Hydraulics Flashcards
Where can you monitor hydraulic quantity and pressure?
STATUS page or Hydraulic Synoptic Display
Which hydraulic systems or systems normally power the Primary flight controls?
All three
Which hydraulic systems or systems normally power the Normal brakes?
Right
Which hydraulic systems or systems normally power the Alternate brakes?
Centre
Which hydraulic systems or systems normally power the Reserve brakes?
Centre
Which hydraulic systems or systems normally power the Steering?
Centre
Which hydraulic systems or systems normally power the Landing gear?
Centre
When would the shut-off valves supplying fluid from the Left and Right reservoirs to the engine driven pumps be closed and the engine driven pumps depressurised?
When the appropriate Engine Fire Switch is pulled
State the hydraulic systems that have the engine driven pumps as their primary power
Left and Right
State the hydraulic systems that have the electrically driven pumps as their primary power
Centre
State the hydraulic systems that have the air driven pumps as their primary power
None
Which demand pumps are air driven?
Those in the Centre system
Before engine start which pump is selected first, and why?
Pressurise the Right System first to prevent fluid transfer between systems. Right ELECTRIC DEMAND pump selector - AUTO, verify that FAULT light is extinguished
After engine start, under what circumstances would you expect the demand pumps to run for the Left and Right systems?
In AUTO position, the L and R demand pumps operate for takeoff, landing, and when system or primary pump pressure is low. In the ON position the demand pump runs continuously
After engine start, under what circumstances would you expect the demand pumps to run for the Centre system?
In AUTO position, a demand pump operates when system and/or primary pump pressure is low, or when system login anticipates a large demand. In the ON position, the demand pump runs continuously (both pumps cannot operate simultaneously when ON is selected for both pumps)
What happens if BOTH Centre system demand pumps are selected to ON?
Only the C1 Demand Pump will operate
Why does the Centre hydraulic system have an isolation feature?
To ensure that, in the event of a leak, sufficient fluid is retained for Reserve Brakes, and also for Nose Gear actuation and steering
What three conditions could open the left (on the synoptic) isolation valve after the Centre system hydraulic quantity falls to a low value?
Airspeed decreases below 60 knots, or hydraulic pressure to the centre system flight controls is low, or the landing gear is selected down, both engines are normal and both engine-driven pumps are providing pressure
When would the Ram Air Turbine (RAT) deploy automatically?
- Both engines have failed and centre system pressure is low
- Both AC transfer busses are unpowered
- All three hydraulic system pressures are low
What systems does the RAT provide hydraulic power to?
Primary flight controls connected to the centre hydraulic system
