Aircraft Trajectory Optimization in the Horizontal Plane

The implementation of Trajectory-Based Operations, invented by the Single European Sky Air Traffic Management Research program SESAR, enables airlines to fly along optimized waypoint-less trajectories and accordingly to significantly increase the sustainability of the air transport system in a business with increasing environmental awareness. However, unsteady weather conditions and uncertain weather forecasts might induce the necessity to re-optimize the trajectory during the flight. By considering a re-optimization of the trajectory during the flight they further support air traffic control towards achieving precise air traffic flow management and, in consequence, an increase in airspace and airport capacity. However, the re-optimization leads to an increase in the operator and controller’s task loads which must be balanced with the benefit of the re-optimization. From this follows that operators need a decision support under which circumstances and how often a trajectory re-optimization should be carried out. Local numerical weather service providers issue hourly weather forecasts for the coming hour. Such weather data sets covering three months were used to re-optimize a daily A320 flight from Seattle to New York every hour and to calculate the effects of this re-optimization on fuel consumption and deviation from the filed path. Therefore, a simulation-based trajectory optimization tool was used. Fuel savings between 0.5% and 7% per flight were achieved despite minor differences in wind speed between two consecutive weather forecasts in the order of 0.5 m s−1. The calculated lateral deviations from the filed path within 1 nautical mile were always very small. Thus, the method could be easily implemented in current flight operations. The developed performance indicators could help operators to evaluate the re-optimization and to initiate its activation as a new flight plan accordingly.

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Individual Condensation Trails in Aircraft Trajectory Optimization

Sustainability ◽

10.3390/su11216082 ◽

2019 ◽

Vol 11 (21) ◽

pp. 6082 ◽

Cited By ~ 3

Author(s):

Judith Rosenow ◽

Hartmut Fricke

Keyword(s):

Global Warming ◽

Trajectory Optimization ◽

Wind Shear ◽

Impact Factors ◽

Factors Influencing ◽

Order Of Magnitude ◽

Aircraft Trajectory ◽

The Impact ◽

Arbitrary Trajectory ◽

Significant Factors

Contrails are one of the driving contributors to global warming, induced by aviation. The quantification of the impact of contrails on global warming is nontrivial and requires further in-depth investigation. In detail, condensation trails might even change the algebraic sign between a cooling and a warming effect in an order of magnitude, which is comparable to the impact of aviation-emitted carbon dioxides and nitrogen oxides. This implies the necessity to granularly consider the environmental impact of condensation trails in single-trajectory optimization tools. The intent of this study is the elaboration of all significant factors influencing on the net effect of single condensation trails. Possible simplifications will be proposed for a consideration in single-trajectory optimization tools. Finally, the effects of the most important impact factors, such as latitude, time of the year, and time of the day, wind shear, and atmospheric turbulence as well as their consideration in a multi-criteria trajectory optimization tool are exemplified. The results can be used for an arbitrary trajectory optimization tool with environmental optimization intents.

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Hierarchical Modeling Approach in Aircraft Trajectory Optimization

IFAC Proceedings Volumes ◽

10.1016/s1474-6670(17)45772-7 ◽

1994 ◽

Vol 27 (13) ◽

pp. 17-22

Author(s):

S. Bocvarov ◽

E.M. Cliff ◽

F.H. Lutze

Keyword(s):

Trajectory Optimization ◽

Hierarchical Modeling ◽

Modeling Approach ◽

Aircraft Trajectory

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In-Flight Aircraft Trajectory Optimization within Corridors Defined by Ensemble Weather Forecasts

Aerospace ◽

10.3390/aerospace7100144 ◽

2020 ◽

Vol 7 (10) ◽

pp. 144 ◽

Cited By ~ 1

Author(s):

Martin Lindner ◽

Judith Rosenow ◽

Thomas Zeh ◽

Hartmut Fricke

Keyword(s):

Traffic Control ◽

Traffic Management ◽

Trajectory Optimization ◽

Air Traffic ◽

Weather Data ◽

Parameter Uncertainties ◽

Weather Forecasts ◽

Fuel Savings ◽

Flight Plan ◽

Aircraft Trajectory

Today, each flight is filed as a static route not later than one hour before departure. From there on, changes of the lateral route initiated by the pilot are only possible with air traffic control clearance and in the minority. Thus, the initially optimized trajectory of the flight plan is flown, although the optimization may already be based upon outdated weather data at take-off. Global weather data as those modeled by the Global Forecast System do, however, contain hints on forecast uncertainties itself, which is quantified by considering so-called ensemble forecast data. In this study, the variability in these weather parameter uncertainties is analyzed, before the trajectory optimization model TOMATO is applied to single trajectories considering the previously quantified uncertainties. TOMATO generates, based on the set of input data as provided by the ensembles, a 3D corridor encasing all resulting optimized trajectories. Assuming that this corridor is filed in addition to the initial flight plan, the optimum trajectory can be updated even during flight, as soon as updated weather forecasts are available. In return and as a compromise, flights would have to stay within the corridor to provide planning stability for Air Traffic Management compared to full free in-flight optimization. Although the corridor restricts the re-optimized trajectory, fuel savings of up to 1.1%, compared to the initially filed flight, could be shown.

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