TNAG-1174-FCO40-1476-Proposed-replacement-airport-for-Hong-Kong-at-Deep-Bay-or-Ch-1982 — Page 107

CONFIDENTIAL

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Comparing Table 1 with Tables 2 and 3 for Chek Lap Kok and the

existing airport, the bias of the Tsim Bei Tsui data set towards lower wind

speeds is quite apparent. For example, the frequency of strong wind occasions

at Tsim Bei Tsui is less than 10% that at Chek Lap Kok and less than half that

at the existing airport. However, because the data set is contaminated by

anemometer sticking, it is inappropriate to conclude that wind speeds in the

Deep Bay area are on the average lower than those locations which are more

exposed to the prevailing easterly winds even though this would have been

consistent with expectations (section 2)..

Taking a cross-wind component of 13 knots as a criterion, the usability

factor of Tsim Bei Tsui as an airport site is close to 98% for runway orientations

in the range of 050-070°. The usability factor exceeds 99.9% if 25-knot cross-

wind is adopted as the criterion.

Over the range of runway orientations examined, the possible utilisations

of the northeast and southwest runways for departure are around 65-70% and 40%

respectively, assuming no operations in tail wind conditions. The percentage utilisation of the northeast runway for departure is highest for the 070°-250°

orientation while the percentage utilisation of the southwest runway for

departure is highest for the 050°-230° orientation.

Table 15 compares the percentage utilisation of hypothetical runways

at different locations. The utilisation of the northeast runway is generally

lowest at Tsim Bei Tsui.

The opposite is true for the southwest runway.

CONFIDENTIAL