Hydraulic Flashcards
What fluid and what PSI for hydraulic system
Skydrol hydraulic
And 3000PSI
The main components of the hydraulic system
2 engine driven pump 4 electrical hydraulic pump One hydraulic transfer unit 3 reservoirs 5 accumulator
How many hydraulic systems
3 systems
What does the hydraulic system provide power to?
Flight spoilers Flight controls Landing gear Nose wheel steering Wheel brakes Trust reversers
Can the fluid from one system be used by another system
No
What is the system logic to activate the AC hydraulic pumps
In flight
EDP or engine fail
Flaps more than than 0
During landing the AC pump stays on for 60 seconds after speed below 50knots
On ground
Flaps more than 0 AND
TL set to T/O OR
Ground speed more than 50
When will the AC pump 2 will automatic be turned on
Engine 1 running and parking brake release
During engine 1 start and N2 more than 40% with parking brake set within 6 min
What is the pump unloader and the flow limiter valve for
To avoid overloading the RAT during is initial spining
What are accumulators for
Maintain constant pressure
Prevents pump cavitation
Important Items controlled by Hydraulic system 2
Inboard brakes
Nose wheel steering
Landing gear
What is the PTU
Power transfer Unit
Uses HYD 1 power to peovide HYD 2 pressure to assist in lowering the gear when HYD EDP 2fail
Purpose of HYD 3 system
Back up for primary flight control
When will the PTU automatically engage
When HEDP 2 fail
And flaps not set to zero or landing gear not up and locked
Reservour 2 more than 12%
How is the overheat protection system work
100c messgae on ICAS
125C Hydraulic shut off valve will close
What does the system 3 contains that system 1 and 2 does not have
Pump unloader and flow limiter
Restrict flow and power from electrical pump 3A so the RAT will not stall
