Which of the following is a function of the boost pump in the tank of a jet transport aircraft?

• A. To pressurize the fuel in the line between the tank and the engine-driven pump
• B. To filter the fuel before it reaches the engine
• C. To cool the fuel before entering the engine
• D. To measure fuel density

Answer: (A)

The main idea here is that the boost pump provides positive pressure to the fuel line between the tank and the engine-driven pump. This ensures a reliable fuel supply during starting and when demand is high, by priming the system and preventing air pockets or suction issues that could stop fuel flow. It makes sure the engine-driven pump can draw fuel smoothly and maintain proper pressure in the feed line.

It isn’t primarily about filtering, cooling, or measuring fuel density. Filtration can be part of the system, but the boost pump’s core role is to pressurize and deliver fuel to the engine-driven pump, not to perform those other functions.