Vol.:(0123456789) 1 3 CEAS Aeronautical Journal https://doi.org/10.1007/s13272-018-0344-x ORIGINAL PAPER Potential of integrated fight scheduling and rotation planning considering aerodynamic-, engine- and mass-related aircraft deterioration M. Lindner 1  · J. Rosenow 1  · S. Förster 1  · H. Fricke 1 Received: 1 March 2017 / Revised: 14 September 2018 / Accepted: 14 November 2018 © Deutsches Zentrum für Luft- und Raumfahrt e.V. 2018 Abstract Aircraft are subject to steady deterioration efects in fight operations resulting in increased fuel consumption due to decreased engine efciency, increased airframe surface roughness and increased operating empty mass. These efects are taken into account in operational fight planning (e.g. fuel calculations) but long-term efciency loss is rarely respected in fight and rotation scheduling. In most cases, each aircraft type per feet series is treated homogeneously and scheduled considering maintenance events, equipment and other restrictions. This work investigates fuel saving potentials by additionally consider- ing the aircraft tail sign-specifc efciency during aircraft to fight assignment. For this purpose, we calculate additional fuel consumption caused by deterioration efects, expressed as performance factor and mass deviation. By using an integrated fight scheduling and aircraft rotation model, aircraft will be reassigned to fights from given fight schedules by minimiz- ing operating costs or fuel consumption. Our research yields in a saving of 22,400 kg fuel for 15 long-haul aircraft (150 kg per reassigned fight on average) based on a fight schedule for a typical week of an air cargo operator. The saving potential depends on the number of fight legs, their distance and the number of available aircraft, their performance variation and loading factor. Although relative savings are of theoretical nature and marginal to total fuel burn (0.2%), we propose an inexpensive approach to decrease total fuel consumption. Furthermore, we show that the usual approach of assigning less efcient aircraft to short fight legs is applicable but does not always provide in the cost minimum solution because low cruising altitudes of short-haul fights adversely afect fuel consumption. Keywords Flight schedule optimization · Aircraft rotation assignment · Aircraft deterioration · Performance deviation factors 1 Introduction 1.1 Motivation Although airlines’ proftability has increased in recent years, an efcient operational planning and scheduling is essential due to a highly competitive market. Especially the assign- ment process of aircraft to fight-legs signifcantly infuences airline’s direct operating costs (DOC), because the DOC not only depend on feet type, but also on each individual aircraft [1]. It is well known that ageing processes of engine and airframe as well as increased aircraft operating mass empty (OME) impact aircraft’s fuel burn up to 6% [2–4]. Most airlines, as well as aircraft’s fight management systems (FMS) consider those efects already in order to improve fuel calculation, using a specifc performance factor. This imposes an interesting research question, which is addressed in this paper: do diferences in aircraft performance (due to deterioration of aerodynamics, engine, and mass) and the resulting diferences in fuel consumption reveal a cost sav- ing potential in the tail assignment process? The authors’ experience is that a small number of airlines claim they use deterioration in the aircraft assignment, whereas others do not consider such an assignment criterion. If they do, a linear fuel consumption factor is printed as a decision support list for manual planning of long-haul feets. In this way, the ben- eft is unclear to the planner, which reduces the motivation * M. Lindner Martin_Lindner@tu-dresden.de 1 Institute of Logistics and Aviation Chair of Air Transport Technology and Logistics, TU Dresden, 01069 Dresden, Germany