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Weather theoryQuestion 333 of 934

Why is frost a hazard to flight?

  1. It adds weight to the wing but does not change the lift
  2. It blocks the pitot tube but leaves the wing unchanged
  3. It matters only in flight, because it melts before takeoff
  4. It disrupts airflow over the wing and can cut lift sharply
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Correct answer: It disrupts airflow over the wing and can cut lift sharply

Frost can drastically reduce lift. Clean the airplane of frost before flight.

Source: Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25C), Chapter 12: Weather Theory — Fog, page 299

Practice weather theory

Questions last reviewed: 18 October 2026