Under which condition will the Blue ELEC pump not operate?

Under which condition will the Blue ELEC pump not operate?

• A. Selected ON, but no engines running on ground
• B. Engines running
• C. In flight
• D. On the ground with engines running

Answer: (C)

The Blue electric fuel pump is part of the wing fuel system and is used mainly to prime the fuel lines and to provide a backup feed when engines aren’t drawing from the wing tanks. In normal flight, the engine-driven pumps supply all the needed fuel pressure, and the system is designed so the electric boost pumps are not energised during airborne operation. That’s why this pump won’t operate when the aircraft is in flight. It’s active on the ground to assist starting or priming, but not when the airplane is airborne.

The Blue electric fuel pump is part of the wing fuel system and is used mainly to prime the fuel lines and to provide a backup feed when engines aren’t drawing from the wing tanks. In normal flight, the engine-driven pumps supply all the needed fuel pressure, and the system is designed so the electric boost pumps are not energised during airborne operation. That’s why this pump won’t operate when the aircraft is in flight. It’s active on the ground to assist starting or priming, but not when the airplane is airborne.