NASA Langley and NLR Research of Distributed Air/Ground Traffic Management

Abstract

Distributed Air/Ground Traffic Management (DAG-TM) is a concept of future air traffic operations that proposes to distribute information, decision-making authority, and responsibility among flight crews, the air traffic service provider, and aeronautical operational control organizations. This paper provides an overview and status of DAG-TM research at NASA Langley Research Center and the National Aerospace Laboratory of The Netherlands. Specific objectives of the research are to evaluate the technical and operational feasibility of the autonomous airborne component of DAG-TM, which is founded on the operational paradigm of free flight. The paper includes an overview of research approaches, the airborne technologies under development, and a summary of experimental investigations and findings to date. Although research is not yet complete, these findings indicate that free flight is feasible and will significantly enhance system capacity and safety. While free flight cannot alone resolve the complex issues faced by those modernizing the global airspace, it should be considered an essential part of a comprehensive air traffic management modernization activity.

Analysis of Airspace Structure and Capacity for Decentralized Separation Using Fast-Time Simulations

“…However, little effort has been devoted towards decentralized airspace design. In particular, there is no consensus in existing literature if some form of traffic organization, or structuring, is also needed to maximize capacity for decentralized separation; while Free Flight researchers advocate that higher densities can be achieved through a reduction of traffic flow constraints [6,11,12], other studies argue that capacity would benefit more from a further structuring of airspace [13,14,15]. These diametrically opposed views indicate that the relationship between airspace structure and capacity is not well understood for decentralization, i.e.…”

Operational Concept for Flight Crews to Participate in Merging and Spacing of Aircraft

“…These include: 1) use suitable but under-utilized airfields 2) build new runways (increase in airport throughput, but expensive and environmental challenges, and overall throughput may be hindered by airspace or ground movement constraints) 3) reduce wake vortex separation criteria (use research data to reduce the landing interval, increasing the maximum IFR rate) 4) reduce the separation buffer added to the minimum separation criteria between aircraft (flight operations would be closer to the established maximum IFR rate). Extensive simulator and flight trial research over the past 30 years by National Aeronautics and Space Administration (NASA) 3,4,5,6,7,8,9 , MITRE 10,11 , and Eurocontrol 12,13 has been conducted to improve runway arrival rates via en route metering and self-spacing of aircraft. A central element of much of this research is an advanced ground tool for the Air Traffic Controller (ATC) that determines an appropriate arrival schedule and landing time interval between aircraft, then computes the appropriate speed required to space aircraft close to the minimum time or distance allowed for the runway conditions.…”

Re-design of an Inbound Planning Interface for Air Traffic Control

“…The language in which the aircrew and ATCos communicate will be one of four-dimensional trajectories, any negotiation or renegotiation of a previously agreed trajectory will always result in a new 4DT. 7,11 The amount of data required to make this possible implies that this type of ATC cannot be conducted by voice alone. Also, instructions which require immediate compliance by the pilot are not easily adapted to the amount of time which is required to enter them in the aircrafts flight management system (FMS) manually.…”

“…[3][4][5] A push is provided by technological advances on the air-and ground side of the ATM-system, which make a new form of air traffic control (ATC) possible. 6,7 The proposed transformation of the ATM-system itself is mainly focused on increasing capacity, safety and efficiency, enabled by an increased amount of data exchange between the ground-(control centers, airports) and air (aircraft) segment. [8][9][10] For this purpose, the four-dimensional trajectory (4DT) is introduced, which specifies an aircraft's planned trajectory in three spatial dimensions and in time.…”