NATOPS - Fuel system Flashcards
How much usable fuel does the integral wing tank and fuselage tank hold total?
427 gallons
When are the fuel boost pumps turned on?
(1) During GTS operation, or
(2) when the engine speed is greater than 42 percent, the aircraft generator is ON and the ENGINE switches are set to ON.
Name the different tanks and compartments.
Fuselage tank (bag type), wing tank (integral), collector tank (center section of wing tank), negative-g compartment (fwd part of collector tank)
What is the purpose of fuel tank pressurization?
Reduce tendency of fuel to boil at high altitudes, and to keep the collector tank full until all other fuel is exhausted.
How much unusable or trapped fuel is there?
About 11 gallons
What happens if both boost pumps fail in flight?
A bypass valve is installed on the manifold which allows the engine driven fuel pump to suction feed directly from the bottom of the negative-g compartment
Will the boost pumps be powered if the generator fails?
They will continue to operate for 30 seconds after generator failure.
What happens to the boost pumps if an Engine switch is selected to OFF?
The No 2 pump shuts down after 30 seconds
***What is the purpose of the fuel shutoff valve?
To isolate the aircraft fuel system from the engine and GTS systems in the event of an emergency
What components does the Fuel flow transmitter send a signal to?
Fuel flow indicator, ASDC or DDS, DEU (Engine display)
What type of probes does the fuel quantity indication system use?
Capacitance type fuel probes
What turns on the FUEL caution light?
A float switch in the negative-g compartment which closes when the usable fuel falls below about 350 lbs ( 10 second delay). Totally separate from fuel quantity indication system
What does the pressure control valve do?
Regulates bleed air to the fuel tanks at 6 psig above datum (ambient) pressure.
***What causes the F PRES caution to illuminate?
Boost pump failure or
loss of fuel tank pressurization (3 psi)
What is the purpose of the two inward relief valves?
Prevent a negative pressure in the tank by allowing air to enter the tank, but also prevent venting to the atmosphere
