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Noise Data (All Areas)

General Noise

Most us experience a variety of sound on a daily basis. According to the Cambridge Dictionary, noise is defined as a sound that is unwanted, unpleasant, or loud.

Noise is not only about how loud the sound is. There are a complex set of factors that drive annoyance both based upon the noise itself and what that noise means to us. A dripping tap is mostly quiet, but it’s repetitive beat can be annoying. A mosquito’s buzzing is also quiet, yet it is high pitched.

Sounds rarely occur in isolation. It is when we build a combined picture of all of the day-today sounds such as traffic and wind, that we start to identify noise. Certain noises, such as a siren, can be easily heard above the day-to-day sound. Other noises may only be heard when the background level is lower, such as during the night. These principles also apply to aircraft. Whilst the sound level will vary depending on your location, what that sound means to us individuals will drive our response to the resulting noise.

London Stansted Airport Noise Data

To understand the noise impact on the local community, the airport has a number of fixed or temporary noise monitors deployed in the local area, generally under or near flight paths. The monitors detect and record the noise levels 24 hours a day, 7 days a week to ANOMS.

A ‘noise event’ is created when the monitor detects noise exceeding the background or local noise level for a noticeable amount of time. This could be due to any number of factors, be it nearby birds, cars or an aircraft. By continuously monitoring the noise level and integrating data from Air Traffic Control (ATC) our systems work to determine if the noise event was generated by an aircraft, or another source. Only events reported as aircraft noise events are reported in our statistics.

The data collected by all of our fixed noise monitors is presented in the dashboard below.

Choose a noise monitor location in the top left hand corner to get started. See our ‘How we manage noise’ page (under the “What are we doing” heading) for more information about noisy aircraft penalties. A number of our noise monitors positioned directly below the flight path are used for fining aircraft on departure and the noise limits are calibrated with respect to the height and distance of the runway to the monitor location.

The dashboard is automatically updated every month and you can access data from previous months using the drop-down. A comprehensive list of aircraft types can be found here.

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Arrivals and Departures

Wind and Runway Direction

To ensure a safe take-off and landing, aircraft depart and arrive into the wind. On take-off, this helps produce the lift required to get airborne and landing into the wind enables a slower speed over the ground. The weather and wind direction can change and therefore the direction that the aircraft are arriving and departing may change to ensure the safest conditions to operate.

Air Traffic Control manages the runway direction for the safest aircraft operations. This includes consideration of the wind at ground level, 1000ft, and 2000ft, as well as the forecasted weather. Local weather forecasts only display wind strength and direction at ground level and this can differ at higher altitudes. Therefore local weather forecasts are not always a reliable indicator of the likely direction that aircraft will be operating.

When the wind is blowing from west to east, the airport will operate in a westerly direction, known as “westerly operations” and the reverse during “easterly operations”. Experience of operations at London Stansted Airport shows an average of over 70% of operations, each year, are westerly and the remaining operations in an easterly direction. The 70/30% split is an annual average and there are months with a much higher/lower proportion of westerly/easterly operations. An image demonstrating the direction of operations can be seen below:

Arrivals

Flight paths for arriving aircraft follow broadly similar patterns, unlike departures which are much more defined. The flight paths ensure separation from other air traffic and avoidance of adverse weather when necessary. This means that there may be variation in airport arrivals at different times of the day.

Aircraft arriving into London Stansted Airport are transferred from the NATS area control centre to the Air Traffic Control approach controller, who sequences aircraft into the arrival pattern. They are then instructed where to fly by the Air Traffic Controllers, where they are directed towards their final approach before landing. When established on final approach to London Stansted Airport, aircraft are transferred from the approach controller to the tower controller before landing.

To minimise the noise of approaching aircraft for communities near arrival paths, a ‘Continuous Descent Approach’ (CDA) is used when possible. Instead of a traditional descent whereby the aircraft reduces altitude in a stepped manner (similar to walking downstairs), they glide at a more constant rate (like an escalator). This keeps aircraft at a higher altitude for longer, minimising noise for local residents before an aircraft joins the ILS (the red shaded area in the image below), as well as providing benefits for fuel efficiency and reducing emissions. Operating a CDA is not always possible due to several factors such as congested airspace or adverse weather conditions which need to be avoided. With the London Stansted Future Airspace project, we plan to facilitate changes that will make CDA easier to deliver. Compliance with this procedure is reported on here and you can find out more about arrivals at London Stansted Airport in the following video.

Please note this video is orientated as if you are positioned on the North of the airfield, looking towards the South.

Departures

Departing aircraft move on the ground from their stands to the runway using taxiways. At the runway, they then await clearance from Air Traffic Control (ATC) to take-off. The weight of a departing aircraft can vary due to the amount of fuel, passengers, luggage, or cargo, and there can be a difference in the noise generated as the aircraft accelerates along the runway to become airborne.

Depending on the aircraft’s destination, the departure will fly one of a number of departure routes (known as Noise Preferential Routes or NPRs). These routes are flown to minimise the overflight of local communities, whilst ensuring separation with other departures and surrounding air traffic, as well as optimising routing to the destination. The NPRs can be seen below. You can find out more about London Stansted Airport departures in the following video.

Please note this video is orientated as if you are positioned on the North of the airfield, looking towards the South.

Aircraft must remain within the NPR until they reach a minimum altitude of either 3,000ft or 4,000ft (depending on the route and time of day or night) after which ATC can provide a more direct routing to the destination. For safety reasons, ATC may sometimes provide instruction to an aircraft to exit the NPR earlier to avoid adverse weather or other air traffic. Compliance with this procedure (known as track keeping) is reported on here.

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Find a particular flight

Introduction

WebTrak is our online flight tracker which provides the aircraft flight number, aircraft type, its height and track.

We also show aircraft which do not operate from our airport. You can see aircraft arriving and departing, sometimes in a holding pattern, operations from other airports nearby, as well as the data direct from our fixed and mobile noise monitors.

WebTrak uses data taken directly from air traffic control (ATC) radar, this is the same data that ATC use to safely manage aircraft in the sky. It is fed directly into the Airport Noise Monitoring and Management System (ANOMS) which powers the flight tracking systems.

Please note: A delay of up to 30 minutes is applied to the replay of ‘live’ data to ensure all data is presented as accurately as possible.

How to use WebTrak

Showing where the help can be found (top left) in webtrak, where historical data can be found (bottom left) and how to move time (slider at bottom)

WebTrak, allows you to both investigate flights above your area in near real-time as well as investigating historical data. There is lots of online help contained in the tool (available through the menu on the left hand side of the screen) to help you understand the icons and method of operation. But to summarise some of the key features, you can:

  • Investigate a specific flight that might have caused a disturbance,
  • Investigate flights from the the busiest part of a day,
  • Discover where a flight was going or where it came from
  • Analyze the proximity of flights to your location by dropping a pin on the map.

Sometimes the tool will display flight routes or rainfall layers. These sorts of overlays provide a great visual tool for analysing flight corridors or understanding adverse weather.

You can also make a complaint about the flight, which will be sent through to us for review. This method helps us because we can immediately identify the aircraft that caused the disturbance.

I can’t see the flight that disturbed me

Webtrak takes a feed directly from Air Traffic Control (ATC) and whilst we aim to display all flights, you may notice that some are missing. This could be due to a number of reasons including:

  • If it was a military, police or civil protection flight
  • If the aircraft was carrying a Government Official or Head of State
  • If the aircraft was operating to/from another airport
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Typical flight paths

Arriving and Departing Aircraft

Every major commercial airport typically has set flight paths for departing aircraft from their runways. These are in place to maintain safety and whilst safety is always the number one priority, these routes are designed to minimise environmental impact as much as possible in terms of fuel burn, emissions and noise impacts. However, airspace congestion and local weather, such as thunderstorms, may result in a large spread in flight paths. Arriving aircraft follow broadly similar patterns, which are not as defined as the flight paths for departing aircraft. Aircraft are directed by ATC to a position where they turn onto a runway heading (the direction of the runway that the aircraft will land on) before making its final approach. At London Stansted Airport there is an Instrument Landing System (ILS) that guides the airport during its final approach to the runway.

The typical flight paths used at London Stansted Airport are shown in the following interactive tool for both westerly and easterly operations. All data has come directly from our Aircraft Noise and Operations Monitoring System (ANOMS), which receives flight data from air traffic control radar. This system is operational 24 hours a day, 7 days a week, continuously tracking and recording aircraft flights to and from the airport. Flight tracks are recorded from radar data centred at the airport. The reason you will see radar tracks ending is because the extent of our radar coverage is 40nm (nautical miles). The graphic below shows arriving aircraft as red tracks with departing aircraft shown as green tracks.

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Aircraft Holding

Holding Stacks

When airports are busy, there can be a build up of aircraft waiting to land, and so aircraft can be placed in a holding stack.

A stack is a fixed circling pattern in which aircraft fly whilst they wait to land. The primary use of a stack is to delay an arriving aircraft due to aircraft congestion, sometimes due to poor weather conditions (e.g. snow clearing) or runway unavailability.

London Stansted Airport has two holding stacks; one called ‘LOREL’ which is located Northwest of the airport and the second, ‘ABBOT’ is located Northeast of the airport. The minimum altitude of aircraft in the stack is 7,000ft in the LOREL hold and 8,000ft in the ABBOT hold, and is set to keep noise on the ground as low as possible. The height of the holding stacks extends up to 14,000ft.

Air Traffic Control (ATC) must ensure there is a safe gap between each aircraft as they come in to land. To achieve this, aircraft will sometimes circle around in the stack until air traffic controllers are able to fit them into the landing pattern. Aircraft are required to carry extra fuel specifically for holding, should this become necessary. Any aircraft with an emergency would take priority and bypass the stack.

You can find out more by watching this video:

Aircraft leaving a stack

People living between the stack and the final approach may hear noise as the aircraft leaves the stack and makes their way to the final approach to London Stansted Airport. As there are no set heights or routes for arriving aircraft, once they have left the stack, aircraft are directed individually by ATC to ensure they are safely spaced for arrival. Therefore, they can legitimately go anywhere they are directed. ATC do this to ensure high levels of safety and efficiency.

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Night Flights

Introduction

As the world becomes more connected, there is a growing demand for air transport, which includes passenger and cargo connectivity around the world, into and out of different time zones. Not only does this make it easier for people to travel for holidays and to see friends and family, but it also helps businesses and the local economy by providing transportation links for time critical goods and services.

London Stansted Airport is one of three airports which have been designated by the Government using powers contained in the Civil Aviation Act 1982. Therefore, most of the controls on night-time flying at Stansted Airport are directly imposed by the Government. The Department for Transport (DfT) is responsible for setting the restrictions. London Stansted Airport strictly monitors compliance with all the restrictions in place. The airport reports weekly on compliance to both the DfT and our airlines. We also report regularly to the Stansted Airport Consultative Committee (STACC) – an independent consultative group made up of representatives from local authorities, councillors, businesses, airlines and the DfT.

London Stansted Airport has always been a 24-hour, seven days a week operation. We recognise however, that at night when there is less background noise, aircraft noise may be more intrusive. Stansted attaches a high priority to managing the noise impacts associated with night operations. So we have chosen to voluntarily enhance the Government’s controls by implementing more stringent measures, including restricting the operation of noisier aircraft types and imposing lower noise penalty limits. Our night noise controls are intended to strike a balance between the economic and social benefits a thriving airport provides and the disturbance which can be caused by night flights.

Aircraft Certification

Aircraft are certified by the International Civil Aviation Organisation (ICAO) according to the levels of noise they produce. They are classified separately for both take-off and landing. Points are allocated to different aircraft types according to how noisy they are. The noisier the aircraft type, the higher the points allocated. This provides an incentive for airlines to use quieter aircraft types.

Restrictions in place

London Stansted Airport has procedures in place to minimise the disruption caused by night flights. These procedures have evolved through consultation with local communities as part of the Noise Action Plan process. The night period is defined as 23:00 to 07:00 hours (local). During this time the following restrictions apply:

  • To encourage airlines to fly as quietly as possible at night, we operate a noisy aircraft penalty. Using our noise monitoring system, we measure the level of noise generated by each departing aircraft. Noise is measured by monitors positioned at fixed points beneath the departure flight paths. Money raised from noisy aircraft penalties is donated to the London Stansted Airport Community Fund which supports local good causes.
  • The noisiest types of aircraft cannot be scheduled between 23:00 to 07:00. Aircraft rated at QC8 and QC16 are banned from operating between 23:00 and 07:00. Aircraft rated at QC4 are banned from operating between 23:30 and 06:00.
  • The Government imposes a night quota and movement limit to the Core Night period 23:30-06:00.

You can read more about how we manage night noise under the ‘What are we doing’ heading, within the ‘How we manage noise’ section.

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Helicopter Operations

Introduction

Helicopter operations at London Stansted Airport are daily occurrences and as with fixed wing aircraft operations, they conform to many operating restrictions, industry codes of best practice and legislation relating to their safe operation. London Stansted Airport is a 24-hour operation and as such, helicopters can operate at any time, and they depart and arrive using the runway.

Most helicopters operating at London Stansted Airport operate under ‘Visual Flight Rules’ and do not fly the Noise Preferential Routes (NPRs) when departing as commercial jet aircraft do. Similarly, helicopters do not arrive in the usual patterns seen with commercial jet aircraft. The pilot navigates using “visual” ground-based features such as roads and rivers which are clearly identifiable from the air. These visual features will not be as visible at night and so many helicopters are now equipped with satellite navigation
equipment which includes a database of all navigation features, including these ground-based features.

The government has set restrictions on the numbers and types of aircraft that can operate throughout the night, these restrictions also apply to helicopters. More information can be found on the ‘Night Flights’ page.

Minimum operating heights for helicopters

Helicopters operate in accordance with the low flying rules contained within The Rules of the Air Regulations 2007 – these state that except with the written permission of the Civil Aviation Authority, an aircraft flying over a congested area of a city, town or settlement shall not fly below a height of 1000ft above the highest fixed obstacle within a horizontal radius of 600 metres of the aircraft.
There are exemptions to the low flying rules when departing or landing at an aerodrome, they include Police and Air Ambulance helicopters which have special dispensation to operate safely at lower levels and may also hover for extended periods. Military helicopters (and aircraft) are not governed by these civil regulations.

Maximum operating heights for helicopters

The maximum height that helicopters can operate in controlled airspace around the airport is 2000ft. There is a safety requirement for helicopters and other light aircraft to remain a safe vertical and lateral distance away from other aircraft at all times.

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Unusual Operations

Unusual Operations

From time to time you may notice an unusual aircraft operation at or around the airport. Below are a number of examples of unusual operations that you may see at London Stansted Airport.

Go-arounds or missed approaches

A go-around, or missed approach, can occur for many reasons such as, an obstruction on the runway preventing the aircraft from landing safely, a change in the wind conditions or that the aircraft cabin is not secure for landing. When coming into land, if a go-around is initiated, the pilot will apply thrust to climb straight ahead and then either turn left or right. Because a go-around can occur at any stage of the approach, the climb and turn could occur before or after reaching the runway. The exact path taken by an aircraft going around will be dependent on surrounding air traffic, the weather, the direction of operation and the point at which it is initiated. However, standard missed approaches, where possible, follow the Buzad Noise Preferential Route.

The aircraft will then be directed by Air Traffic Control who will then position the aircraft to make a second approach to the runway to land. This may mean that aircraft performing a go-around could overfly areas they do not normally at potentially lower than expected altitudes. On occasion, it is not possible to follow a standard missed approach and on these rare occasions, aircraft will be directed by Air Traffic Control to maintain a safe separation from all other air traffic and may overfly areas not usually overflown.

You can find out more by watching this video:

An example of a go-around on Runway 22 (Westerly Operations) can be seen below. As you can see the aircraft took a right turn and orbit around to re-establish for a second, successful, approach on to Runway 22:

Military Flights

On occasions, military aircraft operate at London Stansted Airport. We are limited in our ability to mitigate against the noise impacts of these types of aircraft, however, they are still required to operate within the existing regulations that apply to our regular commercial traffic. Depending on the type of aircraft, noise suppression can be limited.

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Frequently asked questions

Here’s a compilation of some our most frequently asked questions and we’ll endeavour to update this list as new questions emerge:

Who is responsible for managing aircraft noise?

The policy framework and guidelines for managing noise are set at a national and international level but as the airport operator, it is our responsibility to manage noise locally around the airport. We do that by working closely with Air Traffic Control, Airline Stakeholders, the Airport Consultative Committee, the CAA, and the Government.

Can I request that helicopters do not fly over my house?

No, there are no prohibited areas, however, as helicopters are flying visually, we request that they avoid specific locations near the airport.

Can I get a noise monitor installed at my home?

Noise monitors are deployed in the local area to monitor and record noise from both aircraft and background sources. This allows us to evaluate trends and make comparisons between noise levels at different locations. The majority of our monitors have been in their current location for an extended period of time and you can see the location of these monitors within our noise report on this portal.

Whilst it is difficult to re-locate these long-term monitors, the airport has access to a short term monitoring program where noise monitors can be located in areas for short periods. The monitors within this program are typically used to collect data for a study for to further understand a specific issue in a certain area. The monitors are placed in response to requests made through the Consultative Committee from local Parish Councils. However, requests from local residents are taken into considerations as part of the wider monitoring program.

What affects the selection of runways on any given day? And why does the selected runway differ to the wind forecast?

The most common factor is wind direction as aircraft typically take-off and land into wind. However it is not only the wind at ground level that must be considered, but also the wind at altitude, which can often be substantially different. It is for this reason that the local weather forecast may suggest a different wind direction to that in which the airport is operating.

In addition, factors such as the traffic flow, local airport works and thunderstorms may restrict or temporarily alter how runways are used at airports.

What are minimum flying heights for aircraft?

For typical arrival and departure operations to/from airports there are no minimum flying heights although pilots are encouraged to fly using the optimal noise abatement procedures, which are designed to keep the aircraft higher for longer to reduce noise.

Outside of the usual arrival/departure operations, in most regions of the world there are altitude restrictions which pilots must not descent below when they are overflying cities, towns or populous areas. Typically this is 1,000 ft or when over other non-populated terrain 500 ft. However exceptions do apply, for example:

  • Military, police, medical and search and rescue operations
  • in situations where the weather requires lower flying
  • for helicopters flying within specified access lanes
  • where the aircraft is engaged in air work for which the operator has a permit (such as media helicopters)

Planes are flying lower than they used to

Some planes are much larger than others, and the size difference can make a person perceive they are closer, when they are at the same height as previously. Whilst factors such as altitude and temperature can sometimes affect the performance of planes as they take off; for example, hot weather can affect a plane’s ability to climb as quickly as they do in the cooler winter months.

Pilots fly where they want to:

Commercial aircraft that carry passengers and/or cargo are typically operating within controlled airspace managed by Air Traffic Control (ATC). ATC act as a coordinator to ensure aircraft are safely separated and efficiently directed towards their destination. You can view where aircraft fly through this portal or by using our flight tracking tools.

Flight paths have changed:

Aircraft departing from London Stansted Airport are required to follow one of six initial flight paths, known as Noise Preferential Routes (NPRs) until they reach the required minimum altitude of 3,000ft or 4,000ft depending on the route and time of day. It is at this point that the aircraft can be released from the NPR onto a more direct heading to its destination by ATC. Our NPRs are designed to minimise the number of people impacted by aircraft noise by diverting aircraft away from some of the more built-up areas and have been in place since the airport development in the 1990s.

It is not always possible to keep aircraft contained within these NPRs. Adverse weather conditions or the presence of other air traffic may require an aircraft to deviate from the NPR before reaching the minimum required altitude. These deviations are monitored regularly by the airport, and the results are reported online.

Unlike departures, there are no predetermined routes for arriving aircraft. The only area where we can predict the flight path for arrivals is the final approach, the 8 to 10 miles of flight prior to landing where aircraft follow the guidance from the instrument landing system or ILS.  Although typically arrival tracks do tend to concentrate within a similar area, ATC have to be able to direct arrivals anywhere within controlled airspace to maintain safety and efficiency.