Flight Controls System

Question 1

How many elevator control panels?

Answer 1

4 total. 2 per side

Question 2

How are all flight controls powered?

Answer 2

Hydraulically

Question 3

Is there any manual reversion for the flight controls?

Answer 3

No

Question 4

If there is an elevator control jam, what is the mechanism to regain control?

Answer 4

Shear out by manual force

Question 5

Describe the way that the elevator control panels are operated

Answer 5

Control column input -> hydraulic actuator -> inboard elevators-> outboard elevators. The inboard elevators move the outboard elevators

Question 6

What does elevator feel do?

Answer 6

It provides feedback feel to the pilot based on airspeed. Faster=more force required.

Question 7

What powers elevator feel? What is the backup>

Answer 7

Hydraulic system 2 and 3. Backup is springs

Question 8

What elevators are displayed on the secondary EICAS for flight control position?

Answer 8

The outboard elevators

Question 9

What powers stabilizer trim?

Answer 9

Hydraulic system 2 and 3

Question 10

What happens if you move a yoke stabilizer trim switch with the autopilot engaged? What if you move the alternate trim switch with AP engaged?

Answer 10

1 autopilot engaged: Disconnects the autopilot

More than 1 AP engaged: Trim switch inhibited

Movement of the alternate trim: Regardless of how many autopilots engaged, it will trim the plane and not disconnect the AP, but it will give you an EICAS STAB TRIM UNSCHD

Question 11

What is an STCM? How many are there?

Answer 11

Stabilizer Trim Control Module

2 of them

Question 12

If you have only 1 STCM, will the stabilizer trim still work?

Answer 12

Yes, but at half rate

Question 13

The STAB TRIM CUTOUT switches have 3 positions. ON, AUTO, and CUTOUT. What do these switches do?

Answer 13

AUTO: Hydraulic power is supplied to the STCMs. If unscheduled trim is detected, it will cutout hydraulic power
ON: Hydraulic power always supplied to STCMs
OFF: Hydraulic power removed from STCMs

Question 14

Comparing the trim range of the regular yoke stab trim switches versus the alternate stab trim switches, which one provides a greater range of movement?

Answer 14

The alternate stabilizer trim switches

Question 15

The rate of stabilizer trim movement is a function of____

Answer 15

Airspeed. Faster speed = slower stabilizer movement

Question 16

How many takeoff trim ranges?

Answer 16

3. Nose down, mid, and nose up bands

Question 17

What determines the stabilizer trim setting for takeoff?

Answer 17

The FMC calculates it based on gross weight, CG, and takeoff thrust

Question 18

You see an EICAS >STAB GREENBAND. What does this mean?

Answer 18

It means the nose wheel pressure sensor is saying it thinks you didn’t get the correct takeoff stab trim settings based on the weight. Recheck the data

Question 19

Does the aircraft trim itself while hand flying?

Answer 19

Yes, it does with stabilizer trim. It’s called speed and mach stability trim. Function of airspeed

Question 20

How many ailerons on the plane? What are they called (grouping)?

Answer 20

4 total ailerons- 2 on each wing

Divided into 2 groups “inboard” and “outboard”

Question 21

What is aileron lockout? When does it occur?

Answer 21

It prevents overcontrolling at high airspeed. It locks out the outboard ailerons at 238 knots. Unlocks below 238 knots for full control authority

Question 22

How many total spoiler panels per wing?

Answer 22

6 total per wing

Question 23

Of the 6 total spoilers per wing, which are used in flight as speedbrakes? For roll?

Answer 23

Roll: All except furthest inboard

Speedbrakes: All except 2 outboard

Question 24

What can you do if there is a roll control jam?

Answer 24

Higher than normal force can be used to operate on-side ailerons and half the spoilers. This is allowed by use of a jam override mechanism.

If that fails, a shearout will regain control

Question 25

Why is it forbidden to trim the ailerons when the autopilot is engaged?

Answer 25

Because there is no mechanism to prevent it. The yoke will build up pressure and when you disengage the AP, it will snap to the neutral position

Question 26

Why does the EICAS only show the left spoiler panel move in flight and not the right side when using speed brakes?

Answer 26

Because the right side is showing the position of the outboard spoiler, which isnt used as a speedbrake

Question 27

What are the takeoff flap settings? What are the landing settings?

Answer 27

Takeoff: 10 or 20 Landing: 25 or 30

Question 28

How many sections of the LE flaps are there?

Answer 28

3. Inboard, mid, outboard

Question 29

How are the LE flaps powered?

Answer 29

Normal: Pneumatically Backup: Electric motor (slow rate)

Question 30

How many sections of TE flaps are there?

Answer 30

2. Inboard and outboard

Question 31

What powers the TE flaps?

Answer 31

Hydraulic system 1 and 4. 1 is inboard, 2 is outboard Backup: Electric motor (slow rate)

Question 32

What happens when you go from flaps UP to flaps 1?

Answer 32

Inboard and mid LE flaps extend

Question 33

What happens when you go from flaps 1 to 5?

Answer 33

Outboard LE extends (to join mid and inboard), and TE moves to flaps 5

Question 34

How many flap control modes are there? What are they?

Answer 34

3 modes: -Primary: FCUs (flap control units) control the LE flaps pneumatically and TE hydraulically -Secondary: FCUs use electric motors (activates automatically) -Alternate: Bypasses FCSs and gives you direct authority to operate the flaps via the ALTN FLAPS switch

Question 35

What is an FCU? How many?

Answer 35

Flap control unit. 3

Question 36

What protections are available for flap primary mode? In secondary mode? In alternate mode?

Answer 36

Primary: -Asymmetry protection (TE) -Load relief (30 to 25 or 25 to 20) Secondary: -Asymmetry protection (TE) ALTERNATE: No protections

Question 37

In alternate flap mode, does the flap lever work? What is the max flap setting?

Answer 37

No ; max is flaps 25

Question 38

If the standby bus is the only powered AC bus, can you get TE flap position info?

Answer 38

No, it will be an amber X on the flap display

Question 39

When do the LE flaps retract automatically?

Answer 39

When reverse thrust is deployed (inboard and mid)

Question 40

When would the ground spoilers deploy if they are armed?

Answer 40

-Main gear touchdown and, -Thrust lever 1 + 3 near idle

Question 41

If you forget to arm the ground spoilers, will they still activate on landing?

Answer 41

Yes, it just now requires everything that it normally does, PLUS the reverse thrust levers on engine 2 and 4 are pulled up to idle reverse or more.

Question 42

Regarding the ground spoilers, what activated go around protection?

Answer 42

If thrust lever 1 or 3 is advanced past idle, they stow

Question 43

How many rudders are there?

Answer 43

2. Upper and Lower

Question 44

What if the rudder pedals jam?

Answer 44

Shearouts allow you to break through with significant manual force

Question 45

If you lost 1 hydraulic system, would both rudders work?

Answer 45

Yes. And any 2 or 3 failures will cause it to work on only 1 rudder, but it would be flyable

Question 46

What is a feel and trim unit?

Answer 46

For the rudders, to give them realistic feel. Gets harder at higher airspeeds. It also trims the rudders and repositions the neutral point

Question 47

What is a rudder ratio changer? How many are there?

Answer 47

It protects the vertical structure by limiting the rudder displacement at higher speeds. (Not 100% guaranteed to protect the tail) There are 2 of them (upper and lower)

Question 48

What happens if the rudder ratio changer fails?

Answer 48

The rudder stays in the position that it was when the ratio changer failed.

Question 49

How many yaw dampers?

Answer 49

2

Question 50

What powers the yaw dampers?

Answer 50

Hydraulic system 2 (lower rudder) Hydraulic system 3 (upper rudder)