Hydraulics and Fuel Flashcards
BTFANGS
Brakes
Thrust Reversers
Flaps
Airbrakes
Nosewheel Steering
Gear
Stick Pusher
how is hydraulic power provided
variable volume, engine driven pumps
not “on demand”
if one hydraulic pump fails what systems fail
none - either pump can operate all systems
why is the hydraulic system pressurized
prevent foam and provide positive flow of fluid
what operates the on-off hydraulic valve
HP Cocks
HYD OVHT at what temperature
90C
where to check hydraulic fluid level
aft equipment bay
LO PRESS extinguishes at / starts at
1750 psi
1500 psi after 57 second delay
normal hydraulic system pressure
3000 psi
if there is no hydraulic pressure
pressure maintaining valve closes to try to provide 2300 psi for brake operation
auxiliary hydraulic system
6 pint tank
hand pump in flight deck
what does the auxiliary hydraulic system allow the hawker to do
lower landing gear
operate flaps
(enough to fully extend flaps and lower gear)
how many tank sections are there
6 per wing
boost pumps
if only one is operating it will only go to the side with the operating tank
takes 10 minutes with two pumps
18 minutes with one pump
XFEED
opposite tank feeding engine
TRANSFER
opens wing transfer valve and fuel will move to side with operating boost pump
what are boost pumps powered by
PS
what is the Emergency boost pump powered by
PE bus
FUEL LO PRESS
fuel line below 7 psi
Fuel Quantity
right MFD
fuel limitations
fuel cannot be in the ventral tank unless wings each have 3450 lbs
ventral must be full or empty
500 lbs max imbalance
ventral tank must be transferred when each wing reduces to 3300 lbs
ventral tank must be empty for landing
what are the hydraulic pumps
1 engine driven
aux
hand pump
hydraulic pressurization
over pressure 4000 psi
normal pressure 3000 psi
trapped if pumps fail 2300psi
low pressure out 1750
low pressure on. 1500 psi (for 57 seconds)
hydraulic accumulators
main 1000 psi
brake 1000 psi
thrust reverser 1500psi
ponds of fuel is equal to what percent @ 6.7 lbs
15
fuel pumps
jet pumps (4)
boost pumps (2)
engine driven (2)
fuel jet pump description
no moving parts
no electricity
vacuum system
use motive flow off boost pumps
fuel boost pump description
can turn off / on
only controllable pumps
cons of engine driven pumps
if it fails, we fail
provides pressure for fuel to get atomized
where are the fuel annunciators
overhead panel above pump switches
max fuel in order to transfer ventral fuel to wings
3300lbs
minimum wing fuel with fuel in the ventral tank
3450lbs
ventral tank quantity
1500 lb
where is the fuel quantity read
right (copilot) mfd
how long does fuel transfer take
10 minutes or 18 with single boost pump
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 kts
Total usable fuel capacity is
10,000lbs
the maximum lateral imbalance permitted is
500lbs
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
3450lbs fuel
the aircraft fuel system accepts a maximum refueling supply pressure of
50psi
when using the auxiliary system, landing gear should always occur before or after the operation of flaps
before
pulling the AUX HYD SYSTEM lever
disengages balk arm, freeing hand pump for operation
closes on-off valve to block main system pressure and connect landing gear actuators to the reservoir return
landing gear handle no longer controls gear movement
when can the hand pump action be stopped
once all three greens are on and positive resistance is felt to ensure landing gear is down and locked
if one engine driven pump fails ( in relation to what the pressure indicator will show)
the hydraulic pressure indicator will display 3000psi and the applicable low pressure annunciator will illuminate
if both engine driven pumps fail
indicated pressure is 2300 and both low pressure annunciators are illuminated
the main hydraulic reservoir is pressurized to prevent
loss of wheel brakes
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 2300 psi in the main accumulator for normal brake operation
if one engine driven pump fails:
the remaining pump is capable of actuating all subsystems
