Aircraft systems and instrumentsQuestion 605 of 934

What does the yellow arc on a carburetor air temperature gauge show?

  1. The maximum safe temperature of the carburetor
  2. The normal operating range for the carburetor air
  3. The temperatures where carburetor icing may occur
  4. The temperatures where fuel vapor lock may occur
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Correct answer: The temperatures where carburetor icing may occur

If icing conditions exist, the pilot should keep the indicator outside the yellow arc by using carburetor heat.

Source: Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25C), Chapter 7: Aircraft Systems — Induction Systems — Carburetor Air Temperature Gauge, page 171

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Questions last reviewed: 18 October 2026