Hydraulic

Question 1

How many hydraulic systems does the airplane have and what do they power?

Answer 1

3 systems. 1,2,3. They power flight controls, spoilers, landing gear, nose wheel steering, wheel brakes, and thrust reversers.

Question 2

Normal nominal pressure of hydraulic systems

Answer 2

3000 psi

Question 3

CAn you transfer hydraulic fluid from one system to another?

Answer 3

No!

Question 4

How many pumps does each system have?

Answer 4

System 1 and 2 each have an Engine Driven Pump and an electric pump. The electric pump is used as backup.

System 3 has an A pump and a B pump. Both are Electric pumps. A is the primary and B is backup.

Question 5

What drives PTU?

Answer 5

System 1 pressure drives PTU

Question 6

Life cycle of fluids

Answer 6

Leave reservoir to manifold, where it is filtered, then to system components. From there they return to reservoir and are refiltered Depending on the temperature, part will be rerouted for cooling, or return without cooling

Question 7

What happens if there is a flame out?

Answer 7

Since the Engine Driven Pump relies on the engine gearbox, if there is an engine failure, the FADEC- logic will depressurize the respective EDP in order to reduce the torque loads on the engine and facilitate a windmill restart

Question 8

What powered the Electric pump?

Answer 8

AC BUS 2

Question 9

When does the electric pump activate on ground?

Answer 9

When:
- the flaps selected to any position greater than 00 and, the thrust levers are set to takeoff thrust, or the groundspeed is greater than 50kts.
The pump comes ON for the initial T/O roll, as to provide a backup hydraulic power source during the critical takeoff phase of flight

Question 10

Whend oes the electric pump activate?

Answer 10

• EDP failure
  -Flaps selected to any position greater than 0
  Will continue to operate until flaps retracted. AFter, will operate in flight only if EDP or engine failure

Question 11

What is the function of the accumulator?

Answer 11

Stores hydraulic pressure to help maintain constant system pressure during periods of high pump demands that naturally occur.
Additionally, they help maintain reservoir pressure to avoid pump cavitations.

Question 12

Components of system 2

Answer 12

EDP 2 ( engine driven pump ), electric pump, accumulator, and PTU

Question 13

What powers the system 2 electric pump?

Answer 13

AC BUS 1

Question 14

Purpose of PTU

Answer 14

Used pressure from SYSTEM 1 and uses fluid from SYSTEM 2 to generate pressure for SYSTEM 2. It’s function is to ensure adequate pressure is available for operating landing gear during critical phases of the flight

Question 15

Components of SYSTEM 3

Answer 15

Reservoir, 2 electric pumps, and an accumulator

Question 16

What does SYSTEM 3 power?

Answer 16

• Elevator
• Rudder
• Ailerons

Question 17

Primary source of SYSTEM 3

Answer 17

Hydraulic 3A Pump.

Question 18

Function of SYSTEM 3 accumulator

Answer 18

Will provide hydraulic power to the associated flight controls, from RAT deployment until the AC ESS BUS powers the system 3 ELEC PUMP A

Question 19

How does SYSTEM 3 avoid overload on RAT?

Answer 19

Has two dedicated valves. Pump Unload Valve and Flow Limiter Valve

Question 20

Function of Pump unloader

Answer 20

Used to reduce the discharge pressure of the electric pump A during its start-up. The reduction will reduce the pump torque and therefore reduce the electrical power required to start the pump.

Question 21

Function of ** Flow Limiter Valve**

Answer 21

Reduces the amount of Flow provided by the electric hydraulic pump A. Limits the electrical power theat the pump can draw and prevents the electric pump from causing the RAT to stall