APU fuel is drawn from which tank?

• A. Main fuel tank
• B. Left collector tank
• C. Right collector tank
• D. External tank

Answer: (B)

APU fuel comes from a dedicated, secondary fuel source so the auxiliary power unit can run independently of the engines. That source is the left collector tank, which is provisioned to feed the APU through its own fuel line and valve. Using a collector tank keeps the APU from competing with engine fuel in the main tanks and allows for reliable APU operation during ground and non-bleed operations without relying on the engines’ fuel supply.

The main fuel tank is reserved primarily for engine feed, and external tanks aren’t part of standard onboard systems. The right collector tank isn’t the designated APU source in this configuration, so the left collector tank is the correct source for the APU.