Under the flight path
Living or working under a flight path and hearing planes taking off
When planes take off, they have to follow specific routes in the sky which were set by the Government. These routes, which are 3km wide, were specially designed to make sure planes avoid flying over areas where lots of people live, until they reach a certain height.
Air Traffic Control makes sure that pilots stay on these flight paths until they reach 4,000ft on four of Stansted's six flight paths and 3,000ft on the other two during the day and 4,000ft at night. Once they have reached that height, Air Traffic Control can direct them off the flight path towards their destination.
The technical name for these special flight paths for take-off is ‘noise preferential routes’ (NPR). They were set by the Department for Transport in 1989.
Taking off and the importance of wind direction
Another basic aspect of aviation safety is that planes need to land and take off into the wind.
They can take off in the same direction as the wind, but this is only allowed if it’s a very gentle wind – up to 5 knots, which is little more than a breeze. (In aviation, you measure speed in knots – the same as for travel on water. A knot is 1.15 miles per hour.)
Most of the time at Stansted, the wind comes from the south-west. This is known as a ‘south-westerly’ wind.
So, because planes need to fly into the wind most of the time they’ll fly towards the south-west.
Therefore, the Government has set the take off flight paths for when the wind is blowing from the south-west as the above map shows.
Of course, we can’t control the direction of the wind. Because of this, the Government has also set take-off flight paths for the opposite wind direction (towards the north-east) from the other end of the runways. The map also shows the take-off flight paths for this wind direction.
What does this mean locally?
It means that on average, about two thirds of take-offs head towards the south-west and about a third of take-offs head in to the north-east.
The split in wind direction – and therefore, the split in the direction of take-offs – is almost completely dependent on the wind direction and speed, and so varies from year to year and month to month. In fact, the length of time that the runways operate in one direction can vary from a few hours to a few months: it all depends on the weather.
What this means for noise
If you live under one of these take-off flight paths, then you will probably hear some noise when that particular flight path is being used.
If you live beyond the flight path – past the point where the plane reaches 3,000 or 4,000ft – then you might sometimes hear some noise when the plane leaves the flight path to head towards its destination.
If you live alongside (but outside) a flight path, you might hear noise if a plane flies outside the flight path. This can happen if Air Traffic Control tells a pilot to leave a flight path for an operational reason (such as to avoid bad weather). We take good ‘track keeping’ (staying on the flight path) very seriously and around 98% of Stansted's aircraft are ‘on-track’.
This website will tell you what we are doing about this type of noise and how you can find out more or complain if you need to.
Other local procedures
There are also a few operating procedures that planes must follow just at Stansted.
For example, pilots have to avoid flying over the centre of Bishops Stortford. They also have to avoid flying over Sawbridgeworth and Stansted Mountfitchet below 2,500ft. The only reason for flying over would be for safety.
Lastly, planes must also be higher than 4,000ft before they can fly over St Elizabeth's centre at Much Hadham.
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