Are the fuel boost pumps AC or DC powered?

Are the fuel boost pumps AC or DC powered?

• A. DC powered
• B. AC powered
• C. Both AC and DC
• D. Not powered

Answer: (A)

Fuel boost pumps are electric devices that maintain positive fuel pressure to feed the engines, especially during start or if the engine-driven pump can’t supply enough flow. In most aircraft, the electrical system is DC (for example, 28 volts), and these pumps are powered by that DC system. That makes DC power the straightforward, reliable source for these pumps, without needing inverters or additional conversion hardware. Using AC would require an inverter to convert DC to AC, which adds weight, complexity, and a potential failure path in a critical system, so the standard arrangement is DC powered. Not powered isn’t correct because these pumps must run to ensure fuel delivery.

Fuel boost pumps are electric devices that maintain positive fuel pressure to feed the engines, especially during start or if the engine-driven pump can’t supply enough flow. In most aircraft, the electrical system is DC (for example, 28 volts), and these pumps are powered by that DC system. That makes DC power the straightforward, reliable source for these pumps, without needing inverters or additional conversion hardware.

Using AC would require an inverter to convert DC to AC, which adds weight, complexity, and a potential failure path in a critical system, so the standard arrangement is DC powered. Not powered isn’t correct because these pumps must run to ensure fuel delivery.