Hydraulics Flashcards
1
Q
Briefly describe the HYD systems.
A
- There are three separate HYD Systems - L, R, and C. The L and R are identical, and the C is considered “heavy.”
- The L & R are primarily powered by their respective EDPs and backed up by Electric Demand Pumps. The C System is Primarily driven by two Electric Pumps, and reinforced with an Air Driven Pump.
- Any one system can provide aircraft controllability.
- The Reservoirs are pressurized by the bleed air system.
2
Q
What items are Hydraulic Powered?
A
- L - Flt Ctrls
- R - PES, Norm Brks, Flt Ctrls
- C - E1 - Altn Brks, Nose Wheel Steering (ISLN VALVE)
- C - E2, ADP - LND GR, FLPS, SLTS, HDG, T-Skd, FLT CTRLs
- C - RAT - (CHECK VALVE) - FLT CTRLs
3
Q
How can the pilot see HYD QTY?
A
- EICAS Status Page
- RF = Re-Fill Prior to Dispatch
- OF = Overfill
4
Q
What does a SYS PRESS light indicate?
A
- That individual system has inadequate pressure.
5
Q
When does the HDG Activate? What Services are available?
A
- Dual Main Bus Fail.
- L/R TX, CA FLT INST, STBY AC/DC, HOT, BATT Busses.
- Everything L of ALTN GR, not including EICAS and AutoBrakes.
6
Q
What does an illuminated PRESS light indicate?
OVHT?
A
- That specific pump is not providing pressure.
- That specific pump is overheated?
7
Q
What does an illuminated QTY light indicate?
A
- Low Quantity (about 50%)
8
Q
When do Demand Pumps Activate?
A
- In AUTO, whenever there is high demand, or the primary pump is not providing adequate pressure.
- When selected ON.
9
Q
How much HYD Fluid do we need for dispatch?
A
- No “RF.”
- Approximately 75%
10
Q
If all three systems have been fucked, will the pilot still be able to break after landing?
A
- Yes, due to the standpipe in the Center System, and the Reserve Brakes.
11
Q
How does the HYD system’s design increase the probability of breaking and steering ability after fluid loss?
A
- There is a standpipe in the Center System that ensures fluid and an automatic isolation valve for the C1 Electric Pump, ALTN Brakes, and Nose Wheel Steering Systems to ensure integrity.
12
Q
Describe the RAT.
A
- Automatically actuated with a dual engine failure.
- Manually activated by pressing the button.
- FLT CNTRLs only.
- Green PRESS = good.
- Min speed 130 kts.
- “Inhibited” on ground.
- Auto deployment arms at 80 its and tilted mains.
13
Q
What is the procedure for HYD Pump Selection, and why?
A
- Counter Clockwise, slowly, start with R DEMAND ON.
- Clockwise, slowly, OFF.
- To Avoid transferring fluid.
