Autoflight System

Question 1

How many Flight Control Computers are installed?

Answer 1

3: Left, Centre, Right.

FCOM 1 22.20.1

Question 2

How does the autopilot move control surfaces?

Answer 2

3 FCC’s control separate hydraulically powered A/P control servos to operate flight controls and actuators then move the flight control surfaces.

FCOM 1 22.20.1

Question 3

When does the autopilot command flight control surfaces in all three axis?

Answer 3

Multi A/P Approach

FCOM 1 22.20.1

Question 4

What do LNAV, VNAV, LOC and APP have in common?

Answer 4

-Can be ARM/ACTIVATED with a single push.—Can be disarmed by pushing the mode switch a second time.

FCOM 1 22.20.1

Question 5

Which AFDS modes can arm when selected?

Answer 5

LNAV, VNAV, LOC & APP

FCOM 1 22.20.1

Question 6

After engagement, how can localiser and glideslope modes be deactivated?

Answer 6

• Disengaging autopilot and turning off FD’s.
• Select TO/GO

FCOM 1 22.20.1

Question 7

If armed, which modes can be disarmed by a second push of the selection switch?

Answer 7

LNAV, VNAV, LOC, APP

FCOM 1 22.20.1

Question 8

How would you know the autopilot has disengaged?

Answer 8

EICAS warning message “AUTOPILOT DISC” displayed when the autopilot has been manually or automatically disengaged.

FCOM 1 22.20.2

Question 9

When does the autopilot enter an attitude stabilising mode?

Answer 9

If failure only affects the active mode. Annunciated on the PFD.

FCOM 1 22.20.2

Question 10

Below 200 feet RA, how is auto land degradation from LAND 3 to LAND 2 indicated?

Answer 10

Not annunciated.

FCOM 1 22.20.5

Question 11

What happens when the auto throttle is in HOLD mode?

Answer 11

Thrust lever autothrottle servo is inhibited. The Pilot can set the thrust levers manually.

Question 12

At what distance to the active route leg will the LNAV engage, if armed?

Answer 12

2.5NM of active leg.

Question 13

What are the conditions for ATT (roll) mode engagement?

Answer 13

• When autopilot first engaged or FD on in flight, AFDS holds bank 5-30 and will not roll wings level.
• When bank angle less than 5 AFDS will roll wings level.
• Of engaged when more than 30, will reduce bank angle to 30.

Question 14

When does FMC record the barometric altitude and for what reason?

Answer 14

During takeoff the FMC records the barometric altitude as the airplane accelerated through 100KT. This altitude is used to activate LNAV and VNAV, engage autothrottle activation, command acceleration for flap retraction and set climb thrust if an altitude has been selected.

Question 15

What happens to autothrottle operations with reverse thrust selected?

Answer 15

Autothrottle disconnects.

Question 16

What is the effect of an engaged autothrottle upon switching master FMC?

Answer 16

Autothrottle disconnects but can be reactivated.

Question 17

During takeoff, when can the TO/GA switches be used for autothrottle engagement?

Answer 17

• When speed is less than 50KT.

- if autothrottle not engaged then can only be engaged above 400 Feet.

Question 18

List the autothrottle mode sequence during normal takeoff with TO/GA selected.

Answer 18

• IAS less than 65KT: THR REF.

- At 65KT: HOLD

Question 19

At lift off, what is the selectable airspeed and it’s highest limit?

Answer 19

V2 + 10 (Max: V2 + 25)

Question 20

What are the altitudes for the two step runway alignment sequence during landing?

Answer 20

• Initial alignment at 500 feet RA.

- Second alignment at 200 feet RA.

Question 21

Flare mode is not intended for which operation?

Answer 21

Single autopilot or FD only operation.

Question 22

Describe flare mode arm and active operation.

Answer 22

• Arms at 1500 Feet RA when LAND 3 or LAND 2 annunciates.

- At approx 50 Feet RA, autopilot starts flare manoeuvre. Flare replaces G/S pitch flight mode annunciation.

Question 23

Describe Autothrottle operation during ROLLOUT

Answer 23

During Flare:

• Between 30 and 15 Feet RA, the autothrottle retards thrust levers to idle.
• Idle replaces the SPD autothrottle flight mode annunciation.
• At touchdown, the FLARE annunciation no longer displays, and the nose lowers on the runway.

During rollout, the autothrottle IDLE mode remains until the autothrottle disconnects with thrust levers in reverse.

Question 24

During an autoland, which mode engages at approximately 5 feet RA?

Answer 24

Rollout

Question 25

When does the autothrottle re-arm after landing and in which mode?

Answer 25

Ten seconds after the reverse thrust levers are down, autothrottle is armed until flaps are UP. Pushing a TO/GO switch while autothrottle is armed activated the autothrottle in THR REF mode.

Question 26

What happens to reference thrust limit at glideslope capture or flaps are not up?

Answer 26

• The reference thrust limit is locked in GA when flaps are in Landing position or glideslope is captured.
• With flaps out of up, but not in Landing position, activation of VNAV in VNAV PTH changes the reference thrust limit to CRZ.

Question 27

How to select THR or THR REF (autothrottle mode) for Go-around?

Answer 27

First push of the TO/GA switch:

• Roll and Pitch activate in TO/GA.
• Autothrottle activates in THR to establish a minimum 2000FPM climb.
• If current airspeed remains above the target speed for 5 seconds, the target speed is reset to current airspeed.

Second push of TO/GA switch:
-Autothrottle activates in THR REF at full go-around thrust.

Question 28

Which autopilot mode automatically activates above 200 feet during a go-around?

Answer 28

When an LNAV path is available:

• LNAV activates above 50 Feet RA with no autopilot engaged.
• LNAV activates about 200 Feet RA with an autopilot engaged.

TO/GO remains the active roll mode until LNAV automatically activates or another mode is selected.

Question 29

After an automatic go-around, which autopilot remains engaged?

Answer 29

All A/P’s except first in command disengage.