Hydraulics Flashcards
A. The airplane has three independent hydraulic systems to provide power for:
Spoilers Nose wheel steering Landing gear Wheel brakes Thrust reverser Flight controls
hydraulic fluid ____ be transferred from one system to another. All three systems use skydrol hydraulic fluid and operate at a nominal pressure of ____
psig
cannot
3000 psig
POWER TRANSFER UNIT (PTU) CONTROL KNOB (ROTARY ACTION)
OFF:
AUTO:
ON:
OFF: turns the PTU off.
AUTO: allows the PTU to operate automatically, according to hydraulic system logic.
ON: operates the PTU continuously, overriding the hydraulic system logic.
SYS 1 AND SYS 2 ENGINE PUMP SHUTOFF VALVE BUTTONS
(GUARDED)
Pushbuttons:
Pushbuttons:
Closes the hydraulic shutoff valve (SOV), isolating the respective engine driven pump (EDP) from the associated hydraulic system
SYS 1 AND SYS 2 ELECTRIC HYDRAULIC PUMP SELECTOR KNOBS
(ROTARY ACTION)
OFF:
AUTO:
ON:
OFF: turns the associated electrical pump off.
AUTO: allows the associated electrical pump to operate
automatically, according to hydraulic system logic.
ON: operates the associated electrical pump continuously, overriding the system logic.
SYS 3 ELECTRIC HYDRAULIC PUMP B SELECTOR KNOB (ROTARY
ACTION)
OFF:
AUTO:
ON:
OFF: turns the electrical pump off.
AUTO: allows the electrical pump to operate automatically,
according to hydraulic system logic.
ON: operates the electrical pump continuously, overriding
the system logic.
SYS 3 ELECTRIC HYDRAULIC PUMP A SELECTOR KNOB (ROTARY
ACTION)
OFF:
ON:
OFF: turns the electrical pump off.
ON: turns the electrical pump on.
Hydraulic System 1 is comprised of
one reservoir,
one Engine-Driven Pump (EDP 1),
one electric hydraulic pump and
two accumulators.
Hydraulic System 1 supplies
the following systems:
Rudder (upper actuator)
Elevator (left hand outboard actuators)
Thrust reverser (engine 1)
Multi-function spoilers (left and right panels 3 and 4)
Ground spoilers (left and right panel 2)
Outboard brake
Emergency parking brake
The hydraulic systems 1 and 2 are equipped with an overheating protection system. When the hydraulic fluid temperature increases to ___°C, the HYD 1/2 HI
TEMP EICAS caution message will be displayed.
If the fluid temperature reaches ___°C, the shutoff valve (SOV) will automatically actuate, thus isolating the EDP 1/2 from the respective hydraulic flow line.
In the event of hydraulic system overheat (fluid temperature above ___°C), the HYD 1/2 OVERHEAT EICAS warning message will be displayed. In this
case, the SOV can be manually commanded through a guarded pushbutton on the hydraulic system control panel.
100°C,
125°C,
145°C.
The EDP 1/2 is connected to the engine 1/2 ______ and it is the _____ for Hydraulic System 1/2. Its normal operation requires no pilot action.
accessories gearbox
primary power source
The Electric Hydraulic Pump 1 (ACMP 1B) is an alternating current motor pump. It serves as a ____for the EDP 1 and it is powered by the _____
The Electric Hydraulic Pump 2 (ACMP 2B) is an alternating current motor pump. It is used as a ____for the engine driven pump (EDP 2) and it is powered by the_____
backup
AC BUS 2.
backup
AC BUS 1.
In FLIGHT, with the selector knob set to AUTO position, the Hydraulic System logic activates the electric pump in case of:
(a) ______, or
(b) ______.
(a) EDP or engine fail, or
(b) Flaps selected to any position greater than 0°.
On GROUND, with the selector knob set to AUTO position, the Hydraulic System logic activates the electric pump in case of:
Flaps selected to any position greater than 0° and:
(a) Thrust levers set to takeoff thrust, or
(b) Ground speed greater than 50 kt
Also, during takeoff when thrust levers are set to TOGA, the Electric Hydraulic Pumps will be activated for ___s to avoid abrupt hydraulic pressure variations in an event of engine failure.
60 s