Written evidence submitted by the East Twickenham Heathrow Campaign (HEN0030)
East Twickenham Heathrow Campaign was set up by residents' associations covering an area of around 5000 residents. We wish to draw the attention of the Select Committee to a number of serious issues with the Government's draft Heathrow Expansion National Policy Statement (HENPS). While we have concerns about surface transport, air quality, economics, and climate change (see below), aircraft noise remains the primary concern for local communities.
Noise
Most people choosing to live in west/south west London accept a certain level of aircraft noise, but many are worried that, with the proposed 50-60% expansion of flights at Heathrow, the adverse effects are likely to increase significantly. These are our primary noise-related concerns with the HENPS:
Use of outdated noise sensitivity data
The HENPS relies largely on outdated noise sensitivity data (ref 2014 Survey of Noise Attitudes - SoNA), despite the publication in June 2026 of the government-funded Aviation Noise Attitudes Survey (ANAS) and Aviation Night Noise Effects (ANNE) studies. These show that people are adversely affected by aircraft noise at much lower levels than previously seen. That, increases the estimated number currently adversely affected by noise from Heathrow from around 0.9 million to 4.65 million. Only the latest noise sensitivity data must be used in the HENPS.
Flight paths (hence noise impact) currently unknown
The future flight paths for a three-runway Heathrow are unknown because the UK Airspace Design Service has only just begun its work on airspace design for the London area. HENPS data on noise impacts are based on assumptions, which may be incorrect. This is a major national project affecting millions of people. It should only proceed when the relevant airspace design has been completed enabling noise impacts to be reliably assessed.
Noise metrics fail to reflect community experience
The HENPS solely utilises average noise metrics (LAeq) to assess noise impact. But these alone fail to reflect the experience of communities on the ground, given the intermittent nature of aircraft noise. They should be complemented by 'single event metrics' (such as LAmax and Number Above).
LAeq-based noise contours are useful, but fail to differentiate between people whose average noise exposure is just on the contour threshold, and those who suffer far higher noise exposure. The effect is to mask areas of higher concentration.
Reduced respite and need for enhancement of night flight ban
Given a third runway and an increase in air traffic movements (ATMs) of 50-60%, the HENPS requirement for "adequate, predictable respite" is insufficient to preserve current respite benefits. There should be a clear commitment to minimum periods of daily respite, similar to those of today.
While welcoming a 6.5 hour night-flight ban, protection should extend to the shoulder periods either side of the ban during the 23:00-07:00 period through: restrictions on take-offs, limits on arrivals, and use of only the quietest aircraft.
Noise impact improvement forecasts lack credibility
The HENPS (Noise Annex), even using ANAS data, claims that a 50–60% increase in flights will result in 27% fewer people affected by noise as a result of less noisy aircraft. If the Government accepts this forecast, it should make the reduction a legally enforceable requirement.
If there are gains to be made though improved aircraft and engine design, they are an opportunity to benefit the health and well-being of the 4 million people currently affected by aircraft noise by retaining the current 480,000 ATM cap at Heathrow.
Other issues
Surface Transport
The HENPS requires only a "credible plan" for transport improvements rather than a funded scheme. This risks overcrowding on rail services, greater road congestion and substantial future infrastructure costs falling on taxpayers.
Air Quality
Heathrow expansion risks reversing recent improvements in London's air quality. HENPS should protect existing gains, rather than merely avoid new legal breaches, give much greater consideration of emissions from aircraft in flight, and allow for new evidence emerging on ultra-fine particulates up to the time of the DCO to be taken into account.
Economic case
Recent work on expansion was triggered by the Chancellor of the Exchequer claiming that it could lead to GDP growth of 0.43% by 2050. The HENPS forecasts national GDP growth of only 0.05%, with a concentration in London, while DfT modelling indicates a negative Net Present Value of -£24.2 billion to -£62.5 billion. There is no economic case for such a major project.
Climate Change
Pending Climate Change Committee input, it does not seem credible to claim that Heathrow expansion is compatible with Net Zero. Sustainable Aviation Fuels (SAF) are unlikely to be a panacea for increased carbon emissions from aviation growth, given their lack of availability at the required worldwide scale or cost, at least in the medium term, and some major aircraft fuel suppliers have cancelled large scale SAF projects.
Overall
The draft HENPS is based on outdated evidence, uncertain assumptions and a very weak economic case. Heathrow expansion should not be considered until updated noise evidence has been incorporated, future flight paths determined, environmental impacts understood and addressed, sufficient surface transport planned and funding secured, and a credible climate and economic case established.
This submission is on behalf of East Twickenham Heathrow Campaign, a community group set up by local residents’ associations covering an area of around 5000 people, in order to address issues relating to noise and pollution from flights heading into and out of Heathrow. We work with other campaign groups in south west London and the wider area.
While we have serious concerns about the surface transport, economic, air quality and climate change implications of the Government’s draft Heathrow Expansion National Policy Statement (HENPS) - see below - noise is the primary issue for local people.
Most people choosing to live in the west/south west London area accept a certain level of aircraft noise, given the proximity of Heathrow. They are aware that the location of the airport, far closer to highly populated areas than comparable airports, and directly to the west, results in the associated noise already affecting more people than any other airport in Europe. We have six particular concerns relating to the HENPS:
The Aviation Noise Attitudes Survey 2023-2024[1] (ANAS) and Aviation Night Noise Effects (ANNE)[2] study, both published in June 2026 - and data from which were known in government for many months before publication - provide the latest authoritative data on the impact of aircraft noise. They supercede the 2014 Survey of Noise Attitudes 2014 (SoNA) study[3].
These studies conclude that the noise exposure at which people are ‘highly annoyed’ (ISO5666) by aircraft noise is 43 dB LAeq16h (LAeq8h for ANNE). ANAS states (p14 S25) “The percentage highly annoyed from ANAS 2023-2024 is found to be higher than SoNA 2014 at all noise exposures, including in the same geographical areas surveyed in SoNA”. This indicates a much lower threshold of sensitivity to aircraft noise versus the 51dB reported in SoNA, but is in line with WHO recommendations of 45dB. While there are methodological differences between ANAS and SoNA, there is other evidence that public sensitivity to aircraft noise has increased in recent decades, as indicated in this 2019 German/Swiss study[4]. It is clear that 43dB should become the Lowest Observed Adverse Effect Level (LOAEL) daytime standard for the UK, in line with WHO recommendations.
Unfortunately, all but one section of the HENPS, and its Noise Annexe[5], is based on the outdated SoNA data. Applying the ‘Lowest Observed Adverse Effect Level (LOAEL) supported by SoNA, 51db LAeq 16h, indicates (ref para 4.4 of the Noise Annex) that 884,000 people were estimated to be adversely affected by Heathrow in 2024. But the only section (Noise Annex paras 5.13-5.24) applying the new ANAS 43dB threshold reveals, 4,650,000 people were in ‘highly annoyed’ areas in 2024.
This is an important issue for millions of people in local communities. Only the latest noise sensitivity data should be used.
According to a stakeholder briefing by Heathrow on 21 July 2026, the new UK Airspace Design Service (UKADS) is only now (July/Aug 2026) becoming established. It will then on-board airspace work from the airports, including Heathrow. Its brief is to prioritise the definition of a single Airspace Change Proposal for London and the south east, based on three runways at Heathrow. But Heathrow’s work to date has all been based on two runways. The process to arrive at an approved airspace design, especially one as complex as this, is lengthy. No-one will know for some time - probably a few years - where the flight paths for a three-runway Heathrow will be.
The noise modelling used for the HENPS is therefore based on assumptions. As para 2.7 of the Noise Annex admits “the spatial impacts of Heathrow expansion [hence number of people affected] would be expected to be different under different designs”. Some uncertainty in this respect would be reasonable for a new airport surrounded by areas of relatively low populations. But it is not reasonable in the case of Heathrow, with over 4 million people currently affected, and many others potentially affected. Given the already-approved expansions of Gatwick, Stansted, Luton and London City, there is little to suggest a shortage of capacity in the London area in the short or medium term.
The Airspace Design work therefore needs to be completed before decisions are taken on expansion.
The HENPS Noise Annex gives an assessment of the number of individuals and households affected by expansion (based on outdated sensitivities and assumptions on flight paths), using noise contours showing the areas in which average aircraft noise is forecast to exceed a stated threshold. The number of individuals and households contained within the contour is then calculated. This approach has two major inadequacies:
a) Averages alone are insufficient
The noise metrics used in the HENPS, and in the draft Air Navigation Guideline 2026, are adjusted average sound energies: LAeq 16h in decibels (day), LAeq 8h (night). While these are valuable metrics, using an average alone fails to reflect the real life experience of communities on the ground. Unlike a steady rumble of road traffic, aircraft noise is particularly disturbing because it comes in - often irregular - peaks and troughs. Before it was dissolved under the Johnson Government, the Independent Commission on Civilian Aircraft Noise (ICCAN) published a report on metrics[6] which recommended that “supplementary Single Event metrics are routinely published by airports to better reflect the way in which noise is experienced on the ground.” Such metrics are LAmax (peak noise level) and “number above”, such as N65 (the number of aircraft events exceeding 65dB in a given period). N65 was used by Heathrow, for example in their 2025 easterly alternation planning application.
Use of averages alone (such as LAeq) fails to reflect the experience of communities on the ground. They should be complemented by single event metrics (such as LAmax and Number Above).
b) Contours mask concentration.
LAeq-based noise contours fail to differentiate between people and households whose average noise exposure is just on the contour threshold, and those who suffer far higher noise exposure. They are all counted the same. The effect is to mask areas of higher concentration. As well as a general issue, this is of particular concern as the anticipated use of Performance Based Navigation technology may result in narrowing of flight paths and hence concentration of noise - a major issue in the USA.
Currently, communities around Heathrow normally have half-day respite from noise because the airport switches between its two runways at 3pm each day. The HENPS requires proposers to offer “adequate, predictable respite”. But, with three runways, and a 50% increase in flights, it would seem impossible to provide the same duration of respite as today. However, the HENPS gives no indication of who decides that respite is “adequate”. Communities may therefore read “adequate, predictable respite” as meaning "significantly less respite than there is today”. There should be a clear commitment to a minimum periods of daily respite, similar to those of today.
The HENPS requires a “night flight ban” of 6.5 hours between 23:00 and 07:00 (ban times not specified). This is welcome, but little different from the current position, where there are no scheduled departures 22:50-06:00 or arrivals 22:55-04:50. The proposed 6.5 hour ban (the HENPS assumes 23:30-06:00) would stop noise from scheduled movements in the most sensitive period of the night. But the likely result would be a large increase in the early morning, between 06:00-07:00, and perhaps late evening. Late-runners and other special cases will still occur, and are likely to be more numerous in line with the growth in ATMs.
This is significant. The ANNE study[7] reported (para 5.2) that “10% of the sample were ‘highly annoyed’ (HA) at 43dB LAeq,8h” and “10% of the sample were highly sleep disturbed at 44dB LAeq,8h”, but that more granular, hour-by-hour measures revealed that “the lowest aviation noise exposure thresholds for 10% HA were found for 03.00-04.00, 04.00-05.00 and 05.00-06.00 hours, where very low levels of exposure were associated with annoyance (40dB, 36dB, and 40dB, respectively).”
That is in line with the World Health Organisation’s guideline[8]: “For night noise exposure, the GDG strongly recommends reducing noise levels produced by aircraft during night time below 40 dB Lnight [8 hours], as aircraft noise above this level is associated with adverse effects on sleep”.
Given the very large number of people affected by Heathrow noise - more than any other European airport - and the evident importance of sleep to health, as well as the range in normal sleep times, in addition to the high level ban, there should also be:
● A ban on takeoffs between 23:00 and 07:00.
● A limit on the number of landing ATMs within the 8 hour period but outside the ban period (23:00-23:30 and 06:00-07:00), with a maximum of 16 ATMs a day allowed, reflecting the current position.
● Only the quietest categories of aircraft allowed 23:00-07:00.
The duration of the ban should be measured from the final landing at night until the first terminal departure in the morning.
The aviation forecasts on which the HENPS is based cite a 50% increase in the number of Air Traffic Movements (ATMs) at Heathrow, from 480,000 to 722,000 as cited in the HENPS aviation forecast tables[9] (Heathrow Airport Limited (HAL) indicated[10] 756,000 ATMs, a 60% increase, in its 2025 proposal.)
The HENPS makes the extraordinary claim that, despite adding a third runway and increasing the number of flights by 50-60%, the number of people suffering daytime noise disturbance after expansion in 2055 will actually be lower than in 2024 because aircraft are getting less noisy.
Noise Annex para 4.6 states:
“Improvements are largely driven by fleet modernisation, as the introduction of newer, quieter aircraft mitigates the increased noise associated with greater aviation demand. Fleet modernisation comprises two elements: the increased uptake of newer existing aircraft types and the introduction of future aircraft. In this modelling, much [sic] of the reduction in aviation noise around Heathrow can be attributed to the former.”
This is highly questionable. Full details of the underlying calculation are not provided, a linear rate of improvement for new aircraft is assumed, and some of the aircraft involved do not yet exist. But there are other variables at play here, for example (ref UECNA 2022[11]) noise will be increased by expanded use of ‘stretched’ aircraft with higher capacities and load factors, a higher proportion of longer-range flights, and climate change driving higher air temperatures. And it fails to take into account increasing sensitivity to aircraft noise.
The one section of the Noise Annex[12] which applies the ANAS-based threshold for noise annoyance of 43dB applies the “aircraft getting less noisy” logic to claim (para 5.19):
“By 2055, under the 3R scenario, the 43 dB LAeq,16h contour covers an estimated 840 km². This is 42% larger than under the 2R scenario (591 km²) but 24% smaller than in 2024 (1,110 km²). The contour is estimated to include 3,405,000 individuals and 1,495,000 households, representing increases of 33% for both metrics compared with the 2R scenario (2,560,000 individuals and 1,125,000 households). However, this remains below 2024 estimates (4,650,000 people and 1,876,000 households), a decrease of 27% in total individuals and 20% in total households.”
If the Government believes this forecast, it should be willing to include in the HENPS a planned legal requirement to ensure Heathrow delivers the 27% reduction, with appropriate enforcement mechanisms.
Setting aside the credibility of a 27% decrease in the number of people affected, the implication is that it is acceptable for 3.4 million people to be adversely impacted by noise from Heathrow even after three decades of gains in technology. Why?
If there are gains to be made though improved aircraft and engine design, they are an opportunity to benefit the health and well-being of the 4 million people currently affected by aircraft noise by retaining the current 480,000 ATM cap at Heathrow.
The HENPS states (para 5.103):
“The Government’s objectives for surface access to an expanded Heathrow are making public transport the first choice for airport users, minimising the impact on the road network and prioritising environmental sustainability”.
Para 5.105 requires a proposer to “...develop plans to deliver active travel, rail, bus and coach connectivity to and from the airport and set out credible plans for funding these…setting out a plan to provide appropriate infrastructure to stimulate mode shift to public and active modes, while supporting the needs of zero emission vehicles across various modes”.
Para 5.116 “Any application for development consent and accompanying airport surface access strategy must include details of how the applicant will achieve a passenger public transport mode share of:
• At least 50% when annual terminal passenger capacity is 116m or more;
• At least 55% when annual terminal passenger capacity is 130m or more
• For any further capacity increases, the promoter should agree with the Airport Transport Forum and the Secretary of State for Transport on ongoing monitoring and subsequent targets.”
The HENPS refers to an "Annex X" for more detail. There is no Annex X but we presume it refers to "A Strategic Vision for Transport to an Expanded Heathrow Airport" [13]. This document states (para 4.8) “These proposals should support direct and through-running services from the west and/or south where appropriate. Importantly, as stated in the draft Heathrow Expansion NPS, we are not requiring surface access schemes to be brought forward as part of the expansion DCO itself; rather, it requires there to be a credible plan for new rail links to be
delivered ahead of airport capacity reaching 130 million or more passengers per annum.” There are three particular concerns here:
Terminal passenger numbers in 2025 were just below 85 million, and the public transport share was estimated at 46%. Yet rail infrastructure does not have to be included in the proposal for the DSO, just a 'credible plan' to do it for delivery before the passenger numbers reach 130 million. To achieve “At least 50% when annual terminal passenger capacity is 116m or more" without more capacity implies the existing public transport network can absorb an additional 19 million passengers (116x0.50-85x0.46). If no extra capacity is provided much before it reaches 130 million, that implies an extra 26 million passengers on the current network. Can the existing network absorb these numbers?
With no requirement for the proposing companies to commit to financing the required expansion in public transport infrastructure, it will be hard for a future government to refuse to finance it when the airport expansion has happened and there is already overcrowding on the system.
Given the lead time on rail infrastructure projects, especially in such a highly populated and congested area, it appears irresponsible not to require a proposer to make a firm commitment to a fully financed public transport scheme (even if this includes a government contribution).
As local people, we are aware of the pressure on the road network in the vicinity of Heathrow. Yet even if the public transport objectives are met, there will be an additional 12 million passengers on the road network when the airport capacity reaches 116 million (116x0.5-85x0.54). In addition, there will be an expansion of freight, virtually all of which will go by road. This is a recipe for increased congestion and consequent economic and environmental costs.
While air pollution remains a significant issue across London, a recent study by Imperial College[14] showed that pollution-related deaths dropped by 40% between 2019 and 2024, reflecting the electrification of vehicles, and the expansion of the ULEZ. Heathrow expansion would unavoidably increase NOX and other emissions, both as a result of airport operations and increased road traffic, and as a result of a 50-60% increase in flights over areas of high population.
The test proposed in the HENPS that “the scheme would not cause air quality impacts that result in any new breaches of legal obligations on air quality or make existing breaches materially worse” is therefore an unacceptably low bar when the trend is one of improvement. The hard work to reduce pollution in the capital cannot be used to provide headroom for a Heathrow-related increase. The baseline should be the lower of, say, 2024 and 2034.
Aircraft in flight seem to be largely ignored in the air quality documentation in support of the HENPS, which focuses on pollution near the airport. Yet the 2022 ICAO report ‘Impacts of Aviation NOx Emissions on Air Quality, Health, and Climate’[15] states: “Key pollutants for air quality are nitrogen dioxide (NO2), ozone (O3), and fine particulate matter (PM2.5). Cruise emissions are estimated to be the dominant aircraft source of surface level ozone (increase relative to other emissions sources of 0.3 to 1.9% globally) and PM2.5 (increase relative to other emissions sources of 0.14 to 0.4% in high traffic regions) and hence a dominant cause for aviation-induced premature mortality globally.”
The HENPS test requirement that “The Secretary of State will consider air quality impacts over the wider area likely to be affected, as well as in the vicinity of the scheme” is too vague. It should explicitly map on to the London Terminal Manoeuvring Area (LTMA), including Greater London, especially given the overlap between emissions from aircraft using Heathrow with those using other LTMA airports.
Knowledge of the negative impact on health of ultra-fine particulates (particles less than 0.1 μm (100 nm) in diameter - far smaller than PM2.5) is only just developing. But we note that the UFP literature review associated with the HENPS[16] makes clear that aviation is a significant and distinct source, and states: “downwind UFP peaks often persist several km from runways, with concentrations decreasing with distance due to atmospheric dispersion” which makes this issue relevant for our area (around 9km away) as well as those closer to Heathrow.
The HENPS test that “The Secretary of State should also consider what monitoring and enforcement is required to ensure that the residual air quality impacts related to a proposed scheme (after mitigation) do not exceed projections as well as monitoring of emerging pollutants of concern such as UFP” fails to take into account that knowledge in this area is developing. By the time of a DCO application (2029 earliest) the then-government may have established, or be working on, new standards on UFPs. The test should therefore have a proviso enabling the best official view on UFPs at the time of the application to be taken into account.
A key driver for Heathrow expansion came from a speech by the Chancellor of the Exchequer in January 2025 claiming that it would deliver economic growth, and citing a Frontier Economics forecast of 0.43% GDP growth by 2050[17]. However, the HENPS (para 5.90) forecasts only “up to 0.05% to GDP in 2056” - 90% lower.
When the environmental impacts, losses by airport and airlines and other disbenefits are taken into account in the DfT model, the Appraisal Report table 8-1 shows a Net Present Value ranging from -£24.2 billion to -£62.5 billion. This should surely kill the project.
Furthermore, the associated Heathrow Expansion Appraisal Report[18] (table 11.2) makes clear that even the modest 0.05% national GDP growth will not be spread across the regions. Eight of the 12 regions are forecast to see 0.03% or less, with London at 0.19%.
Yet the HENPS states “To meet the Government’s economic growth test, a promoter must show that the scheme is expected to contribute to economic growth at national, regional and local levels”.
We await the Climate Change Committee’s input. But we are concerned at the Government’s promotion of so-called Sustainable Aviation Fuels as a panacea for increased carbon emissions resulting from aviation growth. Of the three categories of SAF (HEFA from used cooking oil etc; SAF from crops, waste etc; and Power-to-Liquids):
● HEFA is limited in volume by feedstock availability (and restricted in the SAF Mandate)
● Power-to-Liquids processes are prohibitively expensive
● Other processes both yield fuels more expensive than existing fuels, and there is a major risk that land which could be used to grow food is turned over to crops for SAF.
Notably in 2025, Shell abandoned a multibillion-dollar plan to convert much of its European jet fuel production to SAF[19], as ”the project would be insufficiently competitive to meet our customers’ need for affordable low carbon products”.
It is hard to see how a drive towards aviation growth can match the drive towards Net Zero.
The draft HENPS is based on outdated evidence, uncertain assumptions and a very weak economic case. Heathrow expansion should not be considered until updated noise evidence has been incorporated, future flight paths determined, environmental impacts understood and addressed, sufficient surface transport planned and funding secured, and a credible climate and economic case established.
July 2026
Endnotes
[1] CAP3131: Aviation Noise Attitudes Survey 2023-2024 | UK Civil Aviation Authority
[2] Aviation Night Noise Effects (ANNE) subjective study report
[3] Survey of Noise Attitudes 2014: Aircraft Noise and Annoyance, Second Edition
[4] Leq + X: Re-Assessment of exposure-response relationships for aircraft noise annoyance and disturbances to improve explained variance, Proceedings of the 23rd International Congress on Acoustics (2019)
[5] Draft Heathrow Expansion National Policy Statement Appraisal of Sustainability (AoS) Noise Annex
[6] A Review of Aircraft Noise Metrics and Measurement (July 2021)
[7] Aviation Night Noise Effects - Subjective Study Report (June 2026)
[8] World Health Organisation’s Environmental Noise Guidelines for the European Region (2018) - para 3.3
[9] Heathrow expansion appraisal report aviation forecast data tables Table 1D ‘Current Trends’ scenario 2024 (483,000 ATMs) vs 2060 (722,000 ATMs)
[10] https://www.heathrow.com/content/dam/heathrow/web/common/documents/expansion/expanding-heathrow-proposal-summary.pdf Page 9, and 10 - 756,000 ATMs
[11] https://uecna.eu/wp-content/uploads/UECNA_Efficiency_vs_Noise_April_2022.pdf
[12] Draft Heathrow Expansion National Policy Statement Appraisal of Sustainability (AoS) Noise Annex
[13] "A Strategic Vision for Transport to an Expanded Heathrow Airport" (June 2026)
[14] “London air pollution deaths fall by 40% since 2019, study finds”
[15] ‘Impacts of Aviation NOx Emissions on Air Quality, Health, and Climate’
[16] Air Quality Support for Review of ANPS - Ultra-fine Particulates Literature Review
[17] https://www.gov.uk/government/speeches/chancellor-vows-to-go-further-and-faster-to-kickstart-economic-growth