What does the term 'critical engine-out' mean?

The term 'critical engine-out' refers specifically to a condition in multi-engine aircraft where one engine becomes inoperative. This situation has significant implications for operational capability and performance of the aircraft. In multi-engine planes, the failure of one engine can lead to a substantial reduction in thrust and can affect the aircraft's ability to maintain altitude, climb performance, and lateral control. Understanding this term is crucial for pilots as they must be aware of how to manage flight in such scenarios, including the necessary procedures and techniques to ensure safety and control.

This concept does not relate to fuel limitations or the complete loss of all engines, which are different situations that have distinct definitions and implications in aviation safety and operation. Additionally, weight limits for fuel pertain more to aircraft loading and balance rather than engine operations. Hence, recognizing the specific challenges posed by a critical engine-out scenario is vital for pilots flying multi-engine aircraft.