Have you ever heard "caution wake turbulence" on the radio? A strong vortex created by a wing as it produces lift can be dangerous to smaller aircraft, as you'll see in the video below.

So here are 5 factors that affect aircraft vortex strength. If you understand these, you'll better understand why you need to be careful as a large plane lands or departs ahead of you.

1) Aircraft Speed

As the velocity of an aircraft increases, the strength of the vortices is typically reduced. That's because flying faster typically requires a lower angle-of-attack. It's also why takeoff and landing are critical times to pay attention to the flight path of large aircraft around you, because they're going relatively slow and creating large vortices.

2) Aircraft Weight

The heavier the aircraft, the more lift must be produced to sustain flight. Increased lift also increases vortex strength. The A380 below is a great example of this.

3) Angle of Attack

Higher angles of attack result in stronger vortices. You have a stronger difference between low and high pressure around the wing with a high angle of attack.

4) Wing Configuration

Clean configurations result in stronger vortices, because higher angles of attack are typically needed.

5) Aircraft Proximity to Ground

When your wing is close the ground, wingtip vortices can't get as big, because as they spin around your wingtip, they impact the ground and dissipate. This is a major part of ground effect.

Wind

While wind doesn't change the strength of vortices produced, it does impact that way vortices affect you. Wind speed and direction determines how vortices travel and dissipate. For instance, if you have a strong crosswind, the vortices produced by a landing airplane will float in the direction of the wind, moving away from the runway.

In short, the strongest vortices are produced by an aircraft that is HEAVY, CLEAN, and SLOW.