When using crossfeed, what limits apply?

• A. Crossfeed is unlimited.
• B. Crossfeed is restricted to a fixed time window of 15 minutes.
• C. Crossfeed is only for long-range missions.
• D. Crossfeed must be used within prescribed limits.

Answer: (D)

Crossfeed operations are controlled by defined limits in the aircraft’s operating manuals. You can use crossfeed to balance fuel between tanks or to supply an engine when the other side’s pumps aren’t able to do so, but you must stay within the prescribed limits for how it’s used. Those limits specify when crossfeed may be used, how long the crossfeed valve can stay open, which pumps and configurations are permitted, and how the crew must monitor fuel balance and CG. This ensure fuel supply integrity, prevent excessive imbalance, and keep the system operating safely. Therefore, crossfeed must be used within prescribed limits.