787 SYS 3 Flt Cntrls

Question 1

In NORMAL flt cntrl mode, yaw controls attempts to maintain zero yaw rate due to engine failure when above what

Answer 1

60 knots ground speed on the ground

Question 2

What are the 3 primary flt cntrl system modes and how are they selected

Answer 2

1) NORMAL
2) SECONDARY
auto with IRU or AHRU fault or all slat/flap position data loss
3) DIRECT
Auto or Manually (Loss of all 3 PFC or turning them off)

Question 3

What Spd does rudder become aerodynamically effective

Answer 3

~60 knots

Question 4

How does pitch trim differ between the NORMAL, Secondary, DIRECT MODES

Answer 4

-Secondary, Direct and Normal on ground..pitch trim moves Stabilizer
-Normal, in air..trim input sent to PFC that moves elevator and trims for predicated Spd then moves Stabilizer to streamline

Question 5

Slat AUTOGAP helps at slow speed by extending Slats from middle to full at high AOA. What mode is it available and what speed does this occur for -8 and -9/10

Answer 5

-NORMAL
-8..225kts
-9/10…240kts

Question 6

What Flt Cntrl mode is is SLAT PREGAP used, why isn’t it AUTOGAP, and what speeds does it enable for -8 and -9/10

Answer 6

-Secondary
-in secondary the system is to slow to respond to AUTOGAP
—8..225 knots; -9/10…240 kts

Question 7

What does the Wheel to Rudder Cross-Tie do, and what Flt Cntrl modes is it available

Answer 7

-Reduces maximum sideslip and vertical fin loads
-Secondary and Direct

Question 8

FLAP/SLAT LOAD RELIEF is the same for all variants. What Flap setting is it active

Answer 8

15 to 30

Question 9

In the secondary flight control mode what functions are not available

Answer 9

-2 Autos (pilot/Spd Brakes)
-2Compensations (pitch and roll/yae assymetry)
-2Protections (envelope/tail strike)
-1Suppression (gust)

Question 10

Which flt cntrl mode is this

Answer 10

Normal
Inputs from controls are translated into Analog and sent to ACEs. ACEs Send to PFCs which calculate the control position command and send it back to ACEs. ACEs convert the data back to analog and then send to PCUs

Question 11

CONTROL SUFACE HYD PWR
-Ailerons
-Elevator
-Rudder
-Flaperon
-Stab
-Rudder

Answer 11

-A: side and center
-E: side and center
-R:
-F: Left=L&R; Right=L&C
-S:
-R: All 3

Question 12

This is the secondary mode. What is the difference in the PFC info sent back to the ACEs and what is the control degradation

Answer 12

-PFCs send simplified commands
-Elevator and Rudder are more sensitive at some speeds and yaw damping is degraded

Question 13

This is the Direct mode. How is Direct Auto and Manually entered

Answer 13

-Auto: ACEs detect failure or lost comm with all 3 PFCs
-Man: select disconnect on Primary Flight Computers switch (panel 1 middle)

Question 14

How does degrading to Direct differ from Secondary

Answer 14

-Same

Question 15

Your in the green, do why do you have this EICAS

Answer 15

-disagreement btwn computed green band and OLEO transducers data
-OLEO transducers out of tolerance
-either OLEO transducer has failed

Question 16

Alternate vs primary pitch trim commands…which wins in all flight control modes

Answer 16

Alternate

Question 17

How does Alternate Pitch Trim switches operate on the ground and in flight for all three modes

Answer 17

-Normal Air -sets new trim ref speed
-Normal ground and ground/air for Secondary and Direct it directly moves the stab

Question 18

What is this speed and what happens when you reach it re: stall protection

Answer 18

-Vmm - min maneuver
-nose-up trim inhibited below this spd

Question 19

What speed is this and what happens at this speed

Answer 19

-Vmin
-Stick shaker

Question 20

What are the 3 Pitch Envelope protections

Answer 20

-over speed
-stall
-tail strike

Question 21

What speed is overspeed protection provided and what are the indications

Answer 21

-Vmo/Mmo
-EICAS WARN OVERSPEED
-Aural Warning Siren
-Trim Ref change inhibited nose down

Question 22

What happens to thrust as speed decreases to near stick shaker

Answer 22

-If Autothrottle is armed but not engaged it will AUTO activate is SPD mode with thrust set for Vmm (top of Amber band) or the Spd set in MCP
-EICAS CAUTION AIRSPEED LOW

Question 23

What are the exceptions to Autothrottle Auto activation for Low Spd

Answer 23

-Won’t activate if:
–Pitch mode FLCH or TO/Ga
–<400’ takeoff; <100’ approach
—Descent in VNAV SPD w/ Autothrottles in HOLD

Question 24

What system monitors for Tailstrike protection, what do they do, does it keep pilot from striking

Answer 24

1) PFCs
2) decrease Elevator deflection
3) No…pilot can override

Question 25

What does the LAM (Land Attitude Modifier) do, when does it apply, and how does it do it

Answer 25

-increases pitch attitude and nose gear height
-higher speed landings with flaps at Landing (20, 25, 30)
-undroops flaperons and raises inboard spoilers

Question 26

How is the Stabilizer moved

Answer 26

-Pitch commands from PRI/ALT pitch trim switches sent to Stab
-STAB is moved by ECU (elec cntrl unit) powered by L2 & R2 AC buses

Question 27

Bank angle protection:
-What mode is it available
-When does it kick in
-What does it do

Answer 27

-Normal only
-Bank >35deg
-control wheel force back to within 30deg

Question 28

What does pulling down your n A/P disengage bar do to bank angle protection

Answer 28

Disables

Question 29

What does this indicate

Answer 29

Bank angle >35

Question 30

If you lose all HYDs, what controls are available and how are pitch and roll maintained

Answer 30

-Electrically actuated Stab/two spoiler pairs
PITCH: primary and alternate pitch switches and control wheel

Question 31

If you have complete loss of flight control signaling, how is the aircraft flown, and which control surfaces are direct wired for this

Answer 31

-Pitch: ALTN PITCH TRIM
-Roll: control wheel
-Stab and spoiler pair

Question 32

When is the Flap and Slat airspeed and altitude extension inhibited and what modes offer this protection

Answer 32

1: 260 kts / 20,000’
2: Primary and Secondary