Proposals for a revised airspace change process

Closed 15 Jun 2016

Opened 15 Mar 2016

Feedback updated 15 Nov 2016

We asked

The purpose of this consultation was for the CAA to learn your views on some changes we are considering making to our airspace change decision-making process.

Our objective is to ensure that it meets modern standards for regulatory decision-making, and that it is seen as fair, transparent, consistent and proportionate. The process should be impartial and evidence-based, and should take proper account of the needs and interests of all affected stakeholders.

You said

We had 110 formal responses to the consultation, which we have published, where we have permission to do so. On the whole, stakeholders were supportive of the proposed new process.

In the ‘closed’ (yes or no) questions we found overwhelming support for the introduction of gateways into the process; engagement on design principles; the options appraisal concept; a single online portal; and the publication of consultation responses online. In addition there was broad support for the publication of airspace change submissions as early as possible, and for the Public Evidence Session.

In the ‘open’ (free text) responses we found there were overwhelmingly positive sentiments about the potential improvements to transparency; engagement (such as the introduction of the design principles stage, although there were also cautions about getting it right in practice) and certainty (such as the introduction of gateways). In addition, there were broadly positive sentiments about the potential improvements to fairness and proportionality (while the majority of sentiments were positive, there were significant numbers raising concern). 

There were however areas of concern or disagreement. Two thirds of those responding, across all categories of respondent, were opposed to responses to an airspace change consultation being made solely through the online portal. We noted some negative sentiments about flexibility and scalability. There were also differences of opinion between stakeholders on certain topics, including independent third-party involvement, appeals, and whether increasing costs were proportionate. We identified and categorised 363 recommendations as to how we could further improve the process.

We did

We are maintaining, for the most part, the process proposed by our consultation, but with some modifications. We will now draft revised guidance on the new process, on which we will consult in spring 2017.

Some changes remain dependent on greater policy clarity from the Government, but the main outcomes are:

  • Fourteen-step process based on the existing process, with gateway sign-offs by the CAA to improve certainty
  • Single bespoke website forming an airspace change portal for anyone to view, comment on and access documents for every airspace change proposal, with offline submissions also accepted for the time being
  •  Airspace change sponsor early engagement with stakeholders on design principles
  • Formal options appraisal for each proposal where the sponsor shows how it has assessed the impacts of different designs at three stages in the process, building in detail as the number of options decreases
  • Recommended use by sponsor of an independent third-party facilitator to make early engagement with stakeholders on design principles more effective, and potentially also for formal consultation
  • Publication of airspace change consultation responses online as they are received
  • Categorising airspace change proposals by ‘Level’ according to the scale of the potential noise impact, to keep the process proportionate – including Level M for some military changes
  • Use of a standard template for formal submission of an airspace change proposal
  • Publication of final airspace change proposal on receipt, or as soon as possible thereafter  
  • Public Evidence Session for some changes with greater impact (‘Level 1’) allowing stakeholders to address the CAA decision-maker once a proposal has been submitted
  • Publication of a ‘minded to’ decision for public review for changes on which we believe there could be a risk of misinterpretation or misunderstanding of some of the evidence
  • CAA timescale commitments for gateway sign-offs and final decision
  • No formal appeal against a CAA decision
  • Clearer timescales and objectives for the Post-Implementation Review
  • No Oversight Committee
  • CAA recovery of additional costs through the en-route unit rate from 2020, and until then through a statutory charge on NERL and airports
  • New process implementation date not before August 2017
  • The immediate introduction of two procedural improvements, in the form of an Airspace Change Process Information Pack including a Regulatory Decision Template.

See also:

Published responses

View submitted responses where consent has been given to publish the response.


Update - October 2016

This consultation closed in June 2016.  Responses, where we have consent to publish, can be viewed by following the link at the foot of this page.  See ‘Feedback’ below for the changes we have decided to make to the process, which will come into effect in 2017.

For full information please see our consultation outcome document


The purpose of this consultation was for the CAA to learn your views on some changes we are considering making to our airspace change decision-making process. Our objective is to optimise our process to ensure that all stakeholders are adequately consulted as part of a transparent, proportionate process. The process should be impartial and evidence-based, and should take proper account of the needs and interests of all affected stakeholders.

This consultation sets out why we believe a review is necessary, and the main findings of Helios, the consultants who carried out an independent review of the process on our behalf. We explain the main principles behind our proposed changes, and, in Chapter 4, details of the specific changes we are considering to each stage of the process. We discuss the impacts we anticipate our proposed changes will have, and invite you to share evidence so we can define these further. In Chapter 6 we also set out the statutory duties the Government has set the CAA, and how we use these in making decisions about airspace. However, this consultation is not about government policy, which is not a matter for the CAA. Neither is it about specific airspace changes that have already happened, or are currently moving through the stages of the existing process.


In addition to these pages, we have also made a full, detailed consultation document available. The questions and text remain the same, but on this online version of the consultation we have reduced some of the text available in the full document.

Chapters 1, 2 and 3 of the full consultation document introduce this consultation, explain the current airspace change process, and explain why we think the current process needs changing. Key points are included on this page, but we have not included them as full chapters in the contents on this online consultation because they do not include any consultation questions.

Appendix A of the consultation discusses the options appraisal that will form part of Stage 2 of the proposed process.

Appendix C of the consultation contains information to supplement Chapter 6, by setting out how we interpret our duty to secure the most efficient use of airspace. There are no questions in these Appendices so they are not included in our contents on these pages, but they are available in the full consultation document.  Appendix C is also available as a PDF under Chapter 6 below.

A glossary of technical phrases and terms is available on pages 11-15 of the full consultation document.

The rest of this section includes key pieces of information drawn from Chapters 1,2 and 3 of the full consultation document, which will help you respond to this consultation.

What are airspace and the airspace change process?

In its simplest terms, airspace is the portion of the atmosphere controlled by a State above its territory and areas over the sea within which a State is contracted by the International Civil Aviation Organization (ICAO) to provide air traffic services. It is an invisible national asset. For air traffic control purposes, airspace can be divided into two main categories, controlled and uncontrolled. Controlled airspace is where air traffic control needs to have positive control over aircraft flying in that airspace to maintain safe separation between them. Uncontrolled airspace is airspace where aircraft are able to fly freely through the airspace without being constrained by instructions in routeing or by air traffic control, unless they request a service.

Controlled airspace contains a network of corridors, or airways. They link the busy areas of airspace above major airports. At a lower level, control zones are established around each airport. These portions are therefore nearer the ground and closer to population centres. Because controlled airspace carries with it requirements that affect the aircraft and pilots that fly in it, an airspace change can impact the users of airspace in different ways. 

The CAA is responsible for approving the overall layout of the published airspace structure and any proposed changes to it.[1] We do so in the context of legal requirements which include safety, the environment and the needs of the consumers of aviation services as well as other duties all set out in section 70 of the Transport Act 2000. For example, changes might be needed to enable UK airspace to accommodate more flights, to incorporate new technology, to allow aircraft to fly more direct routes or to keep them away from particular areas. When we are asked to consider a change to the structure of UK airspace we will consider whether there is any reason why the change ought not to be made. Before agreeing to approve any change we then have to consider safety, environmental impacts (including aircraft noise and emissions) and operational factors.

We therefore require the proposer or ‘sponsor’ of any permanent change to the published airspace structure to follow our airspace change process. 

Figure 2.1: Overview of the airspace change process as published in CAP 725

Current process outlining stages 1-7. Full details on page 24 of consultation document.

These stages begin with outline conversations between the sponsor and the CAA around design options and who should be consulted. The sponsor then consults with interested parties, including, where appropriate, local communities. In the light of responses the sponsor may modify the proposals before making a formal submission of the proposal to the CAA for a decision. Assuming that the proposal is approved, the CAA carries out a review of the change after it has been implemented, typically after one year of operation.

Reasons for changing the current process

The CAA is proposing changes to the current airspace change process because:

  • The airspace structure is a key part of the UK’s national infrastructure but is in need of modernisation. If modernisation is held up, there will be significant impacts not just on air passengers and shippers but also the wider economy. The CAA believes that modernisation of airspace can offer a range of benefits, and in some cases modernisation is required by international obligation. However, it is for the aviation industry to develop specific proposals for change. The CAA needs a rigorous process for ensuring that we can make robust and lawful decisions about those proposals. We will not make a change simply because it enables modernisation; we will only do so once we have also given consideration to the range of factors and stakeholders we have a duty to consider.  Airspace modernisation requires the CAA to consider airspace change proposals on a scale unprecedented in recent years. These proposals may change flight paths[2] and therefore noise impacts, and may also impact airspace users and service providers.
  • Those affected should have the ability and opportunity to respond to consultation before a change is made. The CAA’s decisions on airspace change must balance and take proper account of the needs and interests of all affected stakeholders.
  • Airspace is a finite resource and there are competing demands for it from airspace users with differing needs (commercial air transport, General Aviation, military, unmanned aircraft and so on).  Again, these must be balanced against each other.
  • Communities close to airports increasingly demonstrate their interest in the management of aviation noise and the impact it has on those communities. Some recent airspace change proposals have highlighted a lack of trust between some local communities, the aviation industry and the CAA as regulator. This can sometimes create an impasse on airspace changes – changes which, in totality, might achieve an improved outcome in respect of all the factors we have to consider (although, as a consequence, an individual stakeholder may be in a worse position than if no change were made).
  • It is therefore essential that the CAA’s airspace change process meets modern standards for regulatory decision-making, and above all else is seen as fair, transparent, consistent and proportionate.
  • We need to ‘future-proof’ the process in the light of changing international requirements that are binding on the UK as a European Union Member State.
  • The independent Helios report reviewing the current process found that it could be improved and recommended a number of changes, on which, with some modifications, the CAA has decided to consult.


Our objective is to optimise our airspace change process to ensure that all stakeholders are adequately consulted as part of a transparent, proportionate process. The revised process should be impartial and evidence-based, and should take proper account of the needs and interests of all affected stakeholders. These stakeholders, in no particular order, include:

  • the users of air transport services, i.e. passengers and shippers;
  • those on the ground affected by aviation noise or other environmental impacts;
  • the users of airspace, including commercial operators, General Aviation and the military;
  • other service providers such as air traffic control and airports;
  • others with a legitimate interest, such as environmental bodies and councils.

In doing so we must consider what those needs are today and what they might be in the future. While not everyone will agree with every potential decision on how we develop the infrastructure of our airspace, the methods used to reach those decisions need to be well understood and accepted. One of our aims is to restore confidence in the process where it is currently lacking.

It is also very important that in improving and optimising the airspace change process the CAA does not raise expectations that the new process will give everybody everything that they want. The airspace change process is not designed to be a referendum on views, but it is designed to reach an outcome fairly having regard for the views of all the various stakeholder groups and having considered those views in accordance with section 70 of the Transport Act 2000. To achieve this compromise outcome, there will have to be trade-offs where there are conflicting requirements, which could mean winners and losers. Every airspace change proposal is different and is considered on a case-by-case basis, but often these trade-offs are a matter for the over-arching government policy.

The Helios review of the airspace change process

In 2015, the CAA commissioned management and technology consultants Helios to undertake an independent study of our existing airspace change process. As part of this work, we asked Helios to consult with a range of stakeholders that either use the process or are affected by the decisions resulting from it, and then provide recommendations on how the process could be improved. As part of its review, Helios tested various hypotheses in stakeholder workshops and through an online stakeholder survey. Helios consulted and spoke to representatives of airspace change sponsors, airspace users (including private flyers), and communities. We published Helios’s report on our website[3] on 8 December 2015.

Helios proposed a revised airspace change process based on the current process but with greater transparency and more stages, with approval at certain key points and the CAA being more hands-on than at present, particularly for the consultation phase. Helios recommended that an independent airspace change Oversight Committee be involved for the most significant changes, and that an appeal mechanism be introduced. Helios also proposed that an online portal be established holding all relevant information on airspace change proposals and collecting consultation responses. Helios recommended that the CAA seek greater clarity and guidance from the Government on policy and strategic priorities associated with airspace change.

The CAA‘s preliminary view is that most of Helios’s recommendations appear to address the issues identified with the current process. Our proposals for a revised process on which we are consulting are therefore largely based on what is recommended by the Helios report, with some important modifications which are explained in Chapter 4.

Your views are invited

We are asking for your views on our proposals to revise the airspace change process. We explain why we consider the process needs revising, and the characteristics of the revised process we are currently considering implementing, and we highlight the proposed changes in the form of key principles and actions. Only after we have received views will we be in a position to decide which changes to take forward and incorporate into a republished version of CAP 725, CAA Guidance on the Application of the Airspace Change Process. However, simultaneously with this consultation, we are republishing CAP 725 simply to update references and terminology. We are calling this update the ‘administrative update of CAP 725’.
Your comments will help us to design a fair, transparent and engaging process for handling airspace change proposals, striking the right balance between the interests of passengers and the aviation industry (including private flyers), and people affected by aircraft noise and emissions that impact on air quality (and, more widely, climate change). Your views on these proposals are therefore important to us. We hope that you can find the time to tell us what you think.
This consultation is not a referendum: we will need to take account of all views and balance different and often competing interests. This means that we will not automatically implement every idea or solution that gets the highest proportion of support, particularly if that support comes from only one of the many stakeholder groups we need to take into account.

How to respond to this consultation

We will assume that all responses can be published on our website. When you complete the online consultation there will be an option for you to hide your personal details or refuse publication. In the interests of transparency, we hope people will not refuse publication. If you do send us a separate submission and it includes any material that you do not want us to publish, please also send us a redacted version that we can publish. You should be aware that information sent to and therefore held by the CAA is subject to legislation that may require us to disclose it, even if you have asked us not to (such as the Freedom of Information Act and Environmental Information Regulations). Therefore, if you do decide to send information to the CAA but ask that this be withheld from publication via redacted material, please explain why, as this will help us to consider our obligations to disclose or withhold this information should the need arise.
Before we publish responses we will moderate them to remove unacceptable material such as defamatory or offensive remarks.  We have based our moderation policy on Government guidelines.  It can be found under Related Documents below.  Please think carefully before making statements about a specific organisation or person.  We will be obliged to redact any statements from the published version if they do not meet these guidelines on unacceptable material, and this would deny others the chance to see your views.

CAA stakeholder engagement concerning this consultation

We are willing to meet with any stakeholder organisations to discuss our proposals, subject to the necessary staff being available. Because of limited resources, where possible we will seek to incorporate this as part of existing meetings. For further information please email or telephone Trevor Metson on 020 7453 6230.


[1]       The airspace structure must be distinguished from the processes and procedures devised by air traffic control providers that provide air traffic control within the broad parameters set out by the airspace structure approved by the CAA.

[2]       When we use the term flight paths we are referring to the tracks of aircraft, not necessarily to any approved routes or procedures. 

[3]       As CAP 1356 Helios report: Independent review of the Civil Aviation Authority's Airspace Change Process


What happens next

This consultation has now closed.

Responses, where we have consent to publish, can be viewed by following the links at the foot of this page under 'Related Documents' (offline responses) and 'Published Responses' (online responses).  

See ‘Feedback’ below for the changes we have decided to make to the process.

For full information please see our consultation outcome document. Before introducing the new process, we will, in Spring 2017, publicly consult on draft revised guidance as to how the process will work in practice.


  • Residents affected by aviation
  • Organisations affected by aviation
  • Community groups
  • Airline passenger
  • General Aviation
  • Commercial airlines
  • UAV operators
  • Air taxi operators
  • Military
  • Airport operators
  • Air Navigation Service Providers
  • Industry representative bodies
  • Eurocontrol
  • Government departments
  • Regulatory bodies
  • Elected political representatives
  • National representative organisations or institutes


  • Aircraft noise
  • Aircraft emissions
  • Local air quality
  • Flightpaths
  • Airspace design, categorisation and access
  • Airspace change proposals