Winds on the ATIS

[Ausatco]

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.


:mad: AA

(edited to correct a typo)

[ 20 July 2001: Message edited by: Ausatco ]

[Pika]

In Germany we generally take the wind from the official observation of our weather service. In some instances controllers have to observe the weather themselfs (at regional airports).
On the ATIS we would say: "Wind 290, 15 knots, varying between 240 and 310 degrees." Gusts are only stated when they exceed the avarage windspeed by 10 knots or more.

Hope that helps.

[ 20 July 2001: Message edited by: Pika ]

[Ausatco]

Thank you Pika.

Say the wind was gusting to 25 knots. That does not exceed 10 kt from average, so you would not quote it on the ATIS. What crosswind would you put on the ATIS?(remember that your wind speed on the ATIS would be 15 knots, but your observed crosswind would be 25 knots.)

AA

[Pika]

Hi Ausatco,

We do not issue crosswind readings on the ATIS. We let the pilots calculate that themselfs. With your stated example I would of course issue the gusts 25 kts because it is 10 kts more than the average. Our rule says that gusts have to be stated if they are 10 knots or more above avarage. These regulations are from our German AIP. If you can access your international NOTAM-Office or some other authority who has a copy of the German AIP you can read it on pages GEN 3.5-16 and GEN 3.5-17.
They claim that they have no differences the provisions of ICAO Annex 3 and ICAO Documents 7030 and 8400.

I hope that wasn´t too confusing. Have a nice weekend.

Smile

[Ausatco]

Thank you again, Pika. I should read your posts more carefully. Interesting you don't quote crosswind on the ATIS. It's a must-do here for components => 12 knots.

AA