Fuel is normally supplied to the APU from which side of the fuel manifold when AC fuel pumps are operating?

Fuel is normally supplied to the APU from which side of the fuel manifold when AC fuel pumps are operating?

• A. Left side
• B. Right side
• C. Center
• D. Both sides

Answer: (A)

Fuel routing to the APU is arranged so that, when AC-powered pumps are running, the left side of the fuel manifold supplies the APU. This left-side feed is the dedicated APU supply leg, providing a direct, prioritized path from the AC pumps to the APU’s fuel control, which helps ensure reliable fuel pressure and a smooth start. The other ports (center or right) are used for engine fuel feeds or crossfeed under different conditions, so feeding the APU from the left side avoids competition with engine lines and minimizes priming issues during AC-pump operation.

Fuel routing to the APU is arranged so that, when AC-powered pumps are running, the left side of the fuel manifold supplies the APU. This left-side feed is the dedicated APU supply leg, providing a direct, prioritized path from the AC pumps to the APU’s fuel control, which helps ensure reliable fuel pressure and a smooth start. The other ports (center or right) are used for engine fuel feeds or crossfeed under different conditions, so feeding the APU from the left side avoids competition with engine lines and minimizes priming issues during AC-pump operation.