Overall safety performance of the air traffic management system: Indicators and analysis

Defining means to assess safety performance and delve into their causes is one of the current and future challenges of the ATM sector. Following the experiences of the Aerospace Performance Factor by FAA and EUROCONTROL, this research aims to apply the Analytic Hierarchy Process (AHP) in order to build synthetic and user-friendly safety-related indicators. Through the analysis and combination of the safety events over time (accidents, incidents and issues), this model will pinpoint critical situations and will address the interventions of the decision makers.     

An analysis of the determinants of air traffic volume for European metropolitan areas

This paper examines the determinants of air traffic volume in the major European urban regions, highlighting those that depend on the metropolitan features of cities. We used homogeneous urban and airline data that make international comparisons possible. We found that GDP, the level of economic decision-power, tourism functions, and the distance from a major air market account for more than two-thirds of the variation in air service. This seems to indicate that air service remains profoundly rooted in the metropolitan features of urban regions (notably size and decision-power), even if low-cost airlines are probably less linked to the latter because they partly focus on niche markets and regional airports. Much of the remainder is probably attributable to the specificities of the urban economy, to actors’ strategies and to competition from high-speed trains.     

Optimizing and assigning price levels for air traffic management

Pricing policies could encourage airline companies to modify departure times and routes of their flights in order to reach a route-slot allocation target that minimizes the en-route congestion. The problem of restricting the number of price levels and the assignment of one price level to each sector at each time period is studied using a simulation based on a Logit discrete choice model. In this model, an option is defined as the combination of a departure time and a route. For each flight, a utility is associated to each option and takes into account the flying cost, the cost of ground delay and the prices of crossed sectors. The optimization of the pricing policy considers average flows and minimizes the quadratic difference between desired and expected flows on each option. A heuristic algorithm that involves successive iterations of simulated annealing and gradient methods performs this optimization. The simulated annealing assigns a price level to each sector at each time period, and the gradient algorithm computes new values of price levels. The test of the method on constructed examples indicates that the use of only four price levels does not significantly deteriorate the performance of the system with respect to the use of independent prices.     

An empirically grounded agent based simulator for the air traffic management in the SESAR scenario

In this paper we present a simulator allowing to perform policy experiments relative to the air traffic management. Different SESAR solutions can be implemented in the model to see the reaction of the different stakeholders as well as other relevant metrics (delay, safety, etc). The model describes both the strategic phase associated to the planning of the flight trajectories and the tactical modifications occurring in the en-route phase. An implementation of the model is available as an open-source software and is freely accessible by any user.More specifically, different procedures related to business trajectories and free-routing are tested and we illustrate the capabilities of the model on an airspace which implements these concepts. After performing numerical simulations with the model, we show that in a free-routing scenario the controllers perform less operations but the conflicts are dispersed over a larger portion of the airspace. This can potentially increase the complexity of conflict detection and resolution for controllers.In order to investigate this specific aspect, we consider some metrics used to measure traffic complexity. We first show that in non-free-routing situations our simulator deals with complexity in a way similar to what humans would do. This allows us to be confident that the results of our numerical simulations relative to the free-routing can reasonably forecast how human controllers would behave in this new situation. Specifically, our numerical simulations show that most of the complexity metrics decrease with free-routing, while the few metrics which increase are all linked to the flight level changes. This is a non-trivial result since intuitively the complexity should increase with free-routing because of problematic geometries and more dispersed conflicts over the airspace.     

An econometric analysis of domestic air traffic demand in regional airports: Evidence from India

The Indian aviation industry has a vast potential to grow to cater to its population and commerce through developing air transport services to the regional airports. This paper examines the possible determinants of domestic air traffic demand in Indian regional airports serving below three million passengers per annum. Using multiple regression analysis, we find that distance to the nearest airport and accessibility of the airport significantly affect traffic volumes in regional airports. This study also highlights the specificities of Indian regional airports.     

Statistical characterization of deviations from planned flight trajectories in air traffic management

Understanding the relation between planned and realized flight trajectories and the determinants of flight deviations is of great importance in air traffic management. In this paper we perform an in-depth investigation of the statistical properties of planned and realized air traffic on the German airspace during a 28 day periods, corresponding to an AIRAC cycle. We find that realized trajectories are on average shorter than planned ones and this effect is stronger during night-time than day-time. Flights are more frequently deviated close to the departure airport and at a relatively large angle-to-destination. Moreover, the probability of a deviation is higher in low traffic phases. All these evidences indicate that deviations are mostly used by controllers to give directs to flights when traffic conditions allow it. Finally we introduce a new metric, termed di-fork, which is able to characterize navigation points according to the likelihood that a deviation occurs there. Di-fork allows to identify in a statistically rigorous way navigation point pairs where deviations are more (less) frequent than expected under a null hypothesis of randomness that takes into account the heterogeneity of the navigation points. Such pairs can therefore be seen as sources of flexibility (stability) of controllers traffic management while conjugating safety and efficiency.     

Methods of air traffic management in the airport area including the environmental factor

In the modern approach to air traffic management (ATM), issues related to air quality and climate protection have led to the introduction of a growing number of new restrictions instead of having these issues be the objectives of actions taken. The aim of the study was to investigate whether it is possible to improve air quality while controlling pollution emission by introducing changes in the organization of air traffic control at the airport. For this purpose, mathematical models of emissions were created. These concern the movement of aircraft near the airport and emission of carbon dioxide and the spread of human health related substances emitted from a landing airplane's engine. The first case refers to the possibility of using different arrival procedures. The second case was to adapt the Pasquill formula by treating landing aircraft as a sequence of point-source emissions. As a result of applying the designed models and software tools, it was proven that both a change in the arrival trajectory and a change of the runway can contribute to a reduction of CO₂ emission into the atmosphere. The emission maps created for different aircraft approach profiles show the ability to control the local concentration of harmful emissions. The study clearly shows that the current approach of maximizing throughput is not beneficial to air quality. ATM services should consider the use of other variants of air traffic organization, particularly during periods of reduced traffic.     

International air network structures and air traffic density of world cities

This paper examines international air passenger and cargo flows within and among Asia, Europe, and America, and the degree of air traffic density for major cities worldwide, using a basic gravity model composed of GDP, population, distance, and several dummy variables. The results reveal that many cities are strengthening their position as international air transportation hubs, especially: Tokyo, Hong Kong, Singapore, London, Paris, Frankfurt, Amsterdam, New York, and Miami. Finally, the results show that the air traffic density of three cities, Seoul, Hong Kong, and Amsterdam, is growing at an extraordinary rate.     

Challenges to domestic air freight in Australia: Evaluating air traffic markets with gravity modelling

With two of the busiest air traffic corridors globally, Sydney-Melbourne (SYD-MEL) and Sydney-Brisbane (SYD-BNE), very liberal open skies agreements, and the world's most isolated large city in Perth, air freight in Australia should be destined for substantial growth, but has in contrast to other regions such as the US not yet materialised. This paper identifies challenges surrounding domestic air freight markets in Australia and compares the provision of road vs air freight services utilising gravity modelling methods. Our findings suggest the impedance of domestic air freight services in Australia is greater for regional areas between the primary cities (such as Canberra, between Sydney and Melbourne) than remoter areas (such as Cairns in Northern Australia). Our models show further that in addition to distance, air freight capacity on any of our analysed routes is despite being demand-pulled in terms of GDP dependency significantly attuned to factors at both the origin (in particular domestic trade capability, i.e. manufacturing and logistics) and destination.     

An airline's management strategies in a competitive air transport market

Over the last decade, the demand for domestic and international flights in Korea has increased substantially. To meet the strong flight demands, several low cost carriers have begun to offer flight services. In addition, full service carriers have been motivated to establish their own subsidiary low cost carriers to maintain their market share against rival low cost carriers. This paper studies the management strategies of three kinds of airlines - full service carrier, its subsidiary low cost carrier and rival low cost carrier - based on game theory in the competitive air transport market. Each airline is assumed to act as a player and chooses strategies regarding airfare, flight frequency, and the number of operating aircrafts for specific routes while maximizing its own profits. Demand leakages between the airlines are considered in the flight demand function according to the selected strategies of all airlines. Through various game situations reflecting realistic features, this study provides managerial insights that can be applied in the competitive air transport market.     

An analysis of essential air service structure and performance

The US federal Essential Air Service program was established to subsidize air service to communities unable to retain commercial carriers after airline deregulation in 1978. In this paper, the subsidized service between program communities and commercial hub airports is investigated relative to several Essential Air Service planning objectives. Specifically, observed community hubbing activity is compared with that modeled to minimize hub access cost and maximize community accessibility within the commercial air transport system. Results highlight trends in system performance relative to these planning objectives and indicate that significant potential exists for enhancing the efficiency of the program in light of limited resources.     

Relevance research of threat/ error and undesired states in air traffic management based on Bayesian Network Model

We have realized that the quantitative analysis of safety data is an advanced technology of unsafely events research. Based on the analysis and statistical research on Air Traffic Control irregular events of 2011 using The Threat and Error Management (TEM) model, we have established the Bayesian network model to perform a precise quantitative analysis on the relevance between the threat, error and undesired states in Air Traffic Control operation. This analysis, based on the prior probability, obtained the relevance of the three kinds of safety information above through studying the respective posterior probabilities of threats or errors under undesired states. The result showed that the relevance of controller communication error and undesired states was 75%, and the relevance of Air Traffic Control threats as well as communication error with undesired states in Air Traffic Control was 13.3% and 25%, respectively. Therefore, this research method is of great significance for improving the mechanism of the Air Traffic Control operation risk management.     

Characterization of delay propagation in the air traffic network

We build a delay propagation network based on Bayesian Network approach to study the complex phenomenon of delay propagation within a large network consisting of the 100 busiest airports in the United States. Through topological analysis and probability analysis, we investigate the characterization of delay propagation among airports and the impact of different types of airports on delay propagation. Results indicate that the cumulative degree distribution of the delay propagation network follows an exponential function and flight delays take at most one transhipment to go from each airport to any other airports on average. For each individual airport, the effects of delay propagation are associated with airports size (traffic flow), small airports are easily affected by other airports while large airports are more affecting downstream airports but fewer affected by upstream airports. Finally, we show how the number of affected airports changes as a function of the delayed airports based on different simulation strategies.     

The determinants of air passenger traffic at Turkish airports

Investigating the determinants of air passenger traffic has become commonplace. In contrast with most previous publications, this paper investigates these determinants in an emerging country, Turkey, at the provincial level between 2004 and 2014. We find that GDP/capita, population, distance to alternative airports, tourism, leading cities, and international migrations all support more air traffic. Furthermore, market concentration is associated with less traffic, and the presence of academics with more traffic. Mapping models' residuals suggest catchment areas, surface transport options, domestic migrations and (geo)politics could also matter. Accordingly, it appears the determinants of Turkey's air passenger traffic do not differ from those of developed economies. The results also suggest new airports should be built based on the aforementioned factors.     

An approximate algorithm for the two-dimensional air cargo revenue management problem

For the air cargo revenue management problem, this study developed a solution algorithm based on approximating the expected revenue function in the dynamic programming (DP) model while taking into account the stochastic volume and weight of shipments. In order to alleviate the computational load, the approximation was achieved by computing only a limited number of points in the DP state space. In the simulation experiment, the developed algorithm was compared with a recent heuristic algorithm based on de-coupling the relationship between weight and volume. It was found that the approach of this study can generate higher revenue than the de-coupling control for most of the cases.     

An analysis of the determinants of cruise traffic: An empirical application to the Spanish port system

We study the determinants that affect the capacity of ports to attract cruise ships in Spain. The conclusion is that the likelihood of having cruise traffic is linked to ports located in populous areas and close to large airports, ports not specialized in container traffic but sharing facilities with ferries traffic and ports having a minimum depth of water. The amount of cruise traffic that a port can generate is also related to the population and the air connections, along with the tourist appeal and the facilities shared with other types of port traffic, namely roll-on roll-off and ferries.     

The impact of the current economic crisis on the geography of air traffic volumes: an empirical analysis

This paper presents a comprehensive analysis of air services dynamics during the recent economic crisis. Through a regression analysis, we show that at the country scale, the change in the supply of seats is highly dependent on economic growth, confirming the cyclical nature of the air sector. Hence the crisis of air services has much more affected the USA, Europe and Japan than the rest of the world. However, many countries deviate from this general trend. In a second step, using the existing literature, we explain some of these deviating figures. National specificities and airline strategies seem to influence the intensity of the crisis. We argue that the intensity of the crisis in the US is due to the structural oversupply of the air sector. Through other cases, especially the Middle East, we show that hubbing strategies might reduce the impact of the crisis, or at least make it less dependent upon local economic dynamics. In contrast with other authors, we found no positive impact of the share of low-cost carriers on the supply during the crisis, despite their success in some specific contexts like between Europe and Morocco.     

Effects of work shifts on fatigue levels of air traffic controllers

Fatigue is one of the most important issues since it is considered to be a potential risk factor for human error. Most research related to human fatigue in the aviation industry targets pilots, yet air traffic controllers also experience elevated levels of fatigue that affects aviation safety. Despite this, fatigue is often ignored in literature, as it is a mental and physical status that is difficult to measure. The International Civil Aviation Organization (ICAO) announced the concept of the Fatigue Risk Management System (FRMS) in Annex 6 in 2011, which provides suggestions to reduce aircrew fatigue. In 2016, the Civil Air Navigation Services Organization (CANSO), ICAO, and the International Federation of Air Traffic Controllers' Associations (IFATCA) published the Fatigue Management Guide for Air Traffic Service Providers and for the first time proposed recommendations for air traffic controllers (ATCs) to address this issue. Based on the management guide, this research used the Samn-Perelli fatigue scale to measure air traffic controllers' fatigue levels in an international aerodrome control tower in Taiwan. The results indicated that there were significant differences between day/night shifts, time periods (shift start time, before break time, after break time, and shift end time), and various work schedules. The results also revealed the importance of the timing of the breaks and time on task when arranging work schedules. This research contributes to aviation safety by investigating ATCs' fatigue levels in current work shifts, thereby helping related units to improve and adjust shift schedules in order to reduce the risks related to fatigue.     

An exact solution approach for vehicle routing and scheduling problems with soft time windows

A new column generation based exact optimization approach for the vehicle routing and scheduling problem with semi soft time windows (VRPSSTW) is presented. Elementary shortest path problem with resource constraints and late arrival penalties is solved as a subproblem, which rises from the Dantzig–Wolfe decomposition method. Exact solutions of VRPSSTW and hard time windows variant are compared on Solomon’s benchmark instances as well as on an instance based on Tokyo road network. It was found that the VRPSSTW solution results in fewer routes thus overall costs are reduced and late arrival penalties contribute only a small fraction to total cost.     

Measuring the impact of traffic flow management on interarrival duration: An application of autoregressive conditional duration

The Federal Aviation Administration has several tools in its arsenal to manage traffic flows. However, it is very difficult to assess with certainty the impact of traffic flow management procedures such as Time-Based Flow Management (TBFM) or Traffic Management Initiatives (TMI) on airport performance because operational data are not readily available to analysts. This study uses the case of Fort Lauderdale–Hollywood International Airport (FLL) where traffic flow management procedures have been implemented to manage a reduction of airport capacity due to runway constructions. Based on an Autoregressive Conditional Duration (ACD) model, the analysis shows that the use of traffic flow management procedures contributed to reducing the volatility of interarrival duration whether separation relies on time-metering (TBFM) or distance between aircraft (TMI). The lessons learned from this case study may have important implications for airports whose available capacity is severely constrained.