Hydraulics

Question 1

Green system pumps:
How many pumps?
When does the electric pump run? How long?

Answer 1

4: 2 engine driven, 1 electric, 1 from RAT

When one engine fails, 25 sec to bring gear up within proper time

Question 2

When does the Blue electric pump come on?

what drives the blue system normally?

What does it assist with?

Answer 2

When engine 1 fails, loss of PRIM 1 or 3.

An engine driven pump on 1.

Ensuring 2 actuators are operating the rudder.

Question 3

What normally pressurizes the Yellow system?
When does the electric pump turn on automatically? To assist with?
What does it assist with on the ground?

Answer 3

-Engine 2 driven pump
-engine 2 fail and Flap lever not at 0 , to ensure flap retraction in proper time at TO
-Cargo door operation

Question 4

What controls the Hydraulic system?

Answer 4

1 Hydraulic System Monitoring Unit
(HSMU)

Question 5

What does the Green system Priority Valve do?

Answer 5

• Designed to prioritize Flight Controls in a low pressure situation.
• Cuts off the following high draw items:
  Emergency Generator
  Nosewheel Steering
  Landing Gear

Question 6

Besides flight controls, what are major items on the Blue system?

Answer 6

• Alternate Brakes
• Parking Brake
• Brake accumulator