Which statement correctly describes a Frise-type aileron?

• A. Aileron with trailing edge moving above the wing surface.
• B. Aileron having the nose portion projecting ahead of the hinge line.
• C. Aileron that is mass balanced to reduce flutter.
• D. Aileron mounted on the wing's leading edge.

Answer: (B)

The Frise-type aileron is defined by how its edge is shaped relative to the hinge to influence the airflow and drag on the wing. In this design, the nose portion of the aileron projects ahead of the hinge line. When the aileron moves, that forward portion interacts with the airstream in such a way that extra drag is created on the wing on the side with the up-deflected aileron. This increased drag helps oppose adverse yaw and makes the roll response smoother.

So, the correct description is that the aileron has the nose portion projecting ahead of the hinge line. The other features mentioned—being mounted on the leading edge, being mass balanced to reduce flutter, or a trailing-edge configuration—do not define the Frise style.