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Aircraft systems and instrumentsQuestion 604 of 934

When should carburetor heat not be used?

  1. During a long descent with a closed throttle
  2. When full power is required, as during takeoff
  3. During the engine runup carburetor heat check
  4. When the engine runs rough in a cruise flight
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Correct answer: When full power is required, as during takeoff

Carburetor heat reduces engine output. Use it only to check for or remove carburetor ice.

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

Practice aircraft systems and instruments

Questions last reviewed: 18 October 2026