Which direction does the total drag curve move when spoilers are deployed?

• A. Up and Left
• B. Down and Right
• C. Up and Right
• D. Down and Left

Answer: (A)

Spoilers add drag and reduce lift. When you deploy them, the wing experiences more total drag for a given lift condition, and the wing produces less lift for the same angle of attack. On a typical drag-polar or speed–drag representation, that combination shows as the drag curve moving upward (more drag at each point) and toward lower speeds (the system operates at a lower speed to produce the same lift with the spoilered wing). In short, spoilers make the aircraft dragier and shift the operating point toward the left on the speed axis, so the curve moves up and left. This is why spoilers are used to descend and slow down.