Hydraulics/Fuel Flashcards
BTFANGS
Brakes
Thrust Reversers
Flaps
Airbrakes
Nosewheel Steering
Gear
Stick Pusher
What are the three different pumps in the hydraulic system?
Two variable volume, engine driven pumps, auxiliary pump, and ground hand pump
Is one engine driven pump enough to power all systems?
Yes
What can the auxiliary pump do?
Lower the gear and operate the flaps
How is the auxiliary pump actuated?
Hand pump in the cockpit
How big is the auxiliary hydraulic reservoir?
6 pints
What is the ground hand pump?
Located in rear equipment bay, creates hydraulic pressure on the ground
How big is the main hydraulic reservoir?
2.4 gallons
What closes the on-off hydraulic valve?
The HP COCK lever
What is the purpose of hydraulic accumulators?
Ensure constant hydraulic flow through a pressure storage system to the associated subsystem
What does the HYD OVHT annunciator indicate, and when does it illuminate?
Indicates an overheat condition of the hydraulic system when fluid temp exceeds 90°C
What does the HYD 1/2 LO PRESS annunciator indicate?
Low pressure condition
When does the HYD 1/2 LO PRESS annunciator extinguish?
1,750 psi
When does the HYD 1/2 LO PRESS annunciator illuminate?
1,500 psi after 57 seconds
What is normal hydraulic system pressure?
3,000 psi
When does the hydraulic overpressure relief valve open? What does it do?
Opens at 4,000 psi, returning fluid to reservoir
What happens if both engine-driven hydraulic pumps fail?
Pressure-maintaining valve closes to provide 2,300 psi pressure for brake operations
What is the main accumulator pressure?
1,000 psi
What is the wheel brake accumulator pressure?
1,000 psi
What is the thrust reverser accumulator pressure?
1,500 psi
What does the AUX HYD LO LEVEL annunciator indicate?
Auxiliary tank has decreased by 1/2 pint
How is hydraulic fluid level checked?
Sight gauge in the aft equipment bay
Where are the fuel tanks on the Hawker 900XP?
Left and right integral wing tanks, additional ventral tank
What are the three types of fuel pumps onboard?
Jet pumps, boost pumps, and engine-driven pumps
What are the fuel jet pumps?
Motive-flow, non-moving pumps that push fuel from outboard the wing to the inboard central fuel compartment
What are the fuel electric boost pumps?
One in each wing tank, delivers fuel under pressure to the engine-driven pumps and provide the motive flow to the jet pumps in the fuel system
What are the engine-driven fuel pumps?
Attached to the accessory case and atomizes the fuel for combustion
During normal operations, what are the fuel boost pump switches set to?
ON
What happens when the electric boost pump switches are set to OFF?
Electric boost pumps turned off
What does setting the fuel boost pump switches to EMERG do?
The electric boost pumps are powered by the PE bus
What buses power the electric boost pumps?
Left - PS1, Right - PS2
What is total fuel capacity of the 900XP?
10,000 lbs (8,500 lbs in wings, 1,500 lbs in ventral tank)
How is fuel normally distributed on the 900XP?
Jet pumps draw fuel into the #1 tank compartment, then the electric boost pumps deliver fuel under pressure to the same-side engine via the LP fuel cocks
What happens when the AUX FUEL TRANSFER lever is set to transfer?
With both boost pumps operating: ventral fuel transfers to both wings evenly
With one boost pump operating: ventral fuel transfers to side with operating boost pump
What happens if both boost pumps fail?
Fuel gravity feeds into the #1 compartment and is suctioned out by engine-driven fuel pump - ventral fuel not available
Where does the APU get fuel?
Left wing tank
What happens if the WING FUEL lever is set to the XFEED position?
Fuel from wing tanks are available to either engine
What happens if the WING FUEL lever is set to the TRANSFER position?
Opens the wing transfer valve and fuel will move to the side with the operating boost pump
What do the LP cocks control?
Low pressure fuel valves (one in each engine supply line, can isolate the engine fuel feed lines from the fuel tanks)
What do the HP cocks control?
The fuel valve at the engines
What does the FUEL 1/2 LO PRESS annunciator indicate, and when does it illuminate?
Indicates a low pressure condition when pressure in the engine fuel line falls below 7 psi
What does the AUX FUEL TFR annunciator indicate?
Illuminates when the AUX FUEL TRANSFER lever is moved to the open position
What does the REFUEL ON annunciator indicate?
Any refuel valve is open
What does the WING FUEL XFD/TFR annunciator indicate?
Illuminates when the WING FUEL XFEED TRANSFER lever is moved out of the closed position - in the TRANSFER position, the light flashes
Where is the fuel quantity read?
Right-side MFD, given in pounds
How does the ventral fuel quantity display?
FULL, EMPTY, or hatch marks when in between conditions
What is the maximum wing fuel imbalance?
500 lbs
What is the max wing fuel in order to transfer ventral fuel to wings?
3,300 lbs per side
What is the minimum wing fuel with fuel in the ventral tank?
3,450 lbs per side
What is maximum ventral tank capacity?
1,500 lbs
What is maximum wing tank capacity?
4,250 lbs per side
If one hydraulic engine-driven pump fails:
The hydraulic pressure indicator will display 3,000 psi, and the applicable low-pressure annunciator will illuminate
If both hydraulic engine-driven pumps fail:
Indicated pressure is 2,300 psi, and both low-pressure annunciators are illuminated
The main hydraulic reservoir is pressurized to prevent:
Pump cavitation
The first step in operating the auxiliary hydraulic system is to:
Pull the AUX HYD SYSTEM lever
The purpose of the pressure maintaining valve in the main hydraulic system is:
To maintain 2,300 psi in the main accumulator for normal brake operation
If one engine-driven hydraulic pump fails:
The remaining pump is capable of actuating all subsystems
Boost pumps are located in the:
Left and right wing tanks
There are _______ water drains in the fuel system:
Five
When the ventral tank contains fuel, a low VMO speed warning will sound whenever aircraft speed exceeds:
280 KIAS
Total usable fuel capacity is:
10,000 lbs
The maximum lateral imbalance permitted is:
500 lbs
With both boost pumps inoperative:
Ventral tank fuel cannot be transferred
IF the ventral tank is to be used in flight, it must be full, and each wing must contain more than:
3,450 lbs of fuel
The aircraft fuel system accepts a maximum refueling supply pressure of:
50 psi
