Hydraulics

Question 1

Where are the hyd main components located?

Answer 1

Left wheel fairing, aft of the main tyres

Consist of pumps, accumulators, connectors and main reservoir

Question 2

What pressurises the hyd system?

Answer 2

AC Wild powered electric hydraulic pump

Blue pump - ACW bus 1

Green pump - ACW bus 2

Delivers pressure at 3000 psi

Question 3

What pressurises the blue system on the ground with no power?

Answer 3

An additional DC auxiliary

Question 4

When does the blue auxiliary pump run?

Answer 4

• system pressure drops below 1500 psi
• prop brake is released
• gear handle is down
• at least one engine running

Question 5

What is supplied by the blue hydraulic system?

Answer 5

• nosewheel steering
• flaps
• spoilers
• prop brake
• emergency and park brake

Question 6

What does the green hydraulic system supply?

Answer 6

• landing gear
• normal brakes

Question 7

What is the total capacity of the hydraulic reservoir?

Answer 7

9.6 litres

Question 8

When will the LO LVL light illuminate?

Answer 8

When the level decreases below 2.5 l

Master caution and CAP

Single chime

Question 9

When will the LO PR light illuminate?

Answer 9

When the pressure drops to below 1500 psi

Amber master caution, CAP and single chime

Question 10

When will you get an OVHT light?

Answer 10

When the pump case drain line temp exceeds 121 degrees

You should switch the pump off and the crossfeed valve on

Question 11

What is the accumulator for?

Answer 11

Acts as a shock absorber against pressure surges due to pump operation

Assists the hydraulic pump when there is a high demand on the system

Question 12

What are the red ticks on the hydraulic pressure indicator?

Answer 12

The alert thresholds

Question 13

What powers the blUe system auxiliary pump?

Answer 13

DC Bus 2 or the Hot main BAT bus

Question 14

What happens if you push the auxiliary pump button?

Answer 14

The auxiliary pump will run for 30 secs

Will operate as long as the button is kept depressed

Can be used if there is no power and the battery switch is off

Question 15

For how long will the auxiliary pump run once the prop brake is engaged

Answer 15

15 secs after engagement

Question 16

When will the auxiliary pump stop?

Answer 16

Once main system pressure rises above 2100 psi

Question 17

When will the auxiliary pump stop?

Answer 17

Once main system pressure rises above 2100 psi

Question 18

When will the AUX PUMP LO PR light illuminate?

Answer 18

When the pump pressure drops below 1500 psi

Question 19

When will the crossfeed valve automatically close?

Answer 19

When the fluid level in either reservoir falls below 2.5 litres

Valve cannot be opened if there is LO LVL in either compartment

Question 20

When will the crossfeed valve automatically close?

Answer 20

When the fluid level in either reservoir falls below 2.5 litres

Valve cannot be opened if there is LO LVL in either compartment

Will also close if electrical power is lost

Question 21

How can you verify the operation of the crossfeed valve?

Answer 21

Observe the indications on the hydraulic pressure indicator

Question 22

How can you verify the operation of the crossfeed valve?

Answer 22

Observe the indications on the hydraulic pressure indicator

Question 23

What will happen to the display gauge in the event of loss of electrical power?

Answer 23

All pointers will move to the zero position

Gauge can be temporarily energised by pressing the AUX PUMP pb

Question 24

What does the pressure gauge on the hydraulic bay show?

Answer 24

Indicates the greater of system pressure or accumulator pressure

Will normally show accumulator pressure of 1500 psi unless AC wild power is available or blue aux pump is running

Question 25

What can you do if brake accumulator pressure is insufficient?

Answer 25

AUX pump pb can be used to boost the blue system