What indicates the loss of control effectiveness during a power-on-stall?

The indication of loss of control effectiveness during a power-on stall is most accurately represented by an uncommanded nose drop or rolling motion. In this scenario, as the aircraft approaches the stall condition, the aerodynamic forces acting on the wings and control surfaces change significantly. When the stall occurs, the aircraft may no longer respond predictably to control inputs, resulting in unexpected behavior such as a sudden drop in the nose or an uncommanded roll.

During a power-on stall, especially in climb conditions, the thrust increases the angle of attack, which can quickly lead to a stall if the critical angle is exceeded. When this happens, one wing may stall before the other, leading to asymmetrical lift and resulting in a yawing motion. This dynamic can manifest as an uncommanded nose drop or rolling motion, both of which signal a loss of control effectiveness.

Other options, like a sudden altitude increase, fluctuating airspeed readings, or vibrations in the control surfaces, do not directly indicate a loss of control effectiveness in the same manner. Instead, they might describe unrelated phenomena or misinterpretations of the aircraft’s behavior under normal operating conditions. The uncommanded nose drop or rolling motion is specifically tied to the aerodynamic principles at play during a power-on