Aircraft Fleet Research Articles

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.

Statistical inferences under step stress partially accelerated life testing based on multiple censoring approaches using simulated and real-life engineering data

Evaluating the lifespan distribution of highly reliable commodities under regular use is exceedingly difficult, time consuming, and extremely expensive. As a result of its ability to provide more failure data faster and at a lower experimental cost, accelerated life testing has become increasingly important in life testing studies. In this article, we concentrate on parametric inference for step stress partially life testing utilizing multiple censored data based on the Tampered Random Variable model. Under normal stress circumstances, the lifespan of the experimental units is assumed to follow the Nadarajah–Haghighi distribution, with and being the shape and scale parameters, respectively. Maximum likelihood estimates for model parameters and acceleration factor are developed using multiple censored data. We build asymptotic confidence intervals for the unknown parameters using the observed Fisher information matrix. To demonstrate the applicability of the different methodologies, an actual data set based on the timings of subsequent failures of consecutive air conditioning system failures for each member of a Boeing 720 jet aircraft fleet is investigated. Finally, thorough simulation studies utilizing various censoring strategies are performed to evaluate the estimate procedure performance. Several sample sizes were studied in order to investigate the finite sample features of the considered estimators. According to our numerical findings, the values of mean squared errors and average asymptotic confidence intervals lengths drop as sample size increases. Furthermore, when the censoring level is reduced, the considered estimates of the parameters approach their genuine values.

AIRCRAFT FINANCING INDUSTRY: JURIDICAL ANALYSIS OF GUARANTEE AGREEMENT IN THE AIRCRAFT FINANCING INDUSTRY

All humans require various supports to progress in life, particularly in Indonesia. People's mobility is required at a rapid pace due to the shape of Indonesia as an archipelago. The aviation industry is one of the supporting factors. Indonesians require the use of both domestic and international aircraft. As a result, massive procurement of aircraft fleets takes place. The airline requires financing to support the aviation sector as a capital-intensive and high-technology industry in its procurement. Every business activity must require collateral to prevent the parties from defaulting. As a result, the contents of this journal will explain the entire discussion of financing and collateral in accordance with applicable laws.

Development of Low Emission Combustion Technologies For Modern Aero Gas Turbine Engines: An Overview

The demand for gas turbines for civil aviation is increasing continuously as the air transportation system is changing exponentially. Large fleet of commercial aircraft and large and long-haul flight have raised the demand on high thrust engines. Therefore, focus on fuel efficiency of the engines and control on exhaust gas emissions are increasing keeping in mind the economy and environmental considerations. International Civil Aviation Organization has promulgated the emission levels for civil subsonic turbojet and turbofan engines and making it more and more stringent day by day. This paper overviews various combustor technologies which have been developed over previous decades and are under development currently for present and future aircraft to meet the low emission goals.

Air transport risk modelling simulation of the impact of the sanctions on Russia

The article considers development scenarios and options for adapting Russia’s aircraft fleet to the impact of the sanctions changes on the transport industry and the consequences of it. The main issues on the limitation of the spare parts and materials for aircraft supply have been structured. Alternative options and adjustments to the shortage of components to support aircraft flights have been described. The analysis of the current civil aviation fleet of the country has been carried out and the normative service life of different class categories aircraft studied. The dynamics of changes in the state aircraft fleet over the last 10 years (since the beginning of the sanctions politics has a starting point from the accession of the Republic of Crimea in 2014) has been considered. The short-term prospects of the aviation industry have been defined and recommendations for improvement and a set of measures for adaptation suggested.

Comparative Vacuum Monitoring Solutions to Advance U.S. Air Force KC-46A Condition-Based Maintenance Plus

The KC-46A Pegasus, a Boeing 767 (B767) commercial derivative aircraft (CDA), is a key part of the United States Air Force’s (USAF) efforts to modernize their aging tanker fleet. The Department of Defense (DoD) and the USAF have heavily emphasized the desire and need for Condition-Based Maintenance Plus (CBM+) to improve aircraft maintenance programs such as the KC-46A. This study reviews existing CBM+ practices on B767 and related aircraft fleets at Delta Air Lines to identify initial steps for implementing CBM+ in the KC-46 maintenance program. Specifically, comparative vacuum monitoring (CVM) sensors are proposed for KC-46A structural health monitoring (SHM) as a Federal Aviation Administration (FAA)-certified CBM+ technology. As demonstrated at Delta Air Lines Technical Operations (Delta TechOps), CVM sensors satisfy the technological, procedural, financial, and regulatory requirements to advance KC-46A SHM and serve as a template for future CBM+ initiatives.

Features of vortex trace propagation for aircraft with propellers

The article presents the results of a study of the characteristics of the wake vortex of aircraft with turboprop engines. Using the example of the An-12 aircraft, it is shown that rotating propellers make a noticeable contribution to the propagation of the vortex trail behind the aircraft. This is proved by some studies, as well as numerous observations. It also describes a technique for studying the wake vortex of aircraft with propellers. The method is based on the method of discrete vortices. The relevance of such studies is due to the growing interest of carrier companies in aircraft with turboprop engines. It has been proven that when transporting passengers and cargo on such vessels over distances of 700–800 km, maintenance and fuel costs are reduced by about 30–40%. Therefore, the fleet of turboprop aircraft, such as An-22, An-70, An-12, as well as Tu-95, Il-38, C-130, etc., has been preserved so far. New turboprop aircraft are being developed and put into operation: A-400M, Il-114, Il-112M. The vortex trail behind such aircraft also poses a danger to other aircraft flying behind. A feature of the propagation of the wake vortex behind aircraft with propellers is the interaction of vortices coming off the airframe and vortices from the propellers. As a result, due to the rotation of all the screws in one direction, symmetry is broken in the propagation of vortices descending from the right and left halves of the wing. Therefore, it is important to understand how differently the vortices that descend from the airframe of an aircraft with turboprop engines behave. For the convenience of the study, the method of accounting for the effect of vortices from screws is integrated into a special calculation and software package, also based on the method of discrete vortices. In it, when calculating the characteristics of the wake vortex, the flight weight, speed and altitude of the aircraft, its flight configuration, atmospheric conditions, proximity of the earth, axial velocity in the core of the vortex and some other factors are taken into account. This complex has passed the necessary testing and state registration. A number of measures were carried out to validate and verify the developed complex, confirming the operability of the programs included in it and the reliability of the results obtained from it. The results of the study of the characteristics of the wake vortex behind the Antonov-12 aircraft in the form of vertical velocity spectra and fields of perturbed velocities at various distances from it are presented. It is shown that propellers noticeably affect the propagation of the wake vortex behind turboprop aircraft. This circumstance must be taken into account by the crews of aircraft flying behind such aircraft.

A dynamic predictive maintenance approach using probabilistic deep learning for a fleet of multi-component systems

A dynamic predictive maintenance approach using probabilistic deep learning for a fleet of multi-component systems

Principle and Method for Determining the Calendar Safety Life of Aircraft Structural Protection Systems

The calendar safety life of the surface protection system in aircraft structures is the time limit for it to be used without functional failure at a certain level of reliability and confidence. The reliability of such protection systems and the operational safety and economy of the structure are closely related. This paper firstly establishes two methods for determining the calendar safety life of aircraft structural protection systems under a single service environment and in multiple service environments. A method for determining the reliability of the calendar safety life of the aircraft structural protection system was proposed, and an expression of the relationship between the maintenance costs for the aircraft fleet and the reliability of the calendar safety life of the aircraft structural protection system based on the relationship between the amount of corrosion damage to the structural substrate and the corrosion time and the expression of the calendar safety life of the protection system was established. Finally, taking a hypothetical aircraft fuselage wall plate connection structure as an example, an alternating corrosion fatigue test with protection system specimens was carried out. The process for determining the calendar safety life of the structural protection system and its reliability are given. This method is important to ensure the safety of aircraft structures, improve the efficiency of use, and reduce maintenance costs. Generally speaking, the reliability of the calendar safety life of the structure is 99.9%, and after the analysis in this paper, the reliability of the structural protection system is about 70%.

Predictive Maintenance for Nasa’s Turbofan Engine

NASA's turbofan engine is a vital equipment used in its aircraft fleet. This engine is designed to provide the required thrust for various missions, from scientific research to astronaut training. However, this engine requires regular maintenance to ensure its optimal performance and safe operation. In this paper, we will find the remaining useful life of the turbofan engine by applying data science techniques and machine learning algorithms for predicting more accurate maintenance requirements. We will examine the performance metrics of different machine learning models and tune the parameters of the best model using random search. We will be deployed as an application using Streamlit. The final result of the web application is that it provides the results of the predictions done by the model as a csv file along with the model loss and accuracy.

A stochastic optimization approach for optimal Tail Assignment with knowledge-based predictive maintenance

Abstract Recent developments in the field of data analysis offer enormous potential to derive predictions of future aircraft maintenance necessities from observable aircraft attributes. This procedure is called Predictive Maintenance. The Predictive Maintenance generates considerable business benefits compared to alternatives like reactive or preventive maintenance for various reasons. Nevertheless, recognizing a maintenance necessity is only the first step, since the execution of the maintenance action has to fit into the airlines operational schedule. An essential step to realize financial benefits is to integrate Predictive Maintenance into the airlines optimization processes. To contribute to this task, we expand a well-known Tail Assignment model for the assignment of a potentially heterogeneous fleet of aircraft to a schedule of flights by a number of part failure scenarios. This results in a stochastic mixed integer linear optimization program, for which an optimization algorithm with solution guarantees is developed. This optimization algorithm is based on Benders Decomposition, which is concretized for the Tail Assignment problem and optimized for this task. Using this algorithm, a large proportion of the recovery costs for almost all instances tested is saved. The algorithm solves all instances in a reasonable amount of time. The algorithm uses a state-of-the-art mixed-integer linear solver, implementing a decomposition-based solution procedure for stochastic programs, called the L-shaped method. To demonstrate the potential of the approach, we benchmark our results using four strategies, motivated by commonly used preventive, reactive and passive approaches. Our approach leads to considerable cost savings when compared to each of the four benchmark approaches. The algorithms are tested on a set of instances with up to 80 flights based on a pre-pandemic schedule of a larger German airline. To the best of our knowledge, this article presents the first attempt to implement an exact optimization approach integrating malfunction predictions of the form presented into a Tail Assignment model.

Using this DEMATEL Corporate social responsibility CSR

When discussing Corporate Social Responsibility (CSR) in developing nations, academics and policymakers frequently ignore the perspectives of local producers. This paper fills a void in the literature by explicitly adopting a phenomenological approach and mapping the justifications offered by regional manufacturers to CSR programs in the West. To investigate this topic, data from two qualitative studies on CSR programs in Sialkot, Pakistan’s soccer ball industry were used. Previous research has presented technologies related to managing a green aircraft fleet, including retrofits, fleet renewal, and alternative biofuels, as well as opportunities to carry out retrofits and value emissions. An alternative integer program model has also been developed to optimize fleet replacement strategies within budgets. The Intergovernmental Panel on Climate Change has noted the ineffectiveness of airplane operations. Since 2005, IATA’s Green Teams have been working with airlines to reduce this inefficiency. Improved operational practices are expected to reduce emissions by 2020. Thus, more efficient operations can reduce CO2 emissions and conserve fuel. Any financial benefits from an international plan to cut airplane emissions should be set aside for environmental causes, and these profits must be partially reinvested. Only a few of the additional measures being taken to lower the emissions profile of the global aviation industry include supporting the development and use of more fuel-efficient aircraft and low-carbon, sustainable jet fuels. The Program in Science and Human Affairs at the Battelle Memorial Institute in Geneva was established between 1972 and 1976 to conduct research and address complex and interrelated problem groups using the DEMATEL (Decision-making Testing and Evaluation Laboratory) system. DEMATEL is one of the decision-making tools that employs several criteria to extract the complex structure of a problem. The DEMATEL method is widely used to identify the cause-and-effect relationships among different elements of a complex problem. The objective of DEMATEL is to scale from a complex system and the relationship between causal dimensions it is to model the understandable structure of that system. When measuring complexity, the cause-and-effect relationship of the criteria can be clearly seen. From the result it is seen that Technology (TE) the first rank where as is the infrastructure (IN) is having the lowest rank. Resulting in Technology (TE) ranked first, There Infrastructure (IN) has low rank.

Fleet planning under demand and fuel price uncertainty using actor–critic reinforcement learning

Current state-of-the-art airline planning models face computational limitations, restricting the operational applicability to problems of representative sizes. This is particularly the case when considering the uncertainty necessarily associated with the long-term plan of an aircraft fleet. Considering the growing interest in the application of machine learning techniques to operations research problems, this article investigates the applicability of these techniques for airline planning. Specifically, an Advantage Actor–Critic (A2C) reinforcement learning algorithm is developed for the airline fleet planning problem. The increased computational efficiency of using an A2C agent allows us to consider real-world-sized problems and account for highly-volatile uncertainty in demand and fuel price. The result is a multi-stage probabilistic fleet plan describing the evolution of the fleet according to a large set of future scenarios. The A2C algorithm is found to outperform a deterministic model and a deep Q-network algorithm. The relative performance of the A2C increases as more complexity is added to the problem. Further, the A2C algorithm can compute a multi-stage fleet planning solution within a few seconds.

Why Are Flight Psychologists Important to Flight Safety?

The developments in aircraft technologies both in our country and around the world cause a serious increase in both the aircraft fleets and ticket sales, as well as the number of airline companies, their employees and passengers. These developments in the aviation industry necessitate flight safety and highlight the importance of the human factor (flight crew) by reducing the causality of technical factors in ensuring safety. Studies within this scope show that the main causal factor (65-70%) in aircraft crashes is the flight crew. There are many factors such as physiological, psychological, personal and psychosocial at the basis of the unsuccessful performance of the flight crew. However, the number of studies in the literature that draw attention to the psychological elements of the flight crew is very few. In fact, it is known that the psychological well-being of the flight crew is important for the success of the flight operations, but the airline companies do not have any evaluation obligation regarding this. On the contrary, some negative consequences may be encountered due to the freedom in this matter. In particular, the fact that human factor causation is at a much higher level than previously thought in plane crashes increases the importance of flight psychologists for airline companies today. Therefore, in this study, it is aimed to reveal the importance of flight psychologists on flight safety in civil aviation. In this context, interviews were held with the flight crews of two airlines (private-public). The findings show that flight psychologists are important and necessary in airline companies in order to be able to perform safe flights with healthier flight crews.

Optimization and Decision-Making Framework for Small Unmanned Aircraft Systems Fleet Design

Many unmanned aircraft applications require or benefit from deploying a fleet to perform a mission. Technology innovations such as rapid prototyping and microelectronics enable the use of unmanned aircraft systems (UAS) at lower costs, so the ability to design a bespoke UAS for a specific mission is an additional advantage. The problem of designing the new UAS and allocating the fleet of these aircraft is a challenging optimization problem. Using constrained multi-objective design optimization with an interactive multicriteria decision-making method, which involves the mission customer, the approach in this paper generates UAS designs and fleet allocations and determines preferential solutions for the customer. The paper presents a case study involving a UAS weather profiling mission for the aircraft sizing and fleet allocation and uses inputs from meteorological subject-matter experts acting as customers to demonstrate the functionality of the approach.

Tata Group and Air India: Optimizing Brands, Routes, and Operations in the Airline Portfolio

In January 2022, the Tata Group acquired Air India and Air India Express from the Indian government, marking the culmination of a long privatization process of the government-owned airlines. Before the Air India acquisition, the Tata Group already operated two airlines in the Indian market: Air Asia India and Vistara. Air India was a full-service domestic and international carrier with a large fleet; Vistara was a premium full-service domestic and international carrier with a limited fleet; and Air India Express and Air Asia India were low-cost carriers (LCCs). The Tata Group urgently needed to reduce operating costs and maximize synergies across its airline portfolio, as all four airlines were losing money. Tata wanted to capitalize on the massive growth potential in the Indian airline market by augmenting and modernizing its aircraft fleet, expanding the route network, and improving the brand image of Air India. Some of Tatas decisions were constrained by conditions imposed by the Indian government. The Tata Group would need to move quickly, as customers and investors had high expectations for the turnaround of Air India.

A heuristic maintenance scheduling framework for a military aircraft fleet under limited maintenance capacities

A heuristic maintenance scheduling framework for a military aircraft fleet under limited maintenance capacities

Moral values of a future military pilot as the reliability of predicted professional psychological selection

Abstract. Aim. To identify one of the problems of professional psychological selection of applicants for training in a higher military flight school, to show the importance of moral values in the professional development of a military pilot and the impact of their presence or absence on the quality of the prediction as part of professional psychological selection. At present, the progress and constant modernisation of the Russian Air Force aircraft fleet places ever higher demands on the level of professionalism of a modern military pilot. In this context, there is a growing need for greater numbers of indicators diagnosed during professional psychological selection (PPS) that are later used to predict the success of military flight training and professional activity in general. That is primarily due to the fact that recently more and more attention has been paid to the role of the personality and its integrative function. However, at present, the existing flight crew PPS system does not provide a comprehensive diagnosis of a candidate’s personality.Methods. Based on a theoretical analysis of the work conducted by researchers and practitioners of aviation psychology and various approaches to the study of the professional fitness of flight personnel, it was identified that the key element in the diagnosis of professional fitness is the personality with its integrative function and the whole set of professionally important qualities. The analysis of literature in aviation psychology shows that personal qualities determine motivation, focus and sustained interest in flight work, as well as the social type of behaviour and a person’s adaptation to specific conditions of flight activity and military service.Results. A pilot’s professionalism begins with shaping the personality. Nowadays, the loss of spiritual guidelines has led to a dramatic simplification of moral values and patriotic spirit, and young people are more focused on consumerism. Selecting candidates for military aviation involves the use of a diverse set of diagnostic techniques that helps evaluate the most important psychological and personal qualities. However, the experience of application of personal questionnaires shows that they do not always represent a complete picture of an applicant’s motivation, personality orientation, self-awareness and basic values. The use of projective and hardware-based methods is minimised, the existing automated system for professional psychological selection (ASPPS) is insufficiently equipped with methods that diagnose personal qualities, the emphasis being placed on diagnosing cognitive processes. The century-old history of PPS shows a violation of the principle of personal integrity, which isexpressed in the bias towards psychophysiology. As a result, at present, the existing flight crew PPS does not provide a comprehensive diagnosis of a candidate’s personality.Conclusions. In conclusion, it is noted that the key element in the diagnosis of professional aptitude is the personality with all its PIQ and moral values. Growing numbers of diagnosed indicators in the personal block of the PIQ will enable a comprehensive diagnosis of a candidate, and thanks to a combination of survey and projective methods, it will help increase the reliability of the PPS prediction, provided that an applicant’s personality is treated holistically, based on the principles of an integrative approach to the person as an integral personality.

ANALYSIS OF POSSIBLE MODIFICATION OF TRANSPORT AIRCRAFT TO MEDEVAC IN THE CZECH REPUBLIC

With a growing number of coronavirus patients worldwide, military and civilian transport aircraft are increasingly being used for civilian medical evacuation duties (MEDEVAC) on time-critical flights. This article deals with the possibility of converting an aircraft fleet in the Czech Republic to MEDEVAC. The indication for the analysis of the possibility of transforming transport aircraft was the past and current pandemic situation in the Czech Republic. The main research question is how to implement the modification of a selected airline of the Czech Republic to MEDEVAC. An analysis of the technical data of selected aircraft from Airbus and Boeing was used to investigate this problem. Further, an analysis of the medical equipment required for the MEDEVAC aircraft category was also performed using equipment manufactured in the Czech Republic. The results obtained by the analysis and spatial arrangement of the aircraft deck for the transport of patients with medical equipment confirmed the possibility of such a transformation within the Czech Republic. We consider it important to elaborate on a project that would solve, in detail, all the steps of the conversion of a transport aircraft to MEDEVAC.