hydaulics

Question 1

Engine driven hyd pumps are mounted on what

Answer 1

prop reduction gear box

Question 2

How many psi do the engine driven pumps deliver

Answer 2

3000 psi

Question 3

Describe hyd pumps

Answer 3

1 left engine driven w/ standby electric
2 right engine driven w/ PTU
3 DC motor pump
4 alt landing gear (fo driven)

Question 4

1 Hydraulic System hydraulic pressure for:

Answer 4

Flaps (priority)
Anti Skid / Main Brakes (isolation)
Inboard Roll Spoilers (isolation)
Rudder (lower PCU)
Elevator (outboard PCUs)
Power Transfer Unit (priority)

Question 5

1 hyd reservoir capacity and min quantity

Answer 5

8 quart, min 40%

Question 6

1 standby hyd pump powered by what

Answer 6

AC driven

Question 7

AC driven standby hyd pump auto activates when

Answer 7

left engine fail in flight or
flaps greater than 0 and parking brake is off and
number 1 reservoir is not empty and
AC power is available 
(takeoff and landing)

Question 8

When will the stby hyd press light come on?

Answer 8

When pressing the button to activate the standby hyd pump (does not come on automatically)

Question 9

If pressure in hyd 1 drops below 2100 psi

Answer 9

Priority valve closes

lose - flaps and PTU

Question 10

When does the isolation valve close

Answer 10

quantity low

lose: anti-skid/main wheel brakes, inboard roll spoilers

Question 11

What is the thermal bypass valve?

Answer 11

opens to allow fluid to heat exchanger at certain temperature

Question 12

What is the purpose of the PTU

Answer 12

power transfer unit serve as a back-up for #2 main hydraulic system

Question 13

What is the PTU powered by?

Answer 13

Hydraulic system 1

Question 14

How do you activate the PTU?

Answer 14

Press the PTU CNTRL switch light or automatically

light turns on for both manual and automatic activation of PTU

Question 15

Describe #2 hyd system

Answer 15

reservoir located in right nacelle, 12 q capacity, min 40%, pressurized by right engine driven pump (EDP)

Question 16

2 hyd system provides pressure for

Answer 16

Landing Gear
Outboard Roll Spoilers
Nose wheel steering
Emergency / Parking Brakes
Rudder (Upper PCU)
Elevator (Center PCU)

Question 17

What do you lose if Hyd system two becomes low?

Answer 17

Isolation valve closes
Landing gear
Outboard Roll Spoilers
Nose wheel steering
Emergency/parking brake

Question 18

When is the PTU on?

Answer 18

Takeoff and landing, when the button is pushed, when system two fails

Question 19

Automatic PTU operation occurs if

Answer 19

parking brake off and
flaps greater than 0 and
no 1 system press greater than 2400 psi and
hyd no 2 reservoir not empty

Question 20

When will the PTU shut down

Answer 20

the ptu will shut down and remain latched out if it does not produce pressure for more than 30 seconds when automatically commanded to do so

Question 21

how is the hyd system cooled

Answer 21

fuel, thermal bypass valve opens to heat exchanger for 1 and 2 systems

Question 22

Describe hyd system 3

Answer 22

back up system for elevator (inboard PCUs), reservoir located in environmental compartment, 2.6 q capacity min quant 40%, during normal flight in “active standby” with the isolation valve energized closed

Question 23

hyd 3 is powered by

Answer 23

Dc motor pump at 2600-3250 psi to keep accumulator pumped up

Question 24

What is the DCMP powered by?

Answer 24

standby battery (hot batt bus)

Question 25

When will hyd system 3 activate

Answer 25

manually by HYD 3 ISOL VLV switchlight, automatically by lose of syst 1 or 2 and/or dual engine failure

Question 26

When will you get #3 HYD PUMP caution light

Answer 26

accumulator pressure below 900 psi in flight or

DCMP operates more than 60 seconds on the ground

Question 27

Firewall shutoff valves operate when

Answer 27

engine 1 or engine 2 pull fuel/hyd off handles pulled
no 1 or no 2 hyd reservoir fluid quantity is low
hydraulic fluid over temp
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