Wake-vortex separation distances when flight-path corridors are constrained

Improved precision of the flight paths used by aircraft to approach and depart airports will become available when the global positioning system (GPS) is implemented for air traffic control. It is suggested here that the improved precision be used to constrain the approach and departure corridors so that their cross-sectional sizes are small and constant in size. Such a constraint controls the flight paths of the aircraft, and consequently where their vortex wakes are placed, so that the likelihood of a wake-vortex encounter is reduced. If such a program is coupled with a wake-vortex advisory system, and with the operating system being planned for airports when GPS is implemented, preliminary indications are that the wake-vortex spacings currently being used for instrument flight conditions can be reduced to a uniform distance of 3 n mile. Furthermore, if the smaller GPS flight corridors are utilized by vortex advisory or forecast systems that are currently under development, the requirements to be placed on their capabilities can be substantially reduced.