Heathrow as an example has runways 9 and 27. Which runway would be used for take-off and landing if the wind is straight from the North (360). Cheers AndyPS I seem to have acquired 5 gold stars. Does that mean a huge cash prize is heading my way.MARVELLOUS

If the wind is not a factor, then they would most likely use 27, since the prevailing winds in the UK are Westerly, and because that is true, most of the SIDs from airports in the UK take that into account, i.e. there tend to be more Westerly STARs and SIDs than Easterly ones in the UK. Using 27 would also make sense from a meteorological standpoint, since if the wind picked up, it would most likely pick up from the West.Even if the wind factor was negligible, this is still not the main reason for using 27 in preference though. 27 is preferred because there are more residential areas to the East of Heathrow than to the West, and since aircraft are throttled back on approach, and throttled up on departure, using 27 minimises the noise to the East, although there are still a few noise abatement restrictions to the West, for example, Concorde used to have to throttle back a bit when heading off to the US that way whilst still over the mainland. The two parallel runways are alternated as well, with the swap over happening mid afternoon, in order to vary the flight path over residential areas.Yeah, I got my cash prize for having those stars too, imagine my surprise when 43 million dollars arrived in the post the other day.Al

If the wind is not a factor, then they would most likely use 27, since the prevailing winds in the UK are Westerly, and because that is true, most of the SIDs from airports in the UK take that into account, i.e. there tend to be more Westerly STARs and SIDs than Easterly ones in the UK. Using 27 would also make sense from a meteorological standpoint, since if the wind picked up, it would most likely pick up from the West.Even if the wind factor was negligible, this is still not the main reason for using 27 in preference though. 27 is preferred because there are more residential areas to the East of Heathrow than to the West, and since aircraft are throttled back on approach, and throttled up on departure, using 27 minimises the noise to the East, although there are still a few noise abatement restrictions to the West, for example, Concorde used to have to throttle back a bit when heading off to the US that way whilst still over the mainland. The two parallel runways are alternated as well, with the swap over happening mid afternoon, in order to vary the flight path over residential areas.Yeah, I got my cash prize for having those stars too, imagine my surprise when 43 million dollars arrived in the post the other day.Al

Thanks AlanI was just curious to know.And I suppose there would be variations on that theme around the world as well.I do have the problem sometimes of knowing just what runway I should use for take-off ,(if there is ATIS I can tune in and find out I know,but that isn't always available ).I don't use ATC (fs9)by the way, preferring to select the runway on wind direction only (most times I am correct)however on my last couple of flights the traffic seemed (based on the wind direction) to be using the wrong runway for take-off, but I just put that down to FS mysteries and curiosities.cheers AndyPS 43 Million!A bit stingy that.

Also at Heathrow,. "In weather conditions when the tail wind component is no greater than 5 knots on the main Runway 27R and 27L, these runways will normally be used in preference to Runways 09R and 09L, provided the runway (s) surface is dry."

To add l little more info here, I'm not sure If you are aware of but Heathrow publishes their Runway Alternation document every year for preferred runways at determined months and hours.http://www.heathrowairport.com/assets/Internet/Heathrow_noise/Assets/Downloads/Statics/Heathrow_RunwayAlternation.pdfregards,Igor