PTM Ch. 13 Hydraulic Power System

Question 1

Hydraulics control what?

Answer 1

Actuation of landing gear, flaps, and NWS

Question 2

A separate hydraulic system is provided for what?

Answer 2

Brakes

Question 3

The auxiliary system, pressurized by a hand pump, supplies pressure only for emergency what?

Answer 3

Extension of the landing gear

Question 4

What is the normal pressure in the hydraulic system?

Answer 4

2000 psi

Question 5

What pressurized the main hydraulic system?

Answer 5

Two variable-volume pumps

Question 6

Can the system run on one pump?

Answer 6

Yes but at a reduced rate

Question 7

What kind of hydraulic fluid do we use?

Answer 7

Brayco MIL-H-83282

Question 8

Where do the hydraulic pumps take the fluid?

Answer 8

From the reservoir through shutoff valves.

Question 9

The HYDR PRESS (L/R) annunciators come on when?

Answer 9

To warn that the hydraulic pump output is low or pump failure.

Question 10

What happens if pressure surges in the system?

Answer 10

Dampened by an accumulator

Question 11

The hydraulic reservoir is pressurized by what?

Answer 11

31 psi regulated bleed air

Question 12

The engine-driven pumps draw fluid from where?

Answer 12

Above the standpipes in reservoir

Question 13

The fluid below the standpipes is reserved for what?

Answer 13

Hand pump operation during emergency extension of the landing gear

Question 14

Can the gear be retracted with the aux system?

Answer 14

No

Question 15

When would you use the HYDR SHUT OFF switches?

Answer 15

Only in the event of fire, engine shutdown in flight, or when mx is to be performed

Question 16

What is the 31 psi in the hydraulic reservoir used for?

Answer 16

Keep pressure on hydraulic fluid when in high demand. (Flap and gear extension)

It also prevents foaming of the fluid

Question 17

When does the L/R HYD position disagreement light illuminate?

Answer 17

When the hydraulic SOV is in motion

Question 18

What if the L/R HYD light doesn’t extinguish?

Answer 18

The valve hasn’t fully opened or closed

Question 19

How much fluid is needed in the hydraulic glass fluid-level?

Answer 19

Fluid needs to be in the upper indicator. If there isn’t MX is required.

Question 20

How to use the emergency extension?

Answer 20

1. Follow checklist
2. Airspeed 175 (173 DOWTY)
3. Gear handle- down
4. Emergency release handle- rotate 90 degrees CCW
5. Hand pump valve handle- pull pin and pump

Question 21

Pump handle is used for emergency gear extension to what pressure is achieved?

Answer 21

500-800 psi

Question 22

The purpose of the accumulator in the hydraulic system is for what?

Answer 22

Dampen pressure surges