A320 Hydraulic System Questions

The brakes pressure indication on TRIPLE PRESSURE INDICATOR reads which system pressure?

• Yellow
• Blue
• Green

Explanation: This one's backwards from the intuitive guess. In normal braking (Green), there's no brake pressure indication in the cockpit at all — the triple pressure indicator only comes alive in alternate/parking brake mode, and it always reads Yellow system (and accumulator) pressure, never Green.

Landing Gear - Brakes & Antiskid (Controls & Indicators)

The Eng Pump Fault light extinguishes when the engine pump switch is selected to off except for:

• Reservoir low level.
• Pump low pressure.
• An overheat.

Explanation: The ENG PUMP FAULT light goes out when the crew selects the pump OFF, with one exception: during an overheat, it stays lit for as long as the overheat condition lasts.

Hydraulic - Controls & Indicators (overhead panel)

As long as the landing gear lever is up a hydraulic safety valve closes to cut off the hydraulic supply to the gear when the airspeed is:

• Greater than 260 KIAS.
• Greater than 230 KIAS.
• Less than 260 KIAS.
• Less than 230 KIAS

Explanation: Above 260 KIAS, a safety valve automatically cuts off hydraulic supply to the landing gear system, and it stays cut off below that speed as long as the gear lever remains up.

Landing Gear - General / Description

If you lost the GREEN system, what equipment is lost?

• Reverser 1 and gear retraction.
• Reverser 1, gear retraction and nose wheel steering
• Reverser 2, gear retraction, cargo doors and nose wheel steering.
• Reverser 2 and gear retraction.

Explanation: Green actuates all landing gear/doors and supplies nose wheel steering, and (mirroring the confirmed fact that Yellow loss costs Reverser 2) Green powers Reverser 1 on engine 1's side — so losing Green costs Reverser 1, gear retraction, and nose wheel steering. Cargo doors are Yellow-powered, not Green, so they aren't part of this loss.

Hydraulic - General / Description

If you lost the BLUE system, what equipment is lost?

• The Emergency generator.
• Cargo door
• Nose wheel steering.
• All of the above.

Explanation: The emergency generator is driven off the blue hydraulic circuit, so losing Blue costs it. Cargo doors run on Yellow and nose wheel steering runs on Green — neither is Blue-dependent, so "all of the above" overreaches.

Hydraulic - General / Description

To extend the landing gear with the Gravity Extension Handcrank requires _______ turns of the handle.

• 3 counter-clockwise.
• 2 counter-clockwise.
• 3 clockwise.
• 5 clockwise.

Explanation: Pull the crank out and turn it clockwise for 3 turns, until it reaches the mechanical stop.

Landing Gear - Controls & Indicators (gravity extension)

The RAT is capable of powering a pump which will pressurize:

• Only the blue system.
• All systems.
• The blue and yellow system.
• The blue and green system.

Explanation: The RAT's pump only ever pressurizes the Blue system — it has no connection to Green or Yellow.

Hydraulic - General / Description

How can the pilot switch off the Fire Shut Off Valves?

• By de-pressing the Hydraulic Shut Off Switches.
• By selecting the Hydraulic Valve Switch to the “Closed” position
• By de-pressing the Engine Fire Switches

Explanation: The Green and Yellow fire shutoff valves close when the crew pushes the corresponding ENG 1(2) FIRE pushbutton — there's no separate dedicated hydraulic shutoff switch for this.

Hydraulic - General / Description (Fire Shutoff Valves)