Ty Hoang

A TIME-BASED APPROACH TO METERING ARRIVAL TRAFFIC TO PHILADELPHIA

Time-based metering via the Traffic Management Advisor (TMA) has significantly improved arrival operations at capacity-constrained airports in the western U.S. such as Dallas -Ft. Worth International Airport. Arrival flow management in the northeast corridor is in critical need of improvement to reduce the routine occurrence of airborne holding and in-trail spacing restrictions. However, the implementation and acceptance of time -based metering for a major airport in the tightly-constrained northeast corridor presents challenges beyond those encountered in other regions of the country. Research is underway at NASA Ames Research Center to identify these challenges, comprehend the underlying system dynamics, and develop requirements for a second -generation TMA system —the Multi-Center Traffic Management Advisor —intended to im prove arrival operations at major airports in the northeast corridor. Philadelphia International Airport has been selected as the initial development and test site. Several research activities, including site visits and simulations, have identified four primary technical challenges of metering in this airspace: (1) an infrastructur e that is inadequate for multi-facility coordination, (2) limited ability to absorb delay, (3) uncertain departure times of short-haul PHL arrivals, and (4) workload implications of converting from a miles-in-trail operation to a time-based metering operation. System requirements addressing these technical challenges are discussed.

Distributed Scheduling Architecture for Multi-Center Time-Based Metering

The Traffic Management Advisor (TMA) is an air traffic control automation system currently in use in seven Air Route Traffic Control Centers (ARTCCs) to enable time based metering to busy airports within their airspace. However, this system is limited to operation within a single ARTCC, within about a 200 nautical mile radius of the airport, and on relatively simple streams of traffic. The need for coordinated metering within a greater (300+ nautical mile) radius of an airport, on streams of traffic with significant branching, and across ARTCC boundaries, has been identified. Early tests revealed that TMA could not simply be scaled up to handle such a problem. Instead, a loosely coupled hierarchy of schedules, in which constraints from downstream schedules are passed upstream, is required. Such an architecture reduces the reliance on distant projections of arrival times, making schedules robust to changes in sequence and to additions of aircraft (such as aircraft departing inside the system s scheduling horizon). This architecture is also scaleable, easily reconfigurable, and can be networked together. As such, it can be adapted for use in any size or configuration of airspace and with any number of airports delivering restrictions. An implementation of this distributed scheduling architecture is currently undergoing testing in the TMA-Multi Center system. This paper describes the architecture and its motivation.

Multi-Center Traffic Management Advisor: Operational Test Results

The Multi-Center Traffic Management Advisor (McTMA) is a research prototype system which seeks to bring time-based metering into the mainstream of air traffic control (ATC) operations. Time-based metering is an efficient alternative to traditional air traffic management techniques such as distance-based spacing (miles-in-trail spacing) and managed arrival reservoirs (airborne holding). While time-based metering has demonstrated significant benefit in terms of arrival throughput and arrival delay, its use to date has been limited to arrival operations at just nine airports nationally. Wide-scale adoption of time-based metering has been hampered, in part, by the limited scalability of metering automation. In order to realize the full spectrum of efficiency benefits possible with time-based metering, a much more modular, scalable time-based metering capability is required. With its

CHALLENGES OF FIELD TESTING THE TRAFFIC MANAGEMENT ADVISOR (TMA) IN AN OPERATIONAL AIR TRAFFIC CONTROL FACILITY

The Traffic Management Advisor (TMA), the sequence and schedule tool of the Center/TRACON Automation System (CTAS), was evaluated at the Fort Worth Center in the summer of 1996. This paper describes the challenges encountered during the various phases of the TMA field evaluation, which included system installation, personnel training, and data collection. Operational procedures were developed and applied to the evaluation process that would ensure air safety. The five weeks of field evaluation imposed minimal impact on the hosting facility and provided valuable engineering and human factors data. The collection of data was very much an opportunistic affair, due to dynamic traffic conditions. One measure of the success of the TMA evaluation is that, rather than remove TMA after the evaluation until it could be fully implemented, the prototype TMA is in continual use at ZFW as fully operational version is readied for implementation.

THE MULTI -CENTER TMA SYSTEM ARCHITECTURE AND ITS IMPACT ON INTER -FACILITY COLLABORATION

The success of the Traffic Management Adviso r (TMA) system at Fort Worth Air Route Traffic Control Center (ARTCC) and other ARTCCs has prompted the further development of TMA to address problems in the congested environment of the Northeast corridor of the US National Airspace System (NAS). This reg ion is characterized by terminal areas whose arrivals approach from more than one ARTCC thereby requiring greater coordination in arrival traffic planning. NASA and the FAA are developing a Multi -Center Traffic Management Advisor (McTMA) tool that introduces a new infrastructure to allow individual TMA systems to communicate with each other, thereby forming a Mc TMA network. The prototype system allow s the four ARTCCs of the northeast (New York, Washington, Boston and Cleveland) and the Philadelphia (PHL) Terminal Radar Approach Control Facility (TRACON) to share a regional view of the arrival demand at the PHL airport. This shared view will enable these faci lities to proactively address PHL congestion issues through better coordination and management of traffic into an adjacent air traffic control unit, be it a sector or a facility. This paper presents a high -level description of the McTMA architecture and potential collaboration possibilities that may arise from using the system.

A distributed scheduler for air traffic flow management

A system was developed to efficiently schedule aircraft into congested resources over long ranges and present that schedule as a decision support system. The scheduling system consists of a distributed network of independent schedulers, loosely coupled by sharing capacity information. This loose coupling insulates the schedules from uncertainty in long-distance estimations of arrival times, while allowing precise short-term schedules to be constructed. This “rate profile” mechanism allows feasible schedules to be produced over long ranges, essentially constructing precise short-range schedules that also ensure that future scheduling problems are solvable while meeting operational constraints. The system was tested operationally and demonstrated reduced airborne delay and improved coordination.