What is the primary purpose of having inboard and outboard ailerons?

• A. Increase lift at low speeds
• B. To reduce drag at cruise
• C. Prevent high speed wing twist/aileron reversal
• D. Improve roll control at stall

Answer: (C)

The main idea is to maintain roll control across the speed range by addressing aeroelastic wing twist. As an airplane goes faster, the wing twists under lift, especially near the tips, which can make a single aileron less effective and even reverse the intended roll (ailerons reversal). Having both inboard and outboard ailerons shares the load and changes the way the wing twists respond to a control input, so the overall roll authority remains reliable and predictable at high speeds. This is why the dual-aileron setup is used: to prevent high-speed wing twist and the resulting loss or reversal of roll control. The other options don’t address this aeroelastic stability issue—they describe lift, drag, or stall-related effects that aren’t the primary reason for having inboard and outboard ailerons.