CAP 1616 version 6 permanent airspace change process
Overview of Version 6 of CAP1616.
On 1 October 2026, an updated CAP 1616, version 6 Airspace Change Process will come into effect. This updated process will apply the government’s updated legislation the Air Navigation Directions 2026 and the Air Navigation Guidance 2026.
All new airspace change proposals submitted after 1 October 2026 will follow the CAP 1616 version 6, Airspace Change Process.
The CAP 1616 version 6 permanent airspace change process comprises five stages:
- Stage 1 - propose and develop: The CAA assesses the submitted statement of need, determining the appropriate process. The sponsor then outlines the current-day scenario and develops a draft design to address the statement of need, taking account of the Airspace Modernisation Strategy, while applying the airspace design priorities.
- Stage 2 – consult: The sponsor assesses the impacts of the draft design(s) in their draft design(s) assessment. They then launch a consultation to gather feedback from stakeholders to inform the final design.
- Stage 3 - update and submit: The sponsor considers any updates required to the design and completes their final design assessment. They then finalise their design and submit their final airspace change proposal to the CAA.
- Stage 4 – decision: The CAA reviews and assesses the final airspace change proposal, deciding whether to approve or reject the final proposal. The CAA’s decision is made in the context of our legal duties and government policy.
- Stage 5 - implement: The sponsor implements the approved airspace design taking account of any modifications or conditions set out in the CAA’s decision. Once implemented, the sponsor monitors the safety and impacts of the airspace change.
Level 1 and Level 2 airspace changes are subject to a milestone review at the end of Stage 1 and a gateway assessment in Stage 2.
The milestone review 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.
Levels of airspace change
The CAP 1616 version 6 permanent airspace change process has three levels of airspace change, each with distinct requirements and associated guidance. The airspace change process incorporates additional scalability within each level to ensure that regulatory requirements and guidance are applied in a proportionate manner, commensurate with the scale, complexity and potential impact of the proposed change.
Level 1 will be allocated to airspace change proposals that affect aircraft flight behaviours below 5,000 feet above mean sea level (AMSL) over land.
This will normally require the application of the full set of airspace change process requirements, with limited opportunity for scaling due to the need to assess across a broad set of potential impacts.
Level 1 airspace changes will require detailed consideration of changes to aircraft noise exposure in the vicinity of the airspace change and an assessment using the Department for Transport’s Transport Analysis Guidance (TAG). Level 1 airspace changes will also require an assessment of flight efficiency and an assessment of impacts on protected areas and European sites.
Level 1 proposals will be subject to the Stage 1 milestone review and Stage 2 gateway assessment.
Level 2 will be allocated to airspace change proposals that affect aircraft flight behaviours at or above 5,000 feet AMSL over land or that alter flight behaviours over the sea (at any altitude).
This will primarily focus on the impacts to airspace users and/or present a greater opportunity for scaling against the airspace change process requirements.
Level 2 airspace changes will require an assessment of flight efficiency and an assessment of impacts on protected areas and European sites.
Level 2 proposals will be subject to the Stage 1 milestone review and Stage 2 gateway assessment.
Level 3 will be allocated to airspace change proposals at any altitude over the land or sea where the proposal is expected to have a low impact(s). This will present a greater opportunity for scaling.
Level 3 may apply:
for airspace change proposals relating only to instrument flight procedures below 5,000 feet AMSL, where a quantitative and/or qualitative demonstration shows that the change is likely to result in:
- (for existing procedures) no more than a 3 dB LASmax2 change in aircraft noise; and
- no more than an increase by 10% (or a maximum of 3,650 movements per year) in the total number of aircraft movements in the first two years after the implementation of the airspace change; and
- no change in the normal final approach path of aircraft within 1 nautical mile of the aerodrome or landing site; and
- no change in the impacts to noise, flight efficiency, protected areas and European sites from aircraft utilising other aerodromes;
Or if:
- the airspace design has the potential for a low impact on stakeholders; or
- the change relies on CAA policy which outlines the airspace change requirement; or
- there is established precedent that reduces uncertainty, where concepts and impacts are already understood.
Level 3 proposals follow a streamlined application of the airspace change process. Level 3 airspace changes may require a qualitative assessment of aircraft noise exposure, flight efficiency, impact on protected areas and European sites.
The Stage 1 milestone review and the Stage 2 gateway assessment do not apply.
The non-permanent airspace change process
The CAP 1616 version 6 non-permanent airspace change process comprises five steps:
- Step 1 - initiate
- Step 2 - design, assess and engage
- Step 3 - update and submit
- Step 4 - CAA decision
- Step 5 - implement.
A temporary change to airspace design or an airspace trial are both considered non-permanent airspace change proposals.
Although both involve changes that are implemented for a limited and predefined period, they serve different purposes and the process sponsors must follow differs in some respects. The purpose, nature, and intended outcomes will determine whether a non-permanent airspace change should be progressed as a temporary change to airspace design or an airspace trial.
Approval of a non-permanent airspace change does not create any presumption that the change will become permanent. Any permanent implementation of the airspace change would require a separate proposal to be progressed through the applicable permanent airspace change process in accordance with CAP 1616, airspace change process.
A temporary change to airspace design approved by the CAA is to last for such a fixed period as the CAA considers appropriate, which is normally not to be more than 180 consecutive days (from the first day of a proposal being activated/notified) unless the CAA determines otherwise.
At the end of the approved period, the airspace will revert to its previous classification, structure or operational arrangements, unless otherwise approved by the CAA.
Direction 2 of the Air Navigation Directions 2026 defines an airspace trial as changes to airspace design or air traffic control operational procedures (which, if subsequently made permanent, would constitute a relevant planned and permanent distribution of air traffic), for a fixed duration for the purposes of:
- investigating the feasibility of, or validating proposals for, innovative airspace design, technology, or air traffic control operational procedures, or
- assessing their performance and effect, or
- supporting the development and integration of new airspace user groups into UK airspace.
For the purposes of this process, an airspace trial is implemented for a defined period to test, evaluate or gather evidence on a proposed airspace design and/or proposed air traffic control operational procedures. The evidence gathered may be used to inform future decisions on airspace design, airspace policy or operational arrangements.
An airspace trial approved by the CAA is to last for such fixed period as the CAA considers appropriate, which is normally not to be more than three years unless the CAA determines otherwise.
At the end of the approved trial period, the airspace will revert to its previous classification, structure or operational arrangements, unless otherwise approved by the CAA. The CAA may also, where the CAA considers it appropriate, safe, and practical to do so, require an airspace trial to end before the end of the period for which it was approved.