HYDRAULICS

Question 1

What are the NORM and RAT operating pressures?

Answer 1

NORM = 3000 PSI
RAT = 2500 PSI

Question 2

What does the RAT do?

Answer 2

Allows the BLUE hydraulic system to operate if electrical power is lost to both AC BUS 1 & 2

Question 3

When is the PTU inhibited?

Answer 3

• Parking Brake ON
• One engine start
• Pin in towing position

Question 4

When is the PTU de-inhibited?

Answer 4

• Single Engine Taxi, Parking Brake OFF

- When Pin is taken out after Push Back

Question 5

Which hydraulic systems have fluid shut-off valves?

Answer 5

• Green

- Yellow

Question 6

What operates the fluid shut-off valves for the Green and Yellow System?

Answer 6

The Engine Fire Pb

Question 7

When does the BLUE pump start automatically?

Answer 7

If AC power is available it operates:
- in flight
- on the ground if one engine is running
or
- if the crew has pressed the BLUE PUMP     OVRD Pb on the maintenance panel

Question 8

In case of a Reservoir OVHT, when does the FAULT light on the OHP extinguish?

Answer 8

When the OVHT condition does not exist anymore

Question 9

On which Hydraulic Pumps can you get an OVHT?

Answer 9

Yellow and Blue ELEC pumps

Question 10

What is meant by OVHT on the SD page for Y and B pumps?

Answer 10

The ELEC pump has overheated

Question 11

What causes FAULT lights to illuminate on the OHP with regards to the engine driven pumps?

Answer 11

• RESEVOIR OVHT
• RESEVOIR LOW LVL
• RESEVOIR LOW PRESS
• PUMP LOW PRESS
• PUMP OVHT

Question 12

What causes the Yellow Electrical pump to run automatically?

Answer 12

• Cargo Door Lever operation (inhibits other yellow system functions except alternate braking and eng 2 reversers)