Landing gear

Question 1

Which system control landing gear extension, retraction and sequencing of the doors?

Answer 1

Two LGCIUs (Landing Gear Control and Interface Units)

Question 2

When is control switched from one LGCIU to the other?

Answer 2

• In case of failure

- At the completion of one complete gear cycle at retraction.

Question 3

Which hydraulic system actuates the landing gear and doors?

Answer 3

Green

Question 4

When does the safety valve close?

Answer 4

> 260kts or with the MLG on the ground

Question 5

How many sets of proximity sensors are there?

Answer 5

One set for each LGCIU

Question 6

What happens when turning the gravity extension crank?

Answer 6

• Landing gear hydraulics isolated from green system
• Door and landing gear unlocked
• Gravity drops the gear in to extended position

Question 7

Will the doors close following gravity extension?

Answer 7

No

Question 8

Which LGCIU is connected to the Landing Gear Indicator Panel?

Answer 8

LGCIU 1

Question 9

What is the significance of the red UNLK light?

Answer 9

Gear is not locked in the selected position

Question 10

What is the max nose wheel steering angle?

Answer 10

+/-6° from rudder pedals

+/-75° from hand wheel

Question 11

Which hydraulic system actuate the NWS?

Answer 11

Yellow

Question 12

When does the NWS receive hydraulic pressure?

Answer 12

• A/SKID NWS switch ON
• Towing lever in normal position
• One engine running
• On the ground

Question 13

Which hydraulic system is used for the normal brakes?

Answer 13

Green

Question 14

Which hydraulic system is used for the alternate brakes?

Answer 14

Yellow, backed up by hydraulic accumulator

Question 15

Can the MAX autobrake setting be used on ground and in flight?

Answer 15

Only on ground

Question 16

When does the BSCU change channel?

Answer 16

At each down selection of landing gear

Question 17

What failure modes can the brakes revert to?

Answer 17

• Alternate brakes with antiskid
• Alternate brakes without antiskid
• Alternate brakes without antiskid on accumulator

Question 18

What is compared with the wheel tachometer for antiskid protection?

Answer 18

Aircraft reference speed from ADIRU 1,2 or 3

Question 19

Can the auto brakes be used with antiskid inoperative?

Answer 19

No

Question 20

When is autobrake activated?

Answer 20

When a command for ground spoilers is detected

Question 21

How can the autobrake system be manually disarmed/deactivated

Answer 21

• Ground spoilers retract
• Pushbutton off
• Deflection of brake pedal

Question 22

Which hydraulic system provides pressure for the alternate brakes?

Answer 22

Yellow

Question 23

Can auto brakes be used with alternate brakes?

Answer 23

No

Question 24

Do alternate brakes need to be selected manually?

Answer 24

No

Question 25

How many full brake applications are available on accumulator pressure?

Answer 25

7

Question 26

What is the brake pressure limited to when using alternate brakes without antiskid?

Answer 26

1000psi

Question 27

When is brake pressure indicated on the BRAKES and ACCU PRESS indicator?

Answer 27

Only when the yellow system controls the brake pressure

• Alternate braking activated
• Parking brake applied

Question 28

When does the DECEL light illuminate?

Answer 28

When actual deceleration rate is >80% of commanded

Question 29

Which hydraulic system provides pressure to the parking brake?

Answer 29

Yellow system or accumulator

Question 30

For how long will the accumulator maintain parking brake pressure?

Answer 30

Minimum 12h

Question 31

Will the A/SKID NWS switch position affect the normal brakes?

Answer 31

Yes. Switch off will also deactivate the normal brakes

Question 32

What is VLE?

Answer 32

280 kts

Question 33

What is the effect of initiating a rejected takeoff at low speed (<72kts)?

Answer 33

Autobrakes will not activate due to no spoiler deployment <72kts.

Question 34

What is Vlo?

Answer 34

Extension: 250kts
Retraction: 220kts