State misinterpretation has been identified as a causal factor in several accidents where humans were operating complex systems in dynamic domains. The concept of state misinterpretation, although undefined, is characterised by its unobservability, and its relative infrequency. These features make gathering data about state misinterpretation difficult. It was therefore decided to use archive incident report data; the NASA Aviation Safety Reporting System database was used. A definition of state misinterpretation was formulated and translated into database queries to retrieve relevant incident reports for a homogeneous set of expert pilots over a fixed time period. These reports were encoded using the Cognitive Reliability and Error Analysis Method suitably adapted to analysis of aviation incidents. Each report was categorised by the type of state misinterpretation, and a taxonomy of these types was developed. Those types which occurred more than 20 times were analysed at three levels of abstraction. First, a concordance of individual actions showed that communication failures, missed observations and distractions were the most common causal factors. Second, the sequences of possible causal actions showed that some sequences are common across different types of error and state misinterpretation. Third, the causal trees for each state misinterpretation type were quantitatively compared. The lack of measured similarity between the trees suggests that the types in the taxonomy are distinct. Most of the analysed incidents were preventable by better management of flight crew actions. Two particular sequences of actions dominated the results. The first is where the flight crew missed an observation when they were distracted by a competing task. The second is where a communication failure between the flight crew and air traffic control occurred. Some suggestions are offered about how flight crews can better manage their actions to prevent the occurrence of some types of state misinterpretation, thereby reducing incident numbers.

The research presented in this thesis was initially motivated by the excessive accident rates for inexperienced drivers. Researchers have previously attempted to discover what type of experience is gained during driving, and how this reduces accident liability. This research was primarily concerned with the visual acquisition of information during driving, and how this ability varies with driving experience. The first experiment was conducted to assess which of two methods was the better suited to the assess the hypothesis. The results favoured eye tracking drivers in both the laboratory and while actually driving in the real world. On this basis experiments 2 and 3 were conducted. Experiment 2 required participants to drive along a set route while being eye tracked, while experiment 3 measured the eye movements of participants as they watched driving videos in a laboratory hazard perception test. The former experiment revealed experiential differences that extended the findings in the literature. The latter experiment revealed very few experiential differences however. The failure of the hazard perception test to evoke such differences was discussed in regard to the limitations of eye tracking methodology. If experienced drivers have less accidents than their inexperienced counterparts, then one would expect differences to occur in their search strategies. However, if the differences between drivers of varying experience lie within peripheral rather than foveal vision, the straightforward measuring of eye movements may not reveal the true differences. On the basis of the results so far and the literature, it was suggested that experience may allow greater deployment of attention in the peripheral field. Three artificial experiments were undertaken to assess the relationship between foveal demand and eccentricity, before returning to the driving context. In the two final experiments participants of varying driving experience watched the same hazard perception clips previously used in experiment 3. The primary task was either to rate each clip along the dimensions of danger and difficulty, or to press a foot pedal in response to the appearance of a dangerous event. The secondary task required participants to press a button whenever they saw a peripheral target light. Peripheral detection ability was found to degrade with increases in foveal demand (the appearance of a hazard in the hazard perception clips) and eccentricity. Of most importance however was the effect of experience. As drivers gain experience they are able to devote more attention to the peripheral visual field, though the appearance of a hazard degraded peripheral attention across all eccentricities and levels of experience. A detailed analysis of the time line of degradation revealed that though the experienced drivers suffered a greater degradation of peripheral attention with the appearance of a hazard than the less experienced participants, this degradation occurred for only a split second. Learner drivers however suffered the effects of this demand-modulated degradation of peripheral attention for over two seconds. Together these results provide evidence for an attentional skill that modifies the timing and magnitude of attention focusing due to an increase in foveal demand. This is a skill that seems to be learned with driving experience. The implications of these results to pure attention research and driving research are considered.

This thesis is an empirical investigation of the strategic use of information in the airline industry, and explores the development of competition in the airline industry from an information perspective. The research traces the evolution in the environmental conditions facing airlines from World War I to the present. The research also analyses evolution of the uses of information. Information is an enabler, allowing things to be done, but information can also be a resource in itself. The research finds growing strategic use of information from automation to using information as a resource for strategic flexibility. The main sources of information that airlines use in their strategic efforts are analysed, as well as the ways in which airlines procure this information and the uses they make of it in strategy. The research finds evidence of distinct phases in the evolution of the uses made of information by airlines. Crucial to airline strategic flexibility is local market information acquired informally. However, the evidence also illustrates the serious difficulties airlines face in using the external information about the markets in which they operate in their strategy. Different streams of academic literature support the findings of this empirical research.

This study argues that society's choices between possible technological developments are highly reflective of patterns of political, social, and economic power. Employing insights from recent historical and sociological work on class, gender, consumption and technology the processes by which social relations shaped the design, marketing and uses of the car are explained. In turn, it is argued that the legal and physical infrastructure which developed in the car's wake were extremely expressive of class and gender relations. The interwar years are studied because it was during this period, when the car as a technology was still open to contestation, that the British car culture was defined. This was so because it was during the 1920s and 1930s that car ownership became a reality for millions of middle-class Britons. An analysis of the symbolic, as well as the utilitarian, benefits of ownership is offered and reveals the car's role in the expression of social and gender identity. The extent to which these factors impinged upon the actions of car manufacturers and motor dealers is also related. This perspective and the use of oral evidence has unearthed significant new evidence about the composition of the motoring community. The process through which influential sections of opinion reached a concordance with the car is explained. As it became increasingly useful for them, the professional and commercial middle-classes swung against significant restrictions on car use. Pre-1914 they were often outraged by the danger and inconvenience that were inevitable side effects of rising car ownership. However, once owners themselves they were increasingly attracted to new ideas about road safety which placed more and more emphasis on the education and segregation of other road users. The influential pro-motoring lobby manipulated these developments, a factor which is investigated here for the first time.

This thesis aims at investigating the behaviour of airlines in recently liberalised markets, by making use of the Brazilian air transportation as a case study. In order to accomplish this objective, the following three essays were developed: a study of low cost carrier entry behaviour, an analysis of the pricing behaviour of the major incumbents in the industry, and, finally, an assessment of airline conduct in the most important market in the country. All essays contain empirical investigation performed by making use of data supplied by Brazil’s Department of Civil Aviation, DAC. In the first essay, the entry of Gol Airlines on several Brazilian domestic routes, in 2001 and 2002, is analysed in order to draw inference on the competition between a discounter in rapid expansion and the full-service carriers. A route-choice model is estimated by making use of a flexible post-entry equilibrium profits equation and accounting for endogeneity of the main variables. The second essay aims at empirically investigating the pricing behaviour of the legacy carriers in Brazil, with special focus on reactions to the entry of Gol, in 2001. A study of localised competitive advantage regarding the determinants of pricing power is performed along with the analysis of the pattern of price reactions by the incumbents. A single econometric framework is designed and estimated with panel data controlling for city-specific effects. And finally, the third essay aims at assessing the impacts of economic liberalisation on the route Rio de Janeiro - São Paulo. By making use of both a two-stages budgeting representation of the demand system, and a competition model with product heterogeneity among rivals, and based on the framework of the New Empirical Industrial Organisation, it was possible to examine the existence of a structural change on airlines’ conduct parameters due to the regulatory reform.

A thorough evaluation of the airworthiness of a manned aircraft is vitally important, regardless of the size or function of the aircraft. However, the methods used in light and particularly microlight aircraft certification were largely based upon rules of thumb or methods better suited to larger, higher energy, aircraft programmes. A programme of research has been carried out to develop means by which microlight aircraft certification could be carried out appropriately to this class of aircraft. The stall and immediately post-stall behaviour of an aircraft are shown to be a function of the deceleration rate prior to the stall; therefore it is necessary to use a representative deceleration rate when determining the acceptability of stall and post-stall handling qualities. This research has found means by which the range of deceleration rates likely to be seen in a particular type can be estimated, so that flight test programmes can ensure these rates are included, and thus aircraft are confirmed to have acceptable stalling characteristics. Weightshift controlled microlight aeroplanes, using a Rogallo type wing, rarely show a conventional (square law) relationship between stalling speed and loading; the reason being identified as aeroelastic deformation of the wing with loading. A means by which stalling speed may be estimated for such aircraft at a variety of loadings has been developed. This will allow designers the maximum flexibility in determining operating limits and shows how the stall speed at various flight conditions may be predicted in aircraft operating documentation. The spin is a serious and potentially fatal mode of flight; a spinning evaluation, even for non-aerobatic aeroplanes, is therefore essential. A best practice has been developed and tested for the spin-resistance or spinning evaluation of microlight aeroplanes, including equipment, aircraft and crew preparation, and reporting. The developed methodology is shown to be successful, using the results of certification flight test programmes, and the in-service safety record of aircraft which had been evaluated using these methods. The tumble mode is a little known mode of departure from controlled flight experienced by weightshift controlled microlight aeroplanes. It has been a very significant factor in fatal accident records, being non-recoverable without the use of external safety devices. The mode consists of a nose-down autorotation at a rate of up to 400°/s. The tumble entry mechanism is explained, and advice to operators developed which should prevent tumble entry. Evidence is shown of the nature of the developed tumble – both modelled and through wind tunnel results, which explain how the autorotation occurs. It is also shown how this theory may be applied during testing of an aircraft to develop a tumble resistant aircraft.

It is desirable to make an assessment of likely handling qualities to identify any deficiencies in a helicopter control system at an early stage in the design process before an expensive and potentially dangerous prototype is constructed. Inverse simulation offers a modelling technique that can be used for generating the data needed for such an assessment. Inverse simulation differs from conventional forward simulation in that the vehicle flight path is the input and the state and control time histories required for the task are generated. The inverse algorithm however, does not account for the pilot contribution to the flight data, thus the work herein demonstrates a method whereby this can be achieved. To incorporate pilot effect into the Helinv generated data, the latter is applied as the command signal to the Man-Machine Control System (MMCS), which is a closed loop system encompassing the helicopter vehicle dynamics and a model of the pilot known as the Precision Pilot Model (PPM). The PPM Human Equalisation Characteristics (REC) are determined via a constrained optimisation technique and the pilot effect is added in the system output. Validation of this technique is achieved through a case study whereby several operators, with different levels of experience, pilot a reduced order Puma helicopter model through a predefined mission task in a flight simulator constructed during the project. The equalisation characteristics are then determined for each pilot and compared with those generated using Helinv. A handling qualities assessment is presented for both sets of results and conclusions concerning the validity of Helinv with additional pilot effect finally drawn.

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The deployment of unmanned aerial vehicles (UAV) in military applications increased the research about them and the importance of them. The unmanned helicopters are the most agile and maneuverable vehicles among the unmanned aerial vehicles (UAV). The ability of hovering and low speed cruise makes them even more attractive. Such abilities supply more areas to deploy the usage of the unmanned helicopters like search &amp / rescue, mapping, surveillance. Autonomy is the key property for these vehicles. In order to provide autonomy to an unmanned vehicle, the guidance and the autopilot units are designed in the first step. Waypoints are used to track the desired trajectories. The line of sight guidance is used to reach an active waypoint. In order to realize the guidance commands controllers are designed by using LQR. In addition, position and heading controllers are designed by root-locus method. The trimming and linearization are implemented in order to extract linear models used for controller design. Keywords: Helicopter, control, guidance