What is the function of spoilers on a glider?

The function of spoilers on a glider is to increase drag and reduce lift. Spoilers are panels located on the upper surface of the wing that can be raised to disrupt the airflow over the wing. By doing so, they effectively decrease the lift produced by the wing, which is particularly useful when the pilot wants to descend rapidly or control the glider's descent rate.

When spoilers are deployed, the airflow is disturbed, causing an increase in drag. This increased drag works against the glider's forward motion, which can help manage descent without a significant increase in airspeed. This function can be crucial during landing approaches, allowing the pilot to fine-tune the descent and approach angle for a safe landing. Additionally, using spoilers can help control the glider's approach path when flying in thermal conditions, where managing lift is essential for effective handling.

Other options present different aerodynamic functions but do not accurately describe the specific role of spoilers. For instance, promoting lift or stabilizing flight relates to other control surfaces, while accelerating descent could happen but is more effectively managed through the intentional use of the spoilers to create more drag and reduce lift.