LANDING GEAR AND BRAKES

Question 1

Describe the OFF position of the landing gear?

Answer 1

• Landing gear hydraulic system is depressurized.

FCOM, VOL 2; 14.10.1

Question 2

How many degrees can the nose-wheel steering system turn the nose gear with the tiller, and how many degrees with the rudder pedals?

Answer 2

• 70 degrees in either direction with the tiller
• 7 degrees with the rudder pedalsFCOM, VOL 2; 14.10.2/3

Question 3

When does RTO apply maximum brake pressure?

Answer 3

• All 4 thrust levers are retarded to idle, and
• Groundspeed above 85 knots.FCOM, VOL 2; 14.10.4; 14.20.5

Question 4

What does the BRAKE SOURCE amber light indicate when illuminated?

Answer 4

• Active brake hydraulic sources (systems 4, 1, and 2)
have low pressure

FCOM, VOL 2; 14.10.5

Question 5

What does a white, crosshatched, expanded gear position indication mean?

Answer 5

• Respective landing gear in transit.

FCOM, VOL 2; 14.10.7

Question 6

What does an amber X display on an expanded gear position mean?

Answer 6

• Landing gear position indicator inoperative.

FCOM VOL 2 14.10.7

Question 7

What does a white empty box on the Gear synoptic display indicate?

Answer 7

• Related landing gear door position indicators inoperative.

FCOM VOL 2; 14.10.6

Question 8

What sensing systems control in flight and ground operation of various airplane systems?

Answer 8

• Air/ground sensing system, main gear tilt sensors provide air/ground
signal to relays which control various systems.
• Nose gear extension sensing system provides signals to relays controlling
functions in the stall warning and nose gear steering systems.

FCOM, VOL 2; 14.20.1

Question 9

How does the airplane distinguish between air mode and ground mode?

Answer 9

• A combination of main gear tilt sensors indicate the main gear are tilted
(Air mode), or not tilted.(ground mode)

FCOM, VOL 2; 14.20.1

Question 10

Nose gear extension sensing provides a signal to relays controlling functions in which systems?

Answer 10

• Stall warning
• Nose gear steeringFCOM, VOL 2; 14.20.1

Question 11

What conditions must be satisfied in order for the landing gear lever lock to release?

Answer 11

• Main gear are tilted
• Body gear centred.FCOM, VOL 2; 14.20.2

Question 12

Describe the sequence of events when the landing gear lever is moved UP?

Answer 12

• The landing gear doors open
• Automatic braking occurs
• Landing gear begin to retract.
• EICAS gives related indicationsFCOM, VOL 2; 14.20.2

Question 13

How are the landing gear held in position after retraction?

Answer 13

• Main gear are held in the up position by uplocks
• The nose gear is mechanically locked in the up position.FCOM, VOL 2; 14.20.2

Question 14

During landing gear extension or retraction, state what happens if any gear position disagrees with lever position after normal transit time.

Answer 14

• The EICAS changes to the expanded non-normal format,
• GEAR DISAGREE master caution with beeper.
• Affected gear displayed as in transit, or UP/DOWN if the gear never
unlocked from the UP/DOWN position.

FCOM, VOL 2; 14.20.2/3

Question 15

How does the gear extend through the alternate gear extension system?

Answer 15

• By pushing the alternate gear extend switches
• The gear uplocks and gear door latches are electrically released.
• The gear free-falls
• Gravity and air loads extend the gear, and
• Springs pull the downlocks into the locked positionFCOM VOL 2; 14.20.3

Question 16

When does body gear steering operate?

Answer 16

• When the nose wheel steering angle exceeds 20 degrees
• Ground speed is less than 15 knots.
• As speed increase’s through 20kts on take off, the body gear is hydraulically
centred, and body gear steering is deactivated.

FCOM, VOL 2; 14.20.3

Question 17

When is body gear steering deactivated?

Answer 17

• Ground speed increasing through 20 knots

FCOM, VOL 2; 14.20.3

Question 18

What is the purpose of the brake accumulator?

Answer 18

• Provides parking brake application

FCOM, VOL 2; 14.20.4

Question 19

Describe the difference between normal and alternate anti-skid braking systems?

Answer 19

• Normal brake antiskid provides each main gear wheel with
individual antiskid protection.
• Alternate brake antiskid provides antiskid protection to lateral
wheel pairs (forward and/or aft pair on each truck),
rather than to individual wheels

FCOM, VOL 2; 14.20.4

Question 20

How does the brake torque limiter function in the Alternate brake system?

Answer 20

• Brake torque is sensed on an individual wheel basis.
• signal is sent to the alternate anti-skid valve, and
• Brake pressure is released on a laterally paired wheel basis.FCOM, VOL 2; 14.20.5

Question 21

When do the auto brakes apply after landing?

Answer 21

• All thrust levers are closed,
• Ground mode sensed, and
• The wheels have spun up.FCOM, VOL 2; 14.20.5

Question 22

Which systems contribute to total airplane deceleration on landing?

Answer 22

• Autobrakes
• Thrust reverse
• SpoilersFCOM, VOL 2; 14.20.5

Question 23

Give examples of what would disarm the autobrakes after landing?

Answer 23

• Pedal braking applied,
• Any thrust lever advanced after landing,
• Speedbrake lever moved to DOWN detent after speedbrakes
have been deployed on the ground,
• DISARM or OFF position selected on the autobrakes selector,
• Autobrake fault,
• Normal antiskid system fault, and
• loss of normal brake hydraulic pressure.

FCOM, VOL 2; 14.20.6

Question 24

What hydraulic system pressurizes the brake accumulator?

Answer 24

• System 4

FCOM VOL 2; 14.20.6

Question 25

Can the airplane be stopped with normal accumulator pressure?

Answer 25

• No, the accumulator is not designed to stop the aircraft.

FCOM, VOL 2; 14.20.6

Question 26

Why is it necessary to pressurize hydraulic system 4 before pressurizing the other systems?

Answer 26

• Precludes the transfer of hydraulic fluid from system 1 or 2 into system 4,
when the parking brake is set, and then released.

FCOM, VOL 2; 14.20.6

Question 27

What provides automatic brake source selection?

Answer 27

• Pressure-operated selector valves.

FCOM, VOL 2; 14.20.1

Question 28

What value on the brake temperature monitoring system causes the BRAKE TEMP Advisory EICAS message to appear?

Answer 28

• 5

FCOM, VOL 2; 14.30.1 (bottom)