Hydraulic - Flight Conrols - Landing Gear/Brakes - Flashcards
How many separate hydraulic systems are there on the CRJ 900?
3
Hydraulic systems 1, 2, and 3 normal pressure is?
3000 psi
Low pressure (Caution) occurs at what pressure?
< 1800 psi
High pressure occurs at what pressure?
3200 psi
What is the normal system quantity?
45% to 85%
High temperature condition occurs at what temp?
≥ 96°C
The HYD HI TEMP caution indicates that hydraulic fluid is hot in what part of system?
The reservoir
How many hydraulics pumps are there?
6,
3 full-time (“A” pumps),
3 part-time (“B” pumps)
When will the “B” pumps operate?
Switch ON or
with switches in AUTO at least one generator online
and flaps > 0
When will hydraulic pump 3B operate?
Switch ON or
with the switch in AUTO,
at least one generator online and flaps >0
or ADG deployed
What type of hydraulic fluid is used?
Skydrol
What color is the hydraulic fluid?
Purple
When will pressure relief occur?
≥ 3750 psi
Which yoke is connected to the right aileron?
First officer’s
Which yoke is connected to the left aileron?
Captain’s
How are the ailerons, elevators and rudder actuated?
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
Which yoke controls the right elevator?
First officer’s.
Which yoke controls the left elevator?
Captain’s
What is the purpose of the Multifunction Spoilers (MFS)?
To assist with roll control and serve as a spoiler
in flight and on landing.
Are the Multifunction spoilers operational at any speed?
Yes
How are the MFSs controlled when used for roll assistance?
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.
What is the flight deck indication of a jammed aileron cable?
Both yokes will be jammed
What happens after the ROLL DISC handle is pulled?
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
How is the operable side selected?
By pushing the ROL SEL/PLT ROL switchlight on the unjammed side.
What does pushing the ROL SEL/PLT ROL switchlight accomplish?
Allows the pilot with the operable aileron to control
the on-side MFS panels
What is the flight deck indication of an aileron PCU runaway?
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.
What is occurring when the pilots trim the ailerons or rudder?
The control surface is being repositioned.
There are no trim tabs
What panels are part of the GND LIFT dumping system?
Inboard and outboard
ground spoilers, all 4
MFS panels.
How are the flight controls gust locked?
Hydraulic fluid is trapped during shutdown
How is the Yaw Damper engaged?
YD1 and YD2 engage switch lights on the
center pedestal
How is the Yaw Damper disengaged?
DISC button on the center pedestal.
What controls the yaw damper?
The flight control computer
Is it necessary to disconnect the Yaw Damper on landing?
No
How are the flaps operated?
Electrically.
How many flap segments does the CRJ have?
4 total
2 on each wing
Is there any asymmetrical protection within the flaps?
Yes, if the flap segments differ by > 5 degrees,
the brakes are applied and the flaps will remain at
the current position.
How is STAB TRIM operated?
Electrically.
A split switch on the control yoke operates
two motors and a jack screw changing the horizontal
stabilizer angle of incidence
What systems can operate the STAB TRIM?
CA’s trim switches,
FO’s trim switches,
autopilot and MACH trim
What is the priority for STAB TRIM control?
CA
FO
Autopilot
MACH trim
How is the main landing gear held in the up and down position?
Mechanical up and down locks
How is the nose gear held in the up and down position?
Over center mechanism.
Do the forward nose gear doors remain open after a normal extension?
Yes
How are the nose gear doors actuated?
Mechanically
What is the purpose of the brushes on the main wheel wells?
Aerodynamic seal
Where do you look to determine the position of the landing gear?
EICAS primary page
Which component monitors the position of up locks, down locks, and gear door position and WOW sensors?
PSEU (proximity sensing electronic unit)
Which component ensures that the gear handle cannot be moved to the UP position on the ground?
Down-lock solenoid
Which hydraulic system operates the inboard brakes?
system #3
Which hydraulic system operates the outboard brakes?
system #2
When does the Anti-skid operate?
wheel spin up ≥ 35 kts
or
weight-on-wheels plus 5 seconds
What is the nose wheel steering degree of travel limits with nose wheel steering ON?
8° either side of center for rudder pedals,
80° either side
of center for tiller
At what speed does anti-skid control stop operating?
Wheel speed ≤ 10 knots
