Weather and CPH airport

[Conor.P.M]

I've got a question about whether and take off restrictions.

I'm Flying from Copenhagen to Heathrow (World's worst Airport, Oh the shock!). The weather at Kastrup tomorrow is forecast to be, according to the Danish metrological service, westerly winds gusting up to 72 kph.

Given that the main runways at CPH are SW and NE, at what wind speed and direction will the Airlines (in my case SAS and one of there MD-81 or 82's) or the Airport decide it's better for us to stay where we are?

I'm not worried, in fact the prospect of the Weekend here in Copenhagen is rather appealing, but I'm curious to know what sort of conditions who mean it will no longer be considered safe.

[howflytrg]

Depends. If the winds are out of limits for the a/c type then you will stay on terra firma. Forcast and actual winds can vary quite often, even the wind at the airfield and down town can be two different kettles of fish.

[Conor.P.M]

I appreciate the actual conditions at the airfield can and will vary from the forecast for an entire city area, I'm curious what it would actually take to keep the a/c on the ground.

Can anyone enlighten me as to what the wind limits for the SAS fleet of MD-80's are?

[howflytrg]

Can't say for the MD's but for a 737 the max x-wind is 35kts and depending on the runway state it reduces. When the co-efficient of friction drops between 0.40 and 0.25, or between a braking action of good to poor, this limit is reduced to 15 kts and less than poor or <0.25, 10 kts.

The max Tailwind is 10kts on a 737. For the MD 80's being of similar weights i would imagine these figures would be fairly similar.

[Conor.P.M]

Cheers for the info Mike! I do however have a question. (Even though I spend a lot of time on board aircraft I'm about to prove that it's not spent at the pointy end!). Runway number indicate the direction the Runway faces, so Heathrow's Runway 27R is the northern runway heading west.

However I'm a bit confused at the way wind direction is measured (not exactly required knowledge in my industry).

I'd always assumed that wind direction indicated the direction the wind was heading (so 270 meant it was heading from east to west, as with Runways). In the TAF info you posted above the wind at CPH this afternoon moves from 240 degrees to 290 degrees as the day progresses. You suggest that as the wind direction changes to 290, runway 30 is likely to be used. Does this mean that Runway numbers indicate the 'heading to', but that wind direction indicate the direction the wind is 'coming from'?

I'd always thought that if the wind direction was 270, then runway 09 would face into the wind, but you suggest that in this case runway 27 would in fact be heading into the wind.

It appears I've had that backwards all these years!

[howflytrg]

Wind direction is always the direction 'from'. In an ATIS or from the twr this is in Degrees Magnetic. Other wise the reported wind is Degrees True.