Fuel System Flashcards
During refueling tank venting occurs through VENT VALVES. How are they controlled?
Two VENT VALVES are electronically controlled by a lever next to the refueling coupling or by the gravity fueling switch on the maintenance panel (copilot’s sidewall),
When VENT VALVES are commanded OPEN or CLOSED, what is the sequence?
Left then right
LP bleed air from which engine(s) pressurize the fuel tanks?
ENG 1 and ENG 2
How is FUEL TANK PRESSURE regulated?
The air pressure in the tank is regulated by a pressure reducing valve, located downstream of the engine bleed air system, and two negative pressure relief valves at the wing tips.
Fuel tank pressurization is completely automatic. This system maintains how much pressure?
About 3 psi equally in all tanks.
When will the FUEL LEVEL light illuminate?
1) When fuel level in tank group 1 or tank group 3 is less than 1,000 lbs.
2) When fuel level in tank group 2 is less than 1,100 lbs.
When will LO FUEL 1-2-3 illuminate?
When level drops below 200 lbs.
When the button at the base of the FUEL FLOW indicator is pulled, it resets the fuel used counter to 0. What happens when this button is pushed?
The display becomes an instantaneous digital readout of fuel flow for 30 seconds then reverts to normal fuel used.
What is the purpose of the FUEL FLOW TEST button, located on the maintenance panel?
The FUEL FLOW TEST button is used to test instrument operation (needle slews to 1,200 lbs/hr.)
FUEL SHUTOFF VALVE POSITION LIGHTS when illuminated, indicate what?
TRANS, comes on to signal a discrepancy between the position of one of the valves and that of its control switch.
What is indicated when FUEL 1-2-3 annunciator lights illuminate?
Illuminate when pressure switches on the engine supply lines sense pressure below 4.64 psi.
What is indicated if the XTK light, which is located above the control switch of tank 1 and 3 interconnection valve on the overhead panel, illuminates?
Illuminates to signal that this valve is not CLOSED.
FUELING light illuminates in flight, what is indicated and what should be done?
Indicates, among other things, the non-closure of one or both vent valves and loss of tank pressure.
If possible, reduce airspeed. Avoid any nose high nose up or nose down attitudes and rapid changes in pitch and roll. Monitor the fuel quantity indicators to detect any fuel loss; shorten the flight, if necessary, to prevent loss of fuel through the air vents.
What should be done if FUEL 2 light illuminates in flight?
Set the BOOSTER 2 switch to ST-BY. This turns on the second booster pump associated with the center tanks group.
Pressing the TEST button during fueling should stop the fuel within:
5 seconds
What refueling operations can be accomplished using only the BATTERY BUS alone?
Pressure refueling only.
