Aeronautical Operations Research Articles

Cross-subsidization and U.S. airports

Airports serve as a two-sided market where aeronautical and non-aeronautical operations are complementary. This interdependence means that an increase in aeronautical operations output results in a corresponding increase in non-aeronautical revenues. To retain existing airlines and attract new airline clients, airports should offer reasonable aeronautical fees, which can be subsidized by lucrative non-aeronautical revenues. This raises questions about whether cross-subsidization pricing strategies are used in the U.S. airport industry. To examine this issue, we analyzed data from 59 large and medium hub airports between 2009 and 2019, focusing on the relationship between marginal costs and fees of aeronautical and non-aeronautical operations. The marginal cost was estimated from a translog variable cost function by utilizing a seemingly unrelated regression model. Our study highlights the importance of considering the complex interplay between aeronautical and non-aeronautical operations at airports and the potential for cross-subsidization. We also examined the factors influencing cross-subsidization at airports. The results reveal that large airports are less likely to engage in cross-subsidization compared to their counterpart airports. On the other hand, given that the FAA's airport classification diverges from that in the hub-spoke system, we incorporated airports that serve as hubs for legacy airlines (American, United, and Delta) into our model to account for the influence of hub status. Our findings indicate that hub status does not influence cross-subsidization decisions. In addition, airports governed by local authorities place less emphasis on cross-subsidization whereas the presence of airport competition often incentivizes a more pronounced adoption of cross-subsidization practices. Airports in densely populated areas have diminished focus on cross-subsidization while there is a positive correlation between local GDP and cross-subsidization. Finally, cross-subsidization practices do not differ between airports dominated by LCCs and those without such dominance. Future research should focus on exploring the implications of these findings for the welfare of passengers and other stakeholders in the aviation industry.

QUALITY OF SERVICE AND SECURITY OF AERONAUTICAL COMMUNICATION NETWORKS

Aeronautical communication networks play a decisive role in the aviation industry, enabling real-time data exchange between various systems such ground stations, air traffic control and aircraft. Making sure that both requirements – high-quality-service and security – are met is mandatory to guarantee the efficiency, safety and reliability of aeronautical operations. This paper will go through a comprehensive inquiry of the quality of service and security of aeronautical communication and the relationship between them. The main focus of this paper is the security of aeronautical communications. The paper will examine the main types of aircraft communication types and will describe the cyber threats and the security measures applicable in order to mitigate the threats accordingly.

AVIATION ACCIDENT AND INCIDENT FORECASTING COMBINING OCCURRENCE INVESTIGATION AND METEOROLOGICAL DATA USING MACHINE LEARNING

Studies on safety in aviation are necessary for the development of new technologies to forecast and prevent aeronautical accidents and incidents. When predicting these occurrences, the literature frequently considers the internal characteristics of aeronautical operations, such as aircraft telemetry and flight procedures, or external characteristics, such as meteorological conditions, with only few relationships being identified between the two. In this study, data from 6,188 aeronautical occurrences involving accidents, incidents, and serious incidents, in Brazil between January 2010 and October 2021, as well as meteorological data from two automatic weather stations, totaling more than 2.8 million observations, were investigated using machine learning tools. For data analysis, decision tree, extra trees, Gaussian naive Bayes, gradient boosting, and k-nearest neighbor classifiers with a high identification accuracy of 96.20% were used. Consequently, the developed algorithm can predict occurrences as functions of operational and meteorological patterns. Variables such as maximum take-off weight, aircraft registration and model, and wind direction are among the main forecasters of aeronautical accidents or incidents. This study provides insight into the development of new technologies and measures to prevent such occurrences.

Substitutability research for forward‐scatter meters in indoor low‐visibility environments

AbstractVisibility is a crucial parameter for aeronautical operations. Forward‐scatter meters are recommended to measure it because of inherent advantages. With wide use at airports, the substitutability among forward‐scatter meters is worth paying attention to, especially in low‐visibility environments. To confirm the substitutability among forward‐scatter meters, eight kinds of forward‐scatter meters were installed in an indoor atmospheric environment simulation chamber. The observed values of each of the eight forward‐scatter meters in haze and smoke low‐visibility environments were collected. By least‐squares fitting analysis and the ATE/LER zones method, in the haze, the two sets of CS125 can be substituted for each other in visibilities lower than 2000 m. PWD20 and V30 can be substituted for each other at visibilities lower than approximately 1200 m. From 1200 to 2000 m, the consistency of the two instruments is poor. In the smoke, CS125 and PWD20 display good substitutability with each other when visibility is less than 2000 m. If only focusing on visibilities less than approximately 1000 m, the VPF‐710 and V30 instruments can be substituted with each other.

Analysis of vulnerability of ATM to weather phenomena

Weather conditions and Air Traffic Management (ATM) operations are strongly related, due to the relevant influence that the observed and forecasted weather conditions into assigned airspace have on the operational conditions that are therefore possible for such airspace. In the framework of the SESAR JU funded project CREATE (Innovative operations and climate and weather models to improve ATM resilience and reduce impacts), therefore, a dedicated study has been carried out in order to investigate the relation between weather and ATM. Such study both investigated the consequences that adverse weather conditions can have on ATM and, on the other side, addressed the currently and future available tools that can support ATM in the prediction and management of weather conditions from the aeronautical operations point of view. In this paper, the results of such literature study are outlined. More in details, in the paper first the main outcomes of the study are summarized, in terms of identification of the most relevant weather phenomena that affect the ATM operations, indication of their main impacts on them in terms of operational disruptions and, finally, identification of the associated level of severity. In particular, the above indicated aspects are addressed by taking into specific consideration the enroute and the TMA (Terminal Manoeuvring Area) flight phases and, for each of them, the main affecting weather phenomena and the main affected operations are identified. Then, in the paper the results of the study are summarized about the identification of the most relevant meteo tools that are expressed by state-of-the-art technologies to support the ATM operations in order to properly take into account the weather conditions in a precise and timely manner. This study addresses both the review of available and perspective tools for weather reporting and of the available and perspective numerical models supporting ATM in terms of weather models and air quality models.

A Generalized Approach to Operational, Globally Optimal Aircraft Mission Performance Evaluation, with Application to Direct Lift Control

A unified approach to aircraft mission performance assessment is presented in this work. It provides a detailed and flexible formulation to simulate a complete commercial aviation mission. Based on optimal control theory, with consistent injection of rules and procedures typical of aeronautical operations, it relies on generalized mathematical and flight mechanics models, thereby being applicable to aircraft with very distinct configurations. It is employed for an extensive evaluation of the performance of a conventional commercial aircraft, and of an unconventional box-wing aircraft, referred to as the PrandtlPlane. The PrandtlPlane features redundant control surfaces, and it is able to employ Direct Lift Control. To demonstrate the versatility of the performance evaluation approach, the mission-level benefits of using Direct Lift Control as an unconventional control technique are assessed. The PrandtlPlane is seen to be competitive in terms of its fuel consumption per passenger per kilometer. However, this beneficial fuel performance comes at the price of slower flight. The benefits of using Direct Lift are present but marginal, both in terms of fuel consumption and flight time. Nonetheless, enabling Direct Lift Control results in a broader range of viable trajectories, such that the aircraft no longer requires cruise-climb for maximum fuel economy.

The determinants of aeronautical charges of U.S. airports: A spatial analysis

Using U.S. airport data from 2009 through 2016, this study examines the determinants of aeronautical charges of large and medium hub airports and accounts for the spatial dependence of neighboring airports in a spatial panel regression model. Our results show that U.S. airports' aeronautical charges are spatially dependent, and neighboring airport charges are positively correlated, implying that U.S. airports are in price competition with each other even though they are government-owned infrastructure. Additionally, we find evidence of airport cost recovery through non-aeronautical revenues. This may be indicative of the airport's cross-subsidizing aeronautical operations with non-aeronautical revenues. In addition, we found the airports that share revenues with airlines charge lower aeronautical fees than those that do not share revenues. We also found that more congested airports charge higher aeronautical fees.

Aircraft Noise and Land Use Zoning Compatibility around the Juan Santamaría Airport, Costa Rica

The purpose of this study is to evaluate the noise generated by aeronautical operations around Juan Santamaría Airport and its compatibility with the land use and the proposed zoning around the airport. Aircraft noise can produce discomfort, interference with daily activities, and excessive vibrations; hence, land use planning around airports is of importance.
 Maps were prepared through computational models representing the noise levels generated by the operations of the airport. The operations were analyzed by aircraft type, schedules, and flight tracks, for 2013 and projections for: 2016, 2026, and 2036. Noise level data were collected with a sound level meter at 28 points surrounding the airport.
 Comparing the annual maps of 2013 and 2036 it was determined that 41,24 % of the analyzed area will present clearly perceivable increases (5 dB(A) to 10 dB(A)), and 1,36 % of the area will have double loudness increases (10 dB(A) to 14 dB(A)).
 The 2016 maps show locations where it is recommended to incorporate solutions in the construction regulation that reduce between 25 dB and 30 dB in the residential and scholar areas located within 65 dB(A) and 70 dB(A), such as Coco, Rincón Monge, Rincón Herrera, and Bajo Sorda. This finding is supported by field measurements.
 The proposed zoning was contrasted against the yearly day-night average sound level of 2036. The biggest issue of excessive aircraft noise is located near the west runway where a range above the 75 dB(A) is expected. Any edification of permanent residence must be banned in here.

Application of Markov processes for analysis and control of aircraft maintainability

The process of aircraft operation involves constant effects of various factors on its components leading to accidental or systematic changes in their technical condition. Markov processes are a particular case of stochastic processes, which take place during aeronautical equipment operation. The relationship of the reliability characteristics with the cost recovery of the objects allows us to apply the analytic apparatus of Markov processes for the analysis and optimization of maintainability factors. The article describes two methods of the analysis and control of object maintainability based on stationary and non-stationary Markov chains. The model of a stationary Markov chain is used for the equipment with constant in time intensity of the events. For the objects with time-varying events intensity, a non-stationary Markov chain is used. In order to reduce the number of the mathematical operations for the analysis of aeronautical engineering maintainability by using non-stationary Markov processes an algorithm for their optimization is presented. The suggested methods of the analysis by means of Markov chains allow to execute comparative assessments of expected maintenance and repair costs for one or several one-type objects taking into account their original conditions and operation time. The process of maintainability control using Markov chains includes search of the optimal strategy of maintenance and repair considering each state of an object under which maintenance costs will be minimal. The given approbation of the analysis methods and maintainability control using Markov processes for an object under control allowed to build a predictive-controlled model in which the expected costs for its maintenance and repair are calculated as well as the required number of spare parts for each specified operating time interval. The possibility of using the mathematical apparatus of Markov processes for a large number of objects with different reliability factors distribution is shown. The software implementation of the described methods as well as the usage of tabular adapted software will contribute to reducing the complexity of the calculations and improving data visualization.

Four-Dimensional Aircraft En Route Optimization Algorithm Using the Artificial Bee Colony

Fuel burn releases polluting particles to the atmosphere. Aeronautical operations have been estimated as being responsible for 2% of the total amount of carbon dioxide liberated to the atmosphere each year. Fuel is also one of the major expenses for airlines. Reducing the amount of fuel required to power flights brings benefits to both the environmental and economic aspects of the aeronautical industry. This paper aims to develop a new optimization algorithm that computes fuel-efficient aircraft reference trajectories inspired by the artificial bee’s colony and based on a numerical performance model. The flight trajectory is optimized in terms of speeds, altitudes, and geographical positions, while respecting the required time of arrival constraint. The optimal trajectory is composed of waypoints placed in each of the available dimensions (coordinates, altitudes, and speeds). Winds and temperatures are taken into account. These trajectories will be improved by taking all of the dimensions into consideration simultaneously, instead of improving them one after the other. Results have shown that, when flying under the free-flight concept and fulfilling the required time of arrival constraint, the algorithm saved around 5% of the fuel burn with respect to as-flown flights.

An Approach to Assess the Safety of ADS-B-based Unmanned Aerial Systems: Data Integrity as a Safety Issue

The increasing demand for the use of unmanned aerial systems (UAS) in various social and economic applications has pressed aviation authorities to draw up rules and regulations in order to allow such aircraft to fly in non-segregated airspace. However, issues related to the safety of air traffic operations arise when considering the possibility of both manned and unmanned aircraft coexisting. Thus, surveillance plays a key role in monitoring and controlling air traffic in new scenarios. The positional information provided by the Automatic Dependent Surveillance - Broadcast (ADS-B), originally designed to improve situational awareness for pilots and support controllers in air traffic management, interacts with the Sense and Avoid Systems (S&AS) of the UAS in order to avoid exposure to events of loss of minima separation distances and collisions. As positional information is essential to UASs control systems operation, parameters such as accuracy and integrity reflect the correctness and trustworthiness of this information. This paper presents a qualitative approach to assess safety when using ADS-B systems integrated with UASs in aeronautical operations considering the influence of data integrity as a safety-related parameter. In addition, the possibility of using a methodology previously applied on manned systems for assessing safety on UASs is discussed. A new testing platform (PIpE-SEC) is presented as a possible approach for this safety evaluation.

Airport capacity and congestion pricing with both aeronautical and commercial operations

In this paper, we study airport decisions on pricing and capacity investment with both aeronautical and concession operations. In addition, the airport under consideration is serving air carriers who have market power. We find that a profit-maximizing airport would over-invest in capacity in the sense that the marginal (social) benefit of capacity is smaller than the marginal (social) cost. This tendency of overinvestment still holds when the private airport is under the regulatory constraint of cost recovery in its aeronautical operation (the dual-till regulation). We also find that the capacity investment by a public airport will be socially efficient in the sense that the marginal benefit of capacity is equal to the marginal cost of capacity. However, somewhat surprisingly, the capacity investment of the public airport will be inefficient if it is under regulatory constraints. Specifically, the airport will also over-invest in capacity, whether it is under a single-till regulation or a dual-till regulation. Finally, it is noteworthy that the inefficiency in airport investment is driven by the interaction between the airport and the carriers who have market power.

Interpretation of the Galileo Safety-of-Life Service by Means of Railway RAMS Terminology

The Galileo Safety of Life (SoL) - Level A service has been designed mainly to support aeronautical operations ranging from en-route up to approach with vertical guidance (APV II). This is why the Galileo SoL Service has been specified by means of quality criteria coming from ICAO‘s (International Civil Aviation Organization) Required Navigation Performance (RNP) concept, i.e., in terms of accuracy, integrity, continuity, and availability. However, Galileo SoL – Level A service is also intended for railway signalling which is based on a different safety philosophy. The objective of this paper is to describe links among the Galileo quality criteria and the quality attributes of railway signalling systems (RAMS), according to the CENELEC standards EN 50126, EN 50129 and EN IEC 61508. This paper provides a basic theory and methodology for the employment of the GNSS quality attributes for practical design, validation and verification of railway safety systems based on GNSS. It has been shown that, in spite of the different safety philosophies used in aviation and railway safety systems, the Galileo SoL – Level A service can be described by means of RAMS terminology according to railway standards.

NEWSKY – A concept for networking the sky for civil aeronautical communications

An efficient and sustainable network for aeronautical communications is required to enable the implementation of a range of operational improvements needed to support the expected growth in air transportation. The NEWSKY project (“NEtWorking the SKY”) is co-funded by the European Commission within the 6th Framework Programme and was initiated with the aim to develop a concept of a global aeronautical communication network based on Internet technologies. NEWSKY focuses on the design of an IPv6 based network for air-ground communications by supplementing existing concepts to be applicable to aeronautics. NEWSKY pursues the vision of “Networking the Sky” by integrating different radio link technologies and different applications into a single IP-based aeronautical network. The integration of satellite-based, ground-based and airport communication links is targeted. The envisaged application classes comprise not only safety related services as Air Traffic Services (ATS) and Aeronautical Operation Control (AOC), but also non safety related services as Airline Administrative Communications (AAC) and passenger communications (APC). The transition from the current ACARS and Aeronautical Telecommunication Network based on OSI technologies (ATN/OSI) is considered. As a result, the modular and highly flexible architecture of the proposed NEWSKY approach helps to create a future aeronautical communication system which is viable well beyond 2020.

A “radically new method”: balloon buoy communications of the Baldwin–Ziegler Polar Expedition, Franz Josef Land, June 1902

The history of lighter-than-air operations in the Arctic between 1896 and 1930 has focused almost exclusively upon four expeditions. These are the balloon voyage of the Swede Salomon Andrée in 1896–97, and the dirigible expeditions of the American Walter Wellman in 1906–09, the Norwegian Roald Amundsen with the Italian Umberto Nobile in 1926 and the Nobile expedition of 1928. Largely invisible in this lineage are the aeronautical operations of the Baldwin–Ziegler Polar Expedition on Alger Island in the Franz Josef Land Archipelago in 1902. This article traces expedition leader Evelyn Briggs Baldwin’s interest in aeronautical exploration in the Arctic, which began early in life, led to a failed attempt to join Andrée in 1897 and culminated in his use of message buoys attached to balloons in June 1902. These operations, the fate of its balloon buoys and the historical archaeology of Baldwin’s operational bases in Franz Josef Land and north-east Greenland are examined. Baldwin’s poor planning and bad luck with ice conditions around Franz Josef Land caused him to use his balloon buoys not to reach northwards to the pole, but to send relief messages southwards towards civilization. Like the other polar aeronautical expeditions, Baldwin’s left behind a significant archaeological assemblage that continues to provide evidence for the material analysis of the history of polar exploration.

Studies on Pulse Jet Engine by Wind Tunnel Testing

Simple design and efficiency make pulse jet engines attractive for aeronautical short‐term operation applications. An active control system extends the operating range and reduces the fuel consumption considerably so that this old technology might gain a new interest. The results on wind tunnel experiments have been reported together with the impact of combustion mode (pulse or steady) on system performance.

Concession revenue and optimal airport pricing

Abstract In recent years airports have been under growing pressure to become financially self-sufficient and to pursue profit maximization in their non-aeronautical or concession operations. In this paper we examine the optimal pricing in a model where concession and aeronautical operations of an airport are considered together with an overall break-even constraint. We find that the optimum solution may require a subsidy from concession to aeronautical operations. However, such a cross-subsidy may or may not restore marginal-cost pricing on aeronautical operations. On the other hand, social welfare can be higher when an airport is allowed to make profits in concession operations than when marginal-cost pricing is imposed on concession operations.

Satellite imagery in the prediction of aviation hazards

Satellite meteorological informations in recent years have proved to be a unique tool in aeronautical operations. Although about 12000 stations throughout the world are taking surface synoptic observations several times a day and about 1200 stations upper wind and radiosonde observations twice daily to provide meteorological informations for aeronautical operations, still there are vast data sparse regions over the globe such as big deserts, Inaccessible mountain ranges and oceanic areas. With the launch of first U.S. weather satellite TIROS-l in April 1960, it was possible for the first time to get up-to-date information over the entire globe through visible and infrared imagery. The better quality pictures from polar orbiting satellites received in both visible and infrared channels have been very helpful to an aviation forecaster In recent years over Indian sub-continent. In the present paper, various cloud characteristics associated with potentially hazardous weather phenomena for aviation such as tropical cyclones, jet-streams, squall lines, tornadoes, fogs etc have been discussed with the special emphasis on the safety of the aircraft.

Ground Communications Networks for Aeronautical Operations

Three digital communications networks of the FAA performing essential services in support of the National Air Space System (NAS) are described and discussed. Designated as the Aeronautical Fixed Telecommunications Network (AFTN), the combined Weather Teletypewriter Networks A, C, and O, and the Service B Teletypewriter Network, respectively, these systems carry national and international digital message traffic in support of air traffic control operations and aeronautical weather services. These data are exchanged among the Air Traffic Control Centers, Airport Terminal Facilities, and Flight Service Stations of the FAA and in the case of weather data, with offices of the National Weather Service Military Weather and Flight Operations Offices, airlines, and other commercial and industrial interests. Recent and planned modernization programs resulting in the introduction of major computerized electronic message switching centers are also discussed. The electronic data processor configurations, their modes of operation, and specialized data handling features are described. Planned transition and progress to date in converting from 100 word/min teletypewriter operation to medium speed 1200-2400 Bd data rates and from manual inputs to the increasing use of computergenerated messages and computer-to-computer data exchanges are indicated. With the introduction of computerized switching and control centers the overall integration of FAA communications networks into a more fully unified total communications system with more standardized procedures and formats becomes more practical and achievable. Basic concepts and progress towards this goal are outlined.

Proposed Aerodetic Units of Length

Abstract It is proposed that units of length called nautical spans, chains and feet—and defined respectively to be 60, 1/60 and 1/6,000 nautical miles in length—be adopted internationally for use in weather-service and aeronautical operations. It is also proposed that the mandatory reporting levels for upper air charts he at intervals of one nautical mile of barometric altitude. These proposed units have been selected to provide close numerical correspondences with associated sexagesimal measures of angular position and time; they are shown to interrelate values for time, horizontal angular and linear positions speeds, accelerations, and vertical barometric and geometric positions as closely as possible within our current knowledge of the earth and atmosphere. The kinds of practical advantages which would accrue from the adoption of such geodetically and aerodetically derived units of length in characteristically world-wide weather-service and aeronautical operations are also indicated.