DSC Autoflight

Question 1

What is the low energy alert ?

Answer 1

Computed by the FAC.
Generate an aural low energy “SPEED SPEED SPEED” alert that repeat every 5sec.
=> warn crew of the need to increase thrust to regain positive flight path angle through pitch control.

Question 2

When is the low energy alert available ?

Answer 2

in config 2,3 and FULL based on A/C config, horizontal deceleration and flight path angle

Question 3

What is a good gross error check for calculating green dot ?

Answer 3

Neo a321 below 15000ft, 1,5x Weight in tonnes +110
Others below 20000ft 2x weight +85
FCOM DSC 22-10_50-20

Question 4

Why can you have discrepancy between VAPP on the FMGC and the one displayed on PFD ?

Answer 4

It link to the way the GW is calculated.
The FAC will use FMS inserted gross weight initially but will computes its own based on aerodynamic data for the approach.

Question 5

Can you explain the function of GS mini ?

Answer 5

The system ensures that the ground speed that the aircraft touches down with is maintained
throughout the approach, despite varying wind conditions.
It ensure standard aerodynamic margin VS stall

Question 6

If you loose one FMGC what do you expect to see on the PFD and what impact on the ND ?

Answer 6

1FD1 or 2FD2
message on ND : SET OFFSIDE RNG/MODE or OFFSIDE FM control

Question 7

What methods does the aircraft have to calculate its position ?

Answer 7

MIX IRS position
Computed radio position
GPS position

Question 8

What is the aircraft FM position comprised of ?

Answer 8

Mix IRS and GPS position

Question 9

With a loss FMGC how do you recover the radionavigation ?

Answer 9

Use the backup nav key on the RMP to manually tune radio nav.

Question 10

For ALT planning, what assumptions are made regarding flight level and speed by the FMGC in terms of fuel brun ?

Answer 10

CI 0
FL100 if less than 100NM
FL220 if between 100NM-200NM

Question 11

What is SRS ?

Answer 11

Speed reference system, control the speed via the elevator. => Adjust the pitch to maintain a speed
On takeoff target is V2+10

Question 12

What are the protection associated with SRS ?

Answer 12

• Flight path angle => Mini VS 120ft/min
• Pitch angle protection => Reduce A/C nose up
• Speed limiting => limiting target speed to V2+15kt

Question 13

What is the two ENG operative range of the ATHR ? And single ENG ?

Answer 13

two : Idle to CLB
single: idle to MCT

Question 14

With ATHR failure what FMA would you expect to see while in cruise ?

Answer 14

THR LCK

Question 15

What is the guidance for selecting REV thrust if one THRUST Rev is inop ?

Answer 15

Select both

Question 16

What is the max/min speed you can. set on the FCU ?

Answer 16

399-100/ Mach 0,10-0,99

Question 17

What is BUSS and why/when would you need it ?

Answer 17

Backup speed scale => alternative way of getting some speed info/ alt info
You would use it in case of unreliable Airspeed

Question 18

What data does the BUSS use ?

Answer 18

AoA and GPS for altitude

Question 19

What is the bird and where does it gets its data from ?

Answer 19

Show the track and flight path angle
Computed from IRS and static pressure

Question 20

What is Vref ?

Answer 20

reference speed for normal final approach
Vref = 1,23VS of config full

Question 21

What is Vapp ?

Answer 21

Vapp = VLS + Wind correction( min +5kt up to 15kt)

Question 22

What is Vls ?

Answer 22

lowest selectable speed, varies between 1,13VS during takeoff or 1,23VS to 1,28VS