Definition
The natural production of swirling air currents (vortices) at the wingtips of an aircraft in flight, caused by the pressure difference between the higher-pressure air below the wing and the lower-pressure air above it. As the aircraft moves through the air, this pressure difference causes air to spill around the wingtip from below to above, creating a rotating cone of air that trails behind each wingtip.
Plain English
When an airplane flies, the air pressure under the wing is higher than the air pressure above it. At the wingtip, the higher-pressure air rolls up and around to the lower-pressure side, forming spinning tubes of air that trail behind the plane. These spinning tubes are called wingtip vortices.
Context Anchor
Seen in wake turbulence discussions, especially when spacing behind another aircraft for takeoff, landing, or approach.
Derivation
Vortex comes from the Latin 'vortex' or 'vertex,' meaning a whirling mass or whirlpool. It describes any swirling motion of fluid around a center, which is exactly what happens at the wingtip as air rotates around an axis trailing behind the aircraft.
Why Pilots Care
The resulting vortices create persistent wake turbulence that can roll or pitch a following aircraft, requiring pilots to maintain safe separation distances especially on approach and departure.
Analogy
It is similar to the way a boat leaves a disturbed wake behind it, except here the disturbed flow is spinning air instead of moving water.
Grounding Statement
Picture two invisible, horizontal tornadoes trailing behind the wingtips of every airplane in flight, strongest when the aircraft is heavy, slow, and clean (gear and flaps up).
Intuition Check
Do not think vortex generation happens only behind large jets. Any aircraft producing lift creates vortices; they are usually strongest when the aircraft is heavy, slow, and the wing is working hard.
Example Sentence 1
Vortex generation increases as the aircraft slows down and the wing flies at a higher angle of attack, which is why wake turbulence is most dangerous behind heavy aircraft on approach.
Example Sentence 2
Heavy jets produce stronger vortex generation, so controllers increase spacing behind them on final approach.