Designing 4-D trajectories for super-dense operations given weather constraints

For the Next Generation Air Transportation System (NGATS), we present trajectory design guidelines focusing on dynamic weather avoidance routing in transition airspaces -within 200 nmi of an airport or a set of metroplex airports. Assuming a Net-Centric Operation (NCO) that provides a mechanism to inform all users of hazardous weather constraints and weather avoidance routing requirements, the NGATS can move away from static jet route routing toward a system in which routes are defined dynamically in four dimensions (4D), and adjusted during the course of the day as required by traffic demand and the geometry of severe weather constraints. Such an operational concept will be particularly useful for time periods for which weather is a major constraint to terminal area operations, and when Super-Dense Operations (SDO) are thus required to maintain a high throughput. This paper describes both a Concept of Operations (ConOps) for using 4D trajectories to establish SDO in NGATS and an approach to designing 4D trajectories.