CAP 1616 version 6 questions and answers

We are modernising the way we do airspace design in the UK to ensure we can deliver the changes necessary to modernise airspace efficiently and effectively with the establishment of the UK Airspace Design Service (UKADS).

CAP 1616 is a key framework in enabling airspace modernisation; with government setting policy, industry developing airspace change proposals, and the UK Civil Aviation Authority (CAA) independently deciding whether the proposals meet the required standard. This update will help ensure the airspace change process remains effective, proportionate and fit for the future. The changes:

• Implement the latest government policy set out in the Air Navigation Directions (AND) 2026 and the Air Navigation Guidance (ANG) 2026, which come into effect on 1 October 2026. 
• Reduce unnecessary regulatory burden, supporting innovation and economic growth. 
• Support the modernisation of airspace, enabling the aviation sector to meet future demands. 
• Support UKADS and the delivery of a coordinated, system-wide approach to airspace design in London and the South East.

These changes will help to create a more streamlined and efficient airspace change process while continuing to ensure airspace change decisions are made in a safe and transparent way.

The changes to the airspace change process:

• Implement the latest government policy set out in the Air Navigation Directions (AND) 2026 and the Air Navigation Guidance (ANG) 2026. 
• Reduce unnecessary regulatory burden and support innovation and growth, with a consistent focus on safety, evidence and impact. 
• Support the modernisation of airspace, enabling the aviation sector to meet future demands. 
• Better support complex airspace changes through new provisions for airspace change proposals sponsored by the UK Airspace Design Service (UKADS) ( provider.
• Create clearer requirements, for both permanent airspace changes and non-permanent airspace changes.
• Establish a simpler process structure, reducing the permanent process from seven stages to five stages, and introducing a separate five-step process for non-permanent airspace changes.
• Increase the focus on airspace design, by replacing design principles with the government’s Airspace Design Priorities. These create a consistent framework for developing and assessing airspace designs, together with a transparent hierarchy for balancing competing considerations.
• Introduce earlier regulatory engagement, with a formal Stage 1 milestone for permanent airspace change proposals where sponsors can receive feedback on developing designs before consultation preparation begins.
• Implement a revised engagement and consultation framework, providing greater clarity on who sponsors should engage and consult, while placing greater emphasis on sponsors developing an appropriate strategy for their consultation.
• Aligns environmental assessment requirements with the government’s environmental objectives that the CAA must take into account, while reducing unnecessary regulatory burden and maintaining a consistent focus on evidence and impact.
• Enable a more agile, innovation-focussed non-permanent airspace change process, that supports new users and future flight by extending trial periods from six months to up to three years, and establishing a more proportionate, streamlined process for short-term activities.

The result:

The updated airspace change process is simpler, more proportionate and easier to navigate.

• Reduced permanent process requirements from 113 to 43.
• Streamlined permanent process from seven stages to five.
• Reduced the number of gateways in the permanent process from three to one. Introduction of a milestone review that enables technical design feedback.
• A 25% reduction in text across the document set, creating a clearer structure with more accessible requirements and guidance.
• Removal of post implementation reviews.
• Integration of CAP 1616i environmental assessment and guidance into the main document set.
• Removal of requirements to align to the updated Air Navigation Guidance 2026, with the initial options appraisal, metric requirements and economic assessments removed.
• Embedded airspace design priorities to drive design and shape proposals.
• Applies a proportionate approach based on scale, complexity and impacts.
• Focused stakeholder engagement where it adds value and meaningful consultation.
• Strengthened accountability and consistency in airspace change proposal decisions.
• Ensures decisions continue to focus on safety, viability and enable growth in accordance with the government’s environmental priorities.​​

The Air Navigation Directions 2026 and the Air Navigation Guidance 2026 come into effect on 1 October 2026. CAP 1616 version 6 will therefore also come into effect on 1 October 2026.

The Department for Transport (DfT) have set out in Air Navigation Guidance 2026, the effective date of the guidance.

The Air Navigation Guidance 2026, and therefore CAP 1616 version 6, will apply:

• In respect of all new airspace change proposals commenced after the date at which this guidance comes into effect.
• Where an airspace change proposal designing a block of UK airspace that covers the area of airspace managed by more than one airport and is being sponsored by NERL as the UK Airspace Design Service (UKADS) provider.
• Where the sponsor of a Level 1 or a Level 2 permanent airspace change proposal commenced under the CAA’s 2023 (or earlier) CAP 1616 has not passed the consultation gateway (Stage 3) on its proposal at the date at which this guidance comes into effect

Other airspace change proposals that are in progress will continue on the same version of CAP 1616 that they are currently on provided that an airspace proposal is submitted to the CAA for decision by the end of July 2031. 

Where a sponsor requests it, or where the CAA believes that it is necessary to support the delivery of an airspace cluster, the CAA may require a sponsor to follow a specific version of the guidance even if it falls outside the criteria above.

The CAA will write to each sponsor to outline if their airspace change proposal will transition to the CAP 1616 version 6. For some airspace change proposals, this letter may also include actions the sponsor needs to take to support transition to the new process. These letters will be published on the airspace change portal on 1 October 2026.

CAP 3129 - Onboarding Process for the UK Airspace Design Service (UKADS) Provider for the London TMA Region will be retired and the CAA letter to the UKADS provider for the London TMA region airspace change proposal will outline the actions for transition for the London TMA region airspace change proposal. This letter will be published on the airspace change portal on 1 October 2026. The updated CAP 1616 airspace change process also incorporates relevant elements of CAP 3129, taking account of the Air Navigation Guidance 2026.

Modernisation of UK airspace is essential to ensure that it is fit for purpose in the future. Modernising airspace will make it more efficient and flexible, help UK aviation to achieve net zero emissions by 2050. Furthermore, it will increase the resilience of flights to disruption due to capacity contraction, giving consumers confidence in the network and reducing airline costs. Airspace re-design is a key aspect of modernisation.

CAP 1616 is a key framework in enabling airspace modernisation; with government setting policy, industry developing airspace change proposals, and the UK Civil Aviation Authority independently deciding whether the proposals meet the required policy and process.

Yes. The CAA consulted on proposed changes to CAP 1616 in 2025 and considered the feedback received before publishing CAP 1616 version 6. CAP 1616 must also give effect to the relevant requirements set by government through the Air Navigation Guidance and Air Navigation Directions.

The Department for Transport separately consulted on those documents. The CAA's response to that consultation was published as CAP 3209, and the resulting government requirements have been incorporated into CAP 1616 version 6.

Airspace trials can play a vital role in supporting the development and integration of new airspace users into UK airspace through testing of innovative airspace design, technology or Air Traffic Control operational procedures.

The update to the airspace change process enables a more agile, innovation-focussed non-permanent airspace change process, which supports new users and future flight by extending trial periods from six months to up to three years, and introducing a more proportionate, streamlined process for short-term activities.

Any statement of need received from 15 September 2026 onwards will not be processed until 12 October 2026, under CAP 1616 version 6.

A new statement of need form aligned with CAP 1616 version 6, will be made available from 5 October 2026. Sponsors who submit a statement of need before the new form becomes available may be asked to resubmit their application using the updated template to ensure it meets the requirements of the new process.

Sponsors are therefore encouraged to review the new documentation and use the updated form where applicable to avoid any unnecessary delays.

The CAA has written to sponsors of:

• Permanent airspace change proposals that are not currently in Stages 5, 6, or 7 of CAP 1616 version 5 (or earlier).
• All temporary airspace change proposals.
• All trial airspace change proposals.

Airspace change proposals that are already in Stages 5, 6, or 7 of CAP 1616 version 5 (or earlier versions of CAP 1616 or CAP 725) will continue under their existing process and will not transition to the new CAP 1616 version 6 process.

Sponsors of airspace change proposals that are currently paused will receive a separate letter before 18 September 2026 explaining how the transition arrangements apply to their proposal.

The letters set out how the arrangements apply to each proposal and highlight any actions that may be required from sponsors.

Throughout the development of an airspace change proposal, proposers and sponsors may seek guidance on the requirements of the process from the CAA’s Airspace Regulation team. However, the most appropriate opportunities for the CAA to provide proposers or sponsors with guidance are following the briefing and guidance meeting or gateway assessment.

The process is streamlined to reduce unnecessary regulatory burden and support innovation and growth, with a consistent focus on safety, evidence and impact.

The revised airspace change process makes regulatory requirements as proportionate and streamlined as possible, while retaining requirements that enable the CAA to make informed, evidence-based, transparent decisions.

The timeline for completion of the airspace change process will depend on the complexity of the airspace design and the potential impacts of the airspace change proposal. These factors will determine the amount of design work, analysis, and degree of consultation required. The timeline will also depend on the amount of resource that the sponsor can dedicate to developing their airspace change proposal and producing the associated documentation.

Yes, safety, transparency, proportionality, accountability and consistency remain key principles of the airspace change process. These key principles ensure that when the CAA decides whether to approve a proposal to change UK airspace, we do so in an impartial and evidence-based way.

Effective stakeholder engagement is a vital underpinning of the airspace change process.

In Stage 1 of the permanent airspace change process, the sponsor will gather and test information, identify assumptions and constraints, and engage with a stakeholder reference group before developing the draft design(s). The purpose of this engagement is to test with relevant specialists the information gathered by the sponsor to date and to obtain any additional information necessary to support design work.

The stakeholder reference group should consist only of stakeholders who can provide information which is necessary to address the statement of need, taking account of the Airspace Modernisation Strategy, while applying the airspace design priorities when carrying out design work. Local, parish or town councils may assist in identifying noise sensitive buildings. However, residents impacted by proposed changes to aircraft operations should not be included.

Stakeholders should feel confident that their voice has a formal place in the airspace change process. Potentially impacted stakeholders are identified by the sponsor so they can be engaged or consulted with at relevant stages of the process. Stakeholders will have access to relevant documentation via the airspace change portal. 

We understand people want to have their say on changes that affect them. Consultation remains a core part of the airspace change process, with clear opportunities for those affected to provide feedback, and decisions will continue to be made independently based on evidence and a fair assessment of impacts on communities.

These changes play an important role in modernising UK airspace to deliver benefits like fewer delays, more efficient routes, and lower emissions, while making sure impacts are properly considered.

The CAP 1616 airspace change process establishes the requirements and guidance that sponsors need to comply with when progressing airspace changes. In addition to the engagement activities set out in the process, sponsors are encouraged to communicate more broadly with stakeholders to support understanding and collaboration.

The Air Navigation Guidance 2026, paragraph 105, highlights the importance that airports should have high quality and open engagement with their local stakeholders on an ongoing basis. Paragraph 112 states, “Whether or not they are engaged in a current airspace change process, airports and their air navigation service providers should engage proactively on the noise impact of aircraft operating into and out of their airport with their local communities. This could be achieved through established bodies such as airport consultative committees, other relevant consultative groups, and, where appropriate, through other means such as the internet and social media, to engage and inform their communities as appropriate on relevant air operations.”

Under CAP1616 version 5 (based on the previous Air Navigation Guidance 2017) each sponsor developed its own design principles with stakeholders and evaluated airspace design options against them. CAP1616 version 6 applies the Government's airspace design priorities set out in the Air Navigation Guidance 2026.

The airspace design priorities are the Government's policy on its priorities for UK airspace, intended to inform the CAA and sponsors how the government wants UK airspace to be designed. They are the framework against which draft designs must be developed and evaluated.

The airspace design priorities apply to every proposal, guide the CAA and sponsors how to balance the government’s objectives for UK airspace design and state the order in which in which safety, planning-permitted capacity, noise below 5,000 ft and flight efficiency above 5,000 ft should be prioritised.

The airspace design priorities are national, but they can only be applied to a specific volume of airspace using local information. Before any design work, the sponsor must describe how the airspace is used today and gather the information needed to apply each priority to that location. This includes the design assumptions it will rely on (for example traffic levels and their distribution, runway usage patterns, wind, and the navigation equipment of the aircraft using the airport), the design constraints it must work within (for example terrain and obstacles, neighbouring airports and airspace, procedure design rules, runway capacity and existing planning conditions), the location specific legal obligations, and the location of noise-sensitive buildings, protected areas and European sites that could be overflown.

The sponsor must test this information with a stakeholder reference group, close any gaps, and show the CAA at the Stage 1 milestone what was gathered, how assumptions and constraints were identified and tested, and how they have informed the draft design. Local circumstances therefore shape the design as evidence and constraints, applied within a consistent national framework, rather than as criteria that differ from airport to airport.

The local legal context means the legally binding obligations that already apply to a particular airport or volume of airspace. The main examples are planning conditions and requirements attached to a planning permission or Development Consent Order – including any cap on flights or passengers, night restrictions, or a minimum level of capacity that a development must deliver; noise preferential routes or noise abatement procedures set by a planning authority, often through a section 106 agreement; statutory noise action plans; and any directions or restrictions imposed by the Secretary of State under section 78 of the Civil Aviation Act 1982 at Heathrow, Gatwick and Stansted.

It matters for three reasons. The second airspace design priority requires the airspace design to enable the activity that planning decisions permit, so these obligations are fixed inputs to the design. Secondly, a design that would breach an existing or proposed planning condition or legal obligation cannot be implemented and so is not viable. And finally, identifying these obligations at the start makes clear to everyone which matters have already been decided through the planning system and which remain open to influence in the consultation on the airspace design.

A planning consultation does not negate the need for a consultation on the airspace design. These are two separate decisions, made by two separate systems, and the public is consulted in both. The consultation on the airspace design is not a repeat of the planning process and consultation.

• The planning system decides whether airport infrastructure may be built and how it may be used – through planning permission or a Development Consent Order and the conditions attached to it, including any cap on flights or passengers, night restrictions, or a minimum capacity a development must deliver. Those decisions set the number of flights at an airport and therefore its overall noise and emissions. Communities are consulted on those questions in the planning process, by the applicant and by the planning authority or the Planning Inspectorate, and the decision and its conditions then become fixed inputs to any airspace design. The CAA is a statutory consultee on aviation infrastructure but does not make planning decisions.
• The airspace change process decides something different: how the flights permitted by the planning process are arranged in the air – where routes go, how aircraft climb and descend, how noise below 5,000 ft is minimised, and whether single or multiple routes are used. None of that is settled by the planning decision. These are the issues that the airspace design, which must apply the Government’s airspace design priorities, will determine. How the sponsor has designed the airspace and applied the Government’s airspace design priorities is the subject of the public consultation on the airspace design.

In some cases a sponsor may rely on evidence obtained from a planning process (including its consultation process) if they can demonstrate to the CAA that material is relevant and remains valid for use in the airspace change process. We have introduced this possibility to meet the Government’s guidance that regulators should seek to avoid duplication of regulatory burdens wherever possible.

For proposals under CAP 1616 version 6:

• The sponsor must identify local communities likely to be affected by operations at or below 5,000 ft, including their elected representatives, and set out how the sponsor will reach them. The CAA must be satisfied with the sponsor’s consultation strategy, materials and duration before the sponsor can launch their consultation.
• The consultation must follow the Cabinet Office’s consultation principles and have regard to the Gunning principles, which set out legal expectations for what constitutes an appropriate consultation. The Gunning principles mean that the consultation must take place while the design can still change; give enough information for an informed response without technical knowledge; allow adequate time; and responses must be conscientiously taken into account by the sponsor.
• The sponsor must publish the responses and explain, in a consultation response document, what it changed as a result, what it did not change, and why. If the final design differs substantially from what was consulted on, the CAA can require further consultation.
• The CAA independently assesses whether the process has been followed and how the sponsor has considered the consultation responses. For a proposed change that is of strategic national importance the CAA may hold a public evidence session, where people speak directly to the CAA in public.

The public’s voice being heard does not mean that the CAA can make the decision that every consultee wishes we would make. Consultation is a process through which views of impacted stakeholders on a specific proposal are sought and considered by the sponsor to help  inform the CAA's decision; however it is not a referendum on views and the CAA must make its airspace design decisions within the law and taking account of Government policy. What the airspace change process requires is that the questions which remain open are put to those affected, that their responses are considered on their content, and that the reasons for the outcome are clear and published.

The CAA’s decision is published, with reasons, and can be challenged in the courts.

Potentially impacted local communities have a formal place in the airspace change process. We understand that people want to have their say on changes that may affect them.

Potentially impacted communities can comment on a proposal during the sponsor's public consultation at Stage 2, once the CAA has confirmed at the relevant gateway that the sponsor's consultation strategy and materials meet the process requirements. For a proposed change that is of strategic national importance the CAA may hold a public evidence session at Stage 4 before reaching our decision.

Potentially impacted stakeholders will have access to relevant documentation through the airspace change portal throughout the process, helping them to understand how a proposal is progressing.

Consultation remains a core part of the airspace change process, providing clear opportunities for those affected to provide feedback and have their views heard and considered as proposals are developed and assessed. Decisions will continue to be made independently by the CAA.

There is a milestone review at the end of Stage 1 for Level 1 and Level 2 permanent airspace change proposals. This enables the CAA to review the sponsor’s documents against the Stage 1 requirements and provide feedback. The Stage 1 milestone review is a feedback‑only step and does not result in a decision or require the CAA to provide permission to progress to Stage 2.

At the Stage 2 gateway assessment, the CAA will consider the sponsor’s submission, determine whether the airspace change process requirements up to this point have been met, and provide relevant feedback. Level 1 and Level 2 sponsors must pass the Stage 2 gateway assessment before they can commence their consultation. Passing the gateway assessment does not predetermine the CAA’s regulatory decision on the final airspace change proposal. The Stage 2 gateway assessment is there to determine whether the airspace change process has been followed up to that point.

For Level 1 and Level 2 permanent airspace change proposals, at the Stage 2 gateway assessment, the CAA will consider their submission and determine whether the airspace change process requirements up to this point have been met and provide relevant feedback. The feedback may include observations identifying areas where more information, clarity, or explanation is required to demonstrate how those requirements have been addressed.

Level 1 and Level 2 sponsors must pass the Stage 2 gateway before they can commence their consultation. Passing the gateway does not predetermine the CAA’s regulatory decision on the final airspace change proposal. The Stage 2 gateway is there to determine whether the airspace change process has been followed up to that point.

We have retained the consult gateway in CAP 1616 version 6, as it provides regulatory oversight prior to the sponsor launching their consultation.  A milestone review at Stage 1, together with the Stage 2 gateway, provides the right balance by giving assurance to sponsors and stakeholders that the process requirements have been met before a design is taken forward to consultation.

The Air Navigation Guidance 2026 provides the framework for environmental assessments. The updated guidance seeks to balance environmental objectives by reducing emissions per flight through more efficient airspace design while maintaining a strong focus on minimising adverse impacts on communities.

The Department for Transport’s Air Navigation Directions and Air Navigation Guidance consultation response document provides further detail on the changes to environmental legislation.

Assessing the potential environmental impacts of an airspace change proposal is a core component of the CAA’s decision‑making process. These assessments also ensure that stakeholders can understand how the proposal may affect them.

Environmental assessments required by the CAP 1616 airspace change process are based on defined metrics determined by the Secretary of State in the Air Navigation Guidance 2026. Consistent with the Secretary of State’s direction that the CAA’s process is proportionate and reflects government policies

The Department for Transport (DfT) have set out in Air Navigation Guidance 2026, the effective date of the guidance.

The Air Navigation Guidance 2026, and therefore CAP 1616 version 6, will apply:

• In respect of all new airspace change proposals commenced after the date at which this guidance comes into effect.
• Where an airspace change proposal designing a block of UK airspace that covers the area of airspace managed by more than one airport and is being sponsored by NERL as the UK Airspace Design Service (UKADS) provider.
• Where the sponsor of a Level 1 or a Level 2 permanent airspace change proposal commenced under the CAA’s 2023 (or earlier) CAP 1616 has not passed the consultation gateway (Stage 3) on its proposal at the date at which this guidance comes into effect.

Other airspace change proposals that are in progress will continue on the same version of CAP 1616 that they are currently on provided that an airspace proposal is submitted to the CAA for decision by the end of July 2031. 

Where a sponsor requests it, or where the CAA believes that it is necessary to support the delivery of an airspace cluster, the CAA may require a sponsor to follow a specific version of the guidance even if it falls outside the criteria above.

The CAA will write to each sponsor to outline if their airspace change proposal will transition to the CAP 1616 version 6. For some airspace change proposals, this letter may also include actions the sponsor needs to take to support transition to the new process. These letters will be published on the airspace change portal on 1 October 2026.

CAP 3129 - Onboarding Process for the UK Airspace Design Service (UKADS) Provider for the London TMA Region will be retired and the CAA letter to the UKADS provider for the London TMA region airspace change proposal will outline the actions for transition for the London TMA region airspace change proposal. This letter will be published on the airspace change portal on 1 October 2026. The updated CAP 1616 airspace change process also incorporates relevant elements of CAP 3129, taking account of the Air Navigation Guidance 2026.

There are a small number of airspace change proposals underway using the CAA’s CAP 725 process (the predecessor to CAP 1616). These airspace change proposals are all are post-consultation so they would not be affected as long as they conclude by July 2031.

Level 3 airspace change proposals are not subject to a consultation gateway so would continue on their current guidance and must be completed by the backstop date of July 2031. In practice this will mean that a new sponsor could propose a new Level 3 airspace change proposals up to the effective date of the guidance and it would progress on the Air Navigation Guidance 2017 so long as it was completed by July 2031.