Flight Controls System Flashcards
How many elevator control panels?
4 total. 2 per side
How are all flight controls powered?
Hydraulically
Is there any manual reversion for the flight controls?
No
If there is an elevator control jam, what is the mechanism to regain control?
Shear out by manual force
Describe the way that the elevator control panels are operated
Control column input -> hydraulic actuator -> inboard elevators-> outboard elevators. The inboard elevators move the outboard elevators
What does elevator feel do?
It provides feedback feel to the pilot based on airspeed. Faster=more force required.
What powers elevator feel? What is the backup>
Hydraulic system 2 and 3. Backup is springs
What elevators are displayed on the secondary EICAS for flight control position?
The outboard elevators
What powers stabilizer trim?
Hydraulic system 2 and 3
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?
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
What is an STCM? How many are there?
Stabilizer Trim Control Module
2 of them
If you have only 1 STCM, will the stabilizer trim still work?
Yes, but at half rate
The STAB TRIM CUTOUT switches have 3 positions. ON, AUTO, and CUTOUT. What do these switches do?
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
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?
The alternate stabilizer trim switches
The rate of stabilizer trim movement is a function of____
Airspeed. Faster speed = slower stabilizer movement
How many takeoff trim ranges?
- Nose down, mid, and nose up bands
What determines the stabilizer trim setting for takeoff?
The FMC calculates it based on gross weight, CG, and takeoff thrust
You see an EICAS >STAB GREENBAND. What does this mean?
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
Does the aircraft trim itself while hand flying?
Yes, it does with stabilizer trim. It’s called speed and mach stability trim. Function of airspeed
How many ailerons on the plane? What are they called (grouping)?
4 total ailerons- 2 on each wing
Divided into 2 groups “inboard” and “outboard”
What is aileron lockout? When does it occur?
It prevents overcontrolling at high airspeed. It locks out the outboard ailerons at 238 knots. Unlocks below 238 knots for full control authority
How many total spoiler panels per wing?
6 total per wing
Of the 6 total spoilers per wing, which are used in flight as speedbrakes? For roll?
Roll: All except furthest inboard
Speedbrakes: All except 2 outboard
What can you do if there is a roll control jam?
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
Why is it forbidden to trim the ailerons when the autopilot is engaged?
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
Why does the EICAS only show the left spoiler panel move in flight and not the right side when using speed brakes?
Because the right side is showing the position of the outboard spoiler, which isnt used as a speedbrake
What are the takeoff flap settings? What are the landing settings?
Takeoff: 10 or 20
Landing: 25 or 30
How many sections of the LE flaps are there?
- Inboard, mid, outboard
How are the LE flaps powered?
Normal: Pneumatically
Backup: Electric motor (slow rate)
How many sections of TE flaps are there?
- Inboard and outboard
What powers the TE flaps?
Hydraulic system 1 and 4.
1 is inboard, 2 is outboard
Backup: Electric motor (slow rate)
What happens when you go from flaps UP to flaps 1?
Inboard and mid LE flaps extend
What happens when you go from flaps 1 to 5?
Outboard LE extends (to join mid and inboard), and TE moves to flaps 5
How many flap control modes are there? What are they?
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
What is an FCU? How many?
Flap control unit. 3
What protections are available for flap primary mode? In secondary mode? In alternate mode?
Primary:
-Asymmetry protection (TE)
-Load relief (30 to 25 or 25 to 20)
Secondary:
-Asymmetry protection (TE)
ALTERNATE: No protections
In alternate flap mode, does the flap lever work? What is the max flap setting?
No ; max is flaps 25
If the standby bus is the only powered AC bus, can you get TE flap position info?
No, it will be an amber X on the flap display
When do the LE flaps retract automatically?
When reverse thrust is deployed (inboard and mid)
When would the ground spoilers deploy if they are armed?
-Main gear touchdown and,
-Thrust lever 1 + 3 near idle
If you forget to arm the ground spoilers, will they still activate on landing?
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.
Regarding the ground spoilers, what activated go around protection?
If thrust lever 1 or 3 is advanced past idle, they stow
How many rudders are there?
- Upper and Lower
What if the rudder pedals jam?
Shearouts allow you to break through with significant manual force
If you lost 1 hydraulic system, would both rudders work?
Yes.
And any 2 or 3 failures will cause it to work on only 1 rudder, but it would be flyable
What is a feel and trim unit?
For the rudders, to give them realistic feel. Gets harder at higher airspeeds.
It also trims the rudders and repositions the neutral point
What is a rudder ratio changer? How many are there?
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)
What happens if the rudder ratio changer fails?
The rudder stays in the position that it was when the ratio changer failed.
How many yaw dampers?
2
What powers the yaw dampers?
Hydraulic system 2 (lower rudder)
Hydraulic system 3 (upper rudder)
