2,083 research outputs found

    Performance comparison between TEMO and a typical FMS in presence of CTA and wind uncertainties

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    © 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Best session (Aiport Management & Arrival/Departure operations) paper award - 35th DASC. 2016Continuous Descent Operations (CDO) with Con- trolled Times of Arrival (CTA) at one or several metering fixes could enable environmentally friendly procedures without com- promising airspace capacity. Extending the current capabilities of state-of-the-art Flight Management Systems (FMS), the Time and Energy Managed Operations (TEMO) concept is able to generate optimal descent trajectories with an improved planning and guidance strategy to meet CTA. The primary aim of this paper is to compare the performances of TEMO (in terms of fuel consumption and time error) with respect to a typical FMS, that is an FMS without re-planning mechanism during descent based on time or altitude errors. The comparison is performed through simulation, using an A320-alike simulation model and considering several scenarios in presence of CTA and wind uncertainties. Results show that TEMO is capable of guiding the aircraft along a minimum fuel trajectory still complying with a CTA, even if significant wind prediction errors are present. For a same scenario, a typical FMS without re-planning capabilities or tactical time-error nulling mechanism during the descent, would miss the CTA in most cases.Peer ReviewedAward-winningPostprint (published version

    Effects of speed reduction in climb, cruise and descent phases to generate linear holding at no extra fuel cost

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    Best paper Award in Trajectory Optimisation Track - ICRAT 2016Speed reduction strategies have proved to be useful to recover delay if air traffic flow management regulations are cancelled before initially planned. Considering that for short- haul flights the climb and descent phases usually account for a considerable percentage of the total trip distance, this paper extends previous works on speed reduction in cruise to the whole flight. A trajectory optimization software is used to compute the maximum airborne delay (or linear holding) that can be performed without extra fuel consumption if compared with the nominal flight. Three cases are studied: speed reduction only in cruise; speed reduction in the whole flight, but keeping the nominal cruise altitude; and speed reduction for the whole flight while also optimizing the cruise altitude to maximize delay. Three representative flights have been simulated, showing that the airborne delay increases significantly in the two last cases with nearly 3-fold time for short-haul flights and 2-fold for mid- hauls with the first case. Results also show that fuel and time are traded along different phases of flight in such a way the airborne delay is maximized while the total fuel burn is kept constant.Peer ReviewedAward-winningPostprint (published version

    How much fuel and time can be saved in a perfect flight trajectory? Continuous cruise climbs vs. conventional operations

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    Continuous climb, cruise and decent operations (referred as continuous operations) may contribute to significantly reduce fuel and emissions. Nevertheless, it is obvious that the introduction of such procedures at large scale is not possible with the current air traffic management concept of operations, since flying at constant altitudes is one of the key aspects to strategically separate flows of aircraft. This paper tries to quantify what would be the potential savings of flying such optimised vertical profiles. A multiphase optimal control problem is formulated and solved by means of numerical optimisation. Optimal conventional trajectories (subject to realistic air traffic management practices and constraints) are compared with optimal continuous (and ideal) operations, only subject to aircraft performance constraints. Results show that the continuous cruise phase can lead to fuel savings between 1% and 2% of the total trip fuel for an Airbus A320. Interestingly, continuous operations show also a reduction of trip times between 1% and 5% of the total trip time, depending on the trip distance between origin and destination airports.Peer ReviewedAward-winningPostprint (published version

    Automation of On-Board Flightpath Management

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    The status of concepts and techniques for the design of onboard flight path management systems is reviewed. Such systems are designed to increase flight efficiency and safety by automating the optimization of flight procedures onboard aircraft. After a brief review of the origins and functions of such systems, two complementary methods are described for attacking the key design problem, namely, the synthesis of efficient trajectories. One method optimizes en route, the other optimizes terminal area flight; both methods are rooted in optimal control theory. Simulation and flight test results are reviewed to illustrate the potential of these systems for fuel and cost savings

    Framework for Aircraft Trajectory Planning Towards an Efficient Air Traffic Management

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    This work is partially supported by the Spanish Government through the Ministerio de Ciencia e Innovación, the Comunidad de Madrid, the project i-Math Ingenio Mathematica, and the project Optimización en Computación en Paralelo de Planificación bajo Incertidumbre under grant no. MTM2009-14087-C04-01. This work has been carried out within the framework of the Atlantida project, partially funded by the Spanish Centro para el Desarrollo Tecnológico e Industrial, in which the Universidad Rey Juan Carlos collaborated with GMVAerospace and Defence S.A.Publicad

    Fuel Conservation Strategies for the Vertical Profile of Cruise Flight

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    Fuel conservation strategies are used by airlines with the objective of making their operations more efficient, whether it is from an economical or environmental point of view. This dissertation focuses only on the vertical profile of the cruise phase of long haul commercial flights. Covering legislation, operational standards, communications, surveillance, flight planning and performance aspects. After a description of the previous aspects, the first case study is presented. This case study consists in a comparison between a usual vertical profile of a flight and an optimized one. First a theoretical estimation of the results is presented and then the detailed calculations for the actual flight are described, continuing with an explanation of several factors associated with the results. A summary of a second case study is presented to allow for a comparison between two vertical profile optimization procedures.Estratégias de otimização de combustível são utilizadas pelas companhias aéreas com o objectivo de tornar as suas operações mais eficientes, quer seja do ponto de vista ambiental, quer económico. Existem diversas estratégias para tornar as operações mais eficientes, podendo ser aplicadas em qualquer fase do voo. Nesta dissertação o foco vai centrar-se na aplicação destas técnicas na fase de cruzeiro do voo e focando apenas o perfil vertical do mesmo. É feita uma descrição da legislação aplicável à fase de cruzeiro do voo, falando de distâncias de separação mínimas, dos procedimentos operacionais, das ferramentas de comunicação e vigilância. É também apresentado o modo de construção de um plano de voo e por fim alguns pormenores sobre desempenho. Depois da descrição destes pormenos importantes à realização de um voo, é apresentado o primeiro caso de estudo, descrevendo as ferramentas necessárias, tanto em terra como a bordo, à realização dos voos de teste. Por fim são explicados vários factores que estão associados aos resultados, que são também apresentados e explicados. Um resumo de um segundo caso de estudo é posteriormente apresentado de modo a permitir a comparação entre dois procedimentos de otimização de perfis verticais

    Minimum-fuel, 3-dimensional flightpath guidance of transfer jets

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    Minimum fuel, three dimensional flightpaths for commercial jet aircraft are discussed. The theoretical development is divided into two sections. In both sections, the necessary conditions of optimal control, including singular arcs and state constraints, are used. One section treats the initial and final portions (below 10,000 ft) of long optimal flightpaths. Here all possible paths can be derived by generating fields of extremals. Another section treats the complete intermediate length, three dimensional terminal area flightpaths. Here only representative sample flightpaths can be computed. Sufficient detail is provided to give the student of optimal control a complex example of a useful application of optimal control theory

    En route speed optimization for continuous descent arrival

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    Continuous Descent Arrival (CDA) procedures have been shown to minimize the thrust required during landing, thereby reducing noise, emissions, and fuel usage for commercial aircraft. Thus, implementation of CDA at Atlanta's Hartsfield-Jackson International Airport, the world's busiest airport, would result in significant reductions in environmental impact and airline operating costs. The Air Transportation Laboratory at Georgia Tech, Delta Air Lines, and the local FAA facilities (Atlanta Center and Atlanta TRACON) collaborated to design CDA procedures for early morning arrivals from the west coast. Using the Tool for Analysis of Separation and Throughput (TASAT), we analyzed the performance of various aircraft types over a wide range of weights and wind conditions to determine the optimum descent profile parameters and to find the required spacing between aircraft types at a fixed metering point to implement the procedure. However, to see the full benefits of CDA, these spacing targets must be adhered, lest there will be a loss in capacity or negation of the noise, emissions, and fuel savings benefits. Thus a method was developed to determine adjustments to cruise speeds while aircraft are still en route, to achieve these spacing targets and to optimize fleet wide fuel burn increase. The tool in development, En route Speed Change Optimization Relay Tool (ESCORT), has been shown to solve the speed change problem quickly, incorporating aircraft fuel burn information and dividing the speed changes fairly across multiple airlines. The details of this tool will be explained in this thesis defense. Flight tests were conducted in April-May of 2007, where it was observed that the spacing targets developed by TASAT were accurate but that delivery of these aircraft to the metering point with the desired spacing targets was very challenging without automation. Thus, further flight tests will be conducted in 2008 using the en route spacing tool described above to validate the improvement it provides in terms of accurately delivering aircraft to the metering point.M.S.Committee Chair: Clarke, John-Paul; Committee Member: Barnes, Earl; Committee Member: Pritchett, Am

    Estimation of fuel inefficiencies due to early descents

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    In this project, early descents have been modeled as a combination of two stages. Firstly, a constant - vertical - speed segment beginning at a certain distance, k , before the optimal top of descent (TOD); that eventually intercepts the secon d stage: a nominal (ideal) continuous descent trajectory that would have begun at the optimal TOD and wo uld have then descended at idle thrust until reaching FL100. In both cases, an optimal Mach/CAS profile is maintained. The aforementioned two stages ha ve been simulated separately for several mass ( m ), cruise altitude ( z ) and cost index ( CI ) values using AIRBUS’ Performance Engineering Programs (PEP). In the proposed model, these two trajectories begin at the same point with the same input settings . H owe ver, they do not start descending at the same time, with the TOD of the second stage laying a k distance away from the TOD o f the first. For this reason, an initial k distance cruise segment has been added to the second stage when simulating. T he fuel con sumption of both cases was analyzed and compared using custom Python scripts in order to get a preliminary understanding of the se nsitivity of fuel consumption to the independent variables; and to check for identifiable patterns. Fuel inefficiency was thus defined as the extra fuel consumption resulting from anticipating descent initialization , and calculated as the difference in aircraft mass ( m ) between the TOD of the first stage and the point in which the constant - vertical - speed trajectory intercepts the idle - thrust type. For the aircraft used in this study, the A320 - 232, the extra fuel consumptio n incurred by an early descent reached a maximum relative value of 22.63 % and a maximum absolute value of 116 .9 kg (when k = 75 NM); showing the importance of f urther research into this topic

    Hypersonic Research Vehicle (HRV) real-time flight test support feasibility and requirements study. Part 2: Remote computation support for flight systems functions

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    The requirements are assessed for the use of remote computation to support HRV flight testing. First, remote computational requirements were developed to support functions that will eventually be performed onboard operational vehicles of this type. These functions which either cannot be performed onboard in the time frame of initial HRV flight test programs because the technology of airborne computers will not be sufficiently advanced to support the computational loads required, or it is not desirable to perform the functions onboard in the flight test program for other reasons. Second, remote computational support either required or highly desirable to conduct flight testing itself was addressed. The use is proposed of an Automated Flight Management System which is described in conceptual detail. Third, autonomous operations is discussed and finally, unmanned operations
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