Accession Number:

ADP002705

Title:

Worldwide Experience of Wind Shear during 1981-1982,

Descriptive Note:

Corporate Author:

ROYAL AIRCRAFT ESTABLISHMENT BEDFORD (ENGLAND)

Personal Author(s):

Report Date:

1983-10-01

Pagination or Media Count:

31.0

Abstract:

Large changes of wind and downdraughts Wind Shears have caused several major accidents to airliners. The Royal Aircraft Establishment RAE, with support from the United Kingdom Civil Aviation Authority and British Airways BA, have analysed wind shear data from over 9000 landings by 26 BA B747 aircraft at 71 airports around the world during 1981 and 1982. The data are analysed using Discrete Gust methods developed at the RAE. Time histories of wind velocities and aircraft reactions are presented for 9 of the more interesting events identified. These were selected from 86 examples of large wind shears where the three components of wind velocity have been calculated. An example of a severe downburst in the vicinity of a thunderstorm is also presented. This was measured by the RAE HS125 research aircraft during the Joint Airport Weather Studies JAWS Programme near Denver, Colorado, USA in July 1982. Statistics on the probabilities of encountering wind shears with particular patterns of headwind speed changes have been calculated from the 9000 landings. Effects at different airports, height bands, shear lengths, and patterns have been compared. Suggestions are made for Design Cases of shear that could be used for testing autopilots and wind shear measuring systems. Some possible criteria for the severity of single ramp changes in headwind are presented. Author

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Distribution Statement:

APPROVED FOR PUBLIC RELEASE


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