When a significant part of a stall strip is missing from an airplane wing, it can lead to asymmetrical lateral control at or near stall angles of attack. Stall strips are designed to promote a controlled and predictable stall behavior by altering the airflow across the wing and ensuring that the stall initiates at the root of the wing rather than the tip. This helps in maintaining aileron effectiveness and overall control of the aircraft during critical phases of flight, especially near the stall.
If a stall strip is partially or completely missing, the airflow characteristics over the wing are affected. This can cause the wing to stall more suddenly and unevenly, particularly on one side of the aircraft. As a result, this may lead to uncommanded roll or yaw, making it difficult for the pilot to maintain control and stability of the aircraft during maneuvers near the stall condition.
The other options presented do not accurately reflect the consequences of a missing stall strip. For instance, improved vertical lift efficiency, increased stall speed, and enhanced maneuverability would not be expected outcomes; rather, the loss of a stall strip undermines flight safety and control precision.