Flight Controls

Question 1

What are the three flight control modes?

Answer 1

Normal, Secondary, Direct.

Question 2

How are the primary flight controls powered?

Answer 2

Redundant hydraulic sources.

Question 3

How are the flaps and slats powered after a hydraulic failure?

Answer 3

Electrically (as backup).

Question 4

How are the control column and wheels connected to each other?

Answer 4

Through jam override mechanisms.

Question 5

How are the rudder pedals connected to each other?

Answer 5

Rigidly between the two sides.

Question 6

How many Primary Flight Control computers are there?

Answer 6

3

Question 7

How many Actuator Control Electronics units are there?

Answer 7

4

Question 8

Which unit receives the pilot control orders directly?

Answer 8

ACEs (Actuator Control Electronics units)

Question 9

Where do the ACEs send the pilot control orders?

Answer 9

To the primary flight control computers (PFCs)

Question 10

Why do the PFCs receive other aircraft system data?

Answer 10

To compute appropriate control surface commands for enhanced handling qualities.

Question 11

Where do the PFCs send control commands?

Answer 11

PFCs send the control commands back to the ACEs (to position the flight control surfaces).

Question 12

Where are autopilot commands sent?

Answer 12

To the PFCs (which then produce control surface commands).

Question 13

When do the flaperons droops?

Answer 13

For use as flaps increased lift, drops (move aft & down) in proportion to trailing edge flap extension.

Question 14

When do the ailerons droop?

Answer 14

When flaps 5, 15 or 20 set for T/O.

Question 15

What surfaces are locked out in normal mode?

Answer 15

Ailerons & spoilers 5 & 10 locked out during high speed flight.

Question 16

Why does the rudder have a mechanical hinged tab?

Answer 16

Hinged tab deflects twice as far as rudder control surface for additional yaw control authority.

Question 17

How are the pilot controls affected during autopilot operation?

Answer 17

Autopilot commands move the pilots controls to provide indications of what the autopilot is doing.

Question 18

What is the effect of pilot override on the controls during autopilot operation?

Answer 18

Autopilot disconnects (PFCs disconnect the autopilot and use the pilot control inputs).

Question 19

In which flight control modes is autopilot available?

Answer 19

Normal mode only.

Question 20

When is the PFC self-­‐test performed?

Answer 20

After hydraulic systems are shut down (2 mins after EICAS caution message HYD PRESS SYS +C+R shows).

Question 21

What is the purpose of the flight envelope protection system?

Answer 21

Reduces possibility of inadvertently exceeding the aircraft’s flight envelope.

Question 22

How does the system provide crew awareness of envelope margins?

Answer 22

Through tactile, aural and visual cures (no reduction in pilot control authority).

Question 23

In secondary mode, which protections are not available?

Answer 23

• Autopilot. • Auto speed brakes. • Envelope protection. • Gust suppression. • Thrust asymmetry compensation (TAC). • Yaw damping (may be degraded or inoperative). • Tail strike protection.

Question 24

Which surfaces are provided during mechanical backup operation?

Answer 24

Stabiliser and selected spoilers (4 & 11) are controlled by DCT cables FM FLT deck (allows pilot to fly S&L until electrical system is restarted).

Question 25

On the ground, what are the trim switches on the control wheel for?

Answer 25

Stabiliser is directly positioned when the pilot uses the pitch trim switches.

Question 26

What surface do the primary pitch trim switches move in flight?

Answer 26

Pitch trim switches do not position the stabiliser directly, but do make inputs to the PFCs to chance the trim reference speed.

Question 27

How is the autopilot affected by the alternate pitch trim levers?

Answer 27

Autopilot does not disconnect, but does move stabiliser.

Question 28

At what speed is nose up trim inhibited?

Answer 28

Minimum manoeuvring speed (stall protection limits trim reference speed --> inhibits trim in nose up direction).

Question 29

How are column forces affected when flying near stall speed?

Answer 29

Column forces increase to higher level than would occur for an equivalent out-­‐of-­‐trim condition ABV the minimum manoeuvring speed.

Question 30

When can the autothrottle support stall protection?

Answer 30

If armed and not activated (if speed decreases to stick shaker activation, autothrottle activates in appropriate mode [SPD or THR REF] advancing thrust to maintain minimum manoeuvring speed or speed set in MCP speed window, whichever is greater).

Question 31

. When will overspeed protection occur?

Answer 31

At VMO/MMO.

Question 32

When does elevator variable feel occur?

Answer 32

In normal mode (force increases as airspeed increases & column displacement increases).

Question 33

In secondary and direct modes, what do control column command?

Answer 33

Proportional elevator deflection (instead of a manoeuvre command).

Question 34

How is elevator feel different in secondary and direct modes?

Answer 34

Feels vary W/ flap position (increases W/ flaps up to discourage overcontrol, decreases W/ flaps extended to provide force levels appropriate for APP & LDG).

Question 35

How many hydraulic systems power the stabiliser??

Answer 35

2 (C & R hydraulic systems).

Question 36

If the automatic protection fails, how can stabiliser hydraulic power be removed?

Answer 36

Placing both stabiliser cutout switches to the CUTOUT position (aisle stand).

Question 37

How is stabiliser greenband calculation performed?

Answer 37

Using FMC inputs of CoG, GW and T/O thrust.

Question 38

How is the greenband calculation crosschecked?

Answer 38

Nose gear oleo pressure switch (switch must be selected to nose up or nose down band, then the pressure switch is compared to the computed greenband).

Question 39

Which surfaces are cables driven through the control wheels?

Answer 39

Spoilers 4 & 11.

Question 40

How is aileron trim indicated?

Answer 40

Indicated on a scale on the top of each control column.

Question 41

When is aileron trim inhibited?

Answer 41

When autopilot engaged.

Question 42

When is bank angle protection enabled?

Answer 42

When bank angle exceeds 35o (bank angle protection boundary).

Question 43

How does airspeed affect rudder pedal forces?

Answer 43

Does not vary with airspeed (only proportional to rudder pedal displacement).

Question 44

Which component reduces rudder authority at higher airspeeds?

Answer 44

Rudder ratio changer.

Question 45

When does thrust asymmetry compensation occur?

Answer 45

When L & R engine’s thrust differs by > 10%, except when: • Airspeed < 70kts on GND. • Reverse thrust being used. • Engine thrust data lost.

Question 46

Does TAC move the rudder pedals?

Answer 46

Yes (rudder movement back-­‐driven through rudder pedals, proportionately to difference in engine thrust)

Question 47

. In which mode and to what speed is wheel to rudder cross-­‐tie available?

Answer 47

210kts in normal mode.

Question 48

What does yaw damping provide?

Answer 48

Provides turn coordination and Dutch roll damping.

Question 49

Does gust suppression move the rudder pedals?

Answer 49

No (only improves lateral ride quality through combination of roll & yaw movements).

Question 50

In what modes are gust suppression and TAC available?

Answer 50

Normal mode only.

Question 51

Which surfaces are used as ground speedbrakes?

Answer 51

All spoilers (7 sets on each wing [5 outboard, 2 inboard]).

Question 52

If ARMED, when do the speedbrakes extend?

Answer 52

When LDG gear firmly on the GND (no tilt) and thrust levers idle.

Question 53

Does the speedbrake lever move automatically for extension?

Answer 53

Yes (in normal mode only).

Question 54

If not ARMED, what action causes speedbrake extension?

Answer 54

When either reverse thrust lever moved to reverse idle detent.

Question 55

What is the purpose of the Krueger flap?

Answer 55

Provides a seal between inboard slat and engine nacelle on each wing.

Question 56

What surfaces move with FLAP 1 selected?

Answer 56

Slats only.

Question 57

What are the takeoff flap positions?

Answer 57

Flap 5, 15 and 20 (25 & 30 for LDG).

Question 58

Above what altitude is flap extension inhibited?

Answer 58

20000’ (or 265kts).

Question 59

When will the slats move to the fully extended position?

Answer 59

Flap 25 or 30.

Question 60

When is secondary slat/flap mode automatically engaged?

Answer 60

Whenever primary mode fails to move the flaps or slats to the selected position.

Question 61

How are the slats affected in secondary mode?

Answer 61

When flaps not up (in secondary mode), slats will: • Fully extend if airspeed < 246kts. • Move to the midrange position if the airspeed > 246kts (or will not extend beyond midrange position).

Question 62

How do the slats and flaps extend in alternate mode?

Answer 62

Simultaneously. Pilot must manually select alternate mode. Alternate mode allows DCT manual operation of flaps & slats through the secondary drive electric motors.

Question 63

In which flap positions is load relief available?

Answer 63

Flap 15 to 30 in primary mode only.

Question 64

In which mode is slat load relief available?

Answer 64

Slat load relief in secondary mode only.

Question 65

How does autoslat operation enhance stall characteristics?

Answer 65

Upon receiving signal FM the stall warning, slats automatically extend FM midrange to fully extended LDG position à reduces stall speed.

Question 66

When will the expanded flap indication be displayed?

Answer 66

When any flap/slat is non-­‐normal, including secondary and alternate mode.