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&quotMeeting the ageing aircraft challenge&quot is not just about safety, not just about effectiveness, and not just about economy of support. It is about proactive and reactive optimization of all three service goals throughout long life cycles that span 20 or 30 years, or more, and typically, beyond the originally intended design life. It is therefore about organizational attitudes towards ongoing trend analysis and condition monitoring, and pervading cost benefit assessments of all forms of human innovation across what the author describes as 'the eight sustaining disciplines for long aerospace life cycles', including scientific and technological developments, and opportunities for reliability growth or 'refresh'. Complacency is the root cause of all problems with the design, maintenance and support of all modern infrastructure, and therefore life cycle planners and minders are required to be an enthusiastic but nervous lot - always hoping for the best, but planning for the worst impact of 'Mr Murphy'. Murphy thrives on complacency, is in bed with uncertainty, and never forgets (as we do often) that imperfection (no matter how small) breeds unreliability traps that patiently wait to surprise at some stage along the life cycle journey. He has the upper hand. ...Our best weapons against Murphy are continual, total picture and longer-term situational awareness; caution, vigilance, innovation and collaboration. This research study and thesis is intended as a broad and comprehensive management philosophy, a guide and checklist - a broad scrape of everything 'so deep', rather than coverage of any one-niche aspect of the ageing aircraft challenge in great depth. It includes a brief and simple strategic setting for Australian Military Aerospace requirements, and spans a three axes management philosophy: 1. a toolbox of eight sustaining disciplines, 2. trend analysis and 3. time-cost-benefit assessment. Along with complacency, the prime ageing aircraft 'killers' are identified, as are the key ageing aircraft 'age multipliers'. The eight sustaining disciplines are explained in varying depth, according to their broad significance to the ageing aircraft condition and life cycle. The ever-ubiquitous bathtub reliability curve - the key to understanding, predicting and controlling life cycle behaviour (including costs) - is emphasized. Engineering life cycle minding and capability management are broad focus areas. The eight areas of attention identified for this broad study are: 1. Aerospace design requirements and trends, 2. Science and technology opportunities, 3. Airworthiness, engineering and maintenance philosophy, 4. Reliability behaviour, 5. Operational use and abuse patterns, 6. Logistics support and managing obsolescence, 7. Technical workforce and organizational attitudes (requirements and outlook), and 8. Life cycle costing and budgeting. This thesis primarily draws attention to the fundamental driver of life cycle behaviour - reliability. The critical dependency that life cycle control and prediction has on consistent and high quality trend data collection and analysis is emphasized throughout, and the now pressing need for better identification of ageing aircraft cost growth drivers, and their containment, is linked to reliability trend awareness, manipulation and intervention. The human dimension is included - including coverage of organizational attitudes and what it takes to be a 'high reliability organization'. There are no magic or easy answers to the ageing aircraft condition and challenge. Trend analysis has to be done from the bottom up, system by system, for each fleet type. But over time, with consistent trend data collection, patterns emerge within the sophisticated and stochastic systems behaviour that that ageing aircraft play out. These patterns enable ongoing management of the long life cycle to be more confidently predicted, more assured and with best possible cost growth containment. The best, perhaps only, path to least surprises and best cost containment is now being re-identified in some military aviation organizations as a mature and evolving RAM engineering and RCM framework. RAM-RCM may well be the only recovery from what some admit is a death spiral of ageing aircraft cost growth.

By the year 2020 the number of aircraft will have increased substantially and will be in �Free Flight�(that is, ATC will be devolved to the aircraft rather than being ground based). As an aid to navigation a more advanced form of collision avoidance will be required. This thesis proposes a method of collision avoidance planning using Automatic Dependent Surveillance-Broadcast (ADS-B) and Dynamic Programming (DP). It in essence enables Air Traffic Control (ATC) from within the cockpit for remote or uncontrolled airspace and is a step toward Free Flight. Free Flight requires quite different strategies than those used in the present collision avoidance schemes. This thesis reviews the approaches to collision avoidance used in the Air traffic navigation and to similar problems in other industries. In particular it considers the extended problem of collision avoidance within the framework of path planning. This is a key departure from the approach to aircraft collision avoidance used in the industry to date. Path planning reflects the real goal of an aircraft, which is to reach a particular destination efficiently and safely. Dynamic Programming is one solution method used in other industries for the problem of path planning to avoid collisions with fixed obstacles. The solution proposed herein for the Aircraft case uses Dynamic Programming applied to the moving obstacle case. The problem is first simplified by assuming fixed (static) obstacles for the cost minimisation algorithms. These fixed obstacles are then moved with time and the minimisation process is repeated at each time increment. Although this method works well in most cases, situations can be constructed where this method fails, allowing a collision. A modified approach is then used, whereby the movement of obstacles is included more explicitly (by modifying the shapes of the obstacles to represent motion) in the cost minimisation algorithm and a safe manoeuvre distance for each aircraft is used (by expanding the object size), to allow space for aircraft to execute safe evasive manoeuvres in difficult cases. This modification allows solutions which are complete (with no known cases of failure � collision situations) and should be considered as an important extension to the current Aircraft and Collision Avoidance System (ACAS). The testing of these solutions is focussed on the most difficult cases, and includes aircraft movement in �real space� (that is simulations using real aircraft dynamics together with dynamic programming algorithms running in discrete time steps).

In order to examine the potential impact of military jet overflights and other disturbances on productivity of peregrine falcons (Falco peregrinus), we observed behavioral reactions of peregrines to disturbances at nests along the Tanana River, Alaska during the 1995-1997 breeding seasons. Military jets conducted low-altitude flights over a sample of nests under observation in each year (experimental nests), while other nests were not intentionally overflown (reference nests). Other disturbances occurred at random. Animal noise monitors (ANMs), which collect and store data on noise disturbance levels, were deployed at each observed nest. A total of 878 above-threshold (��� 85 dB) overflights were recorded by the ANMs during the course of the study. A total of 401 close (defined as ��� 1000 m slant distance from the nest) overflights by subsonic F-16, F-15, A-10, Harrier, Jaguar, or Tornado jet aircraft were recorded during observations. Close overflights by military jets accounted for 63% of all observed potential disturbances at experimental nests; they accounted for 2.6% of all observed potential disturbances at reference nests. Other potential disturbances at reference nests included civilian fixed-wing aircraft (41%), boats (33%), avian predators (17%), helicopters (5%), and mammalian predators (1%). Peregrine falcons responded differently to animate and inanimate sources of disturbance, and responded most intensely and most frequently to other raptors, particularly conspecifics. Flight reactions were common, but not in response to inanimate sources. Among inanimate potential disturbances, falcons responded most intensely to boats (6% of reactions involved flight), and least intensely to helicopters (3%) and fixed-wing aircraft (2%). Intensity of reactions to military jets was indistinguishable from that to either boats or other aircraft. Intense behavioral responses (including flight reactions) to military jet overflights were rarely observed in this study, even at slant distances <500 m, and no intense behavioral responses were observed at slant distances >550 m. Peregrine falcon productivity (number of fledglings produced per nesting attempt) in the study area was within the normal range for Interior Alaska and the Tanana River. Dose of jet aircraft disturbance was not correlated with productivity. Productivity was, however, negatively correlated with reactivity of both individual falcons and mated pairs. Those falcons that responded more intensely to overflights tended to have lower productivity. The sensitivity of breeding peregrine falcons to low-altitude jet overflights is a better indicator of subsequent productivity than actual dose of overflights. This is likely a reflection of lower parental quality/investment among breeding pairs with high reactivity (i.e., younger, less experienced parents are less likely to be productive). / Graduation date: 1999

Although the adverse auditory effects of noise have been the focus of occupational health research for decades, little is known about the nonauditory health effects that result from noise exposure. The focus of this research was the nonauditory health effects of exposure to commercial aircraft noise (CAN) overflights. It was theorized that CAN exposure resulted in an ongoing stress-response that had the potential to be harmful to human health over time. Two aspects of CAN were considered; the sound level intensity (dBA), and the frequency of overflights. Data were collected by a stratified random sampling design in the CAN exposed neighborhoods of Eagan, St. Paul, Minneapolis, and Bloomington, and in control communities of Shoreview and Mounds View, all located in Minnesota (n=4000). A written questionnaire was used to measure; (1) health (MOS-36 Scale), (2) behavioral and emotional coping strategies, (3) noise sensitivity, (4) annoyance levels, and (5) demographic data. Aircraft noise levels and overflight data were obtained in cooperation with the Metropolitan Airport Sound Abatement Commission. Results showed significantly higher stress levels and lower health measures by CAN exposure type. These findings occurred primarily in communities exposed to high frequencies of aircraft overflights. Multivariate analysis revealed significant reductions for the three main health measures of General Health (GH), Sense of Vitality (Vitality), and Mental Health (MH), based on CAN exposure type. Post-hoc contrast analysis indicated that GH, Vitality, and MH scores were worst with high frequency of overflights. Behavioral copers had significantly fewer stress symptoms and used fewer stress medications than non-behavioral copers. Non-normalized emotional copers had significant negative associations with Gil, Vitality, and MH; however, these correlations were weak. Noise sensitivity levels were not significantly different among the CAN exposed communities; however noise annoyance levels were significantly higher than controls, and were the highest with high frequency of overflights. Finally, multivariate analysis of covariance indicated significant reduction for health measures based on CAN exposure types after adjusting for all effect modifiers (covariates) in the study. Vitality was the most consistently impacted by CAN exposure, and this was particularly the case for subjects exposed to high frequency of aircraft overflights. / Graduation date: 1996

This thesis presents an effective control design methodology using a one-step-ahead prediction adaptive control law and an adaptive control law based on a Lyapunov function. These control law were applied to a highly maneuverable high performance aircraft, in particular, a modified F/A-18. An adaptive controller is developed to maneuver an aircraft at a high angle of attack even if the aircraft is required to fly over a highly nonlinear flight regime. The adaptive controller presented in this thesis is based on linear, bilinear, and nonlinear prediction models with input constraints. It is shown that the linear, bilinear, and nonlinear adaptive controllers can be constructed to minimize the given cost function or Lyapunov function with respect to the control input at each step. The control is calculated such that the system follows the reference trajectory, and such that control signal remains within its constraints. From several simulation results, the nonlinear controller is controller is better than the linear controller. A nonlinear adaptive control law based on a Lyapunov function is designed such that control inputs are smoother than for the one-step-ahead prediction adaptive controller. / Graduation date: 1994

No description available.

Thesis (Ph.D. in Modeling, Virtual Environments, and Simulation)--Naval Postgraduate School, June 2009. / "June 2009." Thesis advisor: Michael E. McCauley. Performed by the The Modeling, Virtual Environment, and Simulation Institute at the Naval Postgraduate School, Monterey, CA. "Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Modeling, Virtual Environments, and Simulation from the Naval Postgraduate School, June 2009."--P. iii. Includes bibliographical references. Also available online from the Naval Postgraduate School (NPS), Dudley Knox Library Web site and the DTIC Online Web site.

Thesis (M.S.)--Brigham Young University. Dept. of Mechanical Engineering, 2003. / Includes bibliographical references (p. 67-69).

Thesis--Auburn University, 2009. / Abstract. Includes bibliographic references (p.70-72).