FAA Aircraft Dispatcher Practice Exam

Which types of airplanes cause the most significant wake turbulence?

1. Heavy, slow, and clean aircraft

2. Fast jets and lightweight planes

3. Medium-sized aircraft with low speeds

4. All types of aircraft create the same wake turbulence

The correct answer is: Heavy, slow, and clean aircraft

Heavy, slow, and clean aircraft produce the most significant wake turbulence due to the physics of their operation. When an aircraft is flying, it generates vortices as it passes through the air, and these are particularly strong with larger, heavier planes. The weight of the aircraft contributes to the strength of these vortices; thus, heavier aircraft create more intense wake turbulence. The speed of the aircraft also plays a role. Slow-moving aircraft can allow their vortices to linger longer in the air because they do not dissipate as quickly as they do with faster aircraft. Additionally, a "clean" aircraft configuration — which refers to an aircraft that extends its wings and other control surfaces without deploying flaps or landing gear that can disrupt airflow — also enhances the generation of these strong vortices. On the other hand, while lightweight planes and fast jets can create vortices, they do not produce them at the same intensity as heavy aircraft. Therefore, awareness of wake turbulence is particularly crucial when heavy aircraft are involved, especially during takeoff and landing phases when the potential for wake turbulence encounters is highest.