Hydraulics Flashcards
What is the PTU used for?
The PTU uses reserve fluid protected in the left system by a standpipe and pressure provided from the right hydraulic system to power the left side flaps, slats, steer and gear.
No fluid is transferred.
What is powered by the left hydraulic system?
Flaps, slats, steer and gear Flight controls Left thrust reverser Alternate brakes Main cargo door M
What is powered by the center hydraulic system?
Flight controls
Reserve fluid used by the RAT
What is powered by the right hydraulic system?
Flight controls
Right thrust reverser
Normal brakes
Reserve fluid used by the reserve brakes
How do you power up the electric hydraulic pumps?
You power up the electric hydraulic pumps from right to left to prevent fluid transfer through the brake shuttle valve.
You turn them off left to right.
What does a SYS PRESS annunciator light indicate?
Indicates low system pressure. It will generate an EICAS message.
With the PTU running you can have this light illuminated and show good system pressure.
What does RSVR indicate ?
Low quantity or low head pressure
OVHT indicates what?
OVHT indicates a hot hydraulic pump.
When will the PTU operate?
Anytime left engine pump pressure is insufficient and the right engine pump pressure is sufficient.
What bus is the Ram air turbine switch?
The Ram air turbine switch is on the hot battery bus and is always active.
A green RAT PRESS light indicates what?
Good hydraulic pressure from the rat.
What does UNLKD indicate ?
The Rat is not stowed.
What is the min speed for the Rat to operate?
130 kts.
What does an magenta OF indicate?
A hydraulic system is overfill
What does a magenta RF indicate ?
Low hydraulic quantity.
