Hydraulics Flashcards
L Hydraulic system main functions
Flight controls
L and R System consist of
Reservoir
EDP
Electric demand pump
Where does the reservoir get it’s pressure from
Bleed air system
Do Electric demand pumps become inhibited on the ground
If so which and why
Yes
Left Electric demand pump
To reduce electrical load during engine start
R Hydraulic system main functions
Flight controls
Normal brakes
PES
C Hydraulic system main fuctions
Flight Controls Nose wheel steering Flaps and slats Alternate brakes Landing gear HDG Tail Skid
What does the center system consist of
Reservoir
2 EDP’s
ADG
RAM Air Turbine Pump
What does the green PRESS light mean on the RAT panel
Rat is deployed
Rat is producing Hydraulic pressure
When does the HDG come on
When electrical power is lost on both AC busses
How does the HDG receive it’s pressure
The C Air Driven Pump operates continuously to ensure HDG stays pressurized
What does the RAT provide
It provides hydraulic power to the flight control portion of the Center Hydraulic System
At what speed does the RAT provide adequate Hydraulic power
130kts
Normal Hydraulic System pressure
3000psi
When is the left electric demand pump inhibited and why
On the ground during engine start when only one generator is running
How is the LEFT system hydraulic fluid cooled
By a heat exchanger located in the left Fuel tank
In the event of a Hydraulic leak how does the PES operate
Small amount of fluid trapped in the Left system
How is the RIGHT system fluid cooled
By a heat exchanger located in the right fuel tank
How is the Center system fluid cooled
By a heat exchanger located in the right fuel tank
Which pump in the Center system load sheds and why
C2 pump, to reduce electrical loads
When does the QTY light illuminate on the Hydraulic panel
When quantity less than 0.5
When do the letters RF display on the Eicas Status page
When Quantity less than 0.75
Which pump runs continuously while on the ground and flaps in T/O position
Center Air Demand pump and Right Electric Demand Pump
When does the PES automatically supply power
When failure occures in both Ledt and Center Hydraulic systems
How does the PES system function
Uses right hyd power to drive PTU.
PTU then pressurizes an isolated portion of the left system to power the PES
