Landing Gear

Question 1

What holds the MLG in the extended position?

Answer 1

Mechanical over centering with down locks

Question 2

What holds the nose gear in the retracted position?

Answer 2

A spring loaded, over center type locking mechanism

Question 3

What holds the main gear in the retracted position?

Answer 3

Mechanical up locks and hydraulic system 3 pressure

Question 4

What controls the landing gear?

Answer 4

The proximity sensing electronic unit (PSEU)

Question 5

After the nose gear is extended, do the gear doors close?

Answer 5

No, anytime the nose gear is down the doors are open

Question 6

What ensures the nose wheel is centered prior to retraction into the well?

Answer 6

The ECU sends signal to center after takeoff, and then a centering cam keeps it centered when hydraulic pressure is removed.

Question 7

What compilation can be expected if both hydraulic system 2 and 3 fail?

Answer 7

The nose wheel will not extend for landing

Question 8

Which hydraulic system is used to raise and lower the gear?

Answer 8

Hydraulic system 3

Question 9

When will the “TOO LOW GEAR” aural warning sound?

Answer 9

With a radar altitude below 500 feet at a speed of less than 190 KAIS

Question 10

What is the maximum steering angle for the nose tiller and rudder respectively?

Answer 10

80*

rudder , 8*

Question 11

Why is it important not to move the roller in flight with the gear extended?

Answer 11

The steering will be inoperative as annunciated by the STEER INOP message on the EICAS upon landing

However, you will have no warning in flight.

Question 12

Where can flight crew specifically supplemental maintenance procedures be found to clear a STEER INOP nuisance message?

Answer 12

Supplementary procedures in maintenance or company manuals

Question 13

What is locked wheel protection?

Answer 13

The anti skid control unit (ASCU) monitors each wheel to ensure even rotation.

If 1 wheel entered a skid and is at least 30% slower than the other, the ASCU will release brake pressure to that wheel to balance the rotation speed

Question 14

What is touchdown protection?

Answer 14

This guards from inadvertent Landing with the brakes applied if the pilot is pressing the brake pedals. Braking will not be applied until a wheel spin up of 35 its is achieved, or weight on wheels + 5 seconds

Question 15

What colors does the Brake Temperature Monitoring System display brake heat in?

Answer 15

Green - Normal range between 0 - 6
White - Caution range between 7 - 14
Red - Overheat range between 15 - 20

Question 16

How can an actual temperature be calculated based on the BTMS readings?

Answer 16

Take the readout value and multiply by 35 to determine actual brake temp

Question 17

After a landing or rejected takeoff, what is the minimum turn around time?

Answer 17

15 minutes to insure max brake temperature is reached.

Question 18

Can braking be accomplished through the use of accumulator pressure?

Answer 18

Yes

Question 19

How many brake applications are available from an accumulator charge?

Answer 19

Upto 6

Question 20

What are the brake accumulators charged to?

Answer 20

750 psi

Question 21

How are the tires thermally protected from blowout?

Answer 21

Through the use of 4 thermal fuse plugs in each wheel

Question 22

Can the brake wear indicators be checked without brakes applied?

Answer 22

No. Both hydraulic systems 2 and 3 must be activated and the brakes applied

Question 23

How does the parking brake work?

Answer 23

The parking brake shutoff valve is used to lock the brakes on by trapping hydraulic system 3 pressure. When the hydraulic systems are shutdown, system 3 accumulator pressure should keep the bake applied for an extended period of time