Langing Gear and Brakes

Question 1

What systems are involved in the landing gear and brakes operation?

Answer 1

Landing gear system, brakes system, hydraulic systems 1 and 2

The landing gear system includes controls for retraction and extension, while the brake system is designed for deceleration during ground operations.

Question 2

What type of landing gear does the airplane use?

Answer 2

Retractable tricycle landing gear composed of a nose landing gear and two main landing gears

Each landing gear consists of a conventional dual wheel unit.

Question 3

What does the landing gear control lever do?

Answer 3

Commands normal retraction and extension of the landing gear

The lever is located on the landing gear control panel.

Question 4

What does a green DN indication on the EICAS represent?

Answer 4

Respective landing gear is down and locked

This indicates that the landing gear is in the correct position.

Question 5

What happens when there is a disagreement in landing gear position indications?

Answer 5

Indication changes to red after 20 seconds

A red cross hatched box indicates that the landing gear is in transit and not locked.

Question 6

What is the function of the nose landing gear?

Answer 6

Performs directional control on the ground

It is electronically controlled by the handwheel and rudder pedals.

Question 7

How is the brake system controlled?

Answer 7

Manually or automatically with protections like antiskid function

Hydraulic systems 1 and 2 supply the brake control system.

Question 8

What does the alternate gear extension lever do?

Answer 8

Mechanically actuates the extension of the landing gear in case of hydraulic or electrical failure

It relieves hydraulic pressure and unlocks uplocks.

Question 9

What indicates that the Emergency/Parking brake is engaged?

Answer 9

Emergency/Parking brake light illuminates

This occurs when minimum hydraulic pressure is detected.

Question 10

What does an amber scale and pointer indicate on the MFD status page?

Answer 10

Emergency/parking brake effectiveness is degraded

A white scale with a green pointer indicates normal operating range.

Question 11

What is the purpose of the autobrake system?

Answer 11

Provides automatic braking with constant deceleration at selected rates for landings and rejected takeoffs

It has different modes such as RTO, OFF, LO, MED, and HI.

Question 12

What does the steering disengage switch do?

Answer 12

Disengages the nosewheel steering system

Displays the EICAS status message STEER OFF when pressed.

Question 13

What information does the air/ground positioning system provide?

Answer 13

Senses whether the airplane is on the ground or in flight

This information is used in other airplane systems logic.

Question 14

What is the function of the main landing gear doors?

Answer 14

Actuated automatically during landing gear retraction or extension

Composed of outboard and inboard doors.

Question 15

What does the landing gear warning inhibit button do?

Answer 15

Inhibits the landing gear aural warning

It is a momentary action button that must be pressed in.

Question 16

What does the brake control module provide?

Answer 16

Locked wheel protection, Antiskid protection, Gear retraction braking, Touchdown protection

These features improve braking performance and protect against skidding.

Question 17

What does the Emergency/Parking brake system require to function?

Answer 17

Pressure accumulators isolated from normal hydraulic systems

Provides six full-brake applications in case of hydraulic failure.

Question 18

What is the maximum steering angle of the rudder pedal?

Answer 18

+7°

This is used for small angle turns at higher speeds.

Question 19

What indicates a locked wheel condition?

Answer 19

Locked wheel protection is active when wheel speeds are above 30 knots

The brake control commands relief of hydraulic pressure to prevent locking.

Question 20

What happens when the thrust lever angle indicates an intention to land?

Answer 20

An aural warning ‘LANDING GEAR’ occurs if at least one landing gear is not locked in the DOWN position

A flashing amber frame appears around the landing gear indication on EICAS.

Question 21

What is the purpose of the brake wear pins?

Answer 21

Monitor brake wear on each main wheel

Pins are flush with the bracket when the brakes need replacement.

Question 22

What does the autobrake system do upon touchdown?

Answer 22

Applies pressure only after weight-on-wheels sensors indicate the airplane is on ground for more than 2 seconds

This prevents skidding during landing.

Question 23

What is the function of the thermal fuse plugs in the main wheels?

Answer 23

Melt and release tire pressure during brake overheat

This prevents tire damage due to excessive heat.

Question 24

How is the nosewheel steering system powered?

Answer 24

Powered by hydraulic system 2

It is controlled electronically by the Nosewheel Steering Control Module.

Question 25

What occurs when the landing gear lever is positioned to the UP position?

Answer 25

Releases locks and pressurizes actuators to retract the landing gear ## Footnote Amber cross hatched boxes are displayed in EICAS to indicate transit.

Question 26

What does the downlock release button do?

Answer 26

Bypasses protection logic to allow landing gear retraction ## Footnote Used in abnormal conditions or gear lever failures.

Question 27

What happens to the maximum deflection of the nosewheel commanded by the handwheel as wheel speed increases?

Answer 27

The maximum deflection is reduced as speed increases. ## Footnote This indicates a relationship between speed and steering control effectiveness.

Question 28

What steering method is used for small angle turns at higher speeds?

Answer 28

Rudder pedal steering. ## Footnote This method is more effective in maintaining control during faster maneuvers.

Question 29

When is rudder pedal steering active on the ground?

Answer 29

When the STEER OFF message is not displayed on EICAS and when the handwheel is not pressed. ## Footnote EICAS provides real-time feedback on system status.

Question 30

What is the maximum steering angle of the rudder pedal?

Answer 30

+7°. ## Footnote This defines the limit of rudder input for steering.

Question 31

When is free wheel steering activated?

Answer 31

When towing or when the normal steering system fails. ## Footnote This mode allows for basic steering control without the normal system.

Question 32

How does the steering system disengage to activate free wheel mode?

Answer 32

By pressing the steering disengage button on the control wheels or switching to disengage on the external steering disengage switch. ## Footnote This provides manual control over the steering system.

Question 33

What methods can be used to steer the airplane in free wheel mode?

Answer 33

* Rudder * Differential brakes * Asymmetrical thrust ## Footnote These methods allow for maneuvering despite the loss of normal steering control.

Question 34

What triggers automatic selection of free wheel mode?

Answer 34

* Failure of the air/ground signal * Nose wheel angle greater than 76° * Steering system failure detected ## Footnote These conditions ensure the aircraft can still be maneuvered during critical failures.

Question 35

What is the minimum turning radius for the nosewheel steering?

Answer 35

24.63 meters. ## Footnote This measurement is critical for understanding maneuverability in confined spaces.

Question 36

What are the landing gear operation speeds for retraction and extension?

Answer 36

* VLO for retraction: 220 KIAS * VLO for extension: 250 KIAS * VLE: 265 KIAS ## Footnote These speeds ensure safe operation of the landing gear.

Question 37

What does VLO represent?

Answer 37

The maximum speed at which the landing gear can be safely extended and retracted. ## Footnote This is crucial for maintaining structural integrity during landing gear operations.

Question 38

What does VLE represent?

Answer 38

The maximum speed at which the airplane can be safely flown with the landing gear extended and locked. ## Footnote This ensures safety and performance during flight.

Question 39

What is the maximum tire ground speed?

Answer 39

225 miles per hour, or 195 knots. ## Footnote Exceeding this speed can lead to tire failure.

Question 40

What is required for general servicing of the landing gear and brakes?

Answer 40

Checking and servicing of tire pressure and brake wear as per procedures outlined in the airplane operations manual. ## Footnote Regular maintenance is essential for operational safety.

Question 41

How should tire pressure be measured?

Answer 41

With the tires cold and on ground. ## Footnote This ensures accurate readings and prevents over-inflation.

Question 42

What should the landing gear tire temperature be compared to?

Answer 42

The ambient temperature. ## Footnote This helps in assessing tire performance and safety.

Question 43

Where can you find the procedure for the main landing gear tire pressure check?

Answer 43

In the AOM Chapter 13 - Ground Servicing. ## Footnote This chapter outlines important maintenance procedures.

Question 44

Where can you find the brake wear indicator check procedure?

Answer 44

In the AOM Chapter 13 - Ground Servicing. ## Footnote Regular checks are vital for ensuring braking efficiency.