Spoiler (aeronautics)

Device for reducing lift and increasing drag on aircraft wings

In aeronautics, a spoiler (sometimes called a lift spoiler or lift dumper) is a device which increases the drag and decreases the lift of an airfoil in a controlled way. Most often, spoilers are hinged plates on the top surface of a wing that can be extended upward into the airflow to spoil the streamline flow. By so doing, the spoiler creates a controlled stall over the portion of the wing behind it, greatly reducing the lift of that wing section.

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