Aircraft Fuel System Questions

In a magnetic float switch, what component's movement brings the armature closer to the magnet to operate the micro-switch?

• The counterweight

• The float

• The striker

What is the primary function of the flexible diaphragm within a fuel pressure switch?

• To amplify small pressure changes.

• To isolate the electrical switch mechanism from the fuel.

• To cool the microswitch during operation.

In an electrically operated Low-Pressure (LP) valve, what component cuts off power to the motor at the fully-open and fully-closed positions?

• The electro-magnetic brake

• The reversible electric motor

• The limit switches

Under what condition does a suction valve in the fuel system open?

• When booster pump pressure is applied to the pipeline.

• When suction is applied to the pipeline by the engine-driven pump.

• When the cross-feed valve is commanded open.

What is the purpose of the "interference spider" found in some non-return valves?

• To filter solid contaminants from the fuel.

• To prevent the valve from being installed in the wrong direction.

• To create a vortex for better fuel flow.

Where is an air release valve typically installed in the engine fuel feed line?

• At the lowest point to collect water.

• At the point closest to the engine fuel pump.

• At the highest point to trap air.

For redundancy, how are the two actuators on a critical electrically driven fuel valve typically powered?

• From the same electrical bus.

• From different electrical sources.

• By a dedicated backup battery.

When replacing the sediment bowl on a light aircraft fuel filter, what is a critical precaution?

• The filter element must be replaced at the same time.

• The bowl must be filled with fuel before installation.

• A good seal must be ensured between the bowl and the housing.

What is the primary reason for using flexible couplings in aircraft fuel pipelines?

• To reduce the overall weight of the fuel system.

• To accommodate misalignment and movement from flight loads and temperature variations.

• To increase the flow rate of fuel through the pipes.

In a Vee-clamp coupling, how is the seal between the two pipe fittings achieved?

• With a special thread sealant.

• With an O-ring located in a groove.

• With a gasket made of composite material.