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Purpose of vortex generators

Aviation Mechanic General (AMG) practice question 10 of 20 on Physics for Aviation. ACS element AM.I.J.K10 · difficulty: recall. Want to answer it in a timed quiz? Use the Aviation Mechanic General (AMG) practice mode.

Question bank updated 2026-09-22

QUESTIONVortex generators installed on the upper surface of a wing that flies at high subsonic speed are intended to

  1. Apull high-energy air into the boundary layer to prevent separation
  2. Bduct high-pressure air from the bottom of the wing to the top surface
  3. Cincrease the wing's camber and chord line at low airspeed
Show the answer and explanation

Correct answer: A. pull high-energy air into the boundary layer to prevent separation

  • A — correct Vortex generators are short airfoils arranged in pairs on the upper wing surface. They pull high-energy air down into the boundary layer region and prevent the airflow separation caused by a shock wave forming on the wing.
  • B — incorrect This describes a leading edge slot, which is a duct through the wing, not vortex generators mounted on the surface.
  • C — incorrect Changing camber and chord line is what trailing edge flaps do. Vortex generators do not alter the wing's shape.

BACKGROUND

The boundary layer is the thin layer of air adhering to the wing surface. Several methods are used to keep it under control, including keeping the surface smooth and clean, leading edge slots, suction through small holes on the upper surface, and vortex generators. Vortex generators are used on airplanes that fly at high subsonic speed, where the air over the top of the wing can reach Mach 1 and form a shock wave that causes the air to separate from the upper surface. They are short airfoils, arranged in pairs on the wing's upper surface, positioned so that they pull high-energy air down into the boundary layer region and prevent airflow separation.

STUDY TIP

Remember that vortex generators are a boundary layer control device for high-speed wings, distinct from slots (ducts) and flaps (camber change).

KEY POINTS

  • Vortex generators are small paired airfoils on the upper wing surface
  • They pull high-energy air into the boundary layer
  • Purpose is to prevent shock-induced airflow separation at high subsonic speed

SOURCES

  • FAA-H-8083-30B ch05 "Boundary Layer Control"
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SkyDrill is not affiliated with the FAA. This is an original practice item based on FAA-H-8083-30B Aviation Maintenance Technician Handbook – General, 14 CFR part 43 and part 65. Regulations and handbooks are revised; confirm details against the current edition.