What does a [FUEL BAL] annunciator signify?

The [FUEL BAL] annunciator indicates that there is a fuel imbalance greater than 30 pounds between the left and right fuel tanks for a duration exceeding 2 minutes. This condition is significant because fuel imbalances can affect aircraft performance, handling, and safety. A sustained imbalance can lead to uneven weight distribution, which might necessitate prompt corrective action by the pilots to ensure the aircraft operates within safe limits.

Maintaining balanced fuel loads is essential for optimal aerodynamic performance and fuel efficiency, as well as for achieving proper center of gravity. This warning prompts pilots to take appropriate measures, such as transferring fuel between tanks if the aircraft is equipped with a fuel balancing system, to correct the imbalance before it affects flight operations.