What is the defining feature of severe turbulence?

The defining feature of severe turbulence is characterized by large, abrupt changes in altitude and attitude that can lead to a potential loss of control of the aircraft. This level of turbulence can cause significant disruptions to the flight path and requires pilots to manage their control inputs carefully to maintain stability. In severe turbulence, aircraft can experience sudden and violent movements, making it challenging for both the crew and passengers.

The correct characterization helps distinguish severe turbulence from other types, such as light or moderate turbulence, which do not involve such drastic fluctuations. The nature of severe turbulence often necessitates pilots to engage in active maneuvering and may require them to keep seatbelt signs on to ensure passenger safety.

Contextually, other options describe conditions that do not accurately reflect the severity of the turbulence. Minor control changes and steady, smooth flying are indicative of much lighter conditions, while turbulence that can only be felt by passengers does not encompass the seriousness and operational impact of severe turbulence. Understanding this distinction is crucial for evaluating in-flight conditions and ensuring safety protocols are followed.