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2H2E, 2 hydraulic systems with 2 electric backups

1. How many hydraulic systems are there

Green system is no.1 and Yellow system is no.3 at 5000 psi

2. What hydraulic systems are there and what pressure do they operate at


3. What chapter is the LEHGS system in

By the Green system EMP’s or the auxiliary hydraulic pump

4. How are the cargo doors opened

Yellow system EDP’s or the EMP’s as aux source

5. What hydraulic system does body wheel steering use in normal operation

EHA’s and EBHA’s in chapter 27 items and LEHGS in chapter 32

6. What is the backup source of hydraulic power

2x solenoids and a manual lockup pull ring on EDP are available for declutching

7. How many ways of turning off an EDP are there

No.5 flap boat fairing

8. Where are the Air Hyd heat exchangers located

",Fuel Hyd heat exchanger located in no.1 and 4 pylons

9. "If the Air Hydraulic heat exchanger fails, what other method of cooling is available

De-clutches both engine no.1 EDP’s together

10. If the Hydraulic Eng 1 A+B guarded switch on hydraulic panel is pressed inflight what does it do

",The EDP DISC indication must be cleared by an OMS test

11. "After an EDP clutch has been reset mechanically, what must be done

Case drain hydraulic fluid

12. What fluid goes through the air hydraulic heat exchanger

A pressure vessel containing a metal bellows with Helium gas at 2600 PSI on one side and hydraulic fluid at the other side

13. The high pressure accumulator is constructed how

"Cut the locking wire, undo the screw and turn the valve head emergency device with a spanner to allow dissipation of the high px helium"

14. What must be done before transporting a high pressure accumulator

Green sys no.2 pylon and yellow at no.3 pylon

15. Where are the hydraulic GND connections


16. Which hydraulic system normally operates NWS


17. Which hydraulic system normally operates BGS

2x pylon 2(green) and 2x pylon 3(yellow)

18. Where are the EMP’s located

"Gnd source, 4x EMP’s and cargo door aux pump"

19. What are counted as auxilary hydraulic sources


20. What are counted as backup hydraulic sources for chapter 32

Local Electrical Hydraulic Generation System

21. What does LEHGS stand for

8 EHA’s and 6 or 8 EBHA dependant on mod state

22. What backup sources of hydraulic power are there for flight controls

High jet 5

23. What type of hydraulic fluid is used

",2 fully independent (no PTU) systems at 5000psi (green and yellow system).

24. "How many hydraulic systems, what pressure and what are they called

Local electro hydraulic generation units. Flight controls via EHA and EBHA braking and NWS through LEHGS (local electro hydraulic generation system).

25. What fulfils the part 21 requirement of 3 hydraulic systems

"2 modes (auto and manual, HSMU managed) auto cargo door (green), Body wheel steering (yellow). Active mode has priority. (note, only one pump operates)"

26. How many modes of operation do EMP have? What has priority

At rear of hydraulic pylons. (2G and 3Y)

27. Where are the ground cart connections

Each engine has fire shut off valve upstream of EDP’s.

28. What will stop supply of hyd fluid to EDP’s if engine fire occurs

"Hydraulic system monitor unit (1 for green system, 1 for yellow system). In MEC (not CPIOM function) totally independent of each other."

29. What is the HSMU? Where located? And how do they operate with each other

ENG 1 and 4 pylons.

30. Where are the hydraulic reservoirs located.

"In ENG 2 and 3 pylons, 2 per system"

31. Where are EMP’s located

","Main = EDPs, AUX = EMPs and back is via LEHGS, EBHAs and EHAs"

32. "What will supply main, Aux and back up hyds

"Cannot, no EMPs if HSMUs fail"

33. How would EMP operation be achieved if HMSUs fail

AIR/HYD heat exchanger located in flap track fairing #5

34. What is the primary method of hydraulic fluid cooling

FUEL/HYD heat exchanger located in outboard pylons

35. What is secondary method of hydraulic fluid cooling

"Signals form HSMU, no back up"

36. Where do the GSP HYD indicators get signal from? What is back up

), Odd flt # is pump A, Even flt # is pump B"

37. "In auto mode how many pumps will run (EDPs), how decided?","Only one pump per engine will run, decided by flight number (

"Only PUMP A (green, cargo door ops)"

38. Which EMP is powered by the GND service bus directly for opening the cargo doors

","‘ON’ illuminated in P/B on maint panel, SD will show filled green arrow for pump in operation (not connected line as this is shown when man)"

39. "When EMP is running in auto mode for cargo doors operation, what flight deck indications are there

"HSMU-G is DC BUS 1 and DC GND SVC BUS, HSMU-Y is DC BUS 1 and DC BUS 2"

40. What are the power supplies for HSMU G and Y

Each EDP has a dedicated Px switch that will illuminate a PB fault light and Indication on SD HYD page (all via HSMUs) (PX transducer can carry out function as back up)

41. How is an EDP P/B fault light indication achieved

","2 accumulators, L/H (green) in L/H WLG wheel well and R/H (yellow) in R/H WLG wheel well. Cannot be serviced on aircraft (will only hold px for 4 seconds)"

42. "How many hydraulic system HP power accumulators, where located and how is servicing carried out

"Primary – via dedicated engine (#1 green) (#4 yellow) via RASC, Second – Pneumatic px (via central manifold), Third – Manual/ground cart (via central manifold)"

43. What are the 3 methods of reservoir pressurisation

Switches at GSP (elec) or sprung P/B depress valve at reservoir

44. What are the two methods of reservoir depressurisation

Fluid temperature (reservoir temp sensor)

45. Regarding reservoir hydraulic quantity what is the value measured by the transmitter compensated by before display

",Movable index on ECAM SD and sys quantity indicator at GSP

46. "Fluid level status of ATA 32 LEHGS reservoirs and their HP accumulators , Where can hydraulic system quantity nominal value be displayed

"ECAM SD, GSP reservoir indication test and sight glass at reservoir (degrees C/degrees F)"

47. name 3 available methods of viewing reservoir level

"Display white with an amber cross at fixed position (20degrees, 45.2 litres)"

48. If ATA 32 LEHGS volumes not available or invalid what is the CDS display

",Electrical and mechanical clog indicators

49. "What type of clog indicators do the HP, return and case drain filters have

",Class 4 message which will become class 1 fault after 700 hours

50. "What indication would be received if any of the HP, Return or CD filters have clogged filters

"Mechanical clogging indicator only, not elec monitored"

51. What type of clog indicator does the reservoir filling filter at have

Return filters

52. Which hydraulic filters have a bypass device

"12 total, 4 EMP, 4 Air/HYD heat EXCH (EDP), 2 flap PCU, 1 slat PCU, 1 THS"

53. How many seepage bottles total and where

"Fans are installed downstream of each dual matrix heat exchanger (therefore 2 fans), the fans are driven by hydraulic motors and electrically controlled"

54. How is sufficient air supplied to the AIR/HYD heat exchangers (in flap track fairing 5) on the ground and in low speed conditions? How driven/controlled

If electrical power is lost or system is de-energised the fans will run as the solenoid is energised to stop the fans

55. Explain the ‘fail safe’ operation of the fans in the air/hyd heat exchangers

"Operation will de clutch EDP A and B for particular engine, cannot re-clutch in flight,only manually with engine shut down"

56. What is the function of the (HYD) ENG x A+B red guarded P/B switch on the HYD overhead panel

"2, (x1 depressurise, x1 declutch)"

57. How many solenoids are there per EDP

"HYD panel P/Bs, fire switch and EECs"

58. What can depressurise EDP

Pull ring on each EDP assembly

59. How would you de-clutch a single EDP for dispatch

By using a dedicated function in the OMS (ENG pump DISC indication clear)

60. When an EDP has been re-clutched how would you clear the ‘DISC’ light in the P/B and ‘DISC’ on SD page

Would just de pressurise that particular EDP

61. What would operation of the ENG(x) A or B P/B cause

"At reset port on EDP, check ‘ON’"

62. How would you physically check EDP clutch

HSMU will inhibit during flight

63. What will stop inadvertent operation of the GSP reservoir depressurisation switch

Gives priority to essential users when hyd pressure is low Mechanical spring loaded valve that will shut off supply to WLG at 3200 PSI

64. What is the purpose of the WLG priority valve

","Other green system users are not supplied, solenoid ports pressure to cargo doors only"

65. "In EMP auto operation, how are other green system users supplied in normal configuration

(over speed, over temp and phase imbalance)","Each hydraulic system has 1xMCPU in main avionics, MCPU will control 1xMSU"

66. "How is EMP control and protection achieved

",Near EMPs in pylons number 2 and 3

67. "(Motor Switching Unit) (contactor) which is an electrical shut off device for EMPs, Where are MSUs located

If ambient temp is greater than 75 degrees class 1 message is triggered by FWS (to protect against hot air leakage damage from heat exchanger bellows)

68. What is the purpose of the 2 ambient temp sensors located in flap track fairing 5

"There are 4 in total, 1 Main Leak Measurement Valve (MLMV) and 3 identical LMVs, When MLMV energised flow is directed to 3 LMVs and main sys isolated, LMVs will direct flow to areas of aircraft when energised, operated remotely via OMS, used to monitor flow rate to find internal leaks"

69. What are the HP belly fairing manifold Leak Measurement Valves (LMV)

Sprung closed

70. What will be the position of the LMV when de energised

"Onside (green to AC bus 1 & 2, yellow to AC bus 3 & 4) and green has Ground Service for cargo door operations."

71. What are the power supplies for the hydraulics

"Green - cargo door, Yellow - Body Wheel Steering"

72. What will the yellow and green EMP’s automatically run for

"From no.1 engine air via RASC, the pneumatic system or from an external source via the GSP"

73. Where can the reservoir pressurization air come from for the green system

",The needle will point to 0 in the centre of the green area

74. "On the GSP reservoir filling gauge, what would you see if the system is correctly filled


75. How many pressure switches are fitted to the green HP belly fairing manifold

"With the EMP’s in pylons 2 or 3, there is 1 per EMP"

76. Where does the MSU live and how many are there

They live just inside the entry door to the main avionics bay from the fwd cargo bay. There is 1 per system

77. Where do the MCPU’s live

At least 2 ground powers

78. How many ground powers are required to run an EMP in each system