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Thesis (MTech (Environmental Health))--Cape Peninsula University of Technology, 2006 / Airport operations have become a major source of concern due to aircraft nOIse, particularly in areas close to airports and aircraft flight tracks. Public opposition to aircraft noise is a threat to the continued growth of civil aviation in South Africa. This study investigated the psychological effects of aircraft noise on residents and school activities at a neighbourhood close to the airport, particularly the area located under the flight tracks or adjacent to the landing and departure pattern of aircraft. Bishop Lavis was chosen as the experimental area and Kensington, about 17km away from the airport, was chosen as a control area. Questionnaires coupled with oral interviews and observations were used to gather information. The findings are focused on annoyance and disturbance. The study revealed that noise exposure caused annoyance, activity disturbance and some mild effects on school results, when compared with the control area. Disturbances were experienced in some activities that need concentration. Aircraft noise also caused communication interference, sleep deprivation and affected the teaching process. The community at the experimental area indicated some non-acoustical effects, such as fear of aircraft crashing over their homes but they indicated no willingness to leave the area. As such, it becomes essential when locating and designing airports to optimise flight paths in a way to reduce noise exposure to nearby communities. Recommendations for mitigation of noise exposure are proposed, which include operational procedure, banning chapter I and 2 aircraft, restricting night flights, proper land use planning and enforcing international environmental regulations.

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A significant number of aircraft incidents and accidents have been caused, in part, by flightcrew failure to properly manage cockpit activities, such as failure to initiate activities at the appropriate time, misprioritization of activities, or the failure to appropriately monitor activities and terminate them when required. To facilitate the management of the cockpit activities, a computational aid, the Agenda Manager (AM) has been developed for use in simulated cockpit environments in an investigation which was one aspect of a more extensive research project supported by the NASA Ames Research Center. The AM is directed at the management of goals and functions, the actors who perform those functions, and the resources used by these actors. Development of an earlier AM version, the Cockpit Task Management System (CTMS), demonstrated that it could be used to assist flightcrews in the improvement of cockpit activity management under experimental conditions, assuming that the AM determined pilot goals accurately as well as the functions performed to achieve those goals. To overcome AM limitations based on that assumption, a pilot goal communication method (GCM) was developed to facilitate accurate recognition of pilot goals. Embedded within AM, the GCM was used to recognize pilot goals and to declare them to the AM. Two approaches to the recognition of pilots goals were considered: (1) The use of an Automatic Speech Recognition (ASR) system to recognize overtly or explicitly declared pilot goals, and (2) inference of covertly or implicitly declared pilot goals via use of an intent inferencing mechanism. These two methods were integrated into the AM to provide a rich environment for the study of human-machine interactions in the supervisory control of complex dynamic systems. Through simulated flight environment experimentation, the proposed GCM has demonstrated its capability to accurately recognize pilot goals and to handle incorrectly declared goals, and was validated in terms of subjective workload and pilot flight control performance. / Graduation date: 1997

In this thesis, A nonlinear methodology for the control of the highly maneuverable, high performance aircraft HARV (F-18) is studied by using sliding-mode control (SMC). This control law, which takes a continuous function when the input constraints are not considered, satisfies the reachability condition by which concerned states are driven to their sliding surfaces. Especially, this SMC is generalized for the so-called (square) uncoupled multi-input multi-output (MIMO) system by the use of error dynamics and applied directly to the nonlinear aircraft system without linearizing the system. For the practical application of the SMC to aircraft with input constraints, two control schemes are used, considering that variations of pitch rate q directly affect variations of the angle of attack. The first scheme consists of an ��-q control for the fast response. The second scheme consists an a-control for making the output approach its sliding surface slowly by setting boundary layers and adjusting reachable speeds to the sliding surface. Robustness to parameter uncertainties and disturbances is also studied for the SMC. Especially, when the effect of parameter uncertainties is severe, then multiple boundary layers are set in the neighborhood of sliding surface, in which different reachable speeds to the sliding surface are used to sustain the concerned state within the boundary layer and to reduce the effect of chattering. / Graduation date: 1994

Thesis (Ph. D.)--Pardee RAND Graduate School, 2005. / Includes bibliographical references (p. 98-100). Also available electronically from the RAND web site.

An adaptive pitch axis autopilot design procedure is presented. The design procedure is applicable to both stable and unstable pitch axis models and to those having nonminimum phase. The design approach assumes the adaptive autopilot is activated after achieving level flight. It is shown a rate-feedback compensator can be designed to ensure stable level flight pitch axis operation for the entire desired flight regime. The adaptive control loop design utilizes a pole-placement algorithm. The closed-loop characteristic polynomial is designed to have dominant poles of that of an ideal second order system to obtain the desired transient response. The identification of the system uses a modified least-squares algorithm with a variable forgetting factor. The nonlinear pitch axis model is used in simulations to evaluate the design. Command response tests include the step response and the ramp command response. Simulation results indicate that the adaptive pitch axis autopilot is capable of tracking altitude commands after activation. The closed-loop system response is close to that of the ideal second order system having the dominant poles. / Graduation date: 1991

Advances in computational power have produced great strides in the later design and production portions of an aircraft s life cycle, and these advances have included the internal layout component of the design and manufacturing process. However, conceptual and preliminary design tools for internal layout remain primarily based on historical regressions and estimations a situation that becomes untenable when considering revolutionary designs or component technologies. Bringing internal layout information forward in the design process can encourage the same level of benefits enjoyed by other disciplines as advances in aerodynamics, structures and other fields propagate forward in the design of complex systems. Accurate prediction of the volume required to contain all of an aircraft s internal components results in a more accurate prediction of aircraft specifications, mission effectiveness, and costs, helping determine if an aircraft is the best choice for continued development. This is not a computationally simple problem, however, and great care must be taken to ensure the efficiency of any proposed solution. Any solution must also address the uncertainty inherent in describing internal components early in the design process. Implementing a methodology that applies notions of an intelligent search for a solution, as well as deals robustly with component sizing, produces a high chance of success. Development of a robust, rapid method for assessing the volumetric characteristics of an aircraft in the context of the conceptual and preliminary design processes can offer many of the benefits of a complete internal layout without the immense assignment of resources typical in the detail phase of the design process. A simplified methodology for volumetrically sizing an aircraft is presented here as well as an assessment of the state-of-the-art techniques for volumetric considerations used in current aircraft design literature. A prototype tool using a combination of original code and publicly available libraries is developed and explored. A sample aircraft design is undertaken with the prototype tool to demonstrate the effectiveness of the methodology.