Flight Controls

Question 1

The aircraft is equipped with both primary and secondary flight controls.
The slats and flaps are the secondary flight controls and are referred to as the High Lift Control System (HLCS).
All other flight controls are considered as the Primary Flight Control System (PFCS).

Answer 1

The aircraft is equipped with both primary and secondary flight controls.
The slats and flaps are the secondary flight controls and are referred to as the High Lift Control System (HLCS).
All other flight controls are considered as the Primary Flight Control System (PFCS).

Question 2

If the usual mode of operation degrades, the next level of operation for both the “Primary” and the “Secondary” flight controls is called “Secondary”.
Should the “Primary” flight controls suffer a further degradation of the mode of operation, they will operate in a mode called “Direct”.
The lowest operating mode for the “Secondary” flight controls is the “Alternate” mode.

Answer 2

If the usual mode of operation degrades, the next level of operation for both the “Primary” and the “Secondary” flight controls is called “Secondary”.
Should the “Primary” flight controls suffer a further degradation of the mode of operation, they will operate in a mode called “Direct”.
The lowest operating mode for the “Secondary” flight controls is the “Alternate” mode.

Question 3

The primary flight controls usually operate in a mode called “Normal”, while the secondary flight controls usually operate in a mode called “Primary”.

Answer 3

The primary flight controls usually operate in a mode called “Normal”, while the secondary flight controls usually operate in a mode called “Primary”.

Question 4

Primary Flight Controls

• ailerons
• flaperons
• rudder
• elevators
• stabilizer
• spoilers

Answer 4

Primary Flight Controls

• ailerons
• flaperons
• rudder
• elevators
• stabilizer
• spoilers

Question 5

The PFCS is a three-axis, “Fly-by-wire” system that uses inputs from the control wheels, columns, and rudder pedals during manual flight and uses inputs from the AFDS when the autopilot is engaged.

Answer 5

The PFCS is a three-axis, “Fly-by-wire” system that uses inputs from the control wheels, columns, and rudder pedals during manual flight and uses inputs from the AFDS when the autopilot is engaged.

Question 6

The spoilers are used as speed brakes and to assist in roll control.
There are 7 spoilers on each wing.
In the NORMAL mode spoilers 5 and 10 are locked out during high-speed flight to dampen the roll rate.
During low speed flight, these spoilers (5 and 10) also augment roll control.

Answer 6

The spoilers are used as speed brakes and to assist in roll control.
There are 7 spoilers on each wing.
In the NORMAL mode spoilers 5 and 10 are locked out during high-speed flight to dampen the roll rate.
During low speed flight, these spoilers (5 and 10) also augment roll control.

Question 7

The Elevators provide conventional short-term pitch control until the PFCs automatically trim the Horizontal Stabilizer to neutralize the elevator loads.
Due to inputs from the PFCs, pilot trim inputs are minimized by automatically positioning the elevator surfaces in response to flap or thrust changes.

Answer 7

The Elevators provide conventional short-term pitch control until the PFCs automatically trim the Horizontal Stabilizer to neutralize the elevator loads.
Due to inputs from the PFCs, pilot trim inputs are minimized by automatically positioning the elevator surfaces in response to flap or thrust changes.

Question 8

Yaw damping, gust suppression, thrust asymmetry compensation provides a comfortable and safe flight.

Answer 8

Yaw damping, gust suppression, thrust asymmetry compensation provides a comfortable and safe flight.

Question 9

1) The normal power source for the Flight Controls is the PMGs to the PSAs.
Shown by red PMGs to green PSAs.

2) If the normal sources are not available, the DC buses power the respective PSAs.
Shown by dotted green lines to PSAs.

3) If both PMGs to the Center PSA are not available, the Capt. Flight Instrument Bus powers the Center Flight Control DC Bus PSA.
Shown by dotted green line to PSA.

4) If both sources above have failed, the Hot Battery Bus powers the Left and Center Flight Control DC Bus PSAs.
Shown by curved green lines to PSAs.

Answer 9

1) The normal power source for the Flight Controls is the PMGs to the PSAs.
Shown by red PMGs to green PSAs.

2) If the normal sources are not available, the DC buses power the respective PSAs.
Shown by dotted green lines to PSAs.

3) If both PMGs to the Center PSA are not available, the Capt. Flight Instrument Bus powers the Center Flight Control DC Bus PSA.
Shown by dotted green line to PSA.

4) If both sources above have failed, the Hot Battery Bus powers the Left and Center Flight Control DC Bus PSAs.
Shown by curved green lines to PSAs.

Question 10

The Normal mode provides the highest level of enhanced flight control.
The Autopilot will only function in the Normal mode.
The Normal mode also provides flight envelope protection for Bank Angle, Excessive Yaw, over speed, and Stall.
Note: The pilot can always over-ride these protections if necessary.

Answer 10

The Normal mode provides the highest level of enhanced flight control.
The Autopilot will only function in the Normal mode.
The Normal mode also provides flight envelope protection for Bank Angle, Excessive Yaw, over speed, and Stall.
Note: The pilot can always over-ride these protections if necessary.

Question 11

The PFCs automatically revert to the Secondary mode when they cannot maintain Normal mode operation due to internal faults or lack of required information from other systems.
Note: Manual selection of the Secondary mode is NOT possible.
If the condition that caused the degradation to the Secondary mode was temporary, the system will automatically upgrade to the Normal mode when able.

Answer 11

The PFCs automatically revert to the Secondary mode when they cannot maintain Normal mode operation due to internal faults or lack of required information from other systems.
Note: Manual selection of the Secondary mode is NOT possible.
If the condition that caused the degradation to the Secondary mode was temporary, the system will automatically upgrade to the Normal mode when able.

Question 12

• Gust suppression
• Autopilot
• Thrust asymmetry compensation
• Envelope protection
• Wheel to rudder cross-tie
• Auto speed brakes
• Yaw damping (may be degraded or inop.)

Answer 12

The Flight Envelope Protections and the Autopilot are NOT available in the Secondary mode.
Note the complete list of functions that are NOT available in the Secondary mode: (see above)

Question 13

If all three PFCs fail or communication to the PFCs is lost, the system can automatically revert to the Direct mode.
In the Direct mode, the pilot control signals are directly sent to the flight controls.
The Direct mode provides full airplane control for continued safe flight and landing.
The airplane handling qualities are about the same as when operating in the Secondary mode.

Answer 13

If all three PFCs fail or communication to the PFCs is lost, the system can automatically revert to the Direct mode.
In the Direct mode, the pilot control signals are directly sent to the flight controls.
The Direct mode provides full airplane control for continued safe flight and landing.
The airplane handling qualities are about the same as when operating in the Secondary mode.

Question 14

When the Direct mode is active, the EICAS Caution message PRI FLIGHT COMPUTERS is displayed.
The Flight Envelope Protections and the Autopilot are NOT available in the Direct mode.
Note the list of functions that are NOT available in the Direct mode: (see above)

Answer 14

• Gust suppression
• Autopilot
• Thrust asymmetry compensation
• Envelope protection
• Wheel to rudder cross-tie
• Auto speed brakes
• Yaw damping
• Manual rudder trim cancel switch.

Question 15

The Direct mode can be manually selected by moving the PRIMARY FLIGHT COMPUTERS disconnect switch to the DISC position.
If this switch is returned to the normal AUTO position and the PFCs are operative, the system will automatically upgrade to the highest available mode - Normal or Secondary.

Answer 15

The Direct mode can be manually selected by moving the PRIMARY FLIGHT COMPUTERS disconnect switch to the DISC position.
If this switch is returned to the normal AUTO position and the PFCs are operative, the system will automatically upgrade to the highest available mode - Normal or Secondary.

Question 16

The flight control surface actuators are signaled by 4 Actuator Control Electronics (ACEs).
The system is designed so that a single ACE does not control all surfaces in any axis.
This feature provides redundancy and improves reliability.

Answer 16

The flight control surface actuators are signaled by 4 Actuator Control Electronics (ACEs).
The system is designed so that a single ACE does not control all surfaces in any axis.
This feature provides redundancy and improves reliability.

Question 17

When hand flying in the Normal or Secondary mode, the pilot inputs are converted to analog electronic signals by the control position transducers.
The position transducers send their signals to the ACEs and the ACEs convert the signals to digital format and then send the signals to the PFCs.

Answer 17

When hand flying in the Normal or Secondary mode, the pilot inputs are converted to analog electronic signals by the control position transducers.
The position transducers send their signals to the ACEs and the ACEs convert the signals to digital format and then send the signals to the PFCs.

Question 18

The PFCs modify the control signals as necessary to enhance the control surface commands.
The signal modification is based upon air data, inertial data, flap / slat position, engine thrust, and radio altitude information.

Answer 18

The PFCs modify the control signals as necessary to enhance the control surface commands.
The signal modification is based upon air data, inertial data, flap / slat position, engine thrust, and radio altitude information.

Question 19

After the signals are processed, the PFCs send the enhanced signals back to the ACEs, which convert the signals from digital, back to analog, and send the signals to the Power Control Units (PCUs).
Of course these signals move at the speed of light, so the flight control input appears immediate.

Answer 19

After the signals are processed, the PFCs send the enhanced signals back to the ACEs, which convert the signals from digital, back to analog, and send the signals to the Power Control Units (PCUs).
Of course these signals move at the speed of light, so the flight control input appears immediate.

Question 20

Things are a little different when the autopilot is engaged.
The digital control signals originate in the Autopilot Flight director Computers (AFDCs), and are directly sent to the PFCs, which enhance and send the signals to the ACEs.
As always, the ACEs provide analog command signals to the PCUs to position the surface.

Answer 20

Things are a little different when the autopilot is engaged.
The digital control signals originate in the Autopilot Flight director Computers (AFDCs), and are directly sent to the PFCs, which enhance and send the signals to the ACEs.
As always, the ACEs provide analog command signals to the PCUs to position the surface.

Question 21

The PFCs automatically perform a self-test when the hydraulic systems are shut down.
During the test, various indications appear as shown here.
All indications return to normal when the test is complete. The test takes about two minutes from the time that the EICAS Caution message HYD PRESS SYS L+C+R is displayed.

Answer 21

The PFCs automatically perform a self-test when the hydraulic systems are shut down.
During the test, various indications appear as shown here.
All indications return to normal when the test is complete. The test takes about two minutes from the time that the EICAS Caution message HYD PRESS SYS L+C+R is displayed.

Question 22

In the Normal mode, flight envelope protection reduces the possibility of inadvertently exceeding the airplane’s flight envelope.
This system provides crew awareness of envelope margins through tactile, aural, and visual cues.

Answer 22

In the Normal mode, flight envelope protection reduces the possibility of inadvertently exceeding the airplane’s flight envelope.
This system provides crew awareness of envelope margins through tactile, aural, and visual cues.

Question 23

Protection is provided for stall protection, overspeed protection, and bank angle protection.
The protection does not reduce the pilot’s control authority, since the pilot can override the protection at any time.

Answer 23

Protection is provided for stall protection, overspeed protection, and bank angle protection.
The protection does not reduce the pilot’s control authority, since the pilot can override the protection at any time.

Question 24

The Direct mode process is simpler. The pilot inputs are converted to analog signals by the control position transducers, and then sent directly to the ACEs to provide the command signals to the flight control surface actuators.
The PFCs are bypassed when operating in the Direct mode.
When the Direct mode is operating, the PFCS flight envelope protections are not available and the Autopilot

Answer 24

The Direct mode process is simpler. The pilot inputs are converted to analog signals by the control position transducers, and then sent directly to the ACEs to provide the command signals to the flight control surface actuators.
The PFCs are bypassed when operating in the Direct mode.
When the Direct mode is operating, the PFCS flight envelope protections are not available and the Autopilot

Question 25

When the Secondary mode is active, the protection modes are not available.
Additionally, the Autopilot cannot be engaged when the Secondary mode is active.
Otherwise, the flow of signals to the ACEs and PFCs is the same as the normal mode.

Answer 25

When the Secondary mode is active, the protection modes are not available.
Additionally, the Autopilot cannot be engaged when the Secondary mode is active.
Otherwise, the flow of signals to the ACEs and PFCs is the same as the normal mode.

Question 26

The EICAS Caution message FLIGHT CONTROLS is displayed if:

• multiple ACE and / or hydraulic system failures occur that cause the loss of a significant number of control surfaces, or
• other flight control system faults are detected.

Answer 26

The EICAS Caution message FLIGHT CONTROLS is displayed if:

• multiple ACE and / or hydraulic system failures occur that cause the loss of a significant number of control surfaces, or
• other flight control system faults are detected.

Question 27

In the event of failure of all electrically controlled surfaces, a mechanical backup is provided to allow the pilot to fly straight and level until the electrical system is restarted.
The mechanical control consists of cable input from the control wheels to operate spoilers 4 and 11(for roll control) and cables from the Alternate Stabilizer Trim Levers to operate the horizontal stabilizer.
Recall that hydraulic pressure is required even when activated by cable control.

Answer 27

In the event of failure of all electrically controlled surfaces, a mechanical backup is provided to allow the pilot to fly straight and level until the electrical system is restarted.
The mechanical control consists of cable input from the control wheels to operate spoilers 4 and 11(for roll control) and cables from the Alternate Stabilizer Trim Levers to operate the horizontal stabilizer.
Recall that hydraulic pressure is required even when activated by cable control.

Question 28

The High Lift Control System (HLCS) is also a “fly-by-wire” system that consists of the slats, Krueger flaps, and trailing edge flaps.
These devices are normally operated hydraulically but can be operated electrically.

Answer 28

The High Lift Control System (HLCS) is also a “fly-by-wire” system that consists of the slats, Krueger flaps, and trailing edge flaps.
These devices are normally operated hydraulically but can be operated electrically.

Question 29

The system is normally controlled by two Flap/Slat Electronic Units (FSEUs).
The HLCS operates in one of three modes: Primary, Secondary, or Alternate.
The Primary and Secondary modes use the FSEUs, but the Alternate mode is directly controlled by the pilot and does not use the FSEUs.
The sequence of extension and retraction is different for the three modes.

Answer 29

The system is normally controlled by two Flap/Slat Electronic Units (FSEUs).
The HLCS operates in one of three modes: Primary, Secondary, or Alternate.
The Primary and Secondary modes use the FSEUs, but the Alternate mode is directly controlled by the pilot and does not use the FSEUs.
The sequence of extension and retraction is different for the three modes.

Question 30

There are 7 slats and 1 Krueger flap on each wing.
The slats can be set to three positions: Cruise (retracted), Takeoff (sealed), and Landing (gapped).
The Krueger flaps have only two positions: Retracted and Deployed.

Answer 30

There are 7 slats and 1 Krueger flap on each wing.
The slats can be set to three positions: Cruise (retracted), Takeoff (sealed), and Landing (gapped).
The Krueger flaps have only two positions: Retracted and Deployed.

Question 31

The trailing edge flaps have an inboard double slotted flap and an outboard single slotted flap.

Answer 31

The trailing edge flaps have an inboard double slotted flap and an outboard single slotted flap.

Question 32

Takeoff can be made with flaps 5, 15, or 20. Notice the normal takeoff setting.
Landing flaps are 25 or 30. Notice the normal, single engine, and go-around settings.

Answer 32

Takeoff can be made with flaps 5, 15, or 20. Notice the normal takeoff setting.
Landing flaps are 25 or 30. Notice the normal, single engine, and go-around settings.

Question 33

The HLCS is equipped with Autoslats, Load Relief, and Skew or Asymmetry protection.

Answer 33

The HLCS is equipped with Autoslats, Load Relief, and Skew or Asymmetry protection.

Question 34

Autoslats:
In the Primary mode, the Slats will automatically extend from the sealed position to the gapped position if an impending stall is detected.
The Slats will automatically retract to the sealed position when the stall condition has been removed.

Answer 34

Autoslats:
In the Primary mode, the Slats will automatically extend from the sealed position to the gapped position if an impending stall is detected.
The Slats will automatically retract to the sealed position when the stall condition has been removed.

Question 35

Load Relief:
In the Primary mode, the flaps will retract if the airspeed exceeds the speed limit for the current flap position.

The flaps will re-extend when the airspeed is below the limit for the selected flap position.

If the airspeed is too high when the Flap lever is selected to extend the flaps, the flaps will not extend until speed is reduced.

In the Secondary mode, the Slats have a Load Relief function, but there is no Load Relief for the Flaps in the Secondary mode.

Answer 35

Load Relief:
In the Primary mode, the flaps will retract if the airspeed exceeds the speed limit for the current flap position.

The flaps will re-extend when the airspeed is below the limit for the selected flap position.

If the airspeed is too high when the Flap lever is selected to extend the flaps, the flaps will not extend until speed is reduced.

In the Secondary mode, the Slats have a Load Relief function, but there is no Load Relief for the Flaps in the Secondary mode.

Question 36

Skew Protection:
The Skew protection system will stop the movement of the slats if a slat segment is not moving symmetrically.
The movement of each slat segment is monitored.

Skew protection ensures that if a slat segment is jammed, the slat drive is interrupted to minimize potential damage to the slats.

Answer 36

Skew Protection:
The Skew protection system will stop the movement of the slats if a slat segment is not moving symmetrically.
The movement of each slat segment is monitored.

Skew protection ensures that if a slat segment is jammed, the slat drive is interrupted to minimize potential damage to the slats.

Question 37

Asymmetry Protection:
The Asymmetry protection system will stop the movement of the slats if the slats on one wing are not in agreement with the slats on the opposite wing.

Asymmetry protection ensures both wings have the same overall slat configuration.

Answer 37

Asymmetry Protection:
The Asymmetry protection system will stop the movement of the slats if the slats on one wing are not in agreement with the slats on the opposite wing.

Asymmetry protection ensures both wings have the same overall slat configuration.

Question 38

Excessive Speed for Flap and Slat Extension:
B777-200 250 knots
B777-200ER and B777-300 265 knots
B777-200LR and B777-300ER 275 knots

Answer 38

Excessive Speed for Flap and Slat Extension:
B777-200 250 knots
B777-200ER and B777-300 265 knots
B777-200LR and B777-300ER 275 knots

Question 39

To protect against inadvertent deployment during cruise, the flap and slat extension from the UP position is inhibited when speed is excessive or the altitude is above approximately 20,000 feet.
The speed considered excessive for each aircraft series is shown here…

Answer 39

To protect against inadvertent deployment during cruise, the flap and slat extension from the UP position is inhibited when speed is excessive or the altitude is above approximately 20,000 feet.
The speed considered excessive for each aircraft series is shown here…

Question 40

Three modes of flap and slat operation are possible:

• PRIMARY (hydraulic operation)
• SECONDARY (electric operation)
• ALTERNATE (electric operation)

Answer 40

Three modes of flap and slat operation are possible:

• PRIMARY (hydraulic operation)
• SECONDARY (electric operation)
• ALTERNATE (electric operation)

Question 41

Primary operation is controlled by the Flap Handle and the Slats and Flaps are hydraulically actuated.

Secondary operation is controlled by the Flap Handle and the Slats and Flaps are electrically actuated.

Alternate operation is controlled by the Alternate Flap Selector and the Slats and Flaps are electrically actuated.

Answer 41

Primary operation is controlled by the Flap Handle and the Slats and Flaps are hydraulically actuated.

Secondary operation is controlled by the Flap Handle and the Slats and Flaps are electrically actuated.

Alternate operation is controlled by the Alternate Flap Selector and the Slats and Flaps are electrically actuated.

Question 42

The ALTERNATE Flap Controls are manually armed by the crew if both PRIMARY and SECONDARY modes are inoperative.
Ensure you consult the appropriate Non-normal procedure.
A selector is used to Extend or Retract the flaps and slats in the ALTERNATE mode.
Note: The flaps and slats can operate independently in either the primary or secondary mode, but independent flap and slat operation in the alternate mode is not possible.

Answer 42

The ALTERNATE Flap Controls are manually armed by the crew if both PRIMARY and SECONDARY modes are inoperative.
Ensure you consult the appropriate Non-normal procedure.
A selector is used to Extend or Retract the flaps and slats in the ALTERNATE mode.
Note: The flaps and slats can operate independently in either the primary or secondary mode, but independent flap and slat operation in the alternate mode is not possible.

Question 43

PRIMARY mode hydraulic power is supplied by the center hydraulic system.

Answer 43

PRIMARY mode hydraulic power is supplied by the center hydraulic system.

Question 44

SECONDARY or ALTERNATE mode power is supplied by the left and right AC busses.

Answer 44

SECONDARY or ALTERNATE mode power is supplied by the left and right AC busses.

Question 45

If flap/slat control is in the Secondary or Alternate mode, or if any Non-normal condition is detected, an expanded flap indication is displayed automatically.
The position of the left and right flaps and slats are separately indicated.

Answer 45

If flap/slat control is in the Secondary or Alternate mode, or if any Non-normal condition is detected, an expanded flap indication is displayed automatically.
The position of the left and right flaps and slats are separately indicated.

Question 46

Selection of flaps 25 commands both the flaps and slats to move to landing positions.
The slats extend first to the down (gapped) position, then the flaps extend to the landing flaps 25 position.

Answer 46

Selection of flaps 25 commands both the flaps and slats to move to landing positions.
The slats extend first to the down (gapped) position, then the flaps extend to the landing flaps 25 position.

Question 47

If the flap or slat is operating in the PRIMARY mode, uncommanded motion first causes an automatic transfer to the SECONDARY mode.
The EICAS message FLAPS PRIMARY FAIL or SLATS PRIMARY FAIL is displayed.
If motion continues, the system shuts down, and the EICAS message FLAPS DRIVE or SLATS DRIVE is displayed.

Answer 47

If the flap or slat is operating in the PRIMARY mode, uncommanded motion first causes an automatic transfer to the SECONDARY mode.
The EICAS message FLAPS PRIMARY FAIL or SLATS PRIMARY FAIL is displayed.
If motion continues, the system shuts down, and the EICAS message FLAPS DRIVE or SLATS DRIVE is displayed.

Question 48

The HLCS is equipped with Autoslats, Load Relief, and Skew or Asymmetry protection.

Answer 48

The HLCS is equipped with Autoslats, Load Relief, and Skew or Asymmetry protection.

Question 49

If a flap overspeed exists, load relief prevents flap extension beyond the 5, 15, 20, or 25 positions until airspeed is sufficiently reduced.
Flap load relief is available only in the PRIMARY mode.

Answer 49

If a flap overspeed exists, load relief prevents flap extension beyond the 5, 15, 20, or 25 positions until airspeed is sufficiently reduced.
Flap load relief is available only in the PRIMARY mode.

Question 50

During Load Relief operations, the Flap Lever does not move, but the EICAS flap display indicates an in-transit flap condition and shows actual flap position.
Load relief for slats is not required in the PRIMARY mode.

Answer 50

During Load Relief operations, the Flap Lever does not move, but the EICAS flap display indicates an in-transit flap condition and shows actual flap position.
Load relief for slats is not required in the PRIMARY mode.

Question 51

Asymmetrical flap and slat protection is available in the PRIMARY and SECONDARY modes.
A detection system detects asymmetrical extension or retraction of an individual flap.
After detection, the flap drive shuts down and the EICAS message FLAPS DRIVE is displa

Answer 51

Asymmetrical flap and slat protection is available in the PRIMARY and SECONDARY modes.
A detection system detects asymmetrical extension or retraction of an individual flap.
After detection, the flap drive shuts down and the EICAS message FLAPS DRIVE is displa

Question 52

Loss of all but the most outboard slats on each wing is also detected.
When slat loss or asymmetry occurs, the system shuts down the slat drive and displays the SLATS DRIVE EICAS message.

Answer 52

Loss of all but the most outboard slats on each wing is also detected.
When slat loss or asymmetry occurs, the system shuts down the slat drive and displays the SLATS DRIVE EICAS message.

Question 53

The SECONDARY mode is automatically engaged whenever the PRIMARY mode fails to move the flaps or slats to the selected position.
Once engaged, the SECONDARY mode remains engaged until the affected system surfaces are fully retracted or Center hydraulic system pressure is restored.

Answer 53

The SECONDARY mode is automatically engaged whenever the PRIMARY mode fails to move the flaps or slats to the selected position.
Once engaged, the SECONDARY mode remains engaged until the affected system surfaces are fully retracted or Center hydraulic system pressure is restored.

Question 54

Speed Limit for Full Slats in Secondary mode:
B777-200 215 knots
B777-200ER 239 knots
B777-300 246 knots
B777LR and B777-300ER 256 knots

Answer 54

Speed Limit for Full Slats in Secondary mode:
B777-200 215 knots
B777-200ER 239 knots
B777-300 246 knots
B777LR and B777-300ER 256 knots

Question 55

Because autoslats are unavailable, the slats are fully extended at all flap positions to improve the stall handling characteristics. Note the airspeed limit for full slat extension is specific for each aircraft series as shown here. Above these speeds, the slat extension is limited to the midrange position. If the slats are already fully extended in the secondary mode and the airspeed subsequently exceeds the limit, the slats will retract to the midrange position.

Answer 55

Because autoslats are unavailable, the slats are fully extended at all flap positions to improve the stall handling characteristics. Note the airspeed limit for full slat extension is specific for each aircraft series as shown here. Above these speeds, the slat extension is limited to the midrange position. If the slats are already fully extended in the secondary mode and the airspeed subsequently exceeds the limit, the slats will retract to the midrange position.

Question 56

Slat load relief is available in the SECONDARY mode.
If the airspeed exceeds the limit for the specific aircraft series, the slats will retract to the midrange position and LOAD RELIEF is displayed.

Answer 56

Slat load relief is available in the SECONDARY mode.
If the airspeed exceeds the limit for the specific aircraft series, the slats will retract to the midrange position and LOAD RELIEF is displayed.

Question 57

Note: If the slats are in the midrange (sealed) position (flaps 1 through 20) when the SECONDARY mode is engaged, they remain in that position until the flaps are retracted to UP, or extended beyond 20.

Answer 57

Note: If the slats are in the midrange (sealed) position (flaps 1 through 20) when the SECONDARY mode is engaged, they remain in that position until the flaps are retracted to UP, or extended beyond 20.

Question 58

On the ground, SECONDARY electric mode extension or retraction is inhibited when groundspeed is less than 40 knots, Center hydraulic system pressure is low, and two of the following three items are true:
- Left engine N2 is less than 50 percent, - Right engine N2 is less than 50 percent, - Primary external power is available.

Answer 58

On the ground, SECONDARY electric mode extension or retraction is inhibited when groundspeed is less than 40 knots, Center hydraulic system pressure is low, and two of the following three items are true:
- Left engine N2 is less than 50 percent, - Right engine N2 is less than 50 percent, - Primary external power is available.

Question 59

If we wait to retract the Flaps/Slats until we’re parked and the engines are shut down, the Secondary mode won’t retract the Flaps/Slats.

Secondary mode retraction/extension is inhibited on the ground:
- with groundspeed < 40 knots,
- Center hyd pressure is low,
and 2 of the following 3 are true:

• Left Engine N2 < 50%,
• Right Engine N2 < 50%,
• Primary Ext Power is available.

Answer 59

If we wait to retract the Flaps/Slats until we’re parked and the engines are shut down, the Secondary mode won’t retract the Flaps/Slats.

Secondary mode retraction/extension is inhibited on the ground:
- with groundspeed < 40 knots,
- Center hyd pressure is low,
and 2 of the following 3 are true:

• Left Engine N2 < 50%,
• Right Engine N2 < 50%,
• Primary Ext Power is available.

Question 60

The ALTERNATE mode must be manually selected.
The Alternate flaps ARM switch disables the PRIMARY and SECONDARY modes and arms the ALTERNATE mode.
The ARM switch also arms the Alternate Flap Selector and engages the electric motors.
When Alternate Flaps are armed, the Flap Lever is disabled.

Answer 60

The ALTERNATE mode must be manually selected.
The Alternate flaps ARM switch disables the PRIMARY and SECONDARY modes and arms the ALTERNATE mode.
The ARM switch also arms the Alternate Flap Selector and engages the electric motors.
When Alternate Flaps are armed, the Flap Lever is disabled.

Question 61

The three-position alternate flaps selector extends and retracts the flaps and slats.
The flaps and slats extend simultaneously, but slat retraction is inhibited until the flaps are up.

Answer 61

The three-position alternate flaps selector extends and retracts the flaps and slats.
The flaps and slats extend simultaneously, but slat retraction is inhibited until the flaps are up.

Question 62

ALTERNATE mode flap and slat extension is limited to slats midrange (sealed) and flaps 20.
Asymmetry protection, uncommanded motion protection, autoslats, and flap/slat load relief are NOT available in the ALTERNATE mode.

Answer 62

ALTERNATE mode flap and slat extension is limited to slats midrange (sealed) and flaps 20.
Asymmetry protection, uncommanded motion protection, autoslats, and flap/slat load relief are NOT available in the ALTERNATE mode.

Question 63

Do not use the ALTERNATE mode on the ground.

Answer 63

Do not use the ALTERNATE mode on the ground.

Question 64

However, unlike conventional airplanes, the control column does not directly position ONLY the elevator in flight.
Instead, the control column commands the PFCs to generate a “pitch maneuver”.
Accordingly, the PFCs automatically position the elevator and the stabilizer to generate the commanded pitch maneuver.

Answer 64

However, unlike conventional airplanes, the control column does not directly position ONLY the elevator in flight.
Instead, the control column commands the PFCs to generate a “pitch maneuver”.
Accordingly, the PFCs automatically position the elevator and the stabilizer to generate the commanded pitch maneuver.

Question 65

The PFCs constantly monitor airplane response to pilot commands and reposition the elevator and stabilizer to carry out these commands.
The PFCs automatically input required pitch responses to thrust changes, gear configuration changes, flap and speed brake configuration changes, turbulence and turns up to 30 of bank.

Answer 65

The PFCs constantly monitor airplane response to pilot commands and reposition the elevator and stabilizer to carry out these commands.
The PFCs automatically input required pitch responses to thrust changes, gear configuration changes, flap and speed brake configuration changes, turbulence and turns up to 30 of bank.

Question 66

For turns up to 30 degrees of bank, the pilot does not need to add additional column back pressure to maintain altitude.
For turns of more than 30 degrees of bank, the pilot does need to add column back pressure.

Answer 66

For turns up to 30 degrees of bank, the pilot does not need to add additional column back pressure to maintain altitude.
For turns of more than 30 degrees of bank, the pilot does need to add column back pressure.

Question 67

When the autopilot is not engaged, as airspeed changes, the pitch control system provides conventional pitch characteristics by requiring the pilot to make control column inputs or trim changes to maintain a constant flight path.
Manual trim is necessary only when changing airspeed.
Manual trim is not necessary when changing configuration.

Answer 67

When the autopilot is not engaged, as airspeed changes, the pitch control system provides conventional pitch characteristics by requiring the pilot to make control column inputs or trim changes to maintain a constant flight path.
Manual trim is necessary only when changing airspeed.
Manual trim is not necessary when changing configuration.

Question 68

Each Elevator is hinged on the rear spar of the horizontal stabilizer and is driven by 2 PCUs.
Each PCU is powered by a different hydraulic system.

Answer 68

Each Elevator is hinged on the rear spar of the horizontal stabilizer and is driven by 2 PCUs.
Each PCU is powered by a different hydraulic system.

Question 69

Each PCU has a pressure-reducing valve that is controlled by an ACE.
If one PCU has failed, the ACE increases pressure on the operating PCU to maintain elevator movement.

Answer 69

Each PCU has a pressure-reducing valve that is controlled by an ACE.
If one PCU has failed, the ACE increases pressure on the operating PCU to maintain elevator movement.

Question 70

Each control column moves three independent position transducers.
The signal from these transducers goes to the ACEs and then on to the PFCs.

Answer 70

Each control column moves three independent position transducers.
The signal from these transducers goes to the ACEs and then on to the PFCs.

Question 71

Two Elevator Feel Units provide feedback feel to the pilot.
The PFCs calculate feel commands based on airspeed.
In general, control column forces increase:
- As airspeed increases or
- As column displacement increases.

Answer 71

Two Elevator Feel Units provide feedback feel to the pilot.
The PFCs calculate feel commands based on airspeed.
In general, control column forces increase:
- As airspeed increases or
- As column displacement increases.

Question 72

When operating in the NORMAL mode the PFCs provide stall protection.
The PFCs cause the elevators to pitch the aircraft down if the aircraft approaches a stall.

Answer 72

When operating in the NORMAL mode the PFCs provide stall protection.
The PFCs cause the elevators to pitch the aircraft down if the aircraft approaches a stall.

Question 73

Two Stabilizer Trim Control Modules (STCMs) control hydraulic pressure to the stabilizer motors and brakes.

Answer 73

Two Stabilizer Trim Control Modules (STCMs) control hydraulic pressure to the stabilizer motors and brakes.

Question 74

The alternate pitch trim levers are linked by cable directly to the stabilizer control valves.
Alternate pitch trim commands have priority over wheel pitch trim commands in all flight control modes.

Answer 74

The alternate pitch trim levers are linked by cable directly to the stabilizer control valves.
Alternate pitch trim commands have priority over wheel pitch trim commands in all flight control modes.

Question 75

In addition to Yaw control, the rudder is used to automatically provide Yaw Damping, Thrust Asymmetry Compensation, Wheel to Rudder Cross-tie, and Gust Suppression.
These features will be described later in this module.

Answer 75

In addition to Yaw control, the rudder is used to automatically provide Yaw Damping, Thrust Asymmetry Compensation, Wheel to Rudder Cross-tie, and Gust Suppression.
These features will be described later in this module.

Question 76

SECONDARY and DIRECT mode yaw control is similar to NORMAL mode yaw control.
Pedal feel forces are unchanged from normal mode; however, rudder response is slightly different.
In SECONDARY and DIRECT modes, the rudder ratio changer is degraded to two fixed ratios determined by flap position.
With flaps up, the rudder response to pedal inputs is less than with the flaps down.

Answer 76

SECONDARY and DIRECT mode yaw control is similar to NORMAL mode yaw control.
Pedal feel forces are unchanged from normal mode; however, rudder response is slightly different.
In SECONDARY and DIRECT modes, the rudder ratio changer is degraded to two fixed ratios determined by flap position.
With flaps up, the rudder response to pedal inputs is less than with the flaps down.

Question 77

TAC is available except:

• When airspeed is below 70 knots on the ground, or
• When reverse thrust is applied.

Answer 77

TAC is available except:

• When airspeed is below 70 knots on the ground, or
• When reverse thrust is applied.

Question 78

A wheel to rudder cross-tie function provides the capability to counter the initial yaw effects of an engine failure using control wheel inputs only.
Control wheel inputs can deflect the rudder up to 8 degrees.
The Wheel to Rudder Cross-tie system is available only in the NORMAL mode.

Answer 78

A wheel to rudder cross-tie function provides the capability to counter the initial yaw effects of an engine failure using control wheel inputs only.
Control wheel inputs can deflect the rudder up to 8 degrees.
The Wheel to Rudder Cross-tie system is available only in the NORMAL mode.

Question 79

The wheel to rudder cross-tie is separate from the TAC system.
It is automatically activated in flight and ceases to operate when the airspeed reaches 210 knots.
This completes our description of the Wheel to Rudder Cross-tie.

Answer 79

The wheel to rudder cross-tie is separate from the TAC system.
It is automatically activated in flight and ceases to operate when the airspeed reaches 210 knots.
This completes our description of the Wheel to Rudder Cross-tie.

Question 80

The aircraft is equipped with a Gust Suppression function that operates in the NORMAL mode.
This feature reduces the effects of lateral gusts and improves lateral ride quality through a combination of yaw and roll commands.
The system is completely automatic and makes no inputs to the rudder or control wheel.
Therefore, Gust Suppression operation does not move the pedals or control wheels.

Answer 80

The aircraft is equipped with a Gust Suppression function that operates in the NORMAL mode.
This feature reduces the effects of lateral gusts and improves lateral ride quality through a combination of yaw and roll commands.
The system is completely automatic and makes no inputs to the rudder or control wheel.
Therefore, Gust Suppression operation does not move the pedals or control wheels.

Question 81

The aircraft is equipped with Yaw Damping.
In the NORMAL mode, the yaw damping function provides turn coordination and Dutch roll damping.
In the SECONDARY mode yaw damping may operate in a degraded mode or be completely inoperative. Yaw damping is inoperative in the DIRECT mode.

Answer 81

The aircraft is equipped with Yaw Damping.
In the NORMAL mode, the yaw damping function provides turn coordination and Dutch roll damping.
In the SECONDARY mode yaw damping may operate in a degraded mode or be completely inoperative. Yaw damping is inoperative in the DIRECT mode.