Aircraft systems and instrumentsQuestion 639 of 934

What is one of the most important safety rules before starting an engine?

  1. Open the cowl flaps fully for engine cooling
  2. Pull the mixture to idle cutoff before cranking
  3. Set the propeller control to the low rpm position
  4. Make sure that no one is near the propeller
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Correct answer: Make sure that no one is near the propeller

The pilot should also chock the wheels and set the brakes to prevent unintentional movement.

Source: Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25C), Chapter 7: Aircraft Systems — Starting System, page 178

Practice aircraft systems and instruments

Questions last reviewed: 18 October 2026