What must be referenced if ACARS performance is not available?

When ACARS performance data is unavailable, pilots should reference the flight deck flip cards. These cards are specifically designed to provide quick access to performance information, procedures, and operational limitations that are crucial during flight operations. They serve as an important resource for pilots to ensure they can still make informed decisions regarding aircraft performance and handling without relying on automated systems.

In situations where ACARS cannot deliver the required performance data, the flip cards ensure that critical information remains accessible, helping to maintain safety and efficiency in flight operations. Additionally, the flip cards contain essential limitations and guidelines that pilots must adhere to, emphasizing their importance as a backup resource when digital systems fail.