NATOPS - Hydraulic System Flashcards
What does HYD 1 provide hydraulic power for?
Ailerons, Stabilator, flaps, slats, speed brakes, landing gear, nose wheel steering, wheel brakes, arresting hook, and launch bar
What is the hand pump provided for?
Ground testing the general services, and
Charging the wheel brake/emergency flap accumulator
What does HYD 2 provide hydraulic power for?
Aileron and stabilator controls, and
is interconnected with the RAT system
Describe the hydraulic pumps
Engine driven, constant pressure, variable displacement type pumps that maintain 3000 psi
How many accumulators are there and what are their functions
Four; Two accumulators (one for each system) provides back up power sources for the primary flight controls during periods of high demands; another provides emergency power to the wheel brakes and flaps; Another provides power for RAT actuator
When does the HYD caution light illuminate and extinguish
It illuminates if the pressure falls to 1,660 ±110 psi, and extinguishes when pressure increases above 2,000 psi
What does the power supply package consist of?
Check valves, a pressure relief valve, and a priority valve
At what pressure does the pressure relief valve open?
3,600 psi
***What is the function of the priority valve?
If the pressure falls to below 1,500 ±100 psi, the priority valve closes to isolate general services from the system to maintain supply to the flight controls
What happens if the reservoir is over pressurized?
A pressure relief valve in the reservoir line bleeds fluid overboard
What is the purpose of the bypass valve?
To return pump pressure when the engine rpm is below 42 percent to reduce engine loads during engine start
How do you close the bypass valve?
Depress the HYD 2 RESET pushbutton in either cockpit with engine rpm above 45 percent
What are the indications of RAT operation?
Illumination of the RAT caution light and a cycling of the HYD 2 pressure indicator between 2,500 to 3,000 psi
How is the RAT stowed?
The RAT can be reset by pressing the HYD 2 RESET button in either cockpit. With HYD 2 pressure above 2,000 psi, sufficient pressure is available to reset the RAT shuttle valve, retract the RAT and restore normal HYD 2 operation. The RAT can be stowed at any airspeed.
***Prior to engine start, what should the brake pressure indicator read?
1250 psi minimum
