Wake Turbulence Limits on Paired Approaches to Parallel Runways

Wake turbulence considerations currently restrict the use of parallel runways less than 2500 feet apart. However, wake turbulence is not a factor if there are appropriate limits on allowed longitudinal pair spacings and/or allowed crosswinds. The tradeoffs between longitudinal spacing and crosswind, needed to prevent wake encounters, are assessed by modeling and by examining existing wake lateral transport data from O'Hare and Dallas/Ft. Worth airports at distances of 1500 to 3000 feet from runway threshold.