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Article
Publication date: 6 September 2021

Bahareh Shafipour-Omrani, Alireza Rashidi Komijan, Seyed Jafar Sadjadi, Kaveh Khalili-Damghani and Vahidreza Ghezavati

One of the main advantages of the proposed model is that it is flexible to generate n-day pairings simultaneously. It means that, despite previous researches, one-day to n

Abstract

Purpose

One of the main advantages of the proposed model is that it is flexible to generate n-day pairings simultaneously. It means that, despite previous researches, one-day to n-day pairings can be generated in a single model. The flexibility in generating parings causes that the proposed model leads to better solutions compared to existing models. Another advantage of the model is minimizing the risk of COVID-19 by limitation of daily flights as well as elapsed time minimization. As airports are among high risk places in COVID-19 pandemic, minimization of infection risk is considered in this model for the first time. Genetic algorithm is used as the solution approach, and its efficiency is compared to GAMS in small and medium-size problems.

Design/methodology/approach

One of the most complex issues in airlines is crew scheduling problem which is divided into two subproblems: crew pairing problem (CPP) and crew rostering problem (CRP). Generating crew pairings is a tremendous and exhausting task as millions of pairings may be generated for an airline. Moreover, crew cost has the largest share in total cost of airlines after fuel cost. As a result, crew scheduling with the aim of cost minimization is one of the most important issues in airlines. In this paper, a new bi-objective mixed integer programming model is proposed to generate pairings in such a way that deadhead cost, crew cost and the risk of COVID-19 are minimized.

Findings

The proposed model is applied for domestic flights of Iran Air airline. The results of the study indicate that genetic algorithm solutions have only 0.414 and 0.380 gap on average to optimum values of the first and the second objective functions, respectively. Due to the flexibility of the proposed model, it improves solutions resulted from existing models with fixed-duty pairings. Crew cost is decreased by 12.82, 24.72, 4.05 and 14.86% compared to one-duty to four-duty models. In detail, crew salary is improved by 12.85, 24.64, 4.07 and 14.91% and deadhead cost is decreased by 11.87, 26.98, 3.27, and 13.35% compared to one-duty to four-duty models, respectively.

Originality/value

The authors confirm that it is an original paper, has not been published elsewhere and is not currently under consideration of any other journal.

Details

Kybernetes, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0368-492X

Keywords

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Article
Publication date: 6 September 2021

Ke Lu, Shanyong Zhao, YUjie Ma, Shangjing Wu and Cheng da Su

This paper aims to present an investigation on flight quality analysis and design of tilt-rotor aircraft combined with corresponding flight quality specifications.

Abstract

Purpose

This paper aims to present an investigation on flight quality analysis and design of tilt-rotor aircraft combined with corresponding flight quality specifications.

Design/methodology/approach

From the perspective of modal characteristics of tilt-rotor aircraft, it focuses on the analysis of the change rules of the longitudinal short-term motion mode, lateral roll convergence mode, spiral mode and Dutch roll mode. Then, the flight quality design research is carried out using the explicit model tracking control method. The quantitative relationship between flight quality requirements and explicit model is established. Accordingly, the closed-loop flight quality of XV-15 tilt-rotor aircraft is evaluated.

Findings

The stability of spiral mode is the result of the interaction of various aerodynamic derivatives and spiral instability occurs in helicopter mode. The other motion modes are stable in full flight mode and meet the requirements of level 1 specified in ADS-33E-PRF and MIL-F-8785C flight quality specifications. There is a quantitative relationship between flight quality requirements and explicit model, and the flight quality of tilt-rotor aircraft is improved through the explicit model tracking control method.

Practical implications

The presented analysis results showed the influence of motion modes and flight quality and the effectiveness of explicit model tracking control method in flight quality improvement, which could be considered as new information for further flight quality design of tilt-rotor aircraft.

Originality/value

The originality of the paper lies in the proposed design and analysis method of the flight quality of tilt-rotor aircraft from the direction of the influence of its aerodynamic derivatives and motion modes.

Details

Aircraft Engineering and Aerospace Technology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1748-8842

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Article
Publication date: 5 August 2021

Gamze Orhan

Deregulation of domestic markets and the liberalization of international markets have dramatically changed air transportation. One of the important results of this change…

Abstract

Purpose

Deregulation of domestic markets and the liberalization of international markets have dramatically changed air transportation. One of the important results of this change is the environmental effects of air transportation. This study aims to examine the implications of air transportation on environmental sustainability in the context of airline business strategies in liberalized and globalized air transport industry.

Design/methodology/approach

The paper discusses the relationship between liberalization, airline strategies and environmental sustainability of air transportation using the related literature. Then, to show some environmental impacts on the axis of the relationship discussed, emission rates for the aircraft landing and take-off phase were calculated on a global basis based on the aircraft traffic.

Findings

The discussion in the paper shows that the liberalization policies and the strategies of airlines supported by these policies, in essence, contradict the environmental sustainability of air transport. Considering the flight share projections of EUROCONTROL for different aircraft types on a global basis and the World Bank’s global flight traffic forecast for the years 2016 and 2025, it has been demonstrated that the number of aircraft departures will increase by 30%, whilst the number of aircraft emissions will increase by 41.5%.

Practical implications

Airlines are one of the main actors that will play a role in reducing the environmental impacts of air transportation. Therefore, this study is important in giving an idea to both policymakers and airline managers on how airline companies’ strategies should be shaped to realize both corporate sustainability and environmentally sustainable air transportation.

Originality/value

There are many studies in the literature regarding the environmental effects of air transport. However, there are not many studies linking environmental impacts with airline strategies that directly affect air transport demand. This study is different in that it gives environmental sustainability by associating it with its root causes.

Details

Aircraft Engineering and Aerospace Technology, vol. 93 no. 8
Type: Research Article
ISSN: 1748-8842

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Article
Publication date: 25 September 2009

H. Murat Afsar, Marie‐Laure Espinouse and Bernard Penz

The purpose of this paper is to provide some heuristic and meta heuristic tools to aid airline companies in flight planning while taking into account maintenance planning…

Abstract

Purpose

The purpose of this paper is to provide some heuristic and meta heuristic tools to aid airline companies in flight planning while taking into account maintenance planning. The objective is to maximize aircraft utilization before the maintenance interventions and to smooth the long‐term flight load of the aircraft so that maintenance checks are regular for all the fleet.

Design/methodology/approach

The proposed methods, based on operational research solution technics, build a flight planning for an airline company. The simulation of the proposed methods is observed over 40 weeks and evaluated with different problem instances and maintenance policies.

Findings

The longest path based method with increasing priority and the simulated annealing are shown to have the best aircraft utilization results.

Research limitations/implications

Further research could propose some methods which build simultaneous maintenance and flight planning.

Practical implications

The economic value and legal considerations of maintenance activities in the airline industry show the importance of maximizing aircraft utilization. The proposed methods are compared to decide the best maintenance policy. These methods are simple and efficient.

Originality/value

This paper provides a connection between an industrial problem of aircraft maximization under maintenance constraints and operational research. Simple but efficient methods are evaluated in terms of two criteria: aircraft maximization and flight load smoothing.

Details

Journal of Quality in Maintenance Engineering, vol. 15 no. 4
Type: Research Article
ISSN: 1355-2511

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Article
Publication date: 1 December 2002

Kazimierz Szumański, Jerzy Bereżański and Andrzej Szumański

The results of preliminary tests concerning estimation and widening of helicopter limiting manoeuvre abilities are presented. Research space applies to super‐ and…

Abstract

The results of preliminary tests concerning estimation and widening of helicopter limiting manoeuvre abilities are presented. Research space applies to super‐ and hipermanoeuvrability problems that are especially important for helicopters, because of better manoeuvrability influence on higher safety level and effectiveness in special applications. In airplane engineering, these types of tests are advanced and aerodynamic system improvements are introduced as well as thrust vector control. There are also new manoeuvres recognized for advanced manoevrability airplanes: Cobra, Kulbit, Hook, Bell, Herbst manoeuvre. Although helicopter is “originally” thrust controlled, systematic researches on this field are still not conducted. The paper deals with the problem of helicopter flight mechanics at low flight speeds. The purpose of performed analysis is to achieve possibility of helicopter angular position control within wide range of angular displacements. This is performed by linear and centrifugal acceleration control. Rotor thrust vector control makes those accelerations appear.

Details

Aircraft Engineering and Aerospace Technology, vol. 74 no. 6
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 26 July 2021

Yonghu Wang, Ray C. Chang and Wei Jiang

The purpose of this paper is to present a quick inspection method based on the post-flight data to examine static aeroelastic behavior for transport aircraft subjected to…

Abstract

Purpose

The purpose of this paper is to present a quick inspection method based on the post-flight data to examine static aeroelastic behavior for transport aircraft subjected to instantaneous high g-loads.

Design/methodology/approach

In the present study, the numerical approach of static aeroelasticity and two verified cases will be presented. The non-linear unsteady aerodynamic models are established through flight data mining and the fuzzy-logic modeling of artificial intelligence techniques based on post-flight data. The first and second derivatives of flight dynamic and static aeroelastic behaviors, respectively, are then estimated by using these aerodynamic models.

Findings

The flight dynamic and static aeroelastic behaviors with instantaneous high g-load for the two transports will be analyzed and make a comparison study. The circumstance of turbulence encounter of the new twin-jet is much serious than that of four-jet transport aircraft, but the characteristic of stability and controllability for the new twin-jet is better than those of the four-jet transport aircraft; the new twin-jet transport is also shown to have very small aeroelastic effects. The static aeroelastic behaviors for the two different types can be assessed by using this method.

Practical implications

As the present study uses the flight data stored in a quick access recorder, an intrusive structural inspection of the post-flight can be avoided. A tentative conclusion is to prove that this method can be adapted to examine the static aeroelastic effects for transport aircraft of different weights, different sizes and different service years in tracking static aeroelastic behavior of existing different types of aircraft. In future research, one can consider to have more issues of other types of aircraft with high composite structure weight.

Originality/value

This method can be used to assist airlines to monitor the variations of flight dynamic and static aeroelastic behaviors as a complementary tool for management to improve aviation safety, operation and operational efficiency.

Details

Aircraft Engineering and Aerospace Technology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1748-8842

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Article
Publication date: 22 July 2021

Sławomir Samolej, Grzegorz Dec, Dariusz Rzonca, Andrzej Majka and Tomasz Rogalski

The purpose of this study is to provide an alternative graph-based airspace model for more effective free-route flight planning.

Abstract

Purpose

The purpose of this study is to provide an alternative graph-based airspace model for more effective free-route flight planning.

Design/methodology/approach

Based on graph theory and available data sets describing airspace, as well as weather phenomena, a new FRA model is proposed. The model is applied for near to optimal flight route finding. The software tool developed during the study and complexity analysis proved the applicability and timed effectivity of the flight planning approach.

Findings

The sparse bidirectional graph with edges connecting only (geographically) closest neighbours can naturally model local airspace and weather phenomena. It can be naturally applied to effective near to optimal flight route planning.

Research limitations/implications

Practical results were acquired for one country airspace model.

Practical implications

More efficient and applicable flight planning methodology was introduced.

Social implications

Aircraft following the new routes will fly shorter trajectories, which positively influence on the natural environment, flight time and fuel consumption.

Originality/value

The airspace model proposed is based on standard mathematical backgrounds. However, it includes the original airspace and weather mapping idea, as well as it enables to shorten flight planning computations.

Details

Aircraft Engineering and Aerospace Technology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1748-8842

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Article
Publication date: 4 May 2021

Luitpold Babel

A major challenge for mission planning of aircraft is to generate flight paths in highly dynamic environments. This paper presents a new approach for online flight path…

Abstract

Purpose

A major challenge for mission planning of aircraft is to generate flight paths in highly dynamic environments. This paper presents a new approach for online flight path planning with flight time constraints for fixed-wing UAVs. The flight paths must take into account the kinematic restrictions of the vehicle and be collision-free with terrain, obstacles and no-fly areas. Moreover, the flight paths are subject to time constraints such as predetermined time of arrival at the target or arrival within a specified time interval.

Design/methodology/approach

The proposed flight path planning algorithm is an evolution of the well-known RRT* algorithm. It uses three-dimensional Dubins paths to reflect the flight capabilities of the air vehicle. Requirements for the flight time are realized by skillfully concatenating two rapidly exploring random trees rooted in the start and target point, respectively.

Findings

The approach allows to consider static obstacles, obstacles which might pop up unexpectedly, as well as moving obstacles. Targets might be static or moving with constantly changing course. Even a change of the target during flight, a change of the target approach direction or a change of the requested time of arrival is included.

Originality/value

The capability of the flight path algorithm is demonstrated by simulation results. Response times of fractions of a second qualify the algorithm for real-time applications in highly dynamic scenarios.

Details

International Journal of Intelligent Unmanned Systems, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2049-6427

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Article
Publication date: 25 February 2021

Ridvan Oruc and Tolga Baklacioglu

The purpose of this paper is to create a new fuel flow rate model for the descent phase of the flight using particle swarm optimization (PSO).

Abstract

Purpose

The purpose of this paper is to create a new fuel flow rate model for the descent phase of the flight using particle swarm optimization (PSO).

Design/methodology/approach

A new fuel flow rate model was developed for the descent phase of the B737-800 aircraft, which is frequently used in commercial air transport using PSO method. For the analysis, the actual flight data records (FDRs) data containing the fuel flow rate, speed, altitude, engine speed, time and many more data were used. In this regard, an empirical formula has been created that gives real fuel flow rate values as a function of altitude and true airspeed. In addition, in the fuel flow rate predictions made for the descent phase of the specified aircraft, a different model has been created that can be used without any optimization process when FDR data are not available for a specific aircraft take-off weight condition.

Findings

The error analysis applied to the models showed that both models predict real fuel flow rate values with high precision.

Practical implications

Because of the high accuracy of the PSO model, it is thought to be useful in air traffic management, decision support systems, models used for trajectory prediction, aircraft performance models, strategies used to reduce fuel consumption and emissions because of fuel consumption.

Originality/value

This study is the first fuel flow rate model for descent flight using PSO algorithm. The use of real FDR data in the analysis shows the originality of this study.

Details

Aircraft Engineering and Aerospace Technology, vol. 93 no. 2
Type: Research Article
ISSN: 1748-8842

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Article
Publication date: 5 April 2021

Agnieszka Kwiek, Cezary Galinski, Krzysztof Bogdański, Jaroslaw Hajduk and Andrzej Tarnowski

According to the study of the space flight market, there is a demand for space suborbital flights including commercial tourist flights. However, one of the challenges is…

Abstract

Purpose

According to the study of the space flight market, there is a demand for space suborbital flights including commercial tourist flights. However, one of the challenges is to design a mission and a vehicle that could offer flights with relatively low G-loads. The project of the rocket-plane in a strake-wing configuration was undertaken to check if such a design could meet the FAA recommendation for this kind of flight. The project concept assumes that the rocket plane is released from a slowly flying carrier plane, then climbs above 100 kilometers above sea level and returns in a glide flight using a vortex lift generated by the strake-wing configuration. Such a mission has to include a flight transition during the release and return phases which might not be comfortable for passengers. Verification if FAA recommendation is fulfilled during these transition maneuvers was the purpose of this study.

Design/methodology/approach

The project was focused on the numerical investigation of a possibility to perform transition maneuvers mentioned above in a passenger-friendly way. The numerical simulations of a full-scale rocket-plane were performed using the simulation and dynamic stability analyzer (SDSA) software package. The influence of an elevator deflection change on flight parameters was investigated in two cases: a transition from the steep descent at high angles of attack to the level glide just after rocket-plane release from the carrier and an analogous transition after re-entry to the atmosphere. In particular, G-loads and G-rates were analyzed.

Findings

As a result, it was found that the values of these parameters satisfied the specific requirements during the separation and transition from a steep descent to gliding. They would be acceptable for an average passenger.

Research limitations/implications

To verify the modeling approach, a flight test campaign was performed. During the experiment, a rocket-plane scaled model was released from the RC model helicopter. The rocket-plane model was geometrically similar only. Froude scales were not applied because they would cause excessive technical complications. Therefore, a separate simulation of the experiment with the application of the scaled model was performed in the SDSA software package. Results of this simulation appeared to be comparable to flight test results so it can be concluded that results for the full-scale rocket-plane simulation are also realistic.

Practical implications

It was proven that the rocket-plane in a strake-wing configuration could meet the FAA recommendation concerning G-loads and G rates during suborbital flight. Moreover, it was proven that the SDSA software package could be applied successfully to simulate flight characteristics of airplanes flying at angles of attack not only lower than stall angles but also greater than stall angles.

Social implications

The application of rocket-planes in a strake-wing configuration could make suborbital tourist flights more popular, thus facilitating the development of manned space flights and contributing to their cost reduction. That is why it was so important to prove that they could meet the FAA recommendation for this kind of service.

Originality/value

The original design of the rocket plane was analyzed. It is equipped with an optimized strake wing and is controlled with oblique, all moving, wingtip plates. Its post-stall flight characteristics were simulated with the application of the SDSA software package which was previously validated only for angles of attack smaller than stall angle. Therefore, experimental validation was necessary. However, because of excessive technical problems caused by the application of Froude scales it was not possible to perform a conventional test with a dynamically scaled model. Therefore, the geometrically scaled model was built and flight tested. Then a separate simulation of the experiment with the application of this model was performed. Results of this separate simulation were compared with the results of the flight test. This comparison allowed to draw the conclusion on the applicability of the SDSA software for post-stall analyzes and, indirectly, on the applicability of the proposed rocket-plane for tourist suborbital flights. This approach to the experimental verification of numerical simulations is quite unique. Finally, a quite original method of the model launching during flight test experiment was applied.

Details

Aircraft Engineering and Aerospace Technology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1748-8842

Keywords

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