The Influence of Vertical Wind Gradients on the Longitudinal Motion of Airplanes
The Influence of Vertical Wind Gradients on the Longitudinal Motion of Airplanes

Author: Joseph Gera

Publisher:

Published: 1971

Total Pages: 28

ISBN-13:

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The present study is an attempt to make an assessment of the influence of wind shear on the longitudinal motion of airplanes. It was assumed that the wind is completely horizontal and its speed varies linearly with altitude. It is shown quantitatively that both glide and climb performance are influenced by wind shear and that trimmed flight at constant airspeed, attitude, and with fixed controls is along a parabolic path relative to the ground. The problem of the landing approach in a wind shear is examined in some detail. Small disturbance theory indicates no wind-shear effect on the short-period motion and the time for the phugoid to damp to half amplitude but the phugoid frequency and damping ratio vary considerably with wind shear. A nondimensional quantity which depends on the wind shear and airspeed is shown to be a fundamental parameter influencing the longitudinal dynamic behavior of the airplane.

Effect of Shear on Aircraft Landing
Effect of Shear on Aircraft Landing

Author: James K. Luers

Publisher:

Published: 1973

Total Pages: 86

ISBN-13:

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A simulation study was conducted to determine the effect of wind shear on aircraft landings. The landing of various type of commercial and military aircraft was digitally simulated starting from an initial altitude of 300 feet. Assuming no pilot feedback during descent, the deviation in touchdown point due to vertical profiles of wind shear was determined. The vertical profiles of wind shear are defined in terms of surface roughness, Z sub 0, and stability, L, parameters. The effects on touchdown due to Z sub 0 and L have been calculated for the different type aircraft. Comparisons were made between the following types of aircraft: (1) C-130E, (2) C-135A, (3) C-141, (4) DC-8, (5) Boeing 747, and (6) an augmentor-wing STOL. In addition, the wind shear effect on touchdown resulting from different locations of the center of gravity and gross weights was also analyzed.

Masters Theses in the Pure and Applied Sciences
Masters Theses in the Pure and Applied Sciences

Author: W. H. Shafer

Publisher: Springer Science & Business Media

Published: 2013-03-14

Total Pages: 307

ISBN-13: 1475757859

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Masters Theses in the Pure and Applied Sciences was first conceived, published, and dis seminated by the Center for Information and Numerical Data Analysis and Synthesis (CINDAS) * at Purdue University in 1957, starting its coverage of theses with the academic year 1955. Beginning with Volume 13, the printing and dissemination phases of the ac tivity were transferred to University Microfilms/Xerox of Ann Arbor, Michigan, with the thought that such an arrangement would be more beneficial to the academic and general scientific and technical community. After five years of this joint undertaking we had concluded that it was in the interest of all concerned if the printing and distribution of the volume were handled by an international publishing house to assure improved service and broader dissemination. Hence, starting with Volume 18, Masters Theses in the Pure and Applied Sciences has been disseminated on a worldwide basis by Plenum Publishing Corporation of New York, and in the same year the coverage was broadened to include Canadian universities. All back issues can also be ordered from Plenum. We have reported in Volume 24 (thesis year 1979) a total of 10,033 theses titles from 26 Canadian and 215 United States universities. We are sure that this broader base for theses titles reported will greatly enhance the value of this important annual reference work. While Volume 24 reports these submitted in 1979, on occasion, certain universities do report theses submitted in previous years but not reported at the time.

A Study of Wind Shear Effects on Aircraft Operations and Safety in Australia
A Study of Wind Shear Effects on Aircraft Operations and Safety in Australia

Author: K. W. Anderson

Publisher:

Published: 1981

Total Pages: 32

ISBN-13: 9780642881823

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Wind shear has been identified as a causal or contributory factor in numerous aircraft accidents in Australia and elsewhere. The prospect of remote sensing equipment for measuring wind shear becoming available led to this study of the ergonomics aspects of aircraft operation in conditions of local variations of wind. Questionnaires completed by 652 military and civilian Australian pilots and air traffic controllers (ATCs) were analysed for subject understanding, detection of wind difficulties, frequency of wind shear and downdraft situations, pilot techniques and forewarning methods. It seems that the term wind shear is familiar to many operators but is subject to various interpretations. Specific definitions (like positive wind shear, reverse wind shear, etc.) were often misunderstood. Standard terminology and improved teaching for pilots and ATCs is recommended, along with an extension of theoretical work on optimal piloting techniques in wind shear and other local variations of wind. Pilots often found terrain-induced downdrafts, especially at Nowra, Perth and Pearce, and thunderstorm wind shears troublesome. Operations in irregular terrain away from major aerodromes were frequently cited for wind shear hazards. Pilot judgements on the most susceptible aircraft types were not readily explicable in terms of size, landing speed or wing loading. Pilots and ATCs indicated that currently used cues in wind shear conditions include visual estimates of glideslope departures, precision approach radar observations and aircraft-based measurements of wind or ground speed. Recently developed ground-based remote sensing equipment appears to offer promise for detecting stable wind shears.