Hydraulics Flashcards
A PTU FAULT is triggered during engine start if the last engine is started within:
40 seconds following the end of the cargo operating
The system operating pressure when powered by the RAT is
2500psi
Engine 1 pump powers the ——— hydraulic system
Green
The blue system is pressurised by
An electric pump
In an emergency the blue system is pressurised by
The Ram Air Turbine
A pump driven by Engine — pressurises the yellow system
Engine 2
The bidirectional Power Transfer Unit enables the yellow system to pressurise the
Green system and vice versa
The PTU comes into action automatically when the differential pressure between the Green and Yellow systems is
Greater than 500psi. The PTU therefore allows the Green system to be pressurised on the ground when the engines are stopped.
The RAT deploys automatically if AC BUS 1 and AC BUS 2
Are both lost.
The RAT can be stowed only when the aircraft
Is on the ground
Priority valves cut off hydraulic power to heavy load users if
Hydraulic pressure in a system gets low
The Leak Measurement Valves measure
The leakage in each circuit
Normal brakes receive pressure from the
Green system
The landing gear receives pressure from the
Green system
Alternate and Park brakes receive pressure from the
Yellow system
NWS receives pressure from the
Yellow System. Green system (VH-YUD)
Reverser Engine 2 is powered by the
Yellow hydraulic system
Engine 1 and 2 PB fault light will remain illuminated when selected off during
An overheat (will remain illuminated as long as the overheat condition lasts)
If AC power is available the Blue hydraulic electric pump operates
In the air.
On the ground, if one engine is running or the crew have pressed the BLUE PUMP OVRD pushbutton on the maintenance panel
Reservoir quantity indication is green unless
The fluid level goes below the warning level, in which case it goes amber.
Hydraulic fluid levels, if at the top of the normal filling range, are
Blue 6.5 litre
Green 14.5 litre
Yellow 12.5 litre
System pressure indication, normally green, becomes amber when
System pressure is less than 1450psi
