A review of aircraft noise in the UK

By John Stewart

The last ten years have not been good for people living under flight paths in the UK.  Despite the introduction of aircraft which have been a little less noisy, the increase in the number of planes has made things worse for very many people.  This has been particularly the case where airports have used narrower flight corridors, resulting in certain communities getting all the flights.  That has meant real misery for people living under those routes.  All-day flying.  And at some airports flights throughout the night as well.

But I believe there is hope that things will improve.  The reason for this is that during the last decade there have been some significant improvements in aircraft noise policy, more engagement with local communities and a commitment by a few airports, most notably Heathrow, to involve communities in the design of new flights paths.  The challenge now is to ensure those changes result real improvements for communities under the flight path.

1. Aircraft noise policy

Why and how has aircraft noise policy improved?  The starting point was 2010 when the Government dropped the third runway at Heathrow.  Heathrow Airport and much of the aviation industry were in shock.  They were taken aback that the big prize of a third runway had been snatched away from them.

Over the next two years the industry reassessed its position.  It began to understand that it was not going to get the expansion it wanted, particularly at Heathrow, if did not engage with local communities and take more notice of their noise concerns.

At HACAN – the community organisation I chair which gives a voice to residents under the Heathrow flight paths – we understood we had a chance to get noise improvements.  We have always opposed a third runway.  We continue to oppose it but we also have seized the opportunity to lobby for improvements to the noise climate whether or not a third runway goes ahead.

Over the last decade, a number of policy measures we have campaigned for over many years have been agreed.

  • There is now recognition that people can be annoyed by aircraft noise at lower levels than was previously acknowledged. The UK Government used to argue most people were not annoyed by aircraft noise until it averaged out over the year at 57 decibels.  Now Government policy recognises that some people can be affected by noise averaging out at 51 decibels over the year.  This is not as low as the 45 decibels the World Health Organisation has recommended but it is a big step in the right direction.  Few other countries officially accept that noise annoyance can start as low as 51 decibels.  The Government is now planning further research into whether the level should be lower.
  • The Government and a number of airports, most notably Heathrow, have recognised that averaging out noise should not be the only way of measuring whether people are annoyed by noise. So a number of complementary metrics are now being used.  These include ‘N’ metrics – which measures the number of planes flying over a community in one day.
  • Government policy now recognises that periods of respite from the noise can be important. In its planning for a third runway Heathrow has guaranteed that no community will experience all-day flying; each community will get a break from the noise.  This will be done through rotating the flight paths.  The new flights paths are being designed in such a way that everybody will get some respite.  It will mean that during the periods when there are planes overhead, there will be a constant stream of them but during the quiet periods the aircraft will be far enough away for the noise to be less noticeable or in some cases not audible at all.  Although some people are understandably worried about how they will cope with the periods of intense noise, the majority of people who contact HACAN want a period of respite each day.  This is also what the surveys and focus groups which Heathrow did found.

2. Flight Paths

Over the next few years the UK will see the biggest changes to its flight paths for half a century.  These changes are being driven by new technology.  Across the world air traffic control is moving from a ground-based system to a satellite system to guide planes.  It will mean that planes will be more concentrated along narrower flight paths.  The new flight paths should allow aircraft to be guided more efficiently.  It will mean airlines will save time and fuel, airports will become more resilient, and the amount of CO2 emitted per plane is expected to fall.  But, of course, narrow, concentrated flight paths will mean life becomes almost unbearable for the communities underneath them unless they can get a break from the noise.

In the UK, Heathrow is leading the way in planning flight paths which work for the community as well as the industry.  

Heathrow is involving communities in designing its flight paths

Heathrow has put a lot of effort in trying to involve communities in the design of the flight paths. It carried out one of the UK’s biggest-ever consultation exercises, distributing over 2 million leaflets, to ask people what sort of new flights they wanted.

People were asked what was most important to them:

  • that the fewest number of people would be affected (which would be done by concentrating all the flight paths over certain communities);
  • or that periods of respite were provided to all communities
  • or that new areas should be avoided

The least popular was the first one so Heathrow are now designing multiple flight paths so that can be rotated while avoiding new areas if at all possible.

Of course it is inevitable that there will still be a lot of noisy Heathrow planes over communities.  If a third runway is built new communities will be impacted and some existing communities will get more planes.  But Heathrow’s commitment that flight paths will be rotated so that no community experiences all-day flight puts it ahead of most other airports in the UK.

At HACAN we are putting a lot of time and effort into helping shape the future flights paths.  Not only is it important that we get the best flight paths and noise climate possible but if Heathrow gets this right, what it has done can be copied by other airports both in the UK and elsewhere.

Good practice at Heathrow could spread to other airports

The contrast between the way Heathrow is involving local communities in drawing up its flight paths and the way most large American airports simply imposed concentrated all-day flying on their communities couldn’t be starker.  Understandably, many American communities and city authorities have rebelled against the new flight paths and a number of court cases have ensued.  Some of the American airports are now watching what Heathrow is doing.  If Heathrow can get it right, it could be of benefit to communities at airports across the world.  ‘Getting it right’ doesn’t mean that people won’t be disturbed by noise.  For the foreseeable future, that will always be the case.  But it does mean taking community needs into account wherever possible in designing flight paths.


3. Engagement

More engagement at a national level

Over the last decade there has been more engagement between local communities and official bodies such as the Department for Transport, the CAA (Civil Aviation Authority) and NATS (air traffic control).  A number of us meet them on a regular basis.  An independent noise authority called ICCAN has been set up.  This is something we campaigned for over many years.


4. Improvements must real for communities

None of this better engagement or improved noise policy will matter too much unless it results in improvements in the noise climate for local communities.  A recent study from the CAA predicted that the overall noise climate at most airports would get worse over the next few years due to the predicted growth in traffic.  The Government is looking to mitigate this through some of the measures it is expected to include in its Aviation White Paper, to be published later this year.  We may see the concept of a ‘noise design envelope’, being piloted at Heathrow, extended to other airports.  This will allow flight numbers to increase only if overall noise limits stay within an agreed – and legally-binding – framework.  The Government is planning to introduce a National Noise Indicator and possible noise caps at many airports.  We will need to see just how strict these will be before we can assess their effectiveness.  ICCAN, the new independent noise authority, will be promoting best practice so that all airports engage more meaningfully with their local communities.

Things can only get better?

I hope so.  Better national policies on aircraft noise are being put in place.  An independent noise authority has been set up.  Airports like Heathrow are developing progressive noise policies which could be rolled out elsewhere.   But the next few years will be crucial.  The projected growth may swamp noise improvements at many airports.  Community concerns may not turn out to be as central as they could be in the planning of the new flight paths at every airport.  And some airports may continue to be pretty dismissive of their communities.  But these concerns can be dealt with.  If they are, the improvements in policies and attitudes we have seen over the last decade could provide the basis for things actually getting better for many communities on the ground during this new decade.