Tactical Conflict Detection with Altitude Restrictions in Terminal Airspace

Abstract

Automated conflict detection in terminal airspace is a challenging problem, in part because key information regarding flight intent is not available. Unlike en route controllers, terminal controllers currently do not enter altitude clearances when they issue them by voice, so the altitude at which a flight will level off is unavailable to the conflict detection automation. This uncertainty increases the likelihood of false alerts. Requiring terminal controllers to enter all altitude clearances may be met with resistance due to workload concerns. This Paper studies a new method in which a ground-based trajectory predictor predicts altitude leveloffs a priori, based on altitude restrictions on published runway descent profiles and at waypoints on nominal interior routes and area navigation departure procedures. The full benefit of the flight-intent information of all altitude clearances is shown to be achievable when controllers only make entry of altitude clearances not attributable to altitude restrictions, which leads to an insignificant workload increase; an unacceptable level of workload increase may result if all altitude clearances are entered during busy hours. In addition, the integration of altitude restriction improves on alert lead time by 16% on average based on operational error cases.