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Computation of Optimal Profiles in Descent and Approach Phases

Abstract : The continued increase of air traffic, which doubles every 15 years, produces large economic benefits but poses environmental issues that put at risk the sustainable development of air transport. Other factors such as jet fuel prices volatility, the introduction of new environmental regulations and intense competition in the airline industry, have stimulated in the last years research on trajectory optimization and flight efficiency topics. The Flight Management System (FMS) is an onboard avionic system, standard in all transport aircraft, which is used by flight crews to manage the lateral and vertical flight-plan. Since current avionic systems are limited in terms of computational capacity, the computations performed by their algorithms are usually done on the basis of conservative hypotheses. Thus, notorious deviations may occur between FMS computations and the actual flight profile flown by the aircraft. The goal of this thesis is to develop an onboard function, which could be integrated in future Airbus cockpits, that computes optimal trajectories, readjusts the flight strategy according to the dynamic aircraft condition and minimizes operating costs. Flight energy management principles has been used for optimizing aircraft trajectories in descent and approach phases with respect to fuel consumption, greenhouse gas and noise emissions. The proposed function has been developed on the basis of dynamic programming techniques, in particular the A* algorithm. The algorithm minimizes a certain objective function by generating incrementally the search space. The exploration of the search space gives the optimal profile that links the aircraft current position to the runway threshold, independently of the current flight mode and aircraft energy condition. Results show 13% fuel savings and a decrease of 12% in gas emissions compared with a best-in-class FMS. Furthermore, the algorithm proposes the flight strategy to dissipate the excess of energy in situations where aircraft fly too high and/or too fast close to the destination runway. A preliminary operational evaluation of the computed trajectories has been conducted in the flight simulators. These tests demonstrate that the computed trajectories can be tracked with current guidance modes, although new modes should be required to decrease the workload of flight crews. In conclusion, this paper constitutes a solid background for the generation of real-time optimal trajectories in light of the automation of descent and approach flight phases.
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Submitted on : Friday, November 13, 2020 - 4:29:07 PM
Last modification on : Wednesday, January 6, 2021 - 2:22:02 PM
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  • HAL Id : tel-03004543, version 1



Ramon Andreu Altava. Computation of Optimal Profiles in Descent and Approach Phases. Mathematical Software [cs.MS]. Université Paul Sabatier - Toulouse III, 2020. English. ⟨NNT : 2020TOU30026⟩. ⟨tel-03004543⟩



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