Thesis (MScEng)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: The air-to-air refuelling of large aircraft presents challenges such as a long fuel transfer time, slow aircraft responses and a large distance between the aircraft CG and the receptacle position. This project addresses some of these issues by adding a control system to keep the receiver aircraft in the correct position relative to the tanker to enable fuel transfer. This project investigates different control strategies which are designed to control the A330-300 during refuelling at one trim condition. The controllers are based on a mathematical aircraft model which was derived from a simulation model received from Airbus. The first set of controllers uses the aircraft actuators directly. Controllers that are based on the CG dynamics and the receptacle dynamics are compared. Due to the large distance between the CG and the receptacle it was found to be essential to control the receptacle position, and not only the CG position. Also, a controller that is based on a model of the receptacle dynamics performs better. The second set of controllers uses the aircraft manual control laws as an inner loop controller. This set of controllers and the last direct actuator controller use the same axial controller that uses the engine thrust to control axial position. It was found that both the direct actuator controller and the manual control laws controller are able to keep the receptacle within the disconnect envelope in moderate turbulence. In both sets of controllers the axial controller fails to keep the receptacle reliably within the disconnect envelope in light turbulence. From the results it is concluded that both the direct actuator control and manual control laws can be used to successfully control the receptacle position in the normal and lateral positions as long as the receptacle kinematics are included in the control design. Using only the engine thrust for axial control is insufficient. Several recommendations are made to improve the axial control and also how these results can be used in future work. / AFRIKAANSE OPSOMMING: Die lug-tot-lug brandstof hervulling van groot vliegtuie het uitdagings soos ’n lang hervullingstyd, stadige vliegtuig dinamika en ’n groot afstand tussen die hervullingspoort en die vliegtuig massamiddelpunt. Hierdie projek spreek sommige van hierdie uitdagings aan deur ’n beheerstelsel by te voeg wat die vliegtuig in die korrekte posisie relatief tot die tenker hou vir brandstofoordrag om plaas te vind. Hierdie projek ondersoek verskillende beheerstrategieë wat ontwerp is om die A330- 300 te beheer by ’n enkele gestadigde toestand. Die beheerders is gebaseer op ’n wiskundige vliegtuigmodel wat vanaf ’n simulasiemodel afgelei is. Die simulasiemodel is vanaf Airbus verkry. Die eerste stel beheerders beheer direk die vliegtuig se beheeroppervlakke. Beheerders wat onderskeidelik die massamiddelpunt en die hervullingspoort beheer word vergelyk. Daar is gevind dat dit essensieel is om die hervullingspoort te beheer en nie slegs die massamiddelpunt nie, as gevolg van die groot afstand tussen hierdie twee punte. Die tweede stel beheerders gebruik die vliegtuig se eie beheerwette as ’n binnelusbeheerder en vorm self die buitelus. Albei stelle beheerders gebruik dieselfde aksiale beheerder wat enjin stukrag gebruik om die aksiale posisie te beheer. Daar is gevind dat beide stelle beheerders die hervullingspoort binne die ontkoppelingsbestek kan hou in die normale en laterale rigtings tydens matige turbulensie. In beide stelle beheerders is dit die aksiale beheerder wat faal om die hervullingspoort betroubaar in posisie te hou, selfs in ligte turbulensie. Vanaf die resultate word afgelei dat beide die direkte beheerder en die buitelusbeheerder gepas is om die laterale en normale posisiebeheer toe te pas mits die dinamika van die hervullingspoort in ag geneem word. Om slegs stukrag te gebruik vir aksiale beheer is nie voldoende nie, en verskeie voorstelle word gemaak om die aksiale beheer te verbeter in toekomstige navorsing.

Denna studie undersöker huruvida den faktiska avkastningen för ett flygbolags aktie skiljer sig från den förväntade avkastningen i samband med att ett av flygbolagets plan kraschar. För att undersöka förekomsten av abnormal avkastning genomförs en eventstudie där 71 flygplanskrascher mellan åren 1980 till och med 2018 undersöks. Resultatet visar att det förekommer en genomsnittlig kumulativ avvikelseavkastning på -4,65% dagen då kraschen sker inklusive nästkommande dag, vilken är statistiskt signifikant på 1%. Vidare har antalet dödsfall som en flygplanskrasch orsakar en statistiskt signifikant påverkan på sambandet med styrkan 1%, där fler dödsfall resulterar i en större negativ kumulativ abnormal avkastning.

The Multiple Cooling Multi-Objective Simulated Annealing Algorithm is used for the conceptual design optimization of a supersonic Unmanned Combat Aerial Vehicle (UCAV). Single and multiobjective optimization problems are addressed while limiting performance requirements between desired bounds to obtain viable aircraft configurations. A conceptual aircraft design code was prepared for planned but flexible combat missions. The results demonstrate that the optimization technique employed is an effective tool for the conceptual design of aircrafts.

In the event of an onboard emergency, air transport pilots are remarkably adept at safely landing their aircraft. However, the tasks of selecting an alternate landing site and developing a safe path to land are very difficult in the high workload, high stress environment of a cockpit during an emergency. The purpose of this research was to develop an automated path planning aid which would assist the pilot in the completion of these tasks. A prototype was developed to test this concept experimentally. The experiment was also intended to gather further information about how pilots think about and accomplish this task as well as the best ways to assist them. In order to better understand the priorities and processes pilots use when dealing with emergency planning, a survey of airline pilots was conducted. The results of this survey highlighted the fact that each emergency is unique and has its own set of factors which are critically important. One factor which is important in many emergencies is the need to land quickly. The survey responses indicated that one of the most important characteristics of a useful tool is that it should provide pertinent information in an easy to use manner, and should not divert too much attention from their other tasks. A number of design goals drove the development of the prototype aid. First, the aid was to work within current aircraft, without requiring substantial redesign on the cockpit. Second, the aid was to help improve pilots' performance without increasing their workload. Finally, the aid was designed to assist pilots in obtaining and processing critical information which influences the site selection and path development tasks. One variation of the aid included a filter dial which allowed pilots to quickly reduce the number of options considered, another variation of the aid did not include such a dial. These two variations of the aid were tested in order to assess the impact of the addition of the filter dial to the system. Though many of the results did not prove to be statistically significant, they suggest that the addition of a filter dial improved the quality of the selected landing site; however, it also increased the time required for the selection. The results were obtained in both familiar and unfamiliar emergencies. The dial was shown to improve the time to complete the task in the case of unfamiliar emergencies. The experiment also compared an optimal ranking system to a non-optimal system, for which results showed no significant difference between the two. This may imply that while pilots did not tend to over rely on the ranking system, under-reliance may need to be addressed by training and a better understanding of the factors which impact the rankings. The participants found that the aid facilitates quick and easy access to critical information. The aid was also useful for processing this information by filtering out options which were inappropriate for a given scenario through the use of the filter dial. The participants also made recommendations about possible improvements which could be made to the system such as better filter settings which are more similar to the way that pilots think about their options.

Multiple Cooling Multi Objective Simulated Annealing algorithm has been combined with a conceptual design code written by the author to carry out a multi objective design optimization of an Agricultural Aerial Robot. Both the single and the multi objective optimization problems are solved. The performance figures of merits for different aircraft configurations are compared. In this thesis the potential of optimization as a powerful design tool to the aerospace problems is demonstrated.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Actually in Brasil there there is a fleet around 1500 agricultural aircraft working on different aplications. The spray aplication by na airplane of crop defenses is increasing on the last years, generating a demand on spraying airplanes, pilots, spare parts for maintenance, fuel and, first of all, operational cost reduction. Base on this, the present master thesis is working as knowledge generator ans presenting results for, in the future, to project an ethanol aeronautical engine that will use on agricultural/spraying airplanes. Operational costs for agricultural airplanes is based on maintenance and in the fuel, that the major part uses aviation gasoline AvGas as fuel. Ethanol comes with a great chance to reduces such costs, due to the price of this fuel is only around 25% of AvGas. The aeronautical engines that flies nowadays with ethanol as fuel are a conversions from AvGas engines, wich generates some problems, the main is consumption increasing. The possibility to reduces operational costs with using a fuel from renewable source and challenge to get an aeronautical engine dedicated to run with ethanol as fuel is what motivates and derecting this research. Development process of a technical system, as an ethanol engine, is complex and requires human and material resources administration, information colect, research and a strenght management of whole development process. Methodology for this work development is based on exploratory research of existing bibliography about development product process, technical systems, aeronautical engines, agricultural aviation and homologation standards for aeronautical engines and your parts and components. Information acquired are presented to provide a data base to meet the need of companies, engineers and designers on a future development. After organization and threatment the data supply the base of influence factors for a project of aeronautical ethanol engine for agricultural airplane. The knowledge about brasilian agricultural airplane fleet and engines used on such airplanes provide detailed information about size and capacity of each airplane and their aplications, including information about their technical and operating characteristics. With this, was able to make entire influence factors for a project of aeronautical ethanol engine for agricultural airplane, such influence factors are divided in four groups that is: Project Scope, Benchmarking, Operating Characteristics and Standards & Homologation. Technical data and information of aeronautical engines and their characteristics was evaluated and compared to observ the tendency of engines with power in a range beetween 151 and 300kW, where more than 80% of those engines in whole brasilian fleet is inside of this range, the major part using AvGas as fuel. Engines running with ethanol generates more power if compared the same engine running with AvGas, for other side, there is a consumption increasing, aorund 40% more and the emissions are decreased, what is a positive point with ethanol use as fuel. / No Brasil, hoje, há uma frota aproximada de 1500 aeronaves agrícolas efetuando operações diversas. A aplicação aérea de defensivos nas culturas agrícolas tem sido crescente nos últimos anos, gerando uma necessidade maior de aeronaves, pilotos agrícolas, peças de reposição e combustível, bem como, e principal quesito, a necessidade de redução dos custos operacionais. É neste ponto que este trabalho entra como gerador de conhecimento apresentando dados e resultados para a obtenção, no futuro, de um motor projetado para o uso de etanol equipar aeronaves de aplicação agrícola.Os custos operacionais das aeronaves agrícolas está baseado na manutenção e no combustível que ela utiliza, na grande maioria é a AvGas gasolina de aviação. O etanol vem com grande chance de reduzir significativamente estes custos, pois seu preço é inferior ao da AvGas, podendo chegar apenas 25% do preço desta. Os motores de aeronaves que voam atualmente com etanol são conversões, o que gera alguns problemas, dentre eles o mais significativo que é o aumento de consumo de combustível. A possibilidade de redução dos custos operacionais com a utilização de combustível produzido de fonte renovável e o desafio de se ter um motor projetado especificamente para o uso de etanol como combustível é o que motiva o estudo e direciona a pesquisa. O processo de desenvolvimento do projeto de sistema técnico, como o de um motor a etanol, é complexo e exige administração dos recursos humanos e materiais, coleta de informações, pesquisa e um rígido gerenciamento de todo o processo para tal desenvolvimento. A metodologia para desenvolvimento do estudo está baseada na pesquisa exploratória de bibliografia existente acerca de desenvolvimento de produtos e sistemas técnicos, motores aeronáuticos, aviação agrícola e normas para homologação de produtos e peças aeronáuticas para aplicação em aeronaves agrícolas. As informações obtidas estão apresentadas de maneira a fornecer uma base de dados capaz de suprir a necessidade de empresas, engenheiros e projetistas num desenvolvimento futuro. Os dados compilados e organizados formam a base para a apresentação dos fatores de influência no projeto de um motor a etanol para aplicação em aeronaves agrícolas. O conhecimento sobre a frota brasileira de aeronaves e os motores utilizados fornecem informações detalhadas sobre o tamanho e capacidade de cada aeronave e suas aplicações, bem como os motores necessários em cada uma destas aeronaves e suas características técnicas e operacionais. Obtêve-se a elaboração completa de todos os fatores de influência para o projeto de um motor aeronáutico a etanol direcionado para aplicação agrícola, tais fatores de influência estão subdivididos em quatro grupos que são: Escopo do projeto, análise comparativa dos motores, características da operação e normas e homologação. Informações e dados técnicos de motores e suas características foram avaliadas e comparadas entre si, de maneira a observar a tandência de utilização de motores na faixa de 151 à 300kW, onde mais de 80% dos motores empregados estão dentro desta faixa e na grande maioria consumindo AvGas. Motores a etanol geram maior potência em detrimento de aumento de consumo, da ordem de 40%, porém, as emissões de gases tóxicos são reduzidas, o que é fator positivo no uso do etanol como combustível.

This thesis deals with design, development and testing of device for collecting fly data in ultralight airplane or helicopter. The basic collected value is a count of fly hours of each pilot. Additional fly data are latitude, longitude and altitude. Purpose of this device is a fair pricing for use of the airplane. Another utilization is in analysis of flight path or in pilot training. This device is succesfully made from miniature computer Raspberry Pi and uses GPS data. A reader will be informed about aviation regulations, embedded systems, global positioning system and wireless internet connection.

This master’s thesis deals with the conceptual design of light surveillance aircraft. It involves modifying of VUT 001 Marabu according to the new requirements, which has been mainly brought by new definition of typical flight. Also there is solved design and geometry surfaces of new aircraft. It contains design and computation of stand for electro-optical monitoring device. Last but not least are calculated important flight performances.

The topic of the thesis is a design of an aicraft for towing of gliders. Based on the background research of the towing aircrafts currently used by the Czech aeroclubs and the analysis of the required characteristics of these aircrafts the design of the new airplane has been created. Moreover, the load of engine mount has been determined according to the CS-VLA directive (a certification guidelines for the Very-light aircrafts). Its construction design as well as strength calculation have been elaborated. The part of the thesis is a 3D model of the aircraft and the engine mount.

The principal objective of this thesis is to propose a Contrail forecasting Service for Aviation(ConSA) and a ConSA client to demonstrate the service. The subject is motivated by the fact that Contrails have a very harmful effect on the environment and it has been researched thoroughly by scientists. But still we do not have an infrastructure to include these researches in the Aviation industry. This thesis has been conducted at Airbus Defence and Space, Friedrichshafen, Germany. The first part of the thesis investigates the existence of contrails. The object of interest i.e. Contrails is caused by the passage of aeroplanes in ice-saturated areas. The algorithm which is used by the service is a part of the research conducted by Prof. Dr. Ulrich Schumann. The input dataset provided by Meteo France is a 4D weather cube. The algorithm computes a threshold temperature and ice supersaturation condition. When both of these conditions are satisfied Contrail formation is certain. In the second part we explain the architecture and solution used i.e. OGC (Open Geospatial Consortium) and LuciadLightspeed to develop Web Services to deploy contrail forecasting methods. Such an architecture fast forwards and eases the task of developer by having inbuilt methods and interfaces. The OGC web services infrastructure has defined web feature service and client interface which ease development of geoinformatics solutions.We also use certain standards like WXXM for exchange of contrail information which will be stated in this chapter. The third part is about the detailed implementation of the ConSA service and client. In this chapter we explain the service and client with uml diagrams to clarify the development concepts. The final part of the thesis explains the results of ConSA service and client, operational benefits of ConSA and concludes the thesis.