13: Hydraulics

Question 1

Power Transfer Unit (PTU)- what is its purpose?

Answer 1

To supply the additional volume of hydraulic fluid
Needed to operate the autoslats and LE flaps and slats
At the normal rate
When syst B EDP is inop

Question 2

Power Transfer Unit (PTU)- operates when the following conditions exist:

Answer 2

• Syst B EDP hyd press drops below limits
• airborne
• flaps not up

Question 3

Landing Gear Transfer Unit- what is its purpose?

Answer 3

To supply the volume of hydraulic fluid
Needed to raise the landing gear
At the normal rate
When syst A EDP volume is lost

Question 4

Landing Gear Transfer Unit- the following conditions must exist:

Answer 4

• airborne
• no 1 engine RPM drops below limit
• ldg gear lever is positioned UP
• either main ldg gear is not up and locked

Question 5

Syst A or B has a standpipe?
Goes down to what percentage?
Which pump would still work?

Answer 5

Syst A

Goes down to 20% unless a leak in the electric pump

Electric pump

Question 6

With which two switches can you manually activate the Standby Hydraulic Pump?

Answer 6

• Flight Control Switches
• Alternate Flaps Master Switch

Question 7

Automatic Operation of the standby pump occurs when the following conditions exist

Answer 7

• loss of system A​ or B
• flaps extended​
• airborne, or wheel speed greater than 60 kts, and​
• FLT​ CONTROL​ switch A​ or B Hydraulic System ON

OR

the main PCU Force Fight Monitor (FFM) trips

Question 8

Prelim Pre-Flight; hydraulic quantity that you should see?

Answer 8

above 76% with all control surfaces in retracted position and no RF

Question 9

If you have a leak in the Standby system, which indication can you expect?

Answer 9

• Standby LOW QUANTITY light
• System B fluid drops to about 70%