DSC Landing gear

Question 1

What controls the landing gear ?

Answer 1

2 LGCIU (landing gear control and interface unit)

Question 2

What is the switch between LGCIU happening ?

Answer 2

After the full RETRACTION of the landing gear

Question 3

When is the landing gear safety valve active ?

Answer 3

Speed more than 260kt with data from ADR1 or ADR3

Question 4

What HYD power the landing gear ?

Answer 4

Green

Question 5

To which LGCIU is connected the Landing gear indicator panel ?

Answer 5

LGCIU 1

Question 6

From which LGCIU does the GPWS receive data ?

Answer 6

LGCIU 1

Question 7

When does the red arrow next to the landing gear lever illuminates ?

Answer 7

when A/C in landing config and gear not down lock

Question 8

What HYD system power the NWS and which computer controls it ?

Answer 8

Yellow
Controlled by the BSCU

Question 9

When does the NWS stop being connected to the rudder ? Hand wheel ?

Answer 9

above 130kt
Above 80kt

Question 10

What are the brakes systems on the A/C ?

Answer 10

Normal brakes => Green HYD
alternate brakes => Yellow HYD

Question 11

When does the switch between the BSCU channels occur ?

Answer 11

When the landing gear is selected DOWN

Question 12

What controls the antiskid ?
When does it become available?

Answer 12

BSCU
>20kt

Question 13

What controls the alternate braking ?

Answer 13

ABCU (alternate braking control unit)

Question 14

What are the different type of alternate braking available and how are they controlled ?

Answer 14

• Alternate braking with antiskid (braking controlled by ABCU and antiskid by BSCU)
• Alternate braking without antiskid (braking by ABCU)
• Alternate braking without antiskid on accumulator (ABCU)

Question 15

What info is used for the antiskid ?

Answer 15

Ref speed from BSCU
BSCU gets speed from ADIRS 1,2 or 3

Question 16

What computers are required for the autobrakes to work ?

Answer 16

At least two SEC operative

Question 17

What do you need to be able to arm the autobrakes ?

Answer 17

• green HYD
• Antiskid
• at least one ADIRS
• no failure in braking system

Question 18

What is the delay after the spoiler for the autobrake to start working ?

Answer 18

2sec

Question 19

What is the target deceleration rate for the autobrakes LOW, MED?

Answer 19

2 m/s² low
3 m/s² Med

Question 20

When will the autobrake trigger on landing ?

Answer 20

When ground spoiler deploy so:
- Ground spoiler armed: Both main gear on ground and both thrust lever idle or one at reverse other below MCT
- Ground spoiler not armed: both main gear on ground and reverse on at least one and other below MCT

Question 21

What HYD system power the park brake ?

Answer 21

Yellow

Question 22

How long can the park brake be maintain for ?

Answer 22

12h

Question 23

What are the main operational consequences of loosing LGCIU 1 + 2 ?

Answer 23

Loss of AP 1+2 and ATHR => Raw data
CAT I
No gear retraction due gravity extension => Fuel burn
No reverser

Question 24

What happens for the gear doors with the gravity extension ?

Answer 24

they remains open

Question 25

What is the approximate increase in fuel brun with the gear extended ?

Answer 25

180%

Question 26

When do you expect to see the DECEL light when using autobrake

Answer 26

when 80% of the selected rate is achieved

Question 27

When might you not see the DECEL light on landing with autobrake ?

Answer 27

Decel rate not achieved due slippery rwy

Question 28

What information is shown on the triple brake indicator ?

Answer 28

pressure of the Yellow HYD when alternate braking activated or on ground with park brake

Question 29

At what speed is the landing gear safety lock active ?

Answer 29

Speed above 260kt, landing gear cannot be operated

Question 30

Do we have to manually set alternate brakes

Answer 30

No, they will self down-reg with failures

Question 31

Describe Normal brakes

Answer 31

Operative when G Hyd available and A/SKID and N/W STRG on Antiskid operative and Autobrake available Braking and antiskid via BSCU

Question 32

Describe Alt braking without ( antiskid

Answer 32

Antiskid deactivated either: *Electrically (A/SKID and N/W STRG off, elec supply failed or BSCU failure) or *Hydraucially (G+Y failure) Brakes on accumulator only, auto limit to 1000psi (7 full brake applications)

Question 33

Do we need inspection after shear pin failure

Answer 33

No if push stopped immediately Yes if tractor touched towbar or if not stopped immediately

Question 34

Max brake temp imbalance?

Answer 34

Temp diff between 2 brakes on 1 gear >150 deg with one >600 deg or <60 deg Ave diff between L and R >200 deg or one brake >900 deg

Question 35

When is autobrake available on TO

Answer 35

>72kt (if spoilers armed they will immediately deploy when TL set to idle)