C-5M Fuel Efficiency Through MFOQA Data Analysis

This study investigates the usage of Military Flight Operations Quality Assurance (MFOQA) data as a means to obtain precise, aircraft-specific fuel loads. Currently, USAF C-5M aircraft include a 4% degrade value in their fueling practices. MFOQA data are analyzed in an attempt to refine this value. Case study data are analyzed from a single C-5M. A model is constructed using smoothing techniques which compare MFOQA actual observations to a baseline flight test model. The resulting figures are applicable to fuel planning and fuel efficiency concepts. Validation is presented through comparison with computerized flight planning software output. Results from the case study analysis are presented within the framework of fleet-wide implementation and maintenance practices

Design techniques to support aircraft systems development in a collaborative MDO environment

The aircraft design is a complex multidisciplinary and collaborative process. Thousands of disciplinary experts with different design competences are involved within the whole development process. The design disciplines are often in contrast with each other, as their objectives might be not coincident, entailing compromises for the determination of the global optimal solution. Therefore, Multidisciplinary Design and Optimization (MDO) algorithms are being developed to mathematically overcome the divergences among the design disciplines. However, a MDO formulation might identify an optimal solution, but it could be not sufficient to ensure the success of a project. The success of a new project depends on two factors. The first one is relative to the aeronautical product, which has to be compliant with all the capabilities actually demanded by the stakeholders. Furthermore, a “better” airplane may be developed in accordance with customer expectations concerning better performance, lower operating costs and fewer emissions. The second important factor refers to the competitiveness among the new designed product and all the other competitors. The Time-To-Market should be reduced to introduce in the market an innovative product earlier than the other aeronautical industries. Furthermore, development costs should be decreased to maximize profits or to sell the product at a lower price. Finally, the development process must reduce all the risks due to wrong design choices. These two main motivations entail two main objectives of the current dissertation. The first main objective regards the assessment and development of design techniques for the integration of the aircraft subsystems conceptual design discipline within a collaborative and multidisciplinary development methodology. This methodology shall meet all the necessities required to design an optimal and competitive product. The second goal is relative to the employment of the proposed design methodology for the initial development of innovative solutions. As the design process is multidisciplinary, this thesis is focused on the on-board systems discipline, without neglecting the interactions among this discipline with all the other design disciplines. Thus, two kinds of subsystems are treated in the current dissertation. The former deals with hybrid-electric propulsion systems installed aboard Remotely Piloted Aerial Systems (RPASs) and general aviation airplanes. The second case study is centered on More and All Electric on-board system architectures, which are characterized by the removal of the hydraulic and/or pneumatic power generation systems in favor of an enhancement of the electrical system. The proposed design methodology is based on a Systems Engineering approach, according to which all the customer needs and required system functionalities are defined since the earliest phase of the design. The methodology is a five-step process in which several techniques are implemented for the development of a successful product. In Step 1, the design case and the requirements are defined. A Model Based Systems Engineering (MBSE) approach is adopted for the derivation and development of all the functionalities effectively required by all the involved stakeholders. All the design disciplines required in the MDO problem are then collected in Step 2. In particular, all the relations among these disciplines – in terms of inputs/outputs – are outlined, in order to facilitate their connection and the setup of the design workflow. As the present thesis is mainly focused on the on-board system design discipline, several algorithms for the preliminary sizing of conventional and innovative subsystems (included the hybrid propulsion system) are presented. In the third step, an MDO problem is outlined, determining objectives, constraints and design variables. Some design problems are analyzed in the present thesis: un-converged and converged Multidisciplinary Design Analysis (MDA), Design Of Experiments (DOE), optimization. In this regard, a new multi-objective optimization method based on the Fuzzy Logic has been developed during the doctoral research. This proposed process would define the “best” aircraft solution negotiating and relaxing some constraints and requirements characterized by a little worth from the user perspective. In Step 4, the formulation of the MDO problem is then transposed into a MDO framework. Two kinds of design frameworks are here considered. The first one is centered on the subsystems design, with the aim of preliminarily highlighting the impacts of this discipline on the entire Overall Aircraft Design (OAD) process and vice-versa. The second framework is distributed, as many disciplinary experts are involved within the design process. In this case, the level of fidelity of the several disciplinary modules is higher than the first framework, but the effort needed to setup the entire workflow is much higher. The proposed methodology ends with the investigation of the design space through the implemented framework, eventually selecting the solution of the design problem (Step 5). The capability of the proposed methodology and design techniques is demonstrated by means of four application cases. The first case study refers to the initial definition of the physical architecture of a hybrid propulsion system based on a set of needs and capabilities demanded by the customer. The second application study is focused on the preliminary sizing of a hybrid-electric propulsion system to be installed on a retrofit version of a well-known general aviation aircraft. In the third case study, the two kinds of MDO framework previously introduced are employed to design conventional, More Electric and All Electric subsystem architectures for a 90-passenger regional jet. The last case study aims at minimizing the aircraft development costs. A Design-To-Cost approach is adopted for the design of a hybrid propulsion system

Aeronautical Engineering: A continuing bibliography, supplement 120

This bibliography contains abstracts for 297 reports, articles, and other documents introduced into the NASA scientific and technical information system in February 1980

Complex fuzzy assessment of green flight activity investments for sustainable aviation

The aviation industry harms the environment mainly via the creation of carbon emissions. Hence, action needs to be taken to ensure the environmental sustainability of the aviation industry such as the recycling of waste products, effective waste management and the introduction of energy efficiency measures. However, at the same time, the implementation of improvements to remediate such problems leads to the creation of additional costs for aviation companies. Companies thus need to conduct comprehensive priority analyses regarding the optimum strategy for the sustainability of the aviation industry. However, there is a very limited number of studies in the literature that focused on which approach should be prioritized. Accordingly, this study aimed at the assessment of the viability of investing in so-called green flight measures in the aviation industry, for which a completely original decision-making model was created. Firstly, the various strategic priorities were weighted and the impact-relation directions between them illustrated aimed at the identification of potential influences by means of a multi stepwise weight assessment ratio analysis (M-SWARA) methodology that incorporates bipolar q-rung orthopair fuzzy sets (q-ROFSs) and golden cut. Secondly, the various flight activities are ranked, and the potential impacts of these activities determined in terms of the strategic priorities of a sustainable aviation industry employing q-ROF as the elimination and choice translating reality (ELECTRE) technique. All the calculations were also computed with intuitionistic fuzzy sets (IFSs) and Pythagorean fuzzy sets (PFSs) aimed at verifying the validity of the findings. The analysis concluded that while energy efficiency comprises the most important factor in terms of strategic priority investment for the circular economy-based aviation industry, emergency response makes up the most crucial activity in the industry. Operational efficiency must be prioritized to decrease the amount of fuel consumed, in connection with which flight routes should be planned according to current weather conditions, which would serve to shorten flight times and, thus, help to increase energy efficiency. Such an approach would make a positive contribution to minimizing carbon emissions aimed at ensuring the sustainability of the aviation industry

Domain-independent method for developing an integrated engineering design tool

Engineering design is a complex, cognitive process requiring extensive knowledge and experience to be done effectively. Successful design depends on appropriate use of available resources. Competitive design cycles mandate convenient and reliable access to engineering tools and information. An integrated engineering design tool (IEDT) has been developed in response to these demands. Further, the tool development efforts have been made systematic by utilizing the engineering design process, which is shown to be a cognitive activity based on Bloom\u27s taxonomy of cognition. The engineering design process consists of six tasks: establishment of objectives, development of requirements, function analysis, creation of design alternatives, evaluation, and improvements to the design. These tasks are shown to map to the six levels of Bloom\u27s cognitive taxonomy: knowledge, comprehension, application, analysis, synthesis, and evaluation. Once engineering design is shown to be a cognitive process it can be employed to make each of the activities required to develop and IEDT, domain investigation, knowledge acquisition, and IEDT design, systematic. Past research has considered these to be largely ad hoc tasks. Application of the engineering design process to each of the three IEDT development tasks is discussed in general terms;A prototype IEDT has been created for the preliminary design of jet transport aircraft wings based on the systematic engineering design approach is used to demonstrate the implementation of the method. The IEDT is embedded in Microsoft Excel 97 with links to other software and executable code. Examples of different implementation strategies are provided. Several wing weight prediction models are included. The incorporation of depth knowledge is done using fuzzy logic. The IEDT is linked to relevant files containing design documentation, parameter information, graphics, drawings, and historical data. The designer has access to trade-off study information and sensitivity analysis and can choose to perform structural analysis or design optimization. The engineer can also consider design issues such as cost analysis. The modular IEDT has been designed to be easily adaptable by design domain experts so that it may continue to be updated and expanded

Gas turbine aero-engines real time on-board modelling: A review, research challenges, and exploring the future

On-board real time modelling for gas turbine aero-engines has been extensively used for engine performance improvement and reliability. This has been achieved by the utilization of on-board model for the engine's control and health management. This paper offers a historical review of on-board modelling applied on gas turbine engines and it also establishes its limitations, and consequently the challenges, which should be addressed to apply the on-board real time model to new and the next generation gas turbine aero-engines. For both applications, i.e. engine control and health management, claims and limitations are analysed via numerical simulation and publicly available data. Regarding the former, the methods for modelling clean and degraded engines are comprehensively covered. For the latter, the techniques for the component performance tracking and sensor/actuator diagnosis are critically reviewed. As an outcome of this systematic examination, two remaining research challenges have been identified: firstly, the requirement of a high-fidelity on-board modelling over the engine life cycle, especially for safety-critical control parameters during rapid transients; secondly, the dependability and reliability of on-board model, which is critical for the engine protection in case of on-board model failure. Multiple model-based on-board modelling and runtime assurance are proposed as potential solutions for the identified challenges and their potential and effectiveness are discussed in detail

Aeronautical engineering: A continuing bibliography with indexes (supplement 286)

This bibliography lists 845 reports, articles, and other documents introduced into the NASA scientific and technical information system in Dec. 1992. Subject coverage includes: design, construction and testing of aircraft and aircraft engines; aircraft components, equipment, and systems; ground support systems; and theoretical and applied aspects of aerodynamics and general fluid dynamics

\u3ci\u3eThe Symposium Proceedings of the 1998 Air Transport Research Group (ATRG), Volume 2\u3c/i\u3e

UNOAI Report 98-4https://digitalcommons.unomaha.edu/facultybooks/1153/thumbnail.jp

Fuel consumption optimization in air transport: a review, classification, critique, simple meta-analysis, and future research implications

This paper presents a review, classification schemes, critique, a simple meta-analysis and future research implication of fuel consumption optimization (FCO) literature in the air transport sector. This review is based on 277 articles published in various publication outlets between 1973 and 2014. A review of 277 articles related to the FCO in air transport was carried out. It provides an academic database of literature between the periods of 1973– 2014 covering 69 journals and proposes a classification scheme to classify the articles. Twelve hundred of articles were identified and reviewed for their direct relevance to the FCO in air transport. Two hundred seventy seven articles were subsequently selected, reviewed and classified. Each of the 277 selected articles was categorized on four FCO dimensions (Aircraft technology & design, aviation operations & infrastructure, socioeconomic & policy measures, and alternate fuels & fuel properties). The articles were further classified into six categories of FCO research methodologies (analytical - conceptual, mathematical, statistical, and empirical- experimental, statistical, and case studies) and optimization techniques (linear programming, mixed integer programming, dynamic programming, gradient based algorithms, simulation modeling, and nature based algorithms). In addition, a simple meta-analysis was also carried out to enhance understanding of the development and evolution of research in the FCO. This has resulted in the identification of 277 articles from 69 journals by year of publication, journal, and topic area based on the two classification schemes related to FCO research, published between, 1973 to December- 2014. In addition, the study has identified the 4 dimensions and 98 decision variables affecting the fuel consumption. Also, this study has explained the six categories of FCO research methodologies (analytical - conceptual, mathematical, statistical, and empirical-experimental, statistical, and case studies) and optimization techniques (linear programming, mixed integer programming, dynamic programming, gradient based algorithms, simulation modeling, and nature based algorithms). The findings of this study indicate that the analytical-mathematical research methodologies represent the 47 % of FCO research. The results show that there is an increasing trend in research of the FCO. It is observed that the number of published articles between the period 1973 and 2000 is less (90 articles), so we can say that there are 187 articles which appeared in various journals and other publication sources in the area of FCO since 2000. Furthermore there is increased trend in research on FCO from 2000 onward. This is due to the fact that continuously new researchers are commencing their research activities in FCO research. This shows clearly that FCO research is a current research area among many research groups across the world. Lastly, the prices of jet fuel have significantly increased since the 2005. The aviation sector’s fuel efficiency improvements have slowed down since the 1970s–1980s due to the slower pace of technological development in engine and aerodynamic designs and airframe materials. We conclude that FCO models need to address the composite fuel consumption problem by extending models to include all the dimensions, i.e. aircraft technology & design, aviation operations & infrastructure, socioeconomic & policy measures, and alternative fuels & fuel properties. FCO models typically comprise all the four dimensions and this reality need to be taken into account in global FCO models. In addition, these models should have objectives or constraints to evaluate the aircraft sizes according to market structure, impact of various policy measures on fuel burn, and near term potential alternative fuel options in the global FCO problem. In the models reviewed, we evaluated that, only the few authors considered these factors. The literature identifies 98 decision variables affecting the fuel consumption related to various dimensions in air transport. So we can conclude that this analysis could represent the informational framework for FCO research in air transport. Our analysis provides a roadmap to guide future research and facilitate knowledge accumulation and creation concerning the application of optimization techniques in fuel consumption of air transport. The addressed dimensions & decision variables could be of potential value to future researchers on the aviation fuel consumption optimization research and is also capable of further refinements. In future, for fuel consumption optimization the explored decision variables could be checked for their reliability and validity and a statistically significant model with minimum number of decision variable could be developed. Further, on the basis of this statistical significant model and with the best market requirement for transport aircraft, the researchers can frame the objective function for fuel consumption minimization problem & decide their dependent variables, independent variables, constant, and constraints. Furthermore, this study will also provide the base for fuel conservation, energy efficiency, and emission reduction in the aviation sector. Document type: Articl

Improving Aircraft Engine Maintenance Effectiveness And Reliability Using Intelligent Based Health Monitoring

Tez (Doktora) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2009Thesis (PhD) -- İstanbul Technical University, Institute of Science and Technology, 2009Minimum bakım maliyeti ile uçakların kullanılabilirliğini artırmak için, Motor durumunu izleme (MDİ) çok rağbet görür hale gelmiştir. Bu çalışma, uçak bakım etkinliği ve güvenilirliğini artırmak için, arızaların olmadan önce saptanmasına imkan sağlayacak, uçuş sırasında MDİ için bir metod geliştirmeyi amaçlamaktadır. Yaklaşan motor arızaları, yakıt akışı (FF), egzoz gaz sıcaklığı (EGT), motor fan devri (N1), motor kompressör devri (N2) vs. parametrelerinin değişmesine sebep olduğundan, motor kötüleşmeleri veya bozulmaları, bunların izlenmesi ile tespit edilebilir. Bu çalışmada, motor durumunu uçuşta izlemek için, bulanık mantık ve sinir ağları kullanılarak, hava yolları tarafından yapılan mevcut manüel MDİ’nin otomasyonu geliştirilmiştir. Daha sonra, MDİ otomasyonu için, çok kullanışlı bir metod olan bulanık mantık seçilmiştir. Farklı motor arızaları için, Türk Hava Yolları’ndaki gerçek veriler ve uzman bilgilerine dayanarak bulanık mantık kural tabanı oluşturulmuştur. MDİ’nin tüm çevrimi MATLAB’teki bulanık mantık modülü ve Visual Basic’te yazılan bir program kullanılarak otomatikleştirilmiştir. Sonuçta, bu metod Türk Hava Yollarındaki motorların izlenmesi için çalıştırılmıştır. Sonuçlar, bu metodun, MDİ’nin kolaylaştırılması ve ekstra adam-saat, insan hatası ve mühendislik uzmanlığı gerekliliği gibi dezavantajları minimuma indirmek için, hava yolları tarafından kullanılabileceği göstermiştir. Bu metot, uçak motorları dışında, uçaklardaki yardımcı güç üniteleri, yapısal elemanlar vb. komponetlere uygulanabilir. Her motor tipi farklı karakterlere sahip olabileceği için, farklı motor tiplerinde bu metot kullanırken kural tabanının revize edilmesi gerekir.Engine Health monitoring (EHM) has been a very popular subject to increase aircraft availability with minimum maintenance cost. The study is aimed at providing a method to monitor the aircraft engine health during the flight with the aim of providing an opportunity for early fault detection to improve airline maintenance effectiveness and reliability. Since the impending engine failures may cause to change the engine parameters such as Fuel Flow (FF), Exhaust Gas Temperature (EGT), engine fan speed (N1), engine compressor speed (N2), etc., engine deteriorations or faults may be identified before they occur by monitoring them. So as to monitor engine health in flight, the automation of current work for EHM which is done manually by airlines is developed by using fuzzy logic (FL) and neural network (NN) models. FL is selected to develop an Automated EHM system (AEHMS), since it is very useful method for automation health monitoring. The fuzzy rule inference system for different engine faults is based on the expert knowledge and real life data in Turkish Airlines fleet. The complete loop of EHM is automatically performed by visual basic programs and Fuzzy Logic Toolbox in MATLAB. Finally, the method is utilized to run for monitoring the engines in Turkish Airlines fleet. This study has shown that AEHMS can be used by airlines or engine manufacturers efficiently to simplify the EHM system and minimize the drawbacks of it, such as extra labor hour, human error and requirement for engineering expertise. This method may also be applicable other than aircraft engines such as auxiliary power unit, structures. Since every engine type has different characters, it is required to revise the fuzzy rules for the concerning engine types.DoktoraPh