Which aircraft characteristic has the greatest impact on wake turbulence?

The characteristic of an aircraft that has the greatest impact on wake turbulence is its weight. Wake turbulence is generated by the lift produced by an aircraft's wings, and heavier aircraft create more significant vortices. These vortices are powerful and can persist longer in the atmosphere, posing a hazard to following aircraft, especially smaller ones.

The strength of the vortices is directly related to the square of the aircraft's weight; thus, as the weight increases, the energy and size of the wake turbulence produced increase as well. This relationship is crucial for air traffic control and flight operations, as it informs pilots and air traffic controllers about the necessary separation distances between aircraft to mitigate the risks associated with wake turbulence.

While other factors such as lateral size, height, and speed can affect the turbulence generated, none have the same profound influence as weight. Lateral size might impact the turbulence's lateral reach, but it is the weight that fundamentally determines the intensity of the wake. Similarly, speed can affect how quickly the vortices dissipate, but once again, the primary determining factor is the weight of the aircraft generating the wake.