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AerodynamicsQuestion 416 of 934

In a propeller airplane, what makes the airplane move forward, according to Newton's third law?

  1. The air above the propeller pulls the airplane forward
  2. The air pushed backward pushes the propeller forward
  3. The propeller pulls the airplane through still air
  4. The engine pushes against the ground
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Correct answer: The air pushed backward pushes the propeller forward

The propeller pushes back the air. The air pushes the propeller, and the airplane, forward.

Source: Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25C), Chapter 4: Principles of Flight — Newton's Basic Laws of Motion, page 93

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Questions last reviewed: 18 October 2026