Fuel, Main Transfer System – Auto Control

ATA28
  • The main transfer system controls the flow of fuel from the center (transfer) tank to the two wing tanks. The system uses jet pumps to move the fuel from the center (transfer) tank to the wing tanks.
  • The Fuel Level Sensing Control Unit (FLSCU) automatically controls the system, but the crew can, if necessary, manually control it from the cockpit.
  • The Engine/Warning Display (EWD) and the System Display (SD) (which together make the ECAM) give main transfer system information to the crew. If specified failures occur:
    • a warning is given on the EWD
    • the FUEL page shows on the SD.
  • When the control valve is open, fuel from the main pumps flows through the control valve and a nozzle in the jet pump 157QM(158QM). The flow of fuel through the nozzle causes a suction in the jet pump. This suction removes the fuel from the center (transfer) tank, through the strainer 220QM(221QM), and moves it (together with the fuel from the main pumps) to the related wing tank.
  • The crew can control the transfer system from the cockpit through the CTR TK XFR and the MODE SEL P/BSWs on the control panel 40VU. When the MODE SEL P/BSW (4QL) is released out (MAN), the automatic control of the transfer system stops. In this configuration, when the CTR TK XFR P/BSWs (5QL, 6QL) are pushed in (ON), the related control valve is opened and transfer starts. When the CTR TK XFR P/BSWs are released out (OFF), the related control valve is closed and transfer stops.
  • The control valve 153QM(154QM) is attached to the bottom skin of the center (transfer) tank as follows:
    • the LH control valve between FR36 and FR42 (LH side)
    • the RH control valve between FR36 and FR42 (RH side).
  • The jet pump 157QM(158QM) and its related strainer 220QM(221QM) is attached to the bottom skin of the center (transfer) tank as follows:
    • the LH jet pump and strainer between FR36 and FR42 (LH side)
    • the RH jet pump and strainer between FR36 and FR42 (RH side).
    • A check valve is installed in the end of the transfer pipe. The check valve stops the movement of fuel from the wing tank collector-cell to the center (transfer) tank.
  • The jet pump has:
    • an inlet body
    • a jet pump body
    • a jet nozzle
    • a non-return valve
    • an outlet body.
  • The jet pump body is connected to the inlet body and the outlet body. The jet pump body fully contains the jet nozzle. The jet pump has two fuel inlets: the pressure inlet and the suction inlet. When fuel from the pressure inlet goes through the jet nozzle, it causes a suction at the suction inlet. The flow of fuel goes through and out of the jet pump outlet body. The non-return valve prevents an opposite flow through the jet pump.
  • Final :
    • Jet Pump có 2 đường inlet , 1 đường pressure inlet từ Main Fuel Pump , đường thứ 2 là suction inlet , đường suction được tạo ra từ lực hút do pressure inlet qua jet nozzle gây ra.
    • Đường suction fuel phải đi qua 1 cái lọc và 1 cái non-return valve từ Center Tank tới Wing Tank.
    • Muốn hút sang bên nào phải bật Main Fuel Pump bên đó.
    • MODE SEL P/BSW (4QL) được nhả , chế độ là Manual.
  • The actuator has an electrical motor that drives a differential gear to turn the ball valve through 90 deg. Limit switches in the actuator control this 90 deg. movement and set the electrical circuit for the next operation. A V-Band clamp attaches the actuator to the flange of the drive assembly. A location peg makes sure that the actuator engages correctly. The see/feel indicator gives an indication of the valve position without removal of the actuator.
  • Fault :
    • The FAULT annunciator of the MODE SEL P/BSW will only come on in the AUTO configuration. If the FAULT annunciator of the MODE SEL P/BSW comes on, the P/BSW must be set to MAN. The crew then have manual control of the main transfer system.
    • The FAULT annunciator of the CTR TK L XFR (CTR TK R XFR) P/BSW can come on in the AUTO or the MAN configuration. If a FAULT annunciator of one of the CTR TK XFR P/BSWs comes on, that P/BSW must be set to OFF.
    • If one of the CTR TK XFR P/BSWs is set to OFF:
      • fuel will transfer from the center (transfer) tank to one wing tank only
      • the crew must crossfeed fuel  from one wing tank to the other to keep the aerodynamic balance of the aircraft.
      • Gravity transfers fuel from the center (transfer) tank if the the two CTR TK XFR P/BSWs are set to OFF. Fuel only gravity transfers to the wing tanks when the level of fuel in the center (transfer) tank is greater than that in the wing tanks. When gravity transfer is in operation, approximately 2000 kg (4409 lb) of unusable fuel will remain in the center (transfer) tank.
  • Một trong các nguyên nhân của FUEL CTR R(L) XFR FAULT
  • Final :
    • Đèn Fault của MODE SEL chỉ sáng trong chế độ AUTO , nếu đèn FAULT sáng , phải nhả về chế độ MANUAL.
    • 2 center tank control valve ( CTR TK L XFR (CTR TK R XFR) ) có thể FAULT ở cả 2 chế độ MANUAL và AUTO . Nếu FAULT thì phải OFF.
    • Nếu chỉ 1 CTR TK XFR Fault , valve còn lại ok , phải dùng crossfeed valve để duy trì cân bằng khí động của máy bay.
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