Aircraft Fleet Research Articles

Selection of helicopters for offshore service using three multi-criteria decision analysis methods: AHP-TOPSIS-2N, THOR 2 and Gaussian AHP-TOPSIS-2N

The aviation and oil and gas industries have shown themselves to be quite consolidated in recent years, which corroborates the growing demand for operational excellence from the main players. Therefore, in the face of an increasingly competitive and fierce market, cost reduction is sought in every way, as a competitive differential against competitors. The aircraft fleet composition for offshore services represents a significant logistical cost for companies. Due to that, this paper aims to order 11 aircraft, compared in 13 different selection criteria, by the use of two multi-criteria decision analysis methods: AHP-TOPSIS-2N and THOR 2. In addition, we will propose a new method (Gaussian AHP – TOPSIS-2N) through the association of the Gaussian AHP with the AHP-TOPSIS-2N. The results showed that the aircrafts AW139, H175 and H215 obtained the best performances and the aircrafts S76, H145 and H225 had the worst performances among the alternatives of the study.

Analisis Efektivitas Pengawasan Pergerakan Pesawat Udara Oleh Apron Movement Control di Apron Area Bandar Udara Internasional Zainudin Abdul Madjid Lombok

The increase in the number of users of air transportation modes that occurred in the last year period was 32.69 percent or 10.7 million people, causing a density in the number of flights and an increase in the fleet of aircraft in operation, therefore it is necessary to monitor aircraft movements, especially in the apron area. carried out properly to avoid accidents or things that could be dangerous for users or personnel on duty or related to air transportation. The purpose of this research is to determine the effectiveness of monitoring aircraft movements carried out by the Apron Movement Control unit in the apron area of Zainudin International Airport Abdul Madjid Lombok. The results of the research found that the process of monitoring aircraft movements in the apron area has been carried out following applicable regulations and rules, however, the equipment used to monitor aircraft movements in the form of CCTV requires repair and rejuvenation, related to the effectiveness of monitoring aircraft movements in the Apron Movement Control unit. Lombok's Zainudin Abdul Madjid International Airport has met five indicators that serve as benchmarks for work effectiveness.

Aircraft fleet optimization by the simplex method

The transport system efficiency and the quality of its operation is organically connected with the improvement of air transportation technical means on the basis of modern science and technology. One of the directions of further aviation transport system development is the creation of methodological basis for optimal aircraft operation. Therefore, the increase in aircraft efficiency is one of the important tasks, as its improvement is associated with savings in material and financial resources, which affects the fleet structure and the process of passenger traffic. The article is intended to substantiate the method of optimizing the use of airline aircraft by means of mathematical apparatus. It has been found that the mathematical model structure is required to form an optimal aircraft fleet. A variant of aircraft fleet formation has been proposed taking into account the mathematical model, built on the basis of linear programming, namely, using the simplex method. It has been determined that the choice of optimal aircraft options is greatly influenced by the value of the parametric series. To obtain a reliable result, the aircraft loading must be 100%, otherwise the error grows due to coefficients at unknown target function. The proposed method of determining the optimal fleet with different types of aircraft and air traffic routes, taking into account the conditions of their usage, allows to recommend airlines to use aircraft with the highest efficiency.

Helicopter Aerial Work: Technology to Meet Growing Needs in Critical Missions

Helicopters provide aerial services such as firefighting, medical transport, agriculture, and construction for critical industries that form the backbone of modern society. These "aerial work" applications comprise the majority of the current market for civilian helicopters and include a diverse set of mission types and flight profiles; in many cases, aerial work applications are meeting growing needs driven by the climate crisis and energy transition. Through a series of more than 180 interviews with operators, pilots, and users across helicopter aerial work, this paper — the largest contemporary study of its kind — surveys the challenges that the industry sees for itself. Part I analyzes and summarizes our original primary source data to provide both qualitative and quantitative assessments of the needs of this community. Part II presents a case study for aerial firefighting, where a growing demand driven by record-breaking climatic changes is straining the existing air crews, aircraft fleet, and firefighting technology. Many issues identified in firefighting are endemic problems that beset other neighboring applications within aerial work such as public services, energy infrastructure, construction, and agriculture; technologies that have the potential to have a significant impact on re ghting are discussed. Part III is an analysis of technology and how it might better meet the needs of helicopter aerial work. We identify characteristics such as compatibility, reliability, and application specialization that are valued by helicopter aerial work customers and operators. In the backdrop of unprecedented venture capital investment and technology development in new types of vertical takeoff and landing aircraft for AAM, this paper's core nding is that the needs of helicopter aerial work are not being met: a venture capital culture prioritizes innovation that can create new markets over solving challenges in existing ones. Innovation for commercial air transport missions that operate under different market, environmental, and operational conditions does not "trickle down" to aerial work. We identify a need for increased collaboration between technologists and the aerial work community and for a more thoughtful approach towards investment and development to meet the growing challenges of the industry.

МЕТОДЫ ОПТИМИЗАЦИИ МОДЕЛЬНОГО РЯДА ПРИ ФОРМИРОВАНИИ СОСТАВА И СТРУКТУРЫ ПАРКА ВОЗДУШНЫХ СУДОВ В РАМКАХ СОЗДАНИЯ ЕДИНОЙ ДАЛЬНЕВОСТОЧНОЙ АВИАКОМПАНИИ

The article considers the urgent task of optimizing the use of the existing and promising fleet of aircraft of domestic production within the framework of the creation of a single Far Eastern airline. The data on the assessment of the required number of aircraft of domestic production through a single consolidated order from all airlines of the Far Eastern region analyzed. It is shown that mathematical modeling and optimization methods play a significant role in the optimal design of the number and nomenclature of aircraft in the region, which are successfully used to select the best parameters and characteristics of aircraft or its subsystems at various stages of design, dividing the task into two interrelated models: parametric and operational. A systematic scientific and methodological approach to the external design of aircraft proposed, so it is possible to generate many design options for aircraft, limiting only those parameters that significantly affect the efficiency of the airline's operation. The result of the study is the fulfillment of the task of optimizing the aircraft model range for subsequent operation in the conditions of the Far North, the Arctic, Siberia and the Far East. The analytical materials obtained allow us to compare the expansion plan of the route air transport network and the calendar plan for the production of aviation equipment for the united Far Eastern airline based on the produced relationship chart between airlines and aircraft manufacturers.

Condition-Based Maintenance scheduling of an aircraft fleet under partial observability: A Deep Reinforcement Learning approach

Condition-Based Maintenance scheduling of an aircraft fleet under partial observability: A Deep Reinforcement Learning approach

Прогнозирование пассажиропотоков социально значимых авиационных маршрутов внутри арктического региона

The Russian Arctic is characterised by the poor development of year-round land routes. In these conditions, air transport is the basis of passenger traffic. However, air mobility of the population in the Arctic regions is significantly lower than that of Russia in general. The article substantiates the need to increase transport accessibility of the Arctic by developing an internal network of socially significant air routes. To create a route network plan, it is necessary to forecast passenger traffic on existing and potential air routes within the Arctic region. To this end, a multiple regression model was used to develop a two-level forecasting approach. At the first level, the proposed method was applied to calculate local passenger traffic between remote settlements and the centre of the Arctic region. At the second level, the findings were examined to forecast passenger traffic between the centres of the Arctic regions and the main airport with direct flights to other regions. To predict passenger flows on potential routes, a probabilistic model of the number of flights by one resident per year was constructed based on an analysis of existing socio-economic relations, purpose of the flight and the existing infrastructure at the start and end points of the route. According to the results of forecasting passenger traffic on existing routes, it is necessary to increase the frequency and regularity of local flights by optimising the aircraft fleet in order to increase the population’s air mobility. At the same time, the results of passenger traffic forecasting on potential routes confirmed the need for subsidised direct flights between the centres of neighbouring Arctic regions with certain social infrastructure facilities.

AeroMAPS: a framework for performing multidisciplinary assessment of prospective scenarios for air transport

AeroMAPS is an open-source software, also available as a web application, for performing multidisciplinary assessment of prospective scenarios for air transport. Such investigations are a significant challenge for aviation stakeholders but are required to explore and evaluate different transition strategies for the sector. The framework presented in this paper aims to provide these stakeholders with a standardised methodology for simulating prospective scenarios. Developed using the Python programming language and easy to use via Jupyter Notebooks or graphical user interfaces, it enables the rapid exploration of various decarbonisation strategies for research or decision-making audiences. Several scientific computing packages are used to facilitate the modular assembly of models and solve complex numerical problems. The framework is structured around various models derived from the academic literature and newly developed ones. In particular, it can be used to model various components of the air transport system (air traffic, aircraft fleet, energy carriers), assess its environmental (climate and energy resources) and cost impacts, and perform environmental sustainability analyses. An application is proposed in this paper in order to understand the capabilities, interests and limits of the software. Future developments are planned to improve existing models, complete environmental analyses and continue extending to other disciplinary fields (economics, regulation, sociology), in order to make AeroMAPS a systemic and holistic aviation integrated assessment model.

Material characterisation of anodising effects on small fatigue crack nucleation in AA7XXX alloys

The precursor cleaning steps in the anodising surface finish process for aluminium alloy aircraft parts are known to lead to etching of surface-breaking intermetallic particles and grain boundaries, which in turn leads to preferential sites for fatigue crack nucleation. Type 1C anodising per MIL-A-8625F, is a favoured aircraft aluminium part corrosion protection treatment meeting modern health and environmental requirements. Type 1C anodising uses electrolysis in a non-chromic acid bath (typically based on sulphuric, boric-sulphuric or phosphoric acid formulations) to develop a thick aluminium oxide surface layer. In previous studies the equivalent initial damage sizes of these nucleation sites was calculated from near surface fatigue crack growth measurements using quantitative fractography in both Type 1C anodised aluminium alloy 7050-T7451 and 7085-T7452. A notable difference was observed in the values for these two materials with AA7085-T7452 equivalent initial damage sizes being significantly smaller. Since these values are critical crack starting size assumptions in fatigue life analysis for aircraft fleets, the observed differences must be investigated and explained for notionally similar alloys under identical conditions.In this work, the material surrounding the population of crack nucleation sites in several Type 1C anodised fatigue tested specimens manufactured from AA7050-T7451 and AA7085-T7452 materials has been characterised using precise surface preparation methods and scanning electron microscopy techniques. It has been demonstrated that there is a statistically significant difference in the number, size, aspect ratio and distribution of surface breaking Al7Cu2Fe intermetallic particles beneath the anodising layer that, when etched out during the anodising process, are responsible for fatigue crack nucleation in 7050-T7451 over 7085-T7452 material. The increased size, angular shape and coverage of these intermetallics in AA7050 serves to increase their effectiveness as preferential locations for fatigue crack nucleation through two mechanisms, as a highly localised stress concentrating feature, as well as through their ability to sample more of the material's microstructural features ensuring a discontinuity is present in the most favourable orientation and location for fatigue crack nucleation.

Забезпечення статичного балансування легкого транспортного літака під час зміни його маршових двигунів

The process of improving the existing aircraft fleet through the development of modifications has become widespread in both domestic and foreign aircraft manufacturing. Under modern conditions, no country in the world is capable of simultaneously modernizing all types of aircraft. Economic and scientific-technical resources are usually directed toward developing those types for which there is the greatest demand. Limiting the number of types in conjunction with developing modifications for existing aircraft significantly contributes to increasing the efficiency of the entire air transport system. Objectively, there are several reasons for modifications in transport-category aircraft. The first reason is associated with increasing discrepancies between technical and economic indicators. The second reason is related to the use of this type of transport in practical human activities, which is progressively expanding. The third reason is the influence of time. Creating modifications allows to a certain extent to resolve the contradiction between the deadlines for creating complex modern technology, which have increased, and the accelerated pace of scientific and technological progress. The subject of this study is the process of ensuring static balancing of a light transport aircraft during the replacement of its propulsion engines. The goal is to develop models for ensuring the static balancing of a light transport aircraft (LTA) in conditions involving changes in its propulsion engines and reconfiguring the lifting surface system while minimizing the aerodynamic quality costs for balancing changes in the LTA. Tasks: Determine the process of ensuring static balancing of transport category aircraft considering the coefficient of static stability degree; peculiarities of applying this coefficient in balancing a LTA; establish the correlation between the coefficient of static stability degree and the aerodynamic polar of a balanced LTA; quantitatively evaluate and minimize the losses of wing aerodynamic quality to achieve static balancing of the LTA. The obtained scientific results enable both the balancing of a LTA and the minimization of aerodynamic quality losses. Conclusions: Based on the obtained dependencies and their numerical analysis, it has been established that when replacing the engines of a light transport aircraft with a payload capacity of 9.1 tons, the coefficient of static stability of 0.15 complies with the requirements of the Airworthiness Standards for Transport Category Aircraft. During the numerical analysis, it was also determined that for such an aircraft, the aerodynamic quality losses amounted to 7%–9%, which is acceptable for the considered aircraft type.

Основні питання створення моделі процесу технічної експлуатації повітряного судна військового призначення

The subject of the research in this article is the creation of a mathematical model of the process of technical operation (PTO) of a military aircraft in the system of information support for the operation of an aircraft. The aircraft is a complex technical system that includes many systems, subsystems, and elements for reliable and error-free functioning, which require constant monitoring of its technical condition to determine the possibility of its intended use. It is proposed to promote PTO in the system of information support for the operation of aircraft operating in real time and to create a mathematical model of the process. We will construct a graph of states and transitions using the transition matrix to describe the PTO of a military aircraft. The purpose of this study is to create a mathematical model of the PTO of a military aircraft in a system of information support for the operation of the aircraft operating on a real time scale. The task: to determine the role and advantage of using the mathematical model of the PTE of a military aircraft in the information support system for the operation of a CMMS-type aircraft operating in real time for its use in forecasting and managing the effectiveness of the PTE. The scientific and practical novelty of the obtained results is as follows: the advantages of the PTE mathematical model of a military aircraft in the CMMS-type aircraft operation information support system, which works in real time before the PTO model by resource and the model when decisions are made at the moment, have been determined state changes. The conclusion of this study is that the use of the proposed PTO model will allow us to evaluate complex reliability indicators in real time, that is, continuously. The considered PTO model of a military aircraft considers all the features of military aircraft operation at the current stage. This allows us to assume the possibility of its use for the entire aircraft fleet of the Air Force Base of the Armed Forces of Ukraine.

Research on the influence of time delay on combat effectiveness of aircraft fleet

Aiming at the influence of time delay on the combat effectiveness of aircraft fleet under the command of airborne warning and control system (AWACS), the process of beyond visual range air combat under the command of AWACS is analyzed, as well as the time delay characteristics in the combat information flow. The air combat situation threat of the aircraft by enemy aircraft is represented by the weighted fusion of the speed threat, angle threat, distance threat, and height threat of the aircraft. The threat matrix is proposed to represent the threat to the whole aircraft fleet. The threat matrix consists of the situational threat between each of our aircraft and each of the enemy aircraft. And the threat matrix of both sides is calculated to obtain the pre-enemy launch probability of both sides. With the two-step adjudication method and capturing the target probability of the missile seeker under the influence of time delay, the probability and number of being destroyed are calculated, as well as the combat effectiveness ratio. The opposing forces of both sides are set, and the calculation results in Matlab are consistent with the actual ones, which verifies the rationality and validity of the model, and can provide a theoretical reference for determining the time accuracy of the air-based network.

Aviation Noise in the United States: The Current State of Federal Aviation Administration Research on Community Response

Despite today's civilian aircraft fleet being quieter than at any time in the history of jet-powered flight, communities in the United States continue to file complaints about aircraft noise. Additionally, the Federal Aviation Administration's (FAA) Neighborhood Environmental Survey (NES) has shown that community response to aviation noise in the United States has changed and the dose-response relationship between noise and annoyance such as the one represented by the Shultz Curve is no longer representative of communities' lived experiences. This paper will examine the current aviation noise environment in the United States, and how the nature of aviation noise and the characteristics of communities that raise significant noise concerns in the United States have changed since the start of widespread use of commercial jet-powered aircraft in the 1960s. This paper will also explore the changing nature of community response to aviation noise based on the FAA's latest research findings on aviation noise and annoyance as detailed in follow-on analyses to the NES.

Aircraft fleet availability optimisation: a reinforcement learning approach

AbstractA fleet of aircraft can be seen as a set of degrading systems that undergo variable loads as they fly missions and require maintenance throughout their lifetime. Optimal fleet management aims to maximise fleet availability while minimising overall maintenance costs. To achieve this goal, individual aircraft, with variable age and degradation paths, need to operate cooperatively to maintain high fleet availability while avoiding mechanical failure by scheduling preventive maintenance actions. In recent years, reinforcement learning (RL) has emerged as an effective method to optimise complex sequential decision-making problems. In this paper, an RL framework to optimise the operation and maintenance of a fleet of aircraft is developed. Three cases studies, with varying number of aircraft in the fleet, are used to demonstrate the ability of the RL policies to outperform traditional operation/maintenance strategies. As more aircraft are added to the fleet, the combinatorial explosion of the number of possible actions is identified as a main computational limitation. We conclude that the RL policy has potential to support fleet management operators and call for greater research on the application of multi-agent RL for fleet availability optimisation.

Cross-Check on Combat Aircraft Data

ABSTRACT This paper presents our findings based on a systematic analysis of eight renowned data sources on combat aircraft data. Focusing on national combat aircraft fleets, we first investigate similarities and differences between the eight data sources. We find dissimilarities both within and between data types (inventory, production, transfer) as well as structural differences in reports and missing data. Second, derived from the data sources and our analysis, we introduce a cross-checked dataset on combat aircraft data. This dataset covers the period 1995–2021 and presents data on all types of market movements (inventory, production, transfers, and abolishment) for 127 families of combat aircraft.

Airlines' network analysis on an air-rail multimodal system

This article explores the potential impact of short-haul flight bans in Spain. We build the rail and flight network for the Spanish peninsula, merging openly available ADS-B-based data, for the reconstruction of air schedules and aircraft rotations, and rail operator data, for the modelling of the rail network. We then simulate a ban that would remove flights having a suitable train replacement, \ie representing a trip shorter than a threshold that we vary continuously up to 15-h. We study the impact in terms of 1) air route reduction, 2) aircraft utilisation and fleet downsizing for airlines, 3) airport infrastructure relief and rail network requirements, 4) CO2 emissions, and 5) possible itineraries and travel times for passengers. We find that a threshold of 3 hours (banning all flights with a direct rail alternative faster than three hours) presents some notable advantages in emissions while keeping the aircraft utilisation rate at an adequate level. Interestingly, the passengers would then experience an increase in their itinerary options, with only a moderate increase in their total travelling times.

A Semi-Supervised Siamese Network for Complex Aircraft System Fault Detection with Limited Labeled Fault Samples

Aircraft onboard systems typically have limited labeled fault samples and large amounts of unlabeled data. To better utilize the information contained in limited labeled fault samples, a deep learning-based semi-supervised fault detection method is proposed, which leverages a small number of labeled fault samples to enhance its performance. A novel sample pairing strategy is introduced to improve algorithm performance by iteratively utilizing fault samples. A comprehensive loss function is employed to accurately reconstruct normal samples and effectively separate fault samples. The results of a case study using real data from a commercial aircraft fleet demonstrate the superiority of the proposed method over existing techniques, with improvements of approximately 16.7% in AP, 9.5% in AUC, and 19.2% in F1 score. Ablation studies confirm that performance can be further improved by incorporating additional labeled fault samples during training. Furthermore, the algorithm demonstrates good generalization ability.

From passenger itineraries to climate impact: Analyzing the implications of a new mid-range aircraft on the global air transportation system

Aircraft design usually focuses on utilizing new technologies to improve mission performance of individual aircraft and, thus, reduce cost, emissions and climate impact of the global air transportation system (ATS). However, efficiency gains in the ATS can also be achieved by improving the alignment of payload–range capabilities and aircraft–route assignment of the overall fleet. Therefore, this article analyzes the implications—from passenger itineraries to climate impact—of a new mid-range aircraft (NMRA), which addresses the current lack of modern, designated mid-range aircraft in commercial production. The analysis is based on simulating and comparing two future scenarios with similar technology levels: one with and one without a NMRA. The core of the applied novel simulation framework is highly integrated models for passenger itinerary preferences, fleet development and aircraft–route assignment. Models for passenger demand as well as aircraft trajectories, emissions and climate impact complement the simulation framework. The results show that introducing a NMRA to the ATS improves the quality of travel for passengers and the alignment of payload–range capabilities and aircraft–route assignment for the overall aircraft fleet. As a consequence, the NMRA reduces the fuel consumption, emissions and climate impact of the ATS in our future scenarios by up to 1.4% (pessimistic) and 2.1% (optimistic). We conclude that a higher fleet diversification and a better alignment of payload–range capabilities and aircraft–route assignment through introducing a NMRA can marginally improve the fuel efficiency and climate impact of the ATS.

Integrating Ice Protection and Noise Abatement Systems for Aircraft Application: A Review

Aircraft icing remains a key aviation hazard as the global fleet of aircraft in various sectors continues to expand, posing a serious threat to flight safety. As previously stated, the growth of this type of aircraft has been accompanied by an increase in noise levels, and aircraft is reportedly the second most bothersome noise source after traffic. However, integrating an acoustic liner with anti-icing techniques on the leading edge of a nacelle would not efficiently eliminate forward radiated noise and improve the thermal performance of the anti-icing system. Hence, it is of the utmost importance to research the integration of ice protection and noise abatement systems for aircraft applications. This review discusses the integration of ice accretion and noise abatement systems in aircraft applications. The prominence of this review is to explain significant features such as ice protection systems, Computational Fluid Dynamics in ice protection, noise abatement systems, and the integration of ice protection systems and noise abatement systems wherever they are described.

Non-parametric analysis of maintenance data for Attitude Indicator of a commercial aircraft fleet

Analysis of maintenance data for a repairable system provides information about the failure behavior of the system. Such information is needed for determining preventive maintenance and retirement policy for the system. Parametric and non-parametric models can be used for analysis. Parametric models require more assumptions about the failure process of the systems under consideration compared to non-parametric models. To verify these assumptions statistical expertise needed. The purpose of this paper is to show that in practice non-parametric estimator of mean cumulative function can be utilized easily to model the failure behavior of a fleet. Mean cumulative function estimates the mean number of failures as function of operating hours. The method is exemplified on the attitude indicator units of a commercial aircraft fleet. Sampling uncertainty of the estimates is quantified by normal approximation confidence intervals.