Definition
Rotating masses of air that trail from the tips of an aircraft's wings whenever the wings are producing lift. Higher pressure air beneath the wing spills around the wing tip toward the lower pressure area above, creating a strong, horizontally-spinning corkscrew of air that streams behind each wing tip. These vortices are the primary component of wake turbulence and are strongest when the generating aircraft is heavy, slow, and clean (flaps and gear retracted).
Plain English
Spinning tubes of air that peel off the back of each wing tip whenever a plane is flying. They are invisible, powerful, and can stay in the air for several minutes after the aircraft has passed.
Context Anchor
Pilots encounter this term in wake turbulence discussions, especially during takeoff, landing, and when following another aircraft.
Derivation
Vortex comes from the Latin vortex / vertex, meaning a whirling mass or whirlpool. The wing tip is simply where these whirlpools of air form -- at the outer edge of each wing.
Why Pilots Care
They produce wake turbulence capable of rolling or upsetting a following aircraft, requiring specific separation distances for safety.
Analogy
A boat leaves a wake in the water behind it. An airplane can leave a wake in the air, and wing tip vortices are a major part of that wake.
Grounding Statement
Picture two invisible twisting ropes of air trailing behind the wing tips of an airplane that just took off.
Intuition Check
Do not think of wing tip vortices as smoke, exhaust, or simple wind behind the airplane. They are rotating air created by a wing that is producing lift.
Example Sentence 1
The tower instructed us to extend our downwind to allow the wing tip vortices from the departing 737 to dissipate before we turned final.
Example Sentence 2
Wing tip vortices are strongest at low speed and high angle of attack during takeoff and landing.