Hydraulics Flashcards
When armed the PTU activates when
L HYD pressure drops below 1500 psi
Operation of the PTU assumes loss of the
Left hydraulic system
When armed, the AUX pump comes on when
L HYD and PTU pressure is <1500 PSI, and
Brake pedals are depressed 10°
What is the Brake Accumulator precharge
1200 psi
If L HYD System fluid is depleted, but AUX fluid remains in the L HYD reservoir, what system can provide braking?
AUX Pump
What is the GEAR EMERGENCY BLOWDOWN accumulator pressure charge
3100 PSI (at 70°F)
What are the hydraulic fluid quantities of the L/R reservoirs
L - 4.8 Gal
R - 1.6 Gal
What is lost if you lose L HYD System?
L Thrust Reverser
If L HYD Pump and PTU are not working, the AUX pump can provide power to…
Flaps, Brakes and Nose Wheel Steering
Can the pilots change Yaw Damper from left to right inflight?
Yes, switch FGCs from 1 to 2, or 2 to 1
What is lost if you lose Right Hydraulic system?
R Thrust Reverser
What will prevent PTU from automatically coming on?
L HYD system fluid <1.5 Gal
R Hyd system hot, temp >104.4°C
The AUX system reservoir is located…
in the left system reservoir
Which hyd system can operate the HMG?
Left or PTU
How is hyd fluid used during the opening of the main entrance door?
hydraulic fluid flowing out of the door system at a controlled rate slows opening of the door.
What activates the PTU?
If the left hydraulic system pressure drops below 1500 psi with more than 1 gallon of fluid in the left system and pressure in the right system.
When will PTU automatically shut off?
Left system pressure >1500 PSI, or
Left or Right system fluid loss, or
Right “HYDRAULIC RESERVOIR HOT” CAS (temp >104° C)
What does the PTU Power?
All left side mechanics except the T/R, left yaw damp and flight controls
Will the AUX PUMP turn OFF with an amber “Aux Hydraulic HOT” CAS?
NO
What components are lost with a loss of the left hyd system fluid?
Left T/R and Landing gear
If landing using only the AUX hydraulic pump, will nose wheel steering be available after landing?
Yes, once WOW is activated
If a hardover is detected, can the system be reset and how?
Yes by pulling and resetting the appropriate CB - IAW the QRH
What components are lost with both the Left and AUX systems inoperative?
Left Yaw damp Left T/R Normal Brakes Flaps NWS Landing Gear Auto Ground Spoilers
How many DPIs on the a/c?
10 In the hell hole 5 on left 3 on right One on PTU One on AUX pump One in the wheel well
What automatically activates the AUX Pump
Switch armed
L and PTU system below 1500PSI
Brake pedals depressed >10°
Aux Hydraulic Boost Pump turns on…
Does Pilot have any control of this?
ON - Hyd pressure in the line drops 20 PSI
OFF- pressure rises > 25 PSI
No. Pilot has no control. It’s fully automatic. Designed to boost AUX pump pressure in the tail compartment.
