Which component is critical in maintaining controlled flight in an engine-out scenario?

Maintaining controlled flight in an engine-out scenario heavily relies on aerodynamic stability. In the event of an engine failure, the pilot must ensure that the aircraft remains stable and controllable without the additional thrust provided by the engine. Aerodynamic stability ensures that the aircraft can maintain its attitude and flight path with minimal input from the pilot. This stability is crucial, as it helps prevent undesirable flight characteristics such as excessive yaw or pitch changes that can occur when thrust from one wing is removed, leading to a loss of control.

Autopilot systems, while helpful in many scenarios, may not function adequately or may not be engaged in an engine-out situation. The landing gear typically has no effect on basic aerodynamic stability during flight, as it is primarily relevant during takeoff and landing phases. Cabin pressure is vital for passenger comfort and safety but does not directly influence the aircraft's aerodynamic control during flight. Thus, the focus on maintaining aerodynamic stability is paramount for ensuring controlled flight when one engine is inoperative.