degrees, the brakes are applied and the flaps will remain at the current position.

Question 37

How is STAB TRIM operated?

Answer 37

Electrically. A split switch on the control yoke operates two motors and a jack screw changing the horizontal stabilizer angle of incidence

Question 38

What systems can operate the STAB TRIM?

Answer 38

CA’s trim switches, FO’s trim switches, autopilot and MACH trim

Question 39

What is the priority for STAB TRIM control?

Answer 39

CA FO Autopilot MACH trim

Question 40

How is the main landing gear held in the up and down position?

Answer 40

Mechanical up and down locks

Question 41

How is the nose gear held in the up and down position?

Answer 41

Over center mechanism.

Question 42

Do the forward nose gear doors remain open after a normal extension?

Answer 42

Yes

Question 43

How are the nose gear doors actuated?

Answer 43

Mechanically

Question 44

What is the purpose of the brushes on the main wheel wells?

Answer 44

Aerodynamic seal

Question 45

Where do you look to determine the position of the landing gear?

Answer 45

EICAS primary page

Question 46

Which component monitors the position of up locks, down locks, and gear door position and WOW sensors?

Answer 46

PSEU (proximity sensing electronic unit)

Question 47

Which component ensures that the gear handle cannot be moved to the UP position on the ground?

Answer 47

Down-lock solenoid

Question 48

Which hydraulic system operates the inboard brakes?

Answer 48

system #3

Question 49

Which hydraulic system operates the outboard brakes?

Answer 49

system #2

Question 50

When does the Anti-skid operate?

Answer 50

wheel spin up ≥ 35 kts or weight-on-wheels plus 5 seconds

Question 51

What is the nose wheel steering degree of travel limits with nose wheel steering ON?

Answer 51

8° either side of center for rudder pedals, 80° either side of center for tiller

Question 52

At what speed does anti-skid control stop operating?

Answer 52

Wheel speed ≤ 10 knots