What is the purpose of spoilers on an aircraft?

The purpose of spoilers on an aircraft is to change lift, drag, and roll. Spoilers are mechanisms that can be deployed on the wings of an aircraft primarily to disrupt the airflow over them, which decreases lift and increases drag. This is particularly useful during descent and landing phases when the pilot wants to reduce altitude quickly without gaining speed. By increasing drag, spoilers help slow down the aircraft, providing better control during approach and landing.

Additionally, spoilers can assist with roll control. When deployed asymmetrically on one wing, spoilers can create a differential in lift between the two wings, allowing the aircraft to roll towards the side with the deployed spoiler. This function enhances maneuverability and aids in turning the aircraft more effectively, particularly at lower speeds.

During takeoff, landing, and in-flight maneuvers, the ability to manipulate lift and drag through the use of spoilers is crucial for maintaining the desired performance and safety of the aircraft.