Learn how wingtip vortices create wake turbulence, when the wake is strongest, and how pilots avoid dangerous roll upsets near runways.
Wingtip vortices are counter-rotating tubes of disturbed air created behind a lifting wing as higher-pressure air flows around each tip towards the lower-pressure upper surface. Pilots avoid the resulting wake turbulence because it can produce a sudden, powerful roll—especially dangerous for a smaller aircraft close to the ground.
How do wingtip vortices form?
In Aviation & Real-World Flying, the practical hazard created by wingtip vortices is called wake turbulence. A lifting wing leaves a sheet of rotating air behind it, which rolls into two concentrated vortices trailing from the wingtips.
The pair normally sinks below the generating aircraft's flight path while also drifting with the wind. The most significant wake begins around rotation on take-off and continues until touchdown because that is when the aircraft is supporting its weight through aerodynamic lift.
Winglets can weaken or reposition the tip flow and reduce induced drag, but they do not remove wake turbulence. Our explanation of how winglets affect wingtip airflow and efficiency covers that distinction in more detail.
Wake turbulence is not the same as jet blast. Jet blast is high-velocity engine exhaust, mainly hazardous behind an aircraft on the ground; wingtip vortices are produced by lift and can persist behind any lifting aeroplane, including gliders.
Why are wingtip vortices dangerous?
A strong vortex can roll an aircraft faster than its ailerons can counteract, causing an abrupt bank, altitude loss or loss of control. The risk is greatest when a light aircraft meets the wake of a much larger aircraft during take-off or landing, where there is little height available for recovery.
An encounter may begin as buffeting before developing into a sharp roll. Crossing a vortex quickly can produce a short jolt, while flying along its core can create a more sustained upset. The wake is invisible in ordinary conditions, so clear skies do not make it safe.
Aircraft size alone does not determine the outcome. Relative weight, speed, wingspan, encounter angle, height and available control authority all matter. A Cessna 172 following an airliner deserves particular caution; readers learning light-aircraft operations can compare this with our practical Cessna 172 flying and landing guidance.
When are wingtip vortices strongest?
Wake is strongest when the generating aircraft is heavy, clean and slow, the standard pilot shorthand for the most demanding combination.
- Heavy: More lift is required to support the aircraft, increasing vortex strength.
- Slow: The wing must operate at a higher angle of attack and generate stronger circulation.
- Clean: A retracted-flap configuration tends to produce a more concentrated wake, although the wake from an aircraft using landing flap can still be dangerous.
Wind mainly controls where the vortices go and how long they remain concentrated. Calm or light-wind conditions may let them linger near the runway. A crosswind moves the pair sideways, while a light quartering tailwind can hold one vortex over or near a runway instead of carrying both safely away.
How do pilots avoid wake turbulence?
Pilots avoid the generating aircraft's path rather than relying only on its present position. The safe response depends on the operation, wind and whether the following aircraft can remain above the wake.
- Use the required separation. Follow the applicable wake-turbulence spacing or time interval assigned for the aircraft categories involved. These standards vary by authority, airport and operation.
- Stay above the preceding flight path. Vortices usually sink, making flight below and behind another aircraft the wrong place to be.
- Land beyond the preceding touchdown point. When following a larger aircraft on approach, remain at or above its approach path and touch down beyond where it landed—but never force an unstable approach or an unsafe long landing.
- Depart before its rotation point only when performance permits. Behind a departing aircraft, lift off before its rotation point and remain above and, where practical and cleared, upwind of its climb path. If that cannot be assured, wait.
- Account for wind drift. Consider whether a crosswind or quartering tailwind could move a vortex onto your runway, including from a parallel runway.
- Ask for more room when needed. A pilot may request extra spacing, delay take-off or go around. Our guide to clear pilot communication with air traffic control explains how such operational requests fit into normal radio work.
An ATC clearance does not prove that the wake has disappeared. In some visual operations, the pilot accepting visual separation also accepts responsibility for maintaining suitable spacing. A common mistake is to follow the preceding aircraft's current position while descending through the path it occupied moments earlier.
How long do wingtip vortices last?
There is no universal safe stopwatch for wingtip vortices; a coherent wake can remain hazardous for several minutes. Its persistence depends on wind, atmospheric turbulence, the generating aircraft and proximity to the ground.
Published wake-separation rules provide the baseline, but pilots still monitor the actual geometry and conditions. At altitude, wake from traffic ahead or crossing above can descend through another aircraft's level. Near the ground, the vortices cannot keep sinking, so they may spread laterally or linger around adjacent runways.
Do flight simulators model wingtip vortices accurately?
Some flight simulators model wake turbulence, but its availability and strength vary by simulator, aircraft, traffic system, add-on and realism setting. Visual wingtip condensation is only a graphic effect unless the simulator separately calculates the disturbed airflow.
Consumer simulation is useful for practising recognition, spacing and go-around decisions, but simulated behaviour must not be used to estimate real-world separation. Our overview of how simulators calculate flight physics and airflow effects explains why wake behaviour differs between flight models.