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Old 7th October 2001 | 08:25
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: ATPL
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From: Ex-pat Aussie in the UK
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The ICAO rule for quoting winds on the ATIS is:-

If the swing in wind direction is 60 deg or less, quote the mean direction. If the variation in wind speed between minimum and maximum is 10kt or less, quote the mean speed.

Say the wind is 260-320deg/10 to 15kt, gusting 20 kt. In ICAO it would be quoted on the ATIS as "Wind 290 degrees,15 knots."

A feature of the ICAO way is that a maximum component may be greater than the windspeed quoted (because the windspeed is an average.) EG, for a RWY 36:-

"Wind 290 degrees, 15 knots, crosswind mean 15 knots, maximum 20 knots. Downwind maximum 4 knots." i.e. ATS quote a wind speed of 15 knots, with a maximum crosswind of 20 knots!

So your "Steady" wind on the ATIS can include quite a variation, which is covered by the wind additives to the approach speed.
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