Flight Controls Flashcards
What is the function of the Power Control Units (PCU)?
To hydraulically move the control surfaces
How many Power Control Units (PCU) are installed on each aileron?
Two
What is the function of the Spoiler Stabilizer Control Unit (SSCU)?
To control the extension and retraction of the Multi-Functional Spoilers and the Ground Lift Dumping System.
What is the function of the Flutter Dampers?
They prevent aileron control surface flutter when all hydraulic fluid is lost in flight
How many Power Control Units (PCU) are installed on each Multi-Function Spoiler (MFS)?
One
What are the functions of the Multi-Function Spoiler (MFS)?
To provide roll assist and lift dumping
Where are the aileron, rudder and elevator positions displayed in the cockpit?
The Flight Controls synoptic page
How are the ailerons connected to operate as single unit?
An interconnect on the Captain and First Officer control yokes
What is the function of the Aileron Disconnect System (ROLL DISC)?
It separates the control wheel interconnect in case of a jam in one of the aileron’s cable runs.
What occurs after extending the Aileron Disconnect Handle (ROLL DISC)?
The control wheel interconnect is separated. The Captain moves the left aileron and right side MFD, while the First Officer moves the right aileron and left side MFD.
What occurs twenty seconds after extending the Aileron Disconnect Handle (ROLL DISC)?
The SSCU commands two amber ROLL SEL lights on the glareshield to illuminate, and the EICAS caution SPOILERONS ROLL message to appear on the Primary Page.
What occurs after pressing the amber illuminated ROLL SEL glareshield switchlight on the side with the unjammed aileron?
It returns the use of the onside MFS to that pilot.
Can the Roll Disconnect Handle be reset in flight by the pilots if necessary?
Yes
What is installed in the aileron system to help the pilots compensate for an uncommanded aileron runaway (PCU Runaway)?
A bungee breakout switch
What does the illumination of green PLT/CPLT ROLL switchlight located on the glareshield indicate?
The pilot who has control of both sets of MFS’s (Onside and Opposite Side)
What are the cockpit indications during an Aileron PCU runaway event?
The green PLT ROLL or CPLT ROLL will illuminate on the glareshield in front of the pilot that should take control of the aircraft prior to ordering the ROLL DISC to be pulled
How many Power Control Units (PCU) are installed on the rudder?
Three
What is installed to provide rudder control in the event of a jammed rudder?
A spring tension breakout
What is the function of the Rudder Travel Limiting System?
The rudder angle is limited as a function of flight conditions (speed, slat/flap positions) in order to maintain directional stability of the aircraft.
Where is the Rudder Travel Limiter displayed in the cockpit?
Flight Controls synoptic page
What is the function of the Yaw Damper?
- To improve the aircraft’s stability by damping out oscillations in yaw to prevent Dutch roll
- To assist turn coordination
How many Yaw Dampers are installed in the CRJ-700?
Two
How are the Yaw Dampers engaged?
By selecting the YD 1 and YD 2 ENGAGE switchlights on the YAW DAMPER panel.
What is the function of the DISC button located on the Yaw Damper Control panel?
This disengages the Yaw Dampers
Will the autopilot operate with one channel of the Yaw Damper inoperative?
Yes
What EICAS message appears when both channels of the Yaw Damper fail?
A YAW DAMPER caution message is displayed on the Primary Page
What message appears when only one channel of the Yaw Damper fails?
A YD 1 or YD 2 status message is displayed on the Status Page
How many Power Control Units (PCU) activate each elevator?
Three
How many separate elevators comprise the elevator system?
Two
What is the function of the Pitch Disconnect Handle (PITCH DISC)?
It is used to isolate a jammed elevator system control.
Is hydraulic power necessary to trim the aileron and rudder systems?
Yes
How is the trimming of the ailerons accomplished?
Activation of the AIL TRIM switches causes hydraulic power to move the actual aileron surface. Actuation of the aileron trim will cause deflection of the control wheels.
How is the trimming of the rudder accomplished?
Activation of the RUD TRIM switch causes hydraulic power to move the actual rudder surface. Actuation of the rudder trim will not cause deflection of the rudder pedals.
How is the trimming of the horizontal stabilizer accomplished?
Two electric trim motors move a jack screw that varies the horizontal stabilizer’s angle of incidence.
What is the function of the Mach Trim System?
It makes allowances for the rearward shift of the aerodynamic center of pressure as the Mach number increases by automatically adjusting the stabilizer.
How is the Slat/Flap System powered?
Electrically
What will power the flaps with the loss of the AC Bus 1 and AC Bus 2?
The ADG
How is electrical load reduced when using the Air Driven Generator (ADG) to operate the flaps?
By operating at half speed
What is the function of the Emergency Flap Switch?
It allows limited flap selection in the event of a mechanical failure of the Flaps/Slats Selector Lever.
What are the restrictions when using the Emergency Flap Switch?
Slats extend to 25, flaps extend to 20 & airspeed must be below 230 knots.
What is the function of the Flight Spoilers?
To provide lift dumping and speed control
What is the function and location of the Multi-Function Spoilers?
The two outboard spoilers on each wing act as Multi-Functional Spoilers to provide roll assist, proportional lift dumping, and ground lift dumping functions.
What is the function and location of the Ground Spoilers?
The two inboard spoilers on each wing act as Ground Spoilers to provide ground lift dumping.
When does the Ground Lift Dumping System automatically deploy?
- The system must be armed
- Both left and right thrust levers at idle or reverse AND
- At least two of the following:
- Left or right MLG weight-on-wheels
- Wheel speed greater than 16 knots
- Radio altitude less than 7 feet
When does the Ground Lift Dumping System automatically retract after landing?
- Either left or right engine less than minimum takeoff setting AND
- Aircraft on the ground for more than 40 seconds AND
- Inboard and outboard wheel speed below 45 knots for 10 seconds
What is the function of the winglets?
They create a forward lift component and a reduction of induced drag that translates into a 3% fuel consumption reduction.
