Systems - HYD/Gear/Brakes Flashcards
What type of Hydraulic Fluid do we use? What color is it?
Skydrol, purple in color.
What is a core principle regarding compressibilty of Hydraulic Fluid
Must be non-compressible.
What are the two main principles of an accumulator?
1) Works as a shock absorber
2) Stores energy which is used when the system pressure decreases.
How many Hydraulic Systems do we have on the EMB-145? How many pumps per system?
2 systems, and 2 pumps per system (1 engine driven and 1 electric).
What is the normal system pressure for the Engine Driven Pump? For the Electric Pump?
1) Eng Driven - 3000 psi
2) Electric - 2900 psi
When will the electric pump turn on automatically?
When in the AUTO position and:
1) Associated Engine drops below 56.4% N2 (Eng Fail)
2) When system pressure drops below 1600 psi.
What is the biggest difference between the Eng. Driven pump and electric pump?
Volume, the Eng driven pump is capable of putting out 10 times the volume of the electric pump.
Where is the Engine Driven Hydraulic Shutoff located? How do you close the valve?
1) Located FWD of the engine driven pump
2) Two ways to close
- Pull Fire Handle
- Eng Pump Shutoff button
Where is the Hydraulic Mule (Cart) Service Point?
External Power Supply which is located on their respective side in the fuselage at the trailing edge of the wing root.
What components does the HYD 1 system supply
Brakes (outboard)
Rudder
Ailerons (Both sides)
Thrust Reversers (on side)
Spoilers (Inboard)
Steering (Nose Wheel)
Landing Gear
What components does the HYD 2 system supply?
Brakes (Inboard)
Rudder
Ailerons (Both Sides)
Thrust Reverser (On Side)
Spoilers (Outboard)
Brake (Emergency/ Parking)
What does the term Mechanical Reversion refer to with respect to the Hydraulic System. What sytems will Mechanically Revert?
1) If the HYD system fails, the systems (Rudder and Aileron) will revert to mechanical operation (Cables)
How do you bring the gear down in the event of the HYD system failure?
Free Fall - use Landing Gear Freefall handle.
What system(s) is on the No 1 Acumulator?
The landing gear.
What system(s) is on the No 2 Acumulator?
Parking/ Emergency Brake
How many applications does the No2 accumulator have on the emergency brake? How long is the hold time?
1) 6 applications
2) 24 hours of hold
What indication will you get in the cockpit when the Parking Brake is set. How many lbs of pressure will activate the Parking Brake
“Brake On” light will come on.
149 lbs of pressure will activate it.
What does the Priority Valve do?
Prioritizes flight controls over landing gear by restricting flow of fluid to the gear when operating the landing gear on the electric Hyd Pump.
What system is the Priority Valve on. Give an example of when it will prioritize?
Only on system 1 and will prioritize when you have a #1 engine failure on Takeoff
What kind of pump is the engine driven pump, what capability does it have with respect to variation of fluid flow?
Piston driven pump that varies the amount of fluid flow based on required draw.
What kind of pump is the electric pump? What are its limitations
Impeller pump with one flow setting (does not vary based on draw) and can’t keep up with high loads (ie. gear retraction).
Where is the FWD Hydraulic accumulator located and what system does it supply?
Right side FWD near the FO window. Supplies the No 1 system.