Airplane trailing vortices

This review surveys the formation, motion, and persistence of trailing vortices as relevant to the safety and productivity of air travel. It highlights findings or shifts made since Widnall's (1975) review in this series. This review also examines the predictability of the vortices (particularly in terms of lifespan), the durability of multiple vortex pairs, the controversy between expectations of vortex decay and of vortex collapse, the many types of turbulence that may influence the flow, the rich interplay between the rotational and the axial velocity fields in the vortex, the various atmospheric and ground-related factors that dominate the late behavior, a few instances of wakes rising back, and the still unexplained bursting of the vortices. The article also briefly covers prospects for detection and control.