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An operating concept and a laboratory analysis methodology were developed and tested to examine how four-dimensional trajectory analysis methods could support higher levels of automation for separation assurance in the National Airspace System. Real-time simulations were conducted in which a human controller generated conflict resolution trajectories using an automated trial plan trajectory generation and analysis function, but only in response to conflicts detected and displayed by an automatic conflict detection function. Objective metrics were developed to compare aircraft separation characteristics and flying time efficiency under automated operations with that of today's operations using common airspace and common traffic scenarios. Simulations were based on recorded air traffic data from the Fort Worth Air Route Traffic Control Center and were conducted using today's and nearly two-times today's traffic levels. The results suggest that a single controller using trajectory-based automation and data link communication of control clearances to aircraft could manage substantially more traffic than under today's conditions, and with improved route efficiency while maintaining separation. The simulation and analysis capability provides a basis for further analysis of semi-automated, or fully automated, separation assurance concepts.

The Dynamic Weather Routes (DWR) tool continuously analyzes active flights in en route airspace and finds simple route corrections to achieve more time-and fuel-efficient routes around convective weather. A strong partnership between NASA, American Airlines (AA), and the Federal Aviation Administration has enabled testing of DWR in real-world air traffic operations. NASA and AA have been conducting a trial of DWR at AA's Integrated Operations Center in Fort Worth, Texas since July 2012. This paper describes test results based on AA's use of DWR for their flights in and around Fort Worth Center (ZFW). Results indicate an actual savings of 3,290 flying minutes for 526 AA revenue flights from January 2013 through September 2014. Of these, 48 flights each indicate a savings of 15 min or more. Potential savings for all flights in ZFW airspace, corrected for savings flights achieve today through normal pilot requests and controller clearances, is about 100,000 flying minutes for 15,000 flights in 2013. Results indicate that AA flights with DWR in use realize about 20% more savings than non-AA flights. A weather forecast analysis examines the extent to which DWR routes rated acceptable by AA users remain clear of downstream weather. A sector congestion analysis indicates congestion could be reduced 19-38% if all flights fly DWR routes rather than nominal weather-avoidance routes.

The Center/TRACON Automaton System (CTAS) is a set of air traffic management tools developed by NASA in conjunction with the FAA. As part of its functionality, CTAS predicts aircraft flight trajectories using aeropropulsive models and the kinetic equations of motion for various flight conditions including climbs. Precise aeropropulsive models for all aircraft types are not yet available to NASA researchers. In an effort to improve climb trajectory prediction of jet aircraft for which CTAS does not have a precise aero-propulsive model, a technique was developed to derive an aero-propulsive model from readily available time-to-climb data found in flight manuals. A case study was performed on a Boeing 737-400, for which time-to-climb data and aero-propulsive model data were known. A new aero-propulsive model, identified by three aerodynamic and one propulsive parameter, was derived from the time-to-climb data. The results showed it was possible to derive an aero-propulsive model for an aircraft type that will allow CTAS to compute time-to-climb for a range of climb speeds that agree closely with known data. This technique was then applied to a Learjet 60, an aircraft type for which a precise aero-propulsive model is not available. A comparison of top-of-climb predictions made with a derived aero-propulsive model and actual top-ofclimb from Learjet 60 radar track data reveal close agreement.

An operating concept and a laboratory analysis methodology were developed and tested to examine how four-dimensional trajectory analysis methods could support higher levels of automation for separation assurance in the National Airspace System. Real-time simulations were conducted in which a human controller generated conflict resolution trajectories using an automated trial plan trajectory generation and analysis function, but only in response to conflicts detected and displayed by an automatic conflict detection function. Objective metrics were developed to compare aircraft separation characteristics and flying time efficiency under automated operations with that of today's operations using common airspace and common traffic scenarios. Simulations were based on recorded air traffic data from the Fort Worth Air Route Traffic Control Center and were conducted using today's and nearly two-times today's traffic levels. The results suggest that a single controller using trajectory-based automation and data link communication of control clearances to aircraft could manage substantially more traffic than under today's conditions, and with improved route efficiency while maintaining separation. The simulation and analysis capability provides a basis for further analysis of semi-automated, or fully automated, separation assurance concepts.