What is a key characteristic of a deep stall?

A deep stall is characterized by a condition where the airflow over the wings and tail is disrupted, leading to a complete loss of lift from the wings. One of the key aspects of a deep stall is that the effectiveness of the aircraft's tail surfaces decreases significantly, especially in turbulent conditions. This happens because the high angle of attack causes the airflow over the tail to become turbulent or even separated, reducing the tail's ability to provide pitch control and exacerbate the stall.

Moreover, this loss of control can lead to a scenario where the pilot is unable to recover effectively from the stall, as the tail cannot create the necessary forces to stabilize the aircraft and control its descent. The other options are not defining characteristics of a deep stall, and understanding the concept of how tail effectiveness diminishes contributes significantly to recognizing the dangers associated with this flight condition.