Draft airspace design guidance

Closed 2 Jul 2017

Opened 31 Mar 2017

Feedback updated 13 Dec 2017

We asked

The purpose of this consultation was for the CAA to learn your views on new guidance that we have drafted to support our new airspace change decision-making process. This followed our consultation in 2016 about what the new process should look like.

The guidance that we drafted defines what will happen in the new process, including each stage a sponsor of an airspace change must complete; the stakeholders they must engage at each stage and our expectations of that engagement; and how the CAA assesses the proposed change.

We invited views as to whether the guidance is appropriate – including whether our description of the stages of the process are comprehensible, transparent and proportionate.

You said

We had 113 formal responses to the consultation, which we have published where we have permission to do so.

The first eight multiple-choice questions asked to what extent (good, mostly, not sufficiently) the draft guidance was comprehensible, transparent and proportionate. For all three criteria (i.e. 24 results):

  • between 57% and 76% of respondents rated the draft guidance overall and for each of the seven stages as meeting or mostly meeting each of the criteria
  • between 29% and 43% of respondents rated the guidance as not meeting the proportionality criterion, with the poorest results on Stage 5 (CAA decision-making) and on the process overall
  • between 24% and 32% of respondents rated the guidance as not meeting the comprehensibility and transparency criteria, except on Stage 5 (CAA decision-making) where 39% of respondents rated the guidance as not meeting the transparency criterion

Detail about how different stakeholder groups responded, and the reasoning they gave in their written answers, is set out and analysed further in our consultation report.

In response to the remaining questions:

  • between 59% and 77% of respondents rated the guidance on temporary airspace changes (formerly Tier 1b) and airspace trials (formerly Tier 1c) as meeting or mostly meeting the three criteria
  • for the proposed new category of a permanent and planned redistribution of air traffic, where we sought views pending a government decision on whether to go ahead with it, there was almost unanimous support to adopt all stages of the airspace change process and (if we exclude a high number of ‘don’t knows’) for scaling it based on potential noise impacts
  • between 55% and 69% of respondents rated the draft best practice guidance on what we now call airspace information (formerly Tier 3) as meeting or mostly meeting the three criteria. 45% of respondents thought this guidance was not sufficiently proportionate.

Free text boxes on each question allowed respondents to give their reasoning and explain how the draft guidance could be improved. Recurring themes were:

  • adverse comments, mostly from residents, about the length and complexity of our guidance, and requests for a more accessible, easy-read version.
  • significantly more comments – from every stakeholder group – on the need for more detailed information to be included in most areas of the guidance document about how the process will work
  • suggestions, mainly from industry, that case studies or illustrative examples would be useful
  • comments that the draft guidance would not improve stakeholder engagement considerably outweighed those that it would; it was suggested that engagement needed to be more prescriptive or should be included at additional steps in the process
  • responses were almost wholly supportive of the use of a third-party facilitator
  • responses regarding the role of the CAA varied from suggestions that the CAA is too heavy-handed and the process disproportionate, resource-intensive and too lengthy (mainly from industry), to the CAA needing to regulate the industry more firmly (mainly from residents) citing a lack of trust in the CAA, or our process, or the industry
  • many respondents (mainly residents), took the opportunity to share their frustration about aviation noise in general, or with the way industry engages with stakeholders, or with matters which are Government policy on airspace and noise to which the CAA, and our airspace change process, must adhere, and which are not in our gift to change.
  • there were many recommendations concerning the actual airspace change process itself (for instance the length of stages, or the process relating to gateways), rather than the draft guidance that supports it.

We did

To understand why some responses said that our guidance was not good enough, we need to understand what respondents would want to see instead. We have therefore gone into great detail as to what respondents said and our responses to specific issues in our consultation response document CAP 1615. We have rated every recommendation made to us as green, red, blue or amber – green means a change we have accepted and made to the guidance and red means one that we have not; blue means that we believe that the recommendation is already reflected in our guidance; and amber means either that a slight clarification is need to the guidance to produce the outcome we intended, or that it is a suggestion we will treat flexibly (we have not amended the guidance to mandate it, but believe it is currently a potential option in light of the wording).

We have taken on board the conflicting sentiments in responses that the guidance is too complex yet needs to be more detailed on certain aspects of the process. This highlights that the guidance needs to be transparent about a detailed and complex regulatory process while also being as accessible as possible.

Below is a high-level summary of the changes we made to the draft guidance to produce the final guidance. There are a large number of text changes, too numerous to list here, but many are just tweaks to language or clarifications.

We published all responses to the consultation unless permission was withheld.


Change made to CAA process and guidance document

Department for Transport policy framework


We have made a number of changes as a result of the outcome of the Department for Transport’s airspace consultation published on 24 October 2017.

We are no longer categorising types of airspace change as Tier 1a/b/c, Tier 2 and Tier 3, as the Government has dropped this categorisation in the light of its consultation. This also removes confusion with Stages 1 to 7 of the process and Levels 1 and 2 of the scaling. The Government has also temporarily removed what was called Tier 2.

The Government has clarified its definition of ‘significantly affected by aircraft noise’ by specifying that this refers to both the number of people affected and also the extent to which people could be subject to adverse health effects. This is a clarification of existing policy, which builds in an assessment of health impacts. As a result, outputs from the WebTAG model will be used to assess the respective noise impacts of different options within airspace change proposals. Our guidance reflects this change.

Guidance document structure

New material for informing non-expert audiences

We will separately produce additional, simplified communications materials to better explain the process to non-experts such as local communities.

New case studies and examples

We aim to invite sponsors to develop a case study with us and with other stakeholders to show how the new process will work in practice. The case studies would be unrelated to any live airspace change proposal to avoid any conflicts of interest.

New examples of drivers of airspace change

A list of examples of issues or opportunities potentially leading to a proposal to change airspace design, including noise mitigation.

Online portal

Publication of consultation responses in batches

Consultation responses will be published on the portal while the consultation is taking place. We will do this regularly during the consultation, at intervals that best manage the resources required for moderating those responses. We may allow the change sponsor to see the responses before they are published (normally 24 hours in advance), so that it has an opportunity to prepare ‘frequently asked question’ responses should it deem this necessary.


Our specification for the full portal development includes the ability to provide notifications, for example showing when a proposal passes through a gateway or begins consultation.

Scaling the process

Greater clarity

We have amended flowcharts to show at which points in the process the CAA considers the appropriate Level. We are adding greater clarity on Level 0 (changes to AIP nomenclature or qualifying remarks only) and unusual aerial activities.

Process gateways

Status of gateway sign-off

We have clarified how the CAA’s sign-off of a gateway may or may not affect our final decision.

Consultation and engagement by change sponsors

Sponsors can go beyond the minimum required by the guidance

We have clarified that sponsors should regard the CAA guidance on consultation and engagement as the minimum required, and may want to go further, without the guidance specifying how.

Sponsor may consider awareness raising or pre-consultation

We see value in industry maintaining ongoing contact with stakeholders, including about changes being considered, prior to the regulatory process commencing.

Clarifying CAA moderation of consultation responses

Guidance and portal text makes clear that consultation responses are moderated for inappropriate language and defamatory comments only, not for factual accuracy.

Categorising consultation responses

We are provide more detail and clarity around what we require of sponsors in assessing and categorising consultation responses. We will require sponsors to:

(a) provide a qualitative summary of the consultation and the issues respondents raised. This could take the form of ‘We asked; you said; we did’, or other written formats.

(b) provide a reason for categorising each response. This could take the form of a list of reasons with a tick-box system.

When categorising a response as one that ‘may impact final proposals’ the sponsor will be able to specify which part(s) of the response are deemed relevant and which are not.

Documenting evidence of two-way sponsor/ stakeholder conversations

Sponsors will be required to publish a record of formal engagement activities and outcomes, and may wish to consider publishing minutes of other meetings beyond what is mandated.

Sponsors may consider a ‘Statement of Community Involvement’, a useful tool to detail the consultation and engagement approach intended throughout Stages 1, 2 and 3, similar to the planning process.

Planning authorities, ACCs

We clarified references to sponsors engaging with planning authorities and/or airport consultative committees at appropriate points in the process.

Environmental assessment

Introduce additional optional metrics

Many people asked us to consider using additional environmental metrics. Subject to consistency with government guidance, where these will clearly add to the evidence base we included them, but, for proportionality reasons, as a recommended best practice.

More guidance on options appraisal and use of WebTAG

We cross-refer to new Government guidance on the key elements of WebTAG (Transport Analysis Guidance) that are useful for conducting an appraisal of noise impacts for an options appraisal of an airspace change proposal.

Options appraisal

More clarity on the use of a base case and ‘do-nothing’ option

We are clearer about the requirement for a baseline and how it should be used. We will expect sponsors to do a baseline to understand the current impacts. This baseline will include any changes that have been agreed but not yet fully implemented. Where ‘do nothing’ is not an option because a change is unavoidable for regulatory or system-wide reasons, a ‘do minimum’ assessment is made, i.e. what is the minimum required to comply with the regulatory change. This does not remove the need for sponsors to assess a baseline.

Decision-making process

Adding more detail on Public Evidence Sessions

We have added more detail on elements of procedure at these sessions, including the role of the Chair and the change sponsor, and who can attend.

Post-implementation review

More timescale flexibility

Where justified, we are allowing more time for stakeholder submissions.

Temporary airspace changes/airspace trials

Monitoring complaints

We have developed suitable criteria for monitoring complaints.

Excluding very short-term airspace restrictions from the process

We have included a list of short-term restrictions imposed for safety or national security reasons that do not require the usual process for a temporary airspace change.

CAA acting on unexpected effects

We have clarified that the CAA may urgently investigate any impacts of an airspace trial, not just noise impact.

Permanent and planned redistribution of air traffic (formerly Tier 2)

Deferred implementation

The Government has for the time being deferred introducing a decision-making role for the CAA for this new category of airspace change.

Airspace information: transparency about airspace use and aircraft movements (formerly Tier 3)

Clarified definition

The Government has clarified the definition of this category.

Identifying potential noise mitigations

We suggest that airports (a) engage stakeholders about whether information they publish reveals any noise issues for which there could be a potential mitigation, and (b) discuss these as part of the airport’s five-yearly noise action plan.

The following documents set out how the process will work from 2 January 2018:

Published responses

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


Download the draft guidance

The consultation documentation comprises the consultation document and some questions, the draft guidance document itself, a draft environmental technical annex to the guidance, and a separate document about a new category of airspace change (known as 'Tier 2') which the Government is proposing to introduce.

Download the draft guidance document (CAP 1520).

Download Annex 1 - the draft environmental technical annex (CAP 1521).

Download Annex 2 - a document about 'Tier 2' airspace changes (CAP 1522).

Download the consultation document and questions (CAP 1523) as a single pdf.

The purpose of this consultation

The purpose of this consultation is for the CAA to learn your views on new guidance that we have drafted to support our new airspace change decision-making process.

In March 2016 the CAA consulted on the principles of a new process that we were proposing. In October 2016 we published our report on that consultation and set out the new process we are now introducing (CAP 1465, available online).

The guidance that we have drafted defines what will happen in the new  process, including each stage a sponsor of an airspace change must complete; the stakeholders they must engage at each stage and our expectations of that engagement; and how the CAA assesses the proposed change.

We are inviting your views as to whether the guidance is appropriate – including your views on whether our description of the stages of the process are comprehensible, transparent and proportionate.

Airspace and its design

Airspace is the volume of space above ground level and extends as far as aircraft can fly. Airspace has to be managed so that it is used safely and efficiently. In the UK, airspace is either considered to be ‘controlled’ or ‘uncontrolled’. In controlled airspace, there is a system of structured routes and aircraft are managed by air traffic control services.

The design of controlled airspace is set out in the UK’s Aeronautical Information Publication (AIP). The CAA makes decisions about whether that published design can change, and we make those decisions in accordance with the legal and policy framework set by Government. We have designed a process that anyone proposing (or ‘sponsoring’) a change must go through, to ensure that we get all the evidence we need to make our decision. The process includes public engagement as part of the design process, as well as options appraisals to produce comparable evidence about the design options.

In addition to the CAA’s decision-making role on the published design of airspace (in the AIP), the Government is currently consulting on policy proposals that would give the CAA a role on other types of changes to airspace.

(Reforming policy on the design and use of UK airspace, available at https://www.gov.uk/government/consultations/reforming-policy-on-the-design-and-use-of-uk-airspace).

The Government’s policy consultation proposes a three-tiered structure for categorising changes to the design of airspace or the way airspace is used. This is summarised in the table below, which sets out those Tiers and the types of changes they refer to, which will be covered in the CAA’s guidance.

Types of airspace change covered by the CAA’s draft guidance

The following table sets out the decision makers for each Tier and is taken from the Government’s airspace and noise policy consultation:

Structure of the draft guidance

The draft guidance on which we are consulting is divided into categories of airspace change – Tiers 1, 2 and 3, with three elements to Tier 1 (1a, 1b and 1c).

The main part of the draft guidance concerns Tier 1a, the seven-stage airspace change process used for permanent changes to the published airspace design. The document guides you through each stage and describes what will happen at each stage of it, and why.

There are other ways that the airspace design or the way it is used can change, and the impacts of such changes can also vary greatly. Therefore this guidance also has shorter sections on the processes that apply to the other tier categories. These are Tiers 1b and 1c covering temporary changes and trials respectively, and Tier 3 covering changes other than to the formal airspace design.

The guidance will, eventually, cover Tier 2 changes also. At present, we are not in a position to set a new process for Tier 2 changes. Instead, we are asking for early views on how we should consider meeting the Government’s proposal.

The appendices to the draft guidance go into more detail about how those involved undertake or engage in various tasks associated with these processes. The appendices cover activities such as how to consult and engage with stakeholders, how to develop design principles, and how the CAA will undertake a post-implementation review. This list is not exhaustive; please see the draft guidance for the full list. 

How to respond to this consultation

Please answer the consultation questions by following the link below. We are asking for comments before 30 June 2017. We cannot commit to taking into account comments received after this date.

The questions include some multiple-choice answers and the opportunity to submit your comments by completing text boxes. Please note that if you prefer not to give a multiple-choice answer, the questionnaire will still allow you to complete the text box. We understand that some stakeholders may prefer not to be constrained by the questions alone. We have therefore also included a text box for general observations not covered by the questions. While we will not refuse a self-contained, separate response sent by email, we will not be able to analyse such responses in the same way that we analyse the online responses. Our strong preference is therefore that you complete the online version.

If you would like to discuss anything about how to respond, please email airspace.policy@caa.co.uk or telephone Trevor Metson on 020 7453 6230. 

We will assume that all responses can be published on our website. When you complete the online form there will be an option for you:

•     to hide your identity including personal details (which will anonymise your response completely), or
•     to refuse publication altogether; in the interests of transparency, we hope people will not refuse publication.

Please note that any submissions not submitted through the online consultation website will be published in their entirety unless you also submit a redacted version with any material that you do not want us to publish, whether this be your identity and/or personal details, or actual content.

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.

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.

Next steps


What happens next

This consultation has now closed.

Responses, where we have consent to publish, can be viewed by following:

  • the link at the top of this page 'Published Responses' for online responses received through this website.  
  • the link at the foot of this page under 'Related Documents' for offline responses not received through this website.

We published the revised guidance document on 13 December 2017.



  • 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
  • Flightcrew
  • Air traffic control staff
  • Aerodrome Operators
  • Government departments
  • Regulatory bodies
  • Elected political representatives
  • European Aviation Safety Agency
  • European Commission
  • International Civil Aviation Organization
  • National representative organisations or institutes
  • Workers' representative bodies


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