Flight Controls

Question 1

Which yoke is connected to the left aileron ?

Answer 1

Captain’s

Question 2

How are the ailerons, elevators and rudders actuated?

Answer 2

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.

Question 3

Which yoke controls the right elevator?

Answer 3

First officer’s

Question 4

Which yoke controls the left elevator?

Answer 4

Captain’s

Question 5

What is the purpose of the multifunction spoilers (MFS)?

Answer 5

To assist with roll control and serve as a spoiler in flight and on landing.

Question 6

Are the multifunction spoilers operational at any speed?

Answer 6

Yes

Question 7

Which yoke is connected to the right aileron?

Answer 7

First Officers

Question 8

How are the MFSs controlled when used for roll assistance?

Answer 8

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

Question 9

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

Answer 9

Both yokes will be jammed

Question 10

What happens after the ROLL DISC handle is pulled ?

Answer 10

The aileron cable and pulley systems are disconnected through torque tubes. Twenty seconds later, if the operable side has not been selected, the amber ROLL SEL switch illuminates.

Question 11

How is the operable side selected?

Answer 11

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

Question 12

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

Answer 12

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

Question 13

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

Answer 13

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 symbol.

Question 14

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

Answer 14

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

Question 15

What panels are part of the GND LIFT dumping system?

Answer 15

Inboard and outboard ground spoilers, all 4 MFS panels

Question 16

How are the flight controls gust locked?

Answer 16

Hydraulic fluid is trapped during shutdown

Question 17

How is the yaw damper engaged?

Answer 17

YD1 and YD2 engage switchlights on the center pedestal

Question 18

How is the yaw damper disengaged?

Answer 18

DISC button on the center pedestal

Question 19

What controls the yaw damper ?

Answer 19

The flight control computer

Question 20

Is it necessary to disconnect the yaw damper on landing?

Answer 20

No

Question 21

How are the flaps operated?

Answer 21

Electrically

Question 22

How many flap segments does the CRJ 900 have?

Answer 22

4 total - 2on each side

Question 23

Is there any asymmetrical protection within the flaps?

Answer 23

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

The Flap Electronic Control Unit (FECU) will prevent the flaps from being reset during flight.

Question 24

How is STAB TRIM operated?

Answer 24

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

Question 25

What systems can operate STAB TRIM?

Answer 25

CA's trim switches FO's trim switches Autopilot and Mach trim

Question 26

What is the priority for STAB TRIM control?

Answer 26

CA FO Autopilot MACH trim

Question 27

Extra | What are the two types of multifunction spoilers (MFS) and how many of them are there

Answer 27

There are 2 on each wing OUTBOARD MFS is SPOILERON INBOARD MFS is FLIGHT SPOILERON

Question 28

Extra | What is a flutter damper

Answer 28

Double acting shock absorber installed on each aileron Prevent flutter when all hydraulic fluid is lost at the PCU during flight (power control unit) Provide additional gust lock on the ground

Question 29

Extra | How many PCUs does the rudder have

Answer 29

3

Question 30

Extra | When does Rudder travel limits exist and how many degrees is it

Answer 30

Writer travel is limited to in-flight condition which is defined as 2 to 3 seconds after lift off to touchdown Router travel limit is automatically programmed 3 to 33° RTL Is a function of Airspeed Flap position Engine Operation

Question 31

How many y’all dampers are there and how do they work

Answer 31

There are two independent -YD1 and YD2 Improve stability by damping out oscillations in yaw Oscillations could lead the dutch roll Operate independently of auto pilot system Controlled by the flight control computers FCC1 Controls YD1 and FCC2 controls YD2

Question 32

Extra | How many elevators are there and how do they work

Answer 32

2 Each elevator is hydraulically powered by three PCUs Left control wheel cable/pulley system is connected to the left elevator PCU Controls are normally interconnected for simultaneous movement from either station PCUs provide gust lock on the ground

Question 33

Extra | What does the pitch disconnect handle do?

Answer 33

Isolates the left elevator system from the right elevator system in the event of a jam Once disconnected the left control will controls the left elevator and the right control wheel controls the right elevator Pull handle up and rotate 90° to lock in position On EICAS page-Obermark represents -23.6° Center mark represents neutral Lower Mark represents +18.4°

Question 34

Extra How does Horizontal Stabilizer Trim work?

Answer 34

Provides pitch trim by varying the horizontal stabilizer angle of incidence from +2° nose down to -13° nose up Position by jack screw driven by chew electric trim motors in control by SSCUs Two channels engage by selecting the channel 1 and channel 2 switch lights on Stabbed trim control panel located on the center pedestal

Question 35

Extra | Mach trim- what is it and how does it work

Answer 35

The mock trim function makes allowances for the rearward shift of the arrow dynamic center of pressure as the Mach number increases. Without correction this shift in the center of pressure causes a negative stick force gradient and decreases longitudinal stability (Mach tuck) above Mach .4 when hand flying. The SSC you automatically adjust the stabilizer as a function of the mock number when the auto pilot is not engaged. Both F cc must signal the need for trim before any trim activity occurs. The automatic mock trim is last in the order of priority. With the auto pilot off and no pilot stabbed trim commands inputted the mock trim automatically moves the stabilizer to compensate for changes in air speed. Mach trim moves a stabilizer at the slowest rate. The Mach trim system, uses Mach speed information from the air data computers (ADC), varies the angle of incidence of the stabilizer by commanding movement of the horizontal stabilizer actuator. Both channels of the SSCU must be operable and at least one STAB Channel in gauge for the mock trim to function