Wake turbulence is another type of clear-air turbulence , but in this case the causes are quite different from those set out above . In the case of wake turbulence , the rotating vortex-pair created by the wings of a large aircraft as it travels lingers for a significant amount of time after the passage of the aircraft , sometimes more than a minute . When this occurs , the lingering turbulence caused by the wake of the wing tips can deflect or even flip a smaller aircraft on the ground or in the air awaiting landing . This phenomenon can also lead to accidents with large aircraft as well . Delta Air Lines Flight 9570 crashed at the Greater Southwest International Airport in 1972 while landing behind a DC-10 . This accident led to new rules for minimum following separation time from " heavy " aircraft . American Airlines Flight 587 crashed shortly after takeoff from John F. Kennedy International Airport in 2001 due to pilot overreaction to wake turbulence from a Boeing 747 . Many aircraft are now made with wingtip devices to improve both the lift-to-drag ratio and fuel economy - such devices may also marginally reduce the strength of the wingtip vortices . However , such changes are not operationally significant ( i.e. do not change the distances or times at which it is safe to follow other aircraft )
American Airlines Flight 587
American Airlines Flight 587
Clear-air turbulence