31. Forward Instrument Panel (Landing Gear)

Question 1

What is the function of the two Landing Gear Control and Interface Units (LGCIUs)?

Answer 1

• Provide sequencing, operation, monitoring, and indications for the landing gear.

• Provide aircraft “In Flight” or “On the Ground” signals to other aircraft systems

Question 2

What hydraulic system powers the landing gear and doors?

Answer 2

Green

Question 3

When does the red arrow in the LND panel illuminate?

Answer 3

Below 750 feet RA, when the aircraft is in the landing configuration and the landing gear is not locked down

Question 4

What happens if airspeed is 280 knots and the Landing Gear lever is selected DOWN?

Answer 4

Nothing. A safety valve shuts off hydraulic power to the landing gear system when airspeed is above 260 knots

Question 5

What do the red UNLK lights indicate?

Answer 5

The landing gear is not locked in the selected position.

Question 6

If LGCIU 1 fails will the lights still work?

Answer 6

Yes, as long as it is still powered.

Question 7

What controls and manages all normal braking functions?

Answer 7

The Brake and Steering Control Unit (BSCU)

Question 8

What happens when the A/SKID & N/W STRG is switched OFF?

Answer 8

• Loss of nose wheel steering

• Braking is powered by the YELLOW system

• Anti-skid is deactivated

• ABCU takes over

Question 9

Which hydraulic systems provide pressure to the brakes?

Answer 9

• Normal brakes – GREEN

• Alternate brakes – YELLOW backed up by a hydraulic accumulator

Question 10

When do the Auto Brakes activate on landing if armed?

Answer 10

When the ground spoilers deploy.

Question 11

What is the difference between LOW and MED AUTO BRK?

Answer 11

• LOW – progressive pressure applied to brakes 4 seconds after ground spoilers deploy in order to decelerate the aircraft at a rate of 5.6 ft./s2

• MED – progressive pressure applied to brakes 2 seconds after ground spoilers deploy in order to decelerate the aircraft at a rate of 9.8 ft./s2

Question 12

What does the AUTO BRK green DECEL light indicate?

Answer 12

Actual rate of deceleration is within 80% of the selected rate.

Question 13

What will cause the MAX AUTO BRK to activate on a rejected takeoff?

Answer 13

• Airspeed above 72 knots, and

• Thrust levers at IDLE, and

• Ground spoiler extension

Question 14

What is the impact of the loss of GREEN hydraulic pressure on the Auto Brakes?

Answer 14

The Auto Brake function is lost, because the aircraft is now relying on the alternate brake system.

Question 15

If on the alternate brake system, what is required in order to maintain Antiskid function, if anything?

Answer 15

At least 1 channel of the BSCU

Question 16

What would happen to the spoilers if they were not armed, but at least one engine was selected into reverse thrust?

Answer 16

They would still deploy, even if they were not armed

Question 17

How many brake applications are available with accumulator pressure?

Answer 17

Approximately 7 full applications

Question 18

What does the BRAKES & ACCU PRESS triple indicator indicate?

Answer 18

YELLOW hydraulic pressure delivered to the left and right brakes

• YELLOW system brake accumulator pressure