FAA Ground School Practice Test

The principle behind lift generation is primarily explained by which of the following?

1. Newton's third law

2. Bernoulli's principle

3. Pitch control principles

4. Drag equations

The correct answer is: Bernoulli's principle

Lift generation in the context of aviation is primarily explained by Bernoulli's principle. This principle states that an increase in the speed of a fluid occurs simultaneously with a decrease in pressure. In terms of an airplane wing, the airfoil is designed so that air travels faster over the top surface of the wing and slower underneath it. This difference in airspeed results in lower pressure on the top surface compared to the pressure beneath the wing, which creates lift. While Newton's third law, which states that for every action there is an equal and opposite reaction, also plays a role in lift generation (as the wing pushes air downwards, and the reactive force pushes the wing upwards), Bernoulli's principle is more directly associated with the pressure differential that leads to lift. Pitch control principles and drag equations focus on different aspects of flight dynamics and aerodynamics. Pitch control pertains to the angle of attack and how it affects aircraft orientation, while drag equations involve the forces opposing an aircraft's motion. These concepts are related to overall flight mechanics but do not directly explain the fundamental principle of lift generation as effectively as Bernoulli's principle does.