Advanced Departure Queue Management

Runway metering is more complicated than controlling the length of the queue of aircraft at the runway, since not all departures are equivalent. Runway metering must also consider the composition of the queue. Just as an empty queue wastes runway capacity, a queue with no flights to a constrained fix wastes capacity at that fix. The FAA’s Terminal Flight Data Manager (TFDM) has requirements to support controllers in managing the runway queue to maintain pressure on the runway and mile-in-trail departure restrictions. Assume a 50 miles-in-trail (MIT) restriction on departures to a fix, surface metering assigns Target Movement Area entry Times separated by 10 minutes, and one of those departures has an issue and is late; an entire slot at the constrained fix could be wasted. To avoid this situation, controllers currently manually front-load at the runway demand for each restriction. Automation that supports surface metering must preserve this ability. To manage both the queue length for a runway and the number of aircraft in the queue subject to a MIT restriction, the TFDM requirements allow multiple simultaneous metering programs, and handle the situation in which a flight may be assigned multiple, different TMATs, by exempting a flight from runway metering if it is subject to MIT metering. However, the currently proposed TFDM implementation, built on existing software, does not support multiple metering programs. Thus, there is an immediate need to develop algorithmic approaches for metering the taxi of departures subject to enroute flow programs, in addition to but with separate control from metering departures to the runway. In Phase 1, this project will validate and deliver alternative methods for accomplishing the multi-objective runway queue management. Phase 2 will focus on runway queue management in a TBO environment, where time-based restrictions replace MIT restrictions, but demand uncertainty persists.