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Flashcards in Hydraulics Deck (21)
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Type of fluid and pressure amount?

Skydrol hydraulic fluid and 3,000 psig


Main components of hydraulic system

Two engine driven pumps
Four electric hydraulic pumps
One hydraulic power transfer unit
Three hydraulic system reservoirs


What powers systems one and two?

An engine driven pump
Backed up by an AC electrical pump


What powers hydraulic system during take off and landing?

Electric pumps used in case of engine failure.


Purpose of power transfer unit?

Transfers power from system one to system two for landing gear retraction and extension if engine pump two is not operational.


What powers system three?

Main electric pump and backed up by auxiliary pump as a back up.


When is PTU not operational?...... Power transfer unit.

It will not be activated when on the ground and airspeed below 50 knots.


Items on system one?

Left outboard elevator
Upper rudder
Engine one reverser
Multi function spoilers three and four
Ground spoiler two
Outboard brakes
EMER/parking brake


Items on system two

Landing gear
Inboard elevator
Aileron inboard
Reverser two
Multi function spoiler 5
Ground spoiler one
Inboard brakes
Nose wheel steering
EMER/parking brake


Items on system three

Right outboard elevator
Lower rudder
Outboard ailerons


When do the electric pumps on system one and two come on automatically?

During take off and landing or when primary engine driven pump is lost.


When does three B operate automatically?

Only when three A is lost and does not come on during take off or landing.


What is the primary pump on system three?

A..... It is always on that is why does not have auto position.


What activates the PTU?

If engine two fails or system two fails during take off or landing when PTU knob is in auto and flaps are not set at zero.


Reason for on position for hydraulic pump switches?

If a failure of corresponding SPDA allows to set to on for use.


When do electric pumps one and two auto turn on?

When flaps are set to any position greater than zero degrees.
Trust levers set to take off thrust
Or ground speed greater than fifty knots
Or when engine driven pumps are not operational


Overheat of system one or two

Caution message at 100 c and auto shutoff at 125
145 gives warning... If three overheats then both pumps shut off at 125

This can be caused by the failure of a pump compensator


Hydraulic items on RAT

Lower rudder
R outboard elevator
Left and right outboard ailerons


Purpose of the system accumulator

Control flight controls until RAT is deployed and spun up if both one and two are off line.


How does system allow for single engine taxi?

With engine one running, releasing the parking brake with switches in auto electric pump two is automatically turned on allowing for nose wheel steering and inboard brakes.


Items on hydraulics

Primary and secondary flight controls
Landing gear
Nose wheel steering
Thrust reversers