Landing Gear & Brakes

Question 1

When does the LANDING GEAR AWU kick in?

Answer 1

1. RA<1200ft, flaps lower than 22 degrees and 1 TLA <59 degress + other TLA <49 degrees
2. RA < 1200ft, flaps between 22 degress and 45 degrees, 1 TLA <59 degress + other TLA <49 degrees
3. Flaps 45 degrees

Question 2

What prevents the accidental raising of the landing gear on the ground

Answer 2

The LGEV solenoid

Question 3

What does the LGEU control

Answer 3

The LGEV

Question 4

What steering authority do you have via the rudder, tiller and both?

Answer 4

5 degress
71 degrees
76 degrees

Question 5

What does a BRAKE DEGRADED message mean?

Answer 5

BCU not working or a total/partial loss of one inboard/outboard system.

Question 6

How long does the parking brake last and how do we know it is still set?

Answer 6

24 hours. Pressure switch illuminates Brakes Set light.

Question 7

How many applications of emergency braking do we get?

Answer 7

6

Question 8

How many weight on wheels switches are there and where are they located

Answer 8

5. 2 on each main gear and one on the nose wheel

Question 9

What powers the LGEU

Answer 9

Essential DC bus

Question 10

In what sense do the wheels retract?

Answer 10

Nose forward, main inward

Question 11

What happens in normal gear extension?

Answer 11

Positioning the Landing Gear​ Lever​ to the DOWN​ position signals​ the​ ​LGEU to command the Landing Gear​ Electrovalve and​ the Nose Gear​ ​Doors​ Solenoid Valve. This​ allows​ pressure from​ the hydraulic​ system​ ​1 to simultaneously​ reach​ the landing​ gear​ and door​ actuators, and​ ​also the up unlock​ actuators

Question 12

How does the landing gear electrical override operate? From where?

Answer 12

This​ system​ ​bypasses​ the LGEU and actuates​ directly​ the​ Landing Gear​ ​Electrovalve and the Nose​ Gear​ Doors​ Solenoid Valve. The control​ ​switch is​ installed inside​ the free-fall lever​ compartment, on the floor,​ ​beside the copilot’s​ seat.

Question 13

How does the free fall system operate? From where?

Answer 13

This​ system​ ​bypasses​ the LGEU and actuates​ directly​ the​ Landing Gear​ ​Electrovalve and the Nose​ Gear​ Doors​ Solenoid Valve. The control​ ​switch is​ installed inside​ the free-fall lever​ compartment, on the floor,​ ​beside the copilot’s​ seat.

Question 14

When would you receive a LG/LEVER disagree warning and what does it mean?

Answer 14

20 seconds after a gear extension/retraction command and one of the wheels is not in the expected position.

Question 15

When would you receive a LG AIR/GROUND fail

Answer 15

Where 2 proximity switches have failed, LGEU has failed or the NG switch disagrees with the AG logic

Question 16

What does the Landing Gear Warning Cutout Button do?

Answer 16

Cancels the AWU if the rad alt is unserviceable and the LG is not down, flaps are lower than 22 and TLAs below 59/45

Question 17

How are the brakes on the outboard wheels controlled

Answer 17

Hydraulic system 1, BCVs 1 and 4.

Question 18

How are the brakes on the inboard wheels controlled

Answer 18

Hydraulic system 2, BCVs 2 and 3

Question 19

How does the brake by wire system operate?

Answer 19

The BCU receives signals from the pedal transducers and commands the respective BCVs

Question 20

What braking protection is offered by the 145?

Answer 20

Anti skid, locked wheel and touchdown.

Question 21

Whats the technique for differential braking on this aircraft? Why?

Answer 21

Release pressure on the opposite wheel, because the anti skid system can only release brake pressure not apply it.

Question 22

When does the anti skid system operate?

Answer 22

Above 10kts

Question 23

When does the locked wheel system operate?

Answer 23

Speeds above 30kts with 30% difference in wheel speed

Question 24

How does touchdown protection operate?

Answer 24

On landing it inhibits braking for 3 seconds or until wheel speed is 50kts.
If the WoW switches are malfunctioning normal braking will be available at 10kts wheel speed.

Question 25

How does gear retraction in flight braking operate?

Answer 25

As soon as the airplane is airborne and the gears are​ ​commanded to retract, it applies braking pressure to the main wheels.​ ​The nose wheels are braked by a stop​ within the nose landing gear ​wheel well.

Question 26

Why must you hold the brakes in order to set/release the parking brake?

Answer 26

To prevent transfer of hydraulic​ fluid from one system to the ​other,

Question 27

When will the brake temp indications on the MFD be green/amber

Answer 27

Less than 200 green (250 on 145 LR)

More than 200 amber (250 on 145 LR)

Question 28

When is the tiller inhibited?

Answer 28

Above 25kts

Question 29

Whats the difference between park brake and emergency braking?

Answer 29

Park brake you must apply toe brakes first before application

Emer brake, just use the park brake handle