GOL 737-8, Руководство по эксплуатации

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737 MAX Flight Crew Operations Manual
Engines, APU -
Engine System Description
MN-FLT-OH-201 7.20.7
Engine Fuel System
Fuel is delivered under pressure from fuel pumps located in the fuel tanks. The
fuel flows through a spar fuel shutoff valve located at the front wing spar. The fuel
passes through the low pressure stage engine fuel pump where pressure is
increased. It then passes through a fuel strainer, the main fuel/oil heat exchanger
where engine oil heats the fuel, the high pressure stage fuel pump and a fuel filter
which removes contaminants. Fuel automatically bypasses the filter if the filter
becomes saturated. Before the fuel bypass occurs, the fuel FILTER BYPASS alert
illuminates on the fuel control panel. Fuel then passes through the fuel metering
unit (FMU), fuel flow transmitter and split control unit (SCU). To meet thrust
requirements, the EEC meters fuel through the FMU.
The spar fuel shutoff valve and engine fuel shutoff valve in the FMU allow fuel
flow to the engine when both valves are open. The valves are open when the
engine fire switch is in and the start lever is in IDLE. Both valves close when
either the start lever is in CUTOFF or the engine fire switch is out. SPAR VALVE
CLOSED and ENG VALVE CLOSED lights located on the overhead panel
indicate valve position.
Fuel flow is displayed on the display unit and is also provided to the flight
management system (FMS).
Note: Fuel flow accuracy is reduced when engines are at idle which will affect
the Fuel Used Readout.
Engine Oil System
Oil from the individual engine tank is circulated under pressure, through the
engine to lubricate the engine bearings and accessory gearbox. The oil quantity
indicator, oil temperature indicator, oil pressure indicator and LOW OIL
PRESSURE alert are all located on the display unit.
The oil system is pressurized by the engine driven oil pump. Oil from the pump
goes through a filter element, servo fuel heater, air cooled oil cooler, and main oil
/fuel heat exchanger to the engine bearings and gearbox. If the filter becomes
saturated with contaminants, oil automatically bypasses the filter. Prior to the oil
bypassing the filter, the OIL FILTER BYPASS alert illuminates on the Engine
Display.
Temperature and pressure sensors provide signals to the EEC for oil temperature
and pressure indications and the LOW OIL PRESSURE alert.
Engine driven scavenge pumps draw oil out of the gearbox and sumps and return
it through the air/oil/debris separator to the oil tank.
March 1, 2021