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Noise page


Gatwick’s noise contours would increase compared to the “do nothing” option across all time periods.


The airport claims that average noise contours would be likely to fall compared to 2019 levels but this relies on uncertain fleet replacement assumptions.


The noise impacts of Gatwick’s proposed growth are inconsistent with government policy. They do not share the benefits of growth between the aviation industry and local communities or ensure that noise is reduced and mitigated as capacity grows. Instead the benefits of growth would accrue wholly to the airport and the wider aviation industry through greater capacity. Communities would suffer substantially increased noise impacts.


Gatwick focuses on average noise metrics that do not properly represent the impact of aircraft noise on people. By using average noise contours it seeks to claim that minor reductions in noise per aircraft (which would generally be inaudible to humans) would outweigh a 35% increase in flight numbers.


The airport’s focus on average noise contours is misleading. It should focus on noise event frequency at all levels of noise that affect people.


The airport is proposing a “noise envelope” which would limit its 51dB noise contour to 146.7km2 in 2032 and 125.7km2 by 2038. The 51dB noise contour covered 136 km2 in 2019.


The proposed noise envelope uses inappropriate metrics and is wholly one-sided.


There are no proposals to limit or manage noise outside the 51dB contour.


The Gatwick Consultation Documents


The Gatwick consultation summary document


The Gatwick consultation overview document





Preliminary Environmental Information Report

Chapter 14: Noise and Vibration



Responding to the consultation


The question, in the Gatwick questionnaire (there are 14 questions in total) is:


Question 13. Managing and mitigating effects: noise envelope


  1. We are proposing to introduce a ‘noise envelope’ to set limits on noise from future operations at Gatwick. The noise envelope would come into effect at the start of a dual runway operation, giving residents certainty that the noise limits it prescribes would not be exceeded. This envelope would then be tightened in the future, giving residents further certainty that air noise levels would have to be lower than they were in 2019 for the full capacity of the Northern Runway Project to be realised.

Do you think the proposed noise envelope is:


Answer: Inappropriate


Please explain your views.


GACC suggestes short response

Gatwick’s analysis of the noise impacts of its proposed expansion is deliberately misleading. Its noise envelope proposals are inconsistent with CAA guidance and unacceptable.  They propose inappropriate metrics and limits, do not comply with government policy, lack adequate enforcement arrangements and have been put forward without stakeholder discussion, in contrast to the approach taken by other airports. 


GACC suggested longer response


Gatwick’s analysis of the noise impacts of its proposed expansion is deliberately misleading. Its claim that there would be less impact from aircraft noise following the expansion than was experienced in 2019 is dishonest.

The concept of a Gatwick noise envelope is welcome, but the airport’s proposals are inconsistent with CAA guidance and unacceptable.  They propose inappropriate metrics and limits, do not comply with government policy, lack adequate enforcement arrangements and have been put forward without stakeholder discussion, in contrast to the approach taken by other airports. 

In relation to metrics, Gatwick has suggested the noise envelope should rely exclusively on Leq 16 hour day 51dB data.  It is well aware that this metric does not adequately reflect the impact of aviation noise on communities, because it fails to take account of the increased frequency of overflight which communities will suffer as a direct result of Gatwick’s expansion plans. In our view no single measure will adequately capture the impact of Gatwick’s proposals or provide protection for residents.  An acceptable noise envelope must therefore incorporate a number of measures including average noise, noise event frequency and overflight. In support of this, CAA paper CAP 1129 says “An envelope is likely to be defined by a combination of parameters”.

More broadly, Gatwick’s proposals do not comply with government aircraft noise policy.  Policy requires the industry to reduce and mitigate noise as airport capacity grows.  Noise must therefore fall from the projected level in 2029 when dual runway operations would commence.  However, Gatwick is proposing that the average noise contour in the day period (which is an inadequate measure for the reasons above) would increase as a result of the proposed growth (rather than reduce from that date as policy requires), and that it would be permitted to be significantly greater than noise levels in 2019.

Government policy also requires the benefits of future growth in aviation to be shared between the aviation industry and local communities.  Gatwick is proposing that its capacity should grow by over 70% in passenger terms and that there would be 35% more aircraft movements.  Benefits to the industry would be very substantial.  By contrast, the airport’s noise impacts, if measured in a meaningful way, would initially increase substantially before potentially declining modestly from new record levels.  There would be no benefits for communities.  The airport has therefore made no attempt to share benefits in the way government policy requires.

In addition:

  1. Gatwick’s proposed metric takes no account of the very significant number of people living outside the proposed 51dB contour, but who are already adversely impacted by Gatwick aircraft noise.
  2. Gatwick states “Where an operating restriction is proposed, the Regulations require a noise assessment and consultation with relevant stakeholders who may be affected by it.” In addition the CAA states “it is essential full agreement is achieved between all stakeholders on the envelope’s criteria, limit values and means of implementation and enforcement”. Gatwick’s approach to noise envelope development fails to meet these requirements. It is seeking to impose its preferred outcome rather than collaborating with stakeholders to develop an approach that might be mutually acceptable.  Relevant stakeholders, including Gatwick’s own Noise Management Board, have not been consulted on the noise envelope proposal. In contrast, other airports have adopted an inclusive approach by setting up dedicated design groups, including community groups and local authority representatives, to facilitate a collaborative and consensual approach to noise envelope development.
  3. Regulation 598/2014 states “the competent authorities shall follow up and monitor the implementation of the operating restrictions and take action as appropriate”. Gatwick’s proposal that it should carry out monitoring and reporting itself, contrary to the regulations, is not acceptable.
  4. Gatwick’s noise envelope proposal makes no mention of what should happen in respect of enforcement if a breach occurs, and doesn’t confirm which body will be responsible for taking any remedial action. It’s critical that, if impacted communities are to have real certainty, the noise envelope process, including how breaches are captured, reported and remediated must be clearly documented. Gatwick’s proposals fail to do so.
  5. Gatwick’s proposals fail to set out the process by which the noise envelope would be reviewed and adjusted if a significant change occurred. Given the FASI(S) airspace change project may make changes to the airspace around the airport, it is critical that a defined process is in place so that the noise envelope can be reviewed and adjusted to ensure it continues to provide the certainty that communities wish for.


There is also question 14.


Question 14. Managing and mitigating effects: noise mitigation


  1. In addition to the Noise Envelope, we are proposing other measures to mitigate the noise effects associated with the Northern Runway Project, including an enhanced Noise Insulation Scheme, the noise envelope, a new noise barrier at the western end of the Northern Runway, and noise barriers to support changes to the highway network. What are your views on our approach to noise mitigation? Please specify the measures to which your comments refer.


GACC is currently seeking external advice on the proposed noise mitigation measures in the consultation and will provide a draft answer to this question when we have that advice.



Submitting a response


Responses can be done through the questionnaire


or else by email, to



or by letter to  FREEPOST RTRB-LUUJ-AGBY



GACC Campaign Office
2 Glovers Gate, Glovers Road, Charlwood, Surrey.  RH6 0EP
Telephone:  01293 862821

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