In-flight simulation investigation of rotorcraft pitch-roll cross coupling

An in-flight simulation experiment investigating the handling qualities effects of the pitch-roll cross-coupling characteristic of single-main-rotor helicopters is described. The experiment was conducted using the NASA/Army CH-47B variable stability helicopter with an explicit-model-following control system. The research is an extension of an earlier ground-based investigation conducted on the NASA Ames Research Center's Vertical Motion Simulator. The model developed for the experiment is for an unaugmented helicopter with cross-coupling implemented using physical rotor parameters. The details of converting the model from the simulation to use in flight are described. A frequency-domain comparison of the model and actual aircraft responses showing the fidelity of the in-flight simulation is described. The evaluation task was representative of nap-of-the-Earth maneuvering flight. The results indicate that task demands are important in determining allowable levels of coupling. In addition, on-axis damping characteristics influence the frequency-dependent characteristics of coupling and affect the handling qualities. Pilot technique, in terms of learned control crossfeeds, can improve performance and lower workload for particular types of coupling. The results obtained in flight corroborated the simulation results

The role of the labour bureaux in South Africa: A critique of the Riekert Commission Report

African Studies Seminar series. Paper presented 1980

A flight-test and simulation evaluation of the longitudinal final approach and landing performance of an automatic system for a light wing loading STOL aircraft equipped with wing spoilers

As part of a comprehensive flight-test investigation of short takeoff and landing (STOL) operating systems for the terminal systems for the terminal area, an automatic landing system has been developed and evaluated for a light wing-loading turboprop-powered aircraft. An advanced digital avionics system performed display, navigation, guidance, and control functions for the test aircraft. Control signals were generated in order to command powered actuators for all conventional controls and for a set of symmetrically driven wing spoilers. This report describes effects of the spoiler control on longitudinal autoland (automatic landing) performance. Flight-test results, with and without spoiler control, are presented and compared with available (basically, conventional takeoff and landing) performance criteria. These comparisons are augmented by results from a comprehensive simulation of the controlled aircraft that included representations of the microwave landing system navigation errors that were encountered in flight as well as expected variations in atmospheric turbulence and wind shear. Flight-test results show that the addition of spoiler control improves the touchdown performance of the automatic landing system. Spoilers improve longitudinal touchdown and landing pitch-attitude performance, particularly in tailwind conditions. Furthermore, simulation results indicate that performance would probably be satisfactory for a wider range of atmospheric disturbances than those encountered in flight. Flight results also indicate that the addition of spoiler control during the final approach does not result in any measurable change in glidepath track performance, and results in a very small deterioration in airspeed tracking. This difference contrasts with simulations results, which indicate some improvement in glidepath tracking and no appreciable change in airspeed tracking. The modeling problem in the simulation that contributed to this discrepancy with flight was not resolved

Flight-test evaluation of STOL control and flight director concepts in a powered-lift aircraft flying curved decelerating approaches

Flight tests were carried out to assess the feasibility of piloted steep curved, and decelerating approach profiles in powered lift STOL aircraft. Several STOL control concepts representative of a variety of aircraft were evaluated in conjunction with suitably designed flight directions. The tests were carried out in a real navigation environment, employed special electronic cockpit displays, and included the development of the performance achieved and the control utilization involved in flying 180 deg turning, descending, and decelerating approach profiles to landing. The results suggest that such moderately complex piloted instrument approaches may indeed be feasible from a pilot acceptance point of view, given an acceptable navigation environment. Systems with the capability of those used in this experiment can provide the potential of achieving instrument operations on curved, descending, and decelerating landing approaches to weather minima corresponding to CTOL Category 2 criteria, while also providing a means of realizing more efficient operations during visual flight conditions

Flight experiments using the front-side control technique during piloted approach and landing in a powered lift STOL aircraft

The essential features of using pitch attitude for glidepath control in conjunction with longitudinal thrust modulation for speed control are described, using a simple linearized model for a powered-lift STOL aircraft operating on the backside of the drag curve and at a fixed setting of propulsive lift. It is shown that an automatic speed-hold system incorporating heave-damping augmentation can allow use of the front-side control technique with satisfactory handling qualities, and the results of previous flight investigations are reviewed. Manual control considerations, as they might be involved following failure of the automatic system, are emphasized. The influence of alternative cockpit controller configurations and flight-director display features were assessed for their effect on the control task, which consisted of a straight-in steep approach flown at constant speed in simulated instrument conditions

The 1990 recreation personnel study: Recreation personnel employed in the central and local government, voluntary and tertiary education sectors in New Zealand: A report prepared for the Recreation Association of New Zealand (RANZ)

To gather information on, and describe, the present status of recreation personnel employed in the central and local government, voluntary and tertiary education sectors in New Zealand, and their: a. conditions of appointment; b. professional and educational backgrounds; c. job activities; d. education and training needs, and e. the extent to which those recreation personnel recognise RANZ as being an organisation which can meet their professional needs

Study of helicopterroll control effectiveness criteria

A study of helicopter roll control effectiveness based on closed-loop task performance measurement and modeling is presented. Roll control critieria are based on task margin, the excess of vehicle task performance capability over the pilot's task performance demand. Appropriate helicopter roll axis dynamic models are defined for use with analytic models for task performance. Both near-earth and up-and-away large-amplitude maneuvering phases are considered. The results of in-flight and moving-base simulation measurements are presented to support the roll control effectiveness criteria offered. This Volume contains the theoretical analysis, simulation results and criteria development

South Africa's regional political economy: A critical analysis of reform strategy in the 1980s.

African Studies Seminar series. Paper presented October, 1985Since the late 1970s the apartheid state has faced a sustained and deepening crisis of legitimation.(1) This crisis has been exacerbated by the attempt, and failure, to implement the post- Soweto 'Total Strategy' reforms - reforms which, in the case of the black people of South Africa, left the territorial and political basis of grand apartheid intact. Since the end of the short-lived boom of 1979-82, the crisis of political legitimacy has been amplified by the slide into economic depression, and the scope for concessionary economic reforms has been drastically curtailed. For some time, the state has been caught up with the immediate threat of escalating opposition in the townships, the symptoms of the deepening economic crisis and spreading international hostility to apartheid. But while this has been happening, elements within the ruling groups, both inside and outside the state, have for some time been attempting to map out a longer-term strategic offensive aimed at defusing political conflict and re-structuring the economy. Faced with a shrinking material basis for concessionary economic reform and growing mobilisation behind the demand for the extension of political rights, the country's ruling groups have begun the search for political solutions to the crisis. The schemes now being formulated take as their starting point the ultimate inevitability of political incorporation of black people into a single national state in South Africa. They aim to meet this in ways that ensure that real power remains in the hands of the ruling classes. The move towards political reforms for black people has gone beyond the stage of discussion and planning in certain areas of policy. Already an important pillar of the emerging strategy has gained expression in local government measures passed in 1985. (2) However much of what is planned has so far only appeared in general policy statements. It is also evident that important facets of the strategy are still in the stage of formulation or are deliberately being held back for the moment. The fluidity of political conditions in South Africa is such that state strategy is the subject matter of open debate and contestation, and is unusually susceptible to official reconsideration and reformulation. Nevertheless we believe it is possible to identify the major contours of an emerging strategy which has been pursued with increasing determination by reformers within the commanding heights of the state since late in 1984. This offensive is significant in that it goes well beyond the policy package associated with the Wiehahn and Riekert Commission reports, the Koornhof Bills, the new constitution, and the confederation of ethnic states - it goes beyond the 'Total Strategy' formulated by PW Botha in the late 1970s. (3) In contrast to these policies, it is based on an abandonment of the political and territorial premises of apartheid, though not necessarily of race or ethnicity, and envisages the eventual reincorporation of the bantustans into a single national South African state. The manner in which this will occur is by no means clear or decided. However, this process of political re-integration of the bantustans is intended ultimately to result in the reorganisation of the territorial basis of South Africa's economic and political system. Central to the reform strategy is the conception that the present provinces and bantustans will be superceded by metropolitan and regionally-based administrative structures through a process of merging, absorption and crosscutting of present geographical boundaries. It is this geographic outcome of the intended reform strategy that has led us to describe the complex of evolving measures as the state's regional strategy. The aim of this article is to describe, anticipate and critically analyse the outlines of the emerging regional strategy. Its three major components are new controls on labour movement and settlement, regional development policies (notably industrial decentralisation), and local and second tier government reforms and corresponding constitutional changes. We examine each of these three components and their interconnections. A central issue taken up in the paper is the debate over the possible construction of a federal system in South Africa. We examine major alternative conceptions of the basis of federalism - geographic and ethnic - and show how they correspond to or contradict other plans to divide South Africa into metropolitan and wider planning and administrative regions. The paper ends with an assessment and critical analysis of the regional strategy

Nurses\u27 Alumnae Association Bulletin, May 1963

President\u27s Letter Alumnae Meetings, 1962 Building Fund Mediocrity Hospital Report Alumnae Notes Social Committee Student Activities Marriages, New Arrivals and Necrology Annual Giving Fund Driv

Nurses\u27 Alumnae Association Bulletin, April 1961

Alumnae Meetings 1960 Social Committee Clara Melville Scholarship Fund Bulletin Committee Private Duty Nurse\u27s Section Report of the School of Nursing and Nursing Service Staff Nurses Association Student Activities Personal Items of Interest Expansion of Jefferson Artificial Kidney Unit Medical Work in the Congo Marriages New Arrivals Necrology Annual Giving Fun