11 - Fuel System Flashcards
What provides static and dynamic venting for the fuel tanks?
NACA vent scoops under the Wings provide static and dynamic venting.
Where are the collector tanks located?
The two collector tanks are located in the center tank at a point that is lower than the left or right wing thanks.
What are the maximum fuel tank capacities?
Total 14,518 pounds
Explain the construction of the wing fuel tanks
The wing tanks are a wet wing design. A sealant is used to seal the tanks so this makes the wing the tank
How is gravity De-fueling accomplished
A gravity defueler adapter can be inserted into the fuel drain valves to accomplish gravity de fueling
How is fuel prevented from flowing to the wingtip during wing low maneuvers?
There are one way flow valves in each wing tank that prevent the flow of fuel to the wing tip.
Explain the fuel vent system.
The NACA scoops have vent Lines connected to the tanks to provide static and dynamic pressure. In flight the NACA events will provide ram air pressure to maintain a positive pressure on the fuel in the tanks. Static ventilation of the tanks during ground operations is provided through the NACA vents.
During climb you notice the total fuel in the center tank increase by 300 pounds, is this a problem?
This is not a problem. Is possible for fuel to flow to the center tank from the vent system during climb and cause fuel quantity readings of the center tank to increase as high as 300 pounds.
What monitors and controls the operation of the fuel system?
A dual channel fuel system computer
Do both fuel computer channels operate at the same time?
One channel operates at a time. When the active channel fails, the standby channel will assume control.
Where is the temperature of the fuel measured?
Left-wing tank
and
In the fuel line to each engine
Explain the general operation of ejector pumps.
Motive fuel flow asked come from a source like the engine high-pressure fuel pump. This motive flow is passed through a venturi-shaped nozzle. The fuel exits the nozzle at an increased velocity that creates a low pressure. This low pressure creates a suction that draws fuel out of the tank.
What powers the fuel ejectors?
Motive flow from the engine high pressure pump. High pressure fuel flows through a venturi-shaped nozzle of the ejector, which creates a low pressure. This then draws fuel out of the tank by suction.
How is fuel transferred from the wing tanks to the collector tanks?
Fuel is transferred by scavenge ejectors. A scavenge ejector is located at the lowest inboard point of each wing tank.
How is fuel moved from the collector tank to the high-pressure engine driven fuel pump?
There is one main ejector pump for each collector tank. Motive flow to operate the main ejector is provided by the high pressure output of the engine driven fuel pump.