Which component is used to move fuel from the tank into the discharge line?

• A. Sump box
• B. Vent
• C. Fuel manifolds
• D. Boost pumps

Answer: (D)

Fuel is moved from the tank into the discharge line by a boost pump, which provides the necessary pressure to push fuel through the system. Gravity alone often isn’t enough to reliably feed the engine, especially during starts, climbs, or maneuvering, so the boost pump creates a positive pressure that primes the lines and keeps fuel flowing toward the engine-driven pumps. Boost pumps are typically electric and located in or near the tanks, activated during startup and in flight as needed to maintain fuel pressure.

The other components have different roles: a sump box collects small amounts of fuel for drainage or sampling; a vent allows air to escape and equalizes pressure; a fuel manifold distributes fuel to multiple outputs but does not actively move fuel from the tank into the discharge line.