Hydraulic Flashcards
What is the capacity of the main system reservoir?
2.4 US GAL
What type of fluid is used?
MIL-H-5606C
What pressurizes the hydraulic reservoir system?
Engine bleed air
What does a HYD OVHT annunciator indicate?
Fluid temperatures in excess of 90C
What does a HYD # LO PRESS annunciator indicate?
Main supply low pressure warning, <= 1500 PSI
What does an EMERG BRK LO PRESS annunciator indicate?
Emergency brakes low pressure warning. Pressure <= 2250 PSI
What is the power source of the hydraulic pressure indicator?
DC electric
What happens to the hydraulic pressure indicator if DC electric power is lost?
Indicator shows OFF
What position must the airbrakes be in IOT properly sight the fluid level gauge?
Airbrakes must be shut
What pressure should the HYD TANK pressure gauge show?
15 PSI
When starting the engines, at what point will the HYD # LO PRESS annunciator extinguish?
1750 PSI
What pressure should the system stabilize at?
3000 PSI
How long is the delay before the low pressure switch activates a low pressure annunciation?
57 seconds?
What can cause both low pressure annunciators to illuminate?
If both pumps fail or if system fluid is lost
What pressure should the pressure indicator show if both pumps fail or if system fluid is lost?
2300 PSI
Why will the pressure indicator show 2300 PSI in the event of system fluid loss or a dual pump failure?
The pressure-maintaining valve has closed, trapping pressure in the main accumulator for normal brake operation
In the event of a dual pump failure or system fluid loss, what system should be available?
Normal brakes
In the event of a dual pump failure or system fluid loss, what systems can be operated by the AUX hydraulic system?
Landing gear and flaps
Is there any indication for system fluid loss?
No
How can system fluid loss from a subsystem be detected?
An abnormal drop in pressure as that subsystem is activated
Can flight be continued in the event of a HYD OVHT indication?
Yes, however fault must be corrected prior to the next flight
How is the AUX hydraulic system pressurized?
The hand pump
What is the capacity and location of the AUX hydraulic tank?
6 pints, located in the nose gear bay
What AUX hydraulic fluid level reduction will result in an AUX HYD LO LEVEL annunciation?
> = .5 pints
Is lowering of the landing gear available via the AUX HYD system if the landing hear position handle is in the up position?
Yes
What must you do first in order to lower the flaps via the AUX HYD system?
Place the flap position lever in the appropriate position
When using the AUX HYD system, what system is always actuated first?
The landing gear
Can the AUX HYD system be used to retract the landing gear?
No
What operations should the AUX HYD reservoir provide sufficient fluid to conduct?
Lowering the landing gear, lowering then retracting the flaps
CAUTION: If the AUX HYD system selection has been made following a main system failure, can you reset the AUX system in flight?
No
CAUTION: What can reseting the AUX HYD system after failure of the main HYD system result in?
Collapsing of the landing gear
What does pulling the AUX HYD SYSTEM lever do?
Releases the balk arm, freeing the hand pump
Closes the on-off valve, allowing hand pump pressure buildup
Positions the dump valve to block main system pressure and to connect main landing gear actuators to the reservoir return
Landing gear handle no longer controls gear movement
CAUTION: When lowering the main landing gear via the AUX HYD SYSTEM, how long must pump action be continued?
Until three greens are achieved AND positive resistance is felt to ensure gear is down and locked
What are the seven hydraulic subsystems
Landing gear Flaps Airbrakes Nosewheel steering Brakes Stick pusher Thrust reversers
What five hydraulic annunciators are powered by the PE bus bar?
HYD 1 LO PRESS HYD 2 LO PRESS AUX HYD LOW LEVEL EMER BRAKE LOW PRESSURE HYD OVHT
What hydraulic electric indicator(s) are powered by the PS2 bus bar?
Main SUPPLY pressure indicator
