TAG responds to the CAA consultation on Draft Airspace Modernisation Strategy 2022–2040

This consultation is important since “airspace modernisation” is effectively altering the aircraft guidance systems to be satellite based making them much more accurate and enabling aircraft to be positioned much more precisely and near each other, increasing the number of aircraft in the sky, narrowing the flight paths, and inflicting the environmental effects much more intensively upon people underneath flight paths.

The argument goes that by placing aircraft in the sky more precisely, stacking can be reduced and routes can be more direct so that environmental effects of aviation are reduced. Experience has shown that this is not necessarily the case and you should not always believe what you are told.

The Consultation details and links can be found at https://consultations.caa.co.uk/policy-development/draft-airspace-modernisation-strategy-2022-2040/consult_view/. The closing date for submitting responses is 4th April 2022.

The questions with our answers are below:

This is part 1 of the consultation document. There is also a part 2 with part 3 being published later

Draft Airspace Modernisation Strategy 2022–2040 consultation questions


About you

A Are you responding in an official capacity on behalf of an organisation?

Please select only one item

☒ Yes

☐ No

If yes, please give us the name of the organisation               Teddington Action Group

 B What is your name?


C What is your email address?


D Are you answering as:


Please select only one item

☐ Airline passenger

☐ Resident affected by aviation

☐ General Aviation (GA), including representative organisations

☐ Remotely Piloted Aerial System

☐ Commercial aviation/aerospace industry including trade associations

☐ Consultancy

☐ Central or local government body including military

☐ Elected political representative e.g. councillor or MP

☐ National organisation (excluding GA organisations and industry trade associations), e.g. NGO

☒ Local organisation e.g. community action group, airport consultative committee or forum

if you fall in more than one category, choose the one that is most relevant to you answering about airspace issues

E Where do you live or where is your organisation based?


Please select only one item

☐ East of England

☐ East Midlands

☐ West Midlands

☐ North East

☐ North West

☐ Northern Ireland

☐ Scotland

☒ South East

☐ South West

☐ Wales

☐ Yorkshire and the Humber


F Is there anything else that you would like us to know about you in connection with your response?

I am representing the Teddington Action Group. Details about us can be found at http://www.teddingtonactiongroup.com/aboutus/

 G Do you consent to your response being published?


Please select only one item

☒ yes, with personal identifying information (organisation, name, respondent category, location, additional information – please note your email address will NOT be published if you choose this option)

☐ yes, anonymised

☐ no

Views on the overall strategy

1 Do you agree with our overall approach in the refreshed Airspace Modernisation Strategy?

Please select only one item

☐ about right

☐ minor modifications needed

☒ major modifications needed

☐ don’t know

If you wish, please explain your answer using the box below. You may, for example, want to consider whether our strategic vision for airspace modernisation out to 2040 is fit for purpose, and give us views on the four strategic objectives we have identified (safety, integration, simplification and sustainability).


For any consultation to be valid it “must include sufficient reasons for particular proposals to allow those consulted to give intelligent consideration and an intelligent response; adequate time must be given for this purpose” [1]. In its current form this consultation fails to do this, by failing to refer to or inform the consultees of the grave environmental consequences that have already taken place through the introduction of airspace modernisation and Performance Based Navigation. The Consultation document says that:

“Airspace modernisation will deliver the Government’s key environmental objectives with respect to air navigation as set out in the Government’s Air Navigation Guidance 2017 [“ANG”] and, in doing so, will take account of the interests of all stakeholders affected by the use of airspace”.

This, at best, is very dubious from published evidence so far, making “intelligent consideration” from the material supplied unlikely:

The USA has introduced its airspace modernization though its “NextGen” program introducing Performance Based Navigation (PBN) and its metropolitan airports navigation upgrade program known as “Metroplex”. The US Department of Transportation produced a report in August 2019 on the benefits of these programs falling well short of expectations. The Department found that benefits had been overestimated by almost 50%. Further, they found that

“While FAA has completed 7 of 12 Metroplex locations, the Agency does not expect to complete all remaining locations until 2021, 4 years later than originally planned. Delays have occurred largely due to increased community concerns about aircraft noise” and

“Since 2014, further delays have occurred as FAA has implemented new PBN procedures at more sites, largely due to increased community concerns about aircraft noise. For example, in fiscal year 2018, FAA cancelled the Phoenix Metroplex project due to litigation related to a previous PBN project”.

Four months later many US senators (one of whom is the current vice president of the USA, Kamala Harris) and members of Congress wrote to the FAA saying amongst other things

“We are writing on behalf of hundreds of thousands of people who continue to suffer the effects of the FAA’s NextGen program…….The noise created by the frequency of flights – in some areas beginning before 6:00am and continuing every few minutes until midnight or later – has had a devastating impact on residents’ quality of life…………In fact communities, cities and states around the country, including in and around the District of Columbia, Phoenix, Boston, San Francisco, Los Angeles, Seattle, Denver, New Jersey and the State of Maryland, have taken legal action as a result of the FAA’s failure to adequately address community concerns.”

In November 2019, the New York Times published an article (as did many other newspapers and journals on the topic) describing people’s experiences. One person interviewed described the situation as “a tinderbox of conflict between airports and the residents that surround them”. Another, who was a postdoctoral researcher in the Boston University School of Public Health, stated that “A misconception about sound is as long we don’t hear it, it doesn’t matter if you hear it,”.  The FAA stated to the New York Times that “it was committed to working with airport and community-sponsored round tables to understand and address concerns regarding noise from aviation” adding that “In the event airspace changes are recommended, care must be taken to avoid simply shifting aircraft noise from one community to another and to ensure broad community buy-in for the proposed changes.”

The US Department of Transportation produced a further report in March 2021 in which they said:

“FAA’s most recent business case projects total NextGen benefits to be over $100 billion less than the Joint Planning and Development Office’s original estimate, and benefits actually achieved to date have been minimal and difficult to measure. FAA’s projections were optimistic about traffic growth and did not account for risk factors. We also found that significant declines in air traffic due to COVID-19 have further extended the timeframe for realizing expected NextGen benefits.”

The report then recommended the following which, according to the report, have been agreed with the FAA:

“1. Publish metrics that measure performance of NextGen improvements across the NAS [National Airspace System].

2. Develop and implement a process that incorporates interim adjusted benefit projections and interim implementation analyses to support prioritization of NextGen programs and deployment locations.

3. Update and provide stakeholders a risk adjusted NextGen benefit projection.”

In September 2021 Senator Van Hollen and other senators and members of Congress wrote again to the FAA saying, inter alia, that:

“We are writing on behalf of our constituents who have been suffering from the adverse effects of the FAA’s NextGen program. While the program has made the airspace more efficient, the concentrated flight paths have created unbearable living conditions for those who live under the channelized air traffic resulting from implementation of NextGen. Despite the best efforts of the DCA Community Noise Working Group (CWG), unhealthy amounts of noise and air pollution continue to plague residents, and no relief is in sight.”

This is all material information required for an intelligent consideration and response to the CAA consultation on airspace modernisation, and shows that the introduction of such a scheme has not, and may well not, “deliver key environmental objectives with respect to air navigation” as the CAA claim. One might ask why the UK aviation authority now charged with providing “independent expert advice on a range of environmental issues including carbon, air-quality and noise” [2] should fail to disclose to people affected by the proposed changes that these changes have been described by members of the legislator of the World’s leading economy as “creating unbearable living conditions”?

This information should be disclosed with comments from the CAA on what the CAA will do to ensure that this does not happen in the UK. The CAA should also comment on whether it intends to follow the US government and the FAA in the recommendations and publish interim analyses.

[1] see the House of Lords case of Regina v North and East Devon Health Authority ex parte Coughlan [2001].

[2] see statement of Robert Courts to Parliament on the 6th September 2021 on the transfer of the functions of ICCAN to the CAA



Air Quality

The CAA consultation document part 1 says at para 2.56

“Due to the effects of atmospheric mixing and dispersion, emissions from aircraft above 1,000 feet are unlikely to have a significant impact on local air quality” referring to the ICAO Document 9889

This is not correct. The ICAO doc 9889 referred to provides that the mixing layer is at 1,000 metres (not feet). Para 2.3 Appendix 1 to Chapter 3 of ICAO doc 9889 states that:

“This reference emissions LTO cycle is intended to address aircraft operations below the atmospheric mixing height or inversion layer. While the actual mixing height can vary from location to location, on average it extends to a height of approximately 914 m (3 000 ft), the height used in deriving airborne TIM. Pollutants emitted below the mixing height can potentially have an effect on local air quality concentrations, with those emitted closer to the ground having possibly greater effects on ground level concentrations.”

There is a reference at para 8.1.4 of Chapter 8 to nitrogen dioxide:

“Note that the impact of an aircraft’s emissions plume, at or above 3,000 ft, on NO2 ground-level concentrations is very small even in a very conservative analysis, and 1,000 ft is the typical limiting altitude for ground level NO2 concerns”

The reference to 1,000’ is to NO2 only and not to other emissions such as particulates, which do very much affect people on the ground at those levels. In addition, the higher the concentration of emissions upon people on the ground, the greater is the risk of mortality upon those people with each increase in exposure.

There are many studies now that show the spread of particulates from aircraft in flight and in particular the elevated concentration of particulates under flight paths. Other studies have shown the huge damage done to health by fine particulates and the fact that they can be transmitted to subsequent generations during pregnancy. Even the Government’s own Air Quality Expert Group of DEFRA, reporting on ultra-fine particles in 2018, said

“The measurements therefore suggest that aircraft plumes mix downwards to a sufficient extent to be detected at ground-level at concentrations similar in magnitude to road vehicle sources. The implications of this work are potentially important for exposure to UFP concentrations. For example, a location such as Heathrow Airport, where aircraft tend to approach the airport from the east (flying over the London conurbation), there is potential for considerable exposure to UFP from aircraft”

Aircraft are over most of London and over large areas to the west at less than 3,000’ emitting ultra-fine particulates, so it is quite wrong to say that “Due to the effects of atmospheric mixing and dispersion, emissions from aircraft above 1,000 feet are unlikely to have a significant impact on local air quality”. Our own study of aircraft heights using the xPlane app, approved by Heathrow, shows that half of the aircraft approaching Heathrow on arrival were at or below 3,000’ by Kings College Hospital, Denmark Hill. By Putney, every single plane was below 3,000’. Taking off to the east, almost all departing flights over Teddington were at or below 3,000’ (with the lowest at 1,600’). Clearly huge areas and huge amounts of population are assessed as not being affected by emissions from aircraft when they are being affected.

One only has to look at the spread of radio-active particles to Wales from Chernobyl in 1986 after its explosion, or the spread of particulates all over the World in 2010 from the Icelandic volcano at Eyjafjallajökull to see that particulates can travel a long way at high altitude.

This error requires a complete re-run of calculations to be conducted at the earliest opportunity to make any meaningful consultation on this topic possible.




Of the ANG, the CAA state at para A19 that “Through the Air Navigation Guidance, the Government acknowledges that there are other legitimate operational objectives, such as the overriding need to maintain a high standard of safety, the desire for sustainable development, and the need to enhance the overall efficiency of the UK airspace network, which the CAA and others are required to take into account and consider alongside the environmental objectives of the Air Navigation Guidance.” Then at A20 the CAA states that “the CAA has applied the competing factors in section 70(2) in the manner it thinks is reasonable having regard to them as a whole”.

This is not correct. The CAA is obliged to take account of the ANG. This means that it must follow the ANG as statutory guidance unless there is a cogent reason for not doing so. The Guidance makes no provision for “trade-offs” as stated in para A18 of the CAA Consultation document. The Guidance must be followed in achieving the stated objectives after safety. There are various “Key Objectives,” and they are to:

    1. limit and, where possible, reduce the number of people in the UK significantly affected by adverse impacts from aircraft noise;
    2. ensure that the aviation sector makes a significant and cost-effective contribution towards reducing global emissions; and
    3. minimise local air quality emissions and in particular ensure that the UK complies with its international obligations on air quality.

Para 3.3 of the ANG sets out the aviation noise altitude-based priorities. These priorities are:

    1. in the airspace from the ground to below 4,000 feet the government’s environmental priority is to limit and, where possible, reduce the total adverse effects on people;
    2. where options for route design from the ground to below 4,000 feet are similar in terms of the number of people affected by total adverse noise effects, preference should be given to that option which is most consistent with existing published airspace arrangements;
    3. in the airspace at or above 4,000 feet to below 7,000 feet, the environmental priority should continue to be minimising the impact of aviation noise in a manner consistent with the government’s overall policy on aviation noise, unless the CAA is satisfied that the evidence presented by the sponsor demonstrates this would disproportionately increase CO2 emissions;
    4. in the airspace at or above 7,000 feet, the CAA should prioritise the reduction of aircraft CO2 emissions and the minimising of noise is no longer the priority;
    5. where practicable, it is desirable that airspace routes below 7,000 feet should seek to avoid flying over Areas of Outstanding Natural Beauty (AONB) and National Parks; and
    6. all changes below 7,000 feet should take into account local circumstances in the development of the airspace design, including the actual height of the ground level being overflown, and should not be agreed to by the CAA before appropriate community engagement has been conducted by the sponsor.

Of single versus multiple routes the ANG states

“3.20 This means there will be situations when multiple routes, that expose more people overall to noise but to a lesser extent, may be better from a noise perspective. Taking account of consultation and the objectives of the airspace change proposal, with regard to assessing and comparing environmental impacts of a proposed change, preferred options should normally be based on those which result in fewer total adverse effects on people.

3.21 For airspace changes where noise levels are expected to lead to fewer measurable impacts on health and the quality of life, greater consideration should be given to how the number of overflights is distributed, and consideration of how the current situation for those overflown will differ for any future options. However, it is important that all decisions are made in line with the altitude-based priorities and that impacts on wider airspace use are also considered.”

None of this is made clear in the CAA consultation papers. Indeed, at A20 the CAA states that “the CAA has applied the competing factors in section 70(2) in the manner it thinks is reasonable having regard to them as a whole”. The CAA is obliged to follow the ANG and it has no discretion in that unless there is a good reason for departure. If it fails to do this, the CAA can expect legal challenges from communities affected.

At para 2.81 of the CAA Consultation paper, the CAA says that the AMS can only be responsible for delivering noise reduction where it has an element of control. Where a decision has been taken through the planning process to increase airport capacity, this is outside the responsibility of the strategy. Whilst this may theoretically be true, it is difficult to conceive of a situation where the CAA will not be involved in an airspace change, whether as a result of a planning decision or not. Firstly, major planning decisions affecting aviation expansion are often taken on advice or using evidence produced by the CAA. Secondly, the CAA cannot wash its hands of the environmental consequences of its actions on the back of some planning decision if there is an airspace change involved. If there is, the ANG must be followed. Thirdly, the airspace change sponsor will have responsibility for the execution of the change, and somebody needs to monitor the execution of the airspace change to ensure that it complies with what the CAA approved, and the representation and statements made in support of the change

In part 2 of the consultation in CAP2298b of the first of the 9 elements it is said that Trajectory-based operations may be enabled through “structured performance-based navigation routes at lower levels”. There is no mention of this being done in accordance with the ANG. The CAA may say that this is implied but the fact is that if the ANG is to be observed, PBN should not happen unless the above priorities are observed. This may become evident when part 3 is published.

There is no reference to any action that will be required or taken to revise the appropriate Noise Action Plan under the Environmental Noise (England) Regulations 2006. This would at least be useful in understanding the extent of the extra noise upon specified numbers of people, together with the intended action to be taken.

At present, the consultation feels as if we are being asked to comment on a landscape wearing a blindfold.



2 Have we captured the drivers for change adequately in Part 1, Chapter 2?

Please select only one item

☐ yes

☒ no

☐ don’t know

If no, please describe what is missing or needs amendment and how this might require a change to the draft strategy.


See above


3 Have we identified the right stakeholder groups in Part 1, Chapter 2?

Please select only one item

☐ yes

☐ no

☒ don’t know

If no, please describe the missing group


Views on the delivery ‘elements’


4 What are your views on the nine delivery ‘elements’?


The nine delivery ‘elements’ are in Tables 4.1, 4.2 and 4.3 in Chapter 4 of Part 1 of the strategy, with more detail in Part 2 and the linked database. In Chapter 5, we also describe five illustrative use cases relating to different aspects of modernised airspace in the 2030s from the perspective of different stakeholders.

The delivery elements are:

Please select only one item

☐ about right

☐ minor modifications needed

☐ major modifications needed

☒ don’t know

If you think modifications are needed, or that something is missing, please explain this below.

In so far as they relate to the environment – see above


5 Part 3 of the AMS will cover who is responsible for deploying the delivery ‘elements’ and related activities, and how. At this early stage, what are your views on any requirements we should have for those tasked with the deployment of those elements and activities?


We wish the Air Navigation Guidance to be properly followed


Views on AMS governance


More information on governance and funding of a broader, refreshed strategy (click here)

The 2018 Airspace Modernisation Strategy, including its delivery and governance structures, was mostly focused on commercial air transport, controlled airspace and larger air navigation service operations. Our refreshed strategy proposes adding new areas of focus, in particular around integration, for example:

– seamless integration of beyond visual line of sight drone operations
– a Lower Airspace Service to better support both self-management of piloted VFR (Visual Flight Rules) aircraft and drone operators in class G airspace
– flight progress information sharing to facilitate increased VFR access to class D airspace
– an improved class G structure
and so on.

However, not all of these new areas of focus sit readily with the current strategy’s delivery and governance, and by inference funding, structures.

Currently, aside from the UK Flight Information Service provided to meet ICAO obligations, and specific arrangements for the North Sea, aircraft outside controlled airspace are either:

– not receiving a service (relying on a traditional ‘see and avoid’ means of deconfliction), or
– benefiting from navigation aids and/or air traffic services that are already established for commercial or military users.

The CAA recognises that there has to be a fair and equitable funding model for users of a modernised airspace.

We would expect to consult on this separately in due course, subject to advice from the Government. With this in mind you may want to tell us how we should alter the Airspace Modernisation Structure governance structure in the meantime, including any thoughts on future approaches to funding. We have asked two questions below.


6 How effective has the AMS governance structure been, for example in terms of overseeing delivery of the strategy, stakeholder engagement or transparency?


Below is the governance structure we last published in CAP 1862 in December 2019, which itself updated the original 2018 CAA/Department for Transport governance annex
CAP 1711b. Further changes have occurred in the last two years.

The existing governance structure has been:

Please select only one item

☐ effective

☐ generally effective but lacking in some areas

☒ wholly or mostly ineffective

☐ don’t know

Please explain the reasons for your answer. We are particularly interested to know:

  • whether it is clear to you who has been responsible for what
  • whether we had the right delivery groups
  • whether they have been properly funded.

Even though the CAA has the ERCD functions and now has the functions of the former ICCAN, there is still no duty of care owed. This is wrong and given the expanded functions, the CAA should have the resources skills and integrity to provide the required services and assume the appropriate levels of responsibility and duty of care.

The governance structure has not been effective in protecting the environment and people affected by aircraft operations. The structure has concentrated on the maximum possible amount of aviation being squeezed into the minimum amount of space. An example is ACOG which has been publishing on social media the “advantages” of airspace modernisation without any consideration at all of the well documented detrimental environmental effects.

The abolition of ICCAN and putting its functions into the CAA has created a serious conflict of interest. This action is contrary to the recommendations of the previous Airports Commission. Effectively, communities are having to endure future airport expansion (even if by more intensive use of existing runways through PBN), without the safeguards recommended – and without anyone having accountability for the environmental and health outcomes. The required organisations to protect the environment and hear the interests of people affected by the aircraft operations are starved of funds out of existence.

There is nothing like enough study or emphasis on the environmental effects of aviation and increased flights over people. For example, the now defunct ICCAN recommended that:

“A new, regular attitudinal survey is begun before the end of 2021, and repeated frequently” in lieu of the discredited SoNA survey of noise attitudes relied upon by the CAA and government.

This has not been done. ICCAN said that:

“The new surveys should be commissioned, run and analysed independent of Government, regulators and industry”.

This has not been done.

There was no study at all by the CAA of the effects of noise below 51dB LAeq notwithstanding that “SoNA found that 7% of respondents in the 51-54 dB LAeq, 16h noise band were highly annoyed” [ICCAN report on SoNA]. ICCAN said that:

“there is limited evidence on the extent of the increase caused by the change effect and its duration; however, current indications suggest that an increase in annoyance after a change can last for at least two years”

and that

“SoNA was not designed to consider the change in noise attitudes caused by an airport undergoing a period of volatility in its operations”

and that many respondents were of the view that

“to measure the actual effect of change on people’s attitudes to noise, surveys need to be conducted over time before and after the change occurs”.

ICCAN found that

“SoNA was conducted at one point in time providing a ‘snapshot’ of attitudes in that period, but it did not measure the change effect”.

The House of Commons Briefing Paper on aviation noise dated the 13th February 2017 states that:

“To take account of people who may be significantly affected by aviation noise at levels that do not exceed the LOAEL [51 dB LAeq 16hr], DfT intends to supplement the risk-based approach with guidance on metrics which can be used to assess the frequency of noise events”.

To the best of our knowledge this has not been done and the CAA should address this.

The World Health Organisation “strongly recommends” substantially lower levels of noise than 51dB LAeq and neither the CAA nor the government has provided any satisfactory reason as to why the WHO strong recommendations have not and should not be followed. We understand that 51dB as the LOAEL is to be reviewed in the light of the WHO’s strong recommendations in their Environmental Noise Guidelines of 2018, and also in the light of the US Analysis of the Neighbourhood Environmental Survey.

The list of defects goes on and on. None of this has been dealt with by either the CAA, ICCAN’s successor, or the government.

All these tasks need to be carried out before a consultation on airspace change. Without these tasks completed and the information gathered and published, it will not be possible to assess what will be the effects of the changes.


7 The refreshed strategy is broader in scope. What changes to governance are needed to deliver the broader strategy, including future approaches to funding?

We are particularly interested to know:

  • whether the structure needs to change
  • whether the co-sponsors need to do anything differently
  • whether any new stakeholders not identified in the existing governance structure need to be added.

For example:

  • to help with delivery of Part 2 of the strategy we might consider introducing a Deployment Steering Group made up of industry representatives at operations director level
  • to help deliver airspace integration we might consider introducing an Integration Steering Group overseeing separate working groups on beyond visual line of sight operations for drones, service provision, airspace structures etc.


The last thing that we need is yet more “steering groups” made up of industry representatives. Industry is already more than adequately represented compared to those interested in the environment.




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  1. 7th March 2022

    I totally concur with all the above comments and hope all your uphill struggles and hard work mean ‘they’ start treating the issue with the respect it deservers
    NB survey completed

  2. Ed Marsh
    24th February 2022

    Thank you so much to those of you in TAG for continuing to put so much work on this. The level of specificity of your responses is impressive and must take a lot of time.
    It is really really appreciated – thank you!!!

  3. Paul Sanders
    23rd February 2022

    Appreciate all your time and effort.
    People of Teddington need to be aware of how many flights pass over them at all heights these days, even with westerly winds. Climate changes and pollution are real issues now and aviation has to be held accountable for its actions with this regard.

  4. David H E Coles
    23rd February 2022

    Enormously grateful to TAG Teddington Action Group for continuing to work upon this and future issues during this time of continued pressure. Pressure typified by all that we can hope to understand in todays world.
    Most grateful and many thanks!

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