What is the primary purpose of flight spoilers during landing?

The primary purpose of flight spoilers during landing is to reduce lift upon landing. As the aircraft approaches the runway, spoilers deploy on the wings, disrupting airflow and effectively decreasing the wing's lift. This reduction in lift helps the aircraft settle onto the runway more firmly, allowing for better control during landing and increasing the effectiveness of the brakes. When the lift is diminished, the aircraft's weight is more effectively transferred to the wheels, improving braking efficiency and reducing the possibility of float, which can lead to excessive ground roll distances.

While options such as increasing lift, assisting in climbing, and maintaining speed are also relevant aspects of aerodynamics and flight operations, they do not pertain to the specific function of spoilers during landing, which is solely focused on increasing control and braking performance by reducing lift.