Hydraulic Power Flashcards
Which hydraulic systems have engine driven pumps?
The green and yellow hydraulic systems.
Name some of the major users of the GREEN system.
Landing gear, nose wheel steering
The yellow system has an engine driven pump, what other means do we have to pressurize the yellow
system?
Electric pump, PTU, and a hand pump for the cargo doors.
How many pumps does the yellow hydraulic system have, not counting the PTU?
The yellow hydraulic system has 3 pumps not counting the PTU (Engine, Electric, Hand).
What does the yellow system hand pump supply pressure for?
Opening the cargo doors.
When does the PTU operate?
When pressure between the green and yellow system drops to a predetermined level.
Can fluid be transferred between hydraulic systems?
No.
Will the PTU operate during Cargo Door operation?
No.
When is the PTU tested?
During second engine start.
Is it possible to pressurize the green hydraulic system on the ground via the PTU?
Yes
What are the hydraulic priority valves, and what is their function?
Priority valves cut off heavy load using units if system pressure drops below a predetermined value
With the airplane on the ground and the blue electric pump switch in AUTO, when will the blue pump be
energized?
With one engine is running.
To emergency extend the gear the crew has to turn the gear crank 3 turns clockwise. What does this
action accomplish?
This shuts off hydraulic pressure to the gear, opens the doors, and unlocks the gear.
After emergency extension do the gear doors remain open?
Yes
Do we have nose wheel steering after emergency gear extension?
No
