In an engine-out scenario with the left engine as the critical engine, the most adverse engine is the

• A. Right engine
• B. Left engine
• C. Center engine
• D. Both equally adverse

Answer: (A)

The main idea here is identifying the critical engine—the engine whose failure would produce the greatest adverse yaw and loss of control. In a typical twin-engine setup, the left engine is considered the critical engine because its failure tends to produce the largest yawing moment toward the dead engine and the most challenging control problem for the pilot to compensate with rudder and throttle adjustments.

Given that the left engine is labeled as the critical engine, the engine whose loss would be most adverse has traditionally been the left engine itself. That’s because losing the critical engine removes the engine that would have caused the greater asymmetric effect, leaving you with the remaining engine whose thrust and the aircraft’s tail and rudder authority must counter the worst-case yaw and roll. If a provided answer states the right engine is the most adverse in this scenario, it would imply a nonstandard configuration (different propeller rotation directions or engine placement) than the common setup where the left is critical. Always check the specific aircraft’s configuration, but with the left engine defined as the critical engine in the question, the left engine’s failure is the most adverse scenario.