Under which conditions does the greatest wake turbulence vortex strength occur?

• A. Heavy, clean, and fast
• B. Light, clean, and slow
• C. Heavy, clean, and slow
• D. Heavy, dirty, and fast

Answer: (C)

The greatest wake turbulence vortex strength occurs under the conditions described in the correct answer: heavy, clean, and slow. Wake turbulence is generated by the lift created by an aircraft's wings, and its strength is influenced by the weight of the aircraft, its configuration, and its speed.

A heavy aircraft generates a stronger lift and consequently produces more intense vortices compared to lighter aircraft. A clean configuration, meaning the aircraft has its landing gear retracted and flaps up, allows for optimal aerodynamics, thus producing powerful vortices. Additionally, when an aircraft is flying slowly, particularly during landing or takeoff phases, the vortices remain more pronounced and have a longer duration in the environment. This results in a higher level of wake turbulence that could pose risks to following aircraft.

In contrast, the other options reflect conditions that either reduce the weight, speed, or aerodynamic efficiency of the aircraft, which would generally decrease the intensity of the wake turbulence produced.