What do ejectors do?

What do ejectors do?

• A. Draw air from the fuel tank to the sump.
• B. Collect fuel from bottom of tank and direct it to the sump box
• C. Seal the sump box to prevent leaks.
• D. Direct fuel from sump back to the top of tank.

Answer: (B)

Ejectors in a fuel system are designed to scavenge liquid fuel from the lower parts of a tank and deliver it to the sump box. They use a small flow of fuel (or a motive air flow) through a nozzle to create a suction effect, which entrains fuel from the bottom of the tank and moves it into the sump. This keeps a steady, density-consistent supply to the fuel pump, even when the aircraft is moving or the tank level is changing. That’s why the description “collect fuel from bottom of tank and direct it to the sump box” best matches what an ejector does. It isn’t about drawing air from the tank, sealing a sump, or returning fuel to the top of the tank, which wouldn’t accomplish the scavenging function needed for reliable fuel feed.

Ejectors in a fuel system are designed to scavenge liquid fuel from the lower parts of a tank and deliver it to the sump box. They use a small flow of fuel (or a motive air flow) through a nozzle to create a suction effect, which entrains fuel from the bottom of the tank and moves it into the sump. This keeps a steady, density-consistent supply to the fuel pump, even when the aircraft is moving or the tank level is changing.

That’s why the description “collect fuel from bottom of tank and direct it to the sump box” best matches what an ejector does. It isn’t about drawing air from the tank, sealing a sump, or returning fuel to the top of the tank, which wouldn’t accomplish the scavenging function needed for reliable fuel feed.