|Heathrow Airport Runway Configuration|
To help limit the noise that the residents of London have to endure from the traffic flying into and out of Heathrow Airport, the airport uses a Runway Alternation Policy.
The runways in use are first and foremost decided by the weather. If the wind is blowing in from the West (most of the time), then runway's 27L/R will be active. If the wind is blowing in from the East, runway's 09L/R will be active instead.
NOTE: The wind direction can change during the course of a day. If it does, the active runways may also change depending on the new wind direction.
Runway's 27L & 27R
When runway's 27L and 27R are the active runways, one runway will be used for arrivals and the other for departures between 06:00 and 15:00. From 15:00 these runways swap over so that the arrivals runway now becomes the departure runway and the departure runway now becomes the arrival runway.
Runway 27L = Arrivals 06:00 - 15:00, Departures 15:00 until last departure.
Runway 27R = Departures 06:00 - 15:00, Arrivals 15:00 until last arrival.
To complicate this a little bit, between 06:00 and 07:00 both 27L and 27R may be used for arriving aircraft at the same time. This dual runway operation is designed to speed up the early morning arrivals before aircraft start to depart at 07:00.
Unfortunately, if the aircraft you want to spot arrives at this time, it may land on either runway meaning you could miss it.
Runway's 09L & 09R
When runway's 09L and 09R are the active runways, 09L will be used for arrivals and 09R will be used for departures. This rule continues all day regardless of the time. To complicate this slightly, aircraft may occasionally land on runway 09R, but this is quite rare.
You can get more information about Heathrow's Runway Alternation Policy as well as a PDF detailing the weekly schedule of active runways (27L and 27R) by following this link.
Heathrow Runway Alternation Policy & PDF
If you have any questions regarding this policy, I'm happy to help. You can either post your question on my Facebook page or send me a tweet on a Twitter. Alternatively, please email me at mcpcshowcaseHD@gmail.com.
In all cases, please allow at least 24 hours for a reply. Thank you.