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AerodynamicsQuestion 422 of 934

Which statement about the layer of air molecules that sticks to a wing surface is correct?

  1. It is called the stagnation layer
  2. It moves at the speed of the free airstream
  3. It is called the camber layer
  4. It is called the boundary layer
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Correct answer: It is called the boundary layer

Air molecules adhere to the wing because of friction. This layer is the boundary layer.

Source: Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25C), Chapter 4: Principles of Flight — Friction, page 89

Practice aerodynamics

Questions last reviewed: 18 October 2026