On a jet turbine aircraft, is there a critical engine?

The notion of a critical engine on a jet turbine aircraft refers to the engine's contribution to the aircraft's directional control and performance, especially in the event of an engine failure. In many multi-engine configurations, an engine that develops asymmetric thrust can cause unnecessary directional control challenges during certain phases of flight like takeoff or approach.

In jet turbine aircraft, particularly those with engines mounted on the wings, there is usually no single critical engine because engines are designed to operate effectively in pairs, often providing balance. This design mitigates the risk of losing control upon the failure of one engine, as the thrust from the remaining engine(s) can still maintain flight stability. Engines operating in opposite directions could refer to the configuration where engines on opposite wings help counteract any yaw moment created by one engine going offline, supporting a more stable operation.

While each engine is essential for optimal performance, the overall architecture of a typical multi-engine jet aircraft ensures redundancy and balanced thrust, thus eliminating the concept of a singular critical engine in most operational circumstances.