Here in Dunnunda we've become obsessed with ICAO harmonisation.
The latest effort is "internationalising" the winds we quote on the ATIS.
The new rule we've been given 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 the new ICAO harmonised way it would be quoted on the ATIS as "Wind 290 degrees,15 knots." Before the harmonisation change it would have been quoted as "Wind 260 to 320 degrees, 10 to 15 knots, gusting 20 knots".
What would you ICAO people in Europe and elsewhere put on your ATIS for this wind? I ask because I believe this bland averaging of the wind removes important parts of the environmental picture that we are supposed to present to the pilot, and which I believe was provided the old way. With the new way how can a pilot assess gustiness, or assess the swing that may introduce a downwind component?
Say your airport has a north-south runway 18/36 and that because the wind is favouring 36, that's what you're using. Our harmonised instruction says that the wind, crosswind and downwind components would be quoted as follows:-
"Wind 290 degrees, 15 knots, crosswind mean 15 knots, maximum 20 knots. Downwind maximum 4 knots." IE, we quote a wind speed of 15 knots, with a maximum crosswind of 20 knots! Do you ICAO people do that? Really?
I say "You ICAO people" because we are told that down here in the Antipodes we are out of step with ICAO. Therefore you must be "in step" and operate to the standard to which our masters aspire.
What do you really do?
Would like aircrew comments on this, too!
Looking forward to your replies.
(edited to correct a typo)
[ 20 July 2001: Message edited by: Ausatco ]