Hydraulics

Question 1

Primary Hydraulic System failure results in loss of

Answer 1

FMC and BUCS inputs

Question 2

Where are the primary hydraulic system dirty filter indicators located?

Answer 2

On the primary manifold

Question 3

Which components and/or systems lose hydraulic power in the event the Utility reservoir is low?

Answer 3

Ammunition Carrier Drive Motor
AWS Elevation Actuator
AWS Azimuth Drive Motor
Pylon Actuators
Tail Wheel Unlock Actuator
Utility side of the Tail Rotor Servo

NOTE: AWS = Area Weapons System

Question 4

During preflight, the utility accumulator pressure gauge should indicate a minimum of _____ psi prior to attempting an APU start.

Answer 4

2600 PSI

Question 5

During preflight, what pressure should the utility hydraulic return actuator gauge indicate?

Answer 5

55 PSI

Question 6

What is the purpose of the hand pump? When is it used?

Answer 6

Charge the utility hydraulic accumulator and fill the primary and utility hydraulic reservoirs

Use if Utility Hydraulic Pressure is less than 2600.

Use after abort start to increase pressure to 3000 PSI.

CAUTION:
Restrictor valve can be ruptured during hand pump replenishment of the utility accumulator. Will not allow pressure to reach 3000 PSI

Question 7

What is the crewstation indication when the tail wheel is unlocked?

Answer 7

“Unlocked” is illuminated on Tail Wheel/NVS Mode Switch panel

Question 8

When is the hydraulic pressure displayed on the ENG page flight format?

Answer 8

When out of normal limits

Question 9

What does the Caution UTIL HYD BYP indicate?

Answer 9

Utility return system indicates a “dirty filter” impending bypass condition.

Question 10

What is the time limit for either Hydraulic System operating in the transient (> 3400 psi) range?

Answer 10

5 sec.

Question 11

How many hydraulic systems are there?

Answer 11

UTIL and PRIMARY

Question 12

What are the main components of the primary hydraulic system?

Answer 12

Primary Hydraulic Pump
Primary Hydraulic Manifold
Flight Control Servoactuators (x4)
Primary Hydraulic Ground Support Equipment Panel

Question 13

What are the 4 servoactuators associated with the primary hydraulic system?

Answer 13

Longitudinal
Collective
Lateral
Directional (on Tail Rotor)

Note: listed in order from left to right look at the nose of the aircraft.

Question 14

(T)(F) It can be argued that there are 3 hydraulic systems.

Answer 14

True.

Utility accumulator - provides emergency hydraulic pressure for the flight controls / APU start/ Rotor Brake

Question 15

The primary hydraulic reservoir uses IPAS to pressurize to ________.

Answer 15

31 ± 3 psi to prevent pump
cavitation/foaming

Question 16

How long can the aircraft fly after emergency hydraulic button is pressed?

Answer 16

30 sec - 6 min

Highly variable. Depending on the situation it might not even work.

Question 17

What happens when the EMERG HYD button is pressed?

Answer 17

Activation opens accumulator isolation valve, allowing fluid pressure through to the flight controls.

Question 18

What are the main components of the utility hydraulic system?

Answer 18

Utility Hydraulic pump
Utility Hydraulic reservoir
Utility Hydraulic manifold
Emergency hydraulic shutoff valve
Utility Hydraulic accumulator assembly
APU start system
Rotor brake actuator
Rotor Brake pressure switch
Flight control servoactuators (in case of loss of primary)