What could cause a fuel imbalance between left and right tanks in a twin-engine aircraft?

What could cause a fuel imbalance between left and right tanks in a twin-engine aircraft?

• A. Fuel density differences between tanks
• B. Unequal pump pressure, clogged lines, faulty selector valve, or routing issues
• C. Pilot error in tank selection
• D. Balanced lines ensure equal flow

Answer: (B)

Fuel imbalance in a twin-engine aircraft happens when the left and right fuel systems don’t deliver equal amounts to their respective engines. Each engine is normally fed from its own tank, but the flow can become unequal if the system on one side is delivering more fuel or the other side is restricted. Unequal pump pressure means one pump pushes fuel harder than the other, so one engine receives more fuel while the other gets less. Clogged lines restrict flow on one side, creating a disparity in delivery. A faulty selector valve can fail to route fuel correctly or fail to close off a path, and routing issues (misconnected or damaged lines) can bias flow toward one side or disrupt the intended crossfeed balance. These mechanical and electrical faults directly affect how much fuel each engine receives, leading to imbalance. While pilot tank selection or the idea of balanced lines might influence balance in some scenarios, the listed faults are the direct causes that disturb actual fuel delivery.

Fuel imbalance in a twin-engine aircraft happens when the left and right fuel systems don’t deliver equal amounts to their respective engines. Each engine is normally fed from its own tank, but the flow can become unequal if the system on one side is delivering more fuel or the other side is restricted. Unequal pump pressure means one pump pushes fuel harder than the other, so one engine receives more fuel while the other gets less. Clogged lines restrict flow on one side, creating a disparity in delivery. A faulty selector valve can fail to route fuel correctly or fail to close off a path, and routing issues (misconnected or damaged lines) can bias flow toward one side or disrupt the intended crossfeed balance. These mechanical and electrical faults directly affect how much fuel each engine receives, leading to imbalance. While pilot tank selection or the idea of balanced lines might influence balance in some scenarios, the listed faults are the direct causes that disturb actual fuel delivery.