What is airspace?

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 committed by international treaty to provide air navigation services (which includes air traffic control). 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 without being constrained by instructions in routeing or by air traffic control, unless they request such a routeing or control 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. The CAA has a policy of keeping the volume of controlled airspace to the minimum necessary to meet the needs of UK airspace users and to comply with its international obligations.

The defined blocks of controlled airspace, and flight procedures and routes within them such as standard departure and arrival routes, are together part of the overall airspace design. This airspace design is published (‘notified’) in the  UK Aeronautical Information Publication (AIP).

What is an airspace change proposal?

Airspace change proposals are requests from a ‘change sponsor’, usually an airport or a provider of air navigation services (including air traffic control), to change the notified airspace design.  Airspace change proposals must follow the CAA’s airspace change process.

This website hosts all airspace change proposals currently under development, including all relevant documents and information, and gives you the chance to submit related feedback.

What is the airspace change process?

The airspace change process is structured, comprising of different stages, steps and gateways depending on the type of airspace change proposal that has been requested.  Both change sponsors and the CAA are involved in the airspace change process, resulting in a final decision by the CAA to approve or reject the airspace change proposal. Full details on the airspace change process can be found in CAP 1616 - Airspace Design: Guidance on the regulatory process for changing airspace design including community engagement requirements. You can view further information on airspace and airspace change, including how the process was developed, on the CAA website.

Types of airspace change

There are various types of airspace change proposal and all of them are required to follow a specific airspace change process.

Change Levels For A Permanent Airspace Change Proposal

The CAA assign a ‘level’ to permanent airspace change proposals according to their potential impact. This ensures that the more significant proposals receive the right amount of regulatory scrutiny, while keeping the airspace change process proportionate for less significant proposals.

Permanent changes to notified airspace design are assigned one of the levels below.

Level 0

Level 0 proposals are changes that do not alter air traffic patterns because they only involve changes to the wording of existing airspace design.

Given the nature of Level 0 changes, they are only required to complete Step 1a of the process.

Level 1

Level 1 are changes that could alter change air traffic patterns below 7,000 ft over an inhabited area. These can include departure and arrival routes at airports.

Level 2

The CAA will only describe a change as Level 2 if it is expected that it will not alter air traffic patterns below 7,000 ft over an inhabited area. They are described as medium to low impact changes. They are sub-divided into Levels 2A, 2B and 2C according to impact:

  • Level 2A changes usually affect aircraft routes between 7,000 ft and 20,000 ft
  • Level 2B changes usually affect aircraft routes above 20,000 ft, over the sea, or are outside controlled airspace above 7,000 ft
  • Level 2C changes usually reflect current airspace use or remove an existing airspace structure

Level M

Level M changes are sponsored by the Ministry of Defence (MoD). Military changes still go through the airspace change process, but they follow different environmental rules to other proposals. They are split into M1 (which could change civil air traffic under 7,000 ft) and M2 (which will not).

These proposals complete all steps of the process in the same way as Level 1 or Level 2 changes respectively.

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Permanent Change To The Notified Airspace Design

The airspace change process for permanent changes to the notified airspace design is summarised below.

Stage 1 DEFINE

Step 1a - Assess Requirements

During the Assess Requirement Step, the change sponsor prepares a Statement of Need setting out what airspace issue it is seeking to address. Having reviewed the Statement of Need, the CAA meets with the change sponsor to agree whether an airspace change is a relevant option to consider, and to have a first discussion about the appropriate scale of the airspace change process.

Step 1b - Design Principles

During the Design Principles step, the sponsor develops the principles which will underpin their proposed options for the change. The design principles encompass the safety, environmental and operational criteria and strategic policy objectives that the change sponsor aims for in developing the airspace change proposal. They are developed through engagement with stakeholders and form a qualitative structure against which design options can be evaluated. Early engagement with stakeholders, optionally facilitated by a third party, may help to avoid disagreement later in the process.

Define Gateway

At the Define Gateway, the CAA reviews and signs-off the documentation relating to Stage 1.

Stage 2 DEVELOP & ASSESS

Step 2a - Options Development

During the Options Development Step, the change sponsor develops one or more design options that address the Statement of Need and align with the defined design principles.

Step 2b - Options Appraisal

During the Options Appraisal Step, each design option, even if there is only one, is assessed to understand the impact, both positive and negative. This is the first of three options appraisals developed during the process.

Develop & Assess Gateway

At the Develop and Assess Gateway, the CAA reviews and signs-off the documentation relating to Stage 2.

Stage 3 CONSULT

Step 3a - Consultation Preparation

During the Consultation Preparation Step, the sponsor plans its stakeholder consultation and engagement, and prepares consultation documents, including the second-phase Full options appraisal with more rigorous evidence for its chosen option(s).

Step 3b - Consultation Validation

During the Consultation Validation Step, the CAA reviews and where appropriate approves the consultation strategy. This is to ensure the strategy is comprehensive, the materials clear and appropriate, and the questions unbiased.

Consult Gateway

At the Consult Gateway, the CAA reviews and signs-off the documentation relating to Stage 3.

Step 3c - Commence Consultation

At the Commence Consultation Step, the change sponsor implements its consultation strategy and launches the consultation.

Step 3d - Collate & Review Responses

During the Collate & Review Responses Step, consultation responses are collated, reviewed and categorised.

Stage 4 UPDATE & SUBMIT

Step 4a - Update Design

During the Update Design Step, the change sponsor considers the consultation responses, identifies any consequent design changes, and updates the options appraisal, submitting these to the CAA for review.

Step 4b - Submit Proposal to CAA

During the Submit Proposal to CAA Step, the change sponsor prepares the formal airspace change proposal using a template and submits it to the CAA.

Stage 5 DECIDE

Step 5a - CAA Assessment

During the CAA Assessment Step, the CAA reviews and assesses the airspace change proposal, and for Level 1 changes offers a Public Evidence Session. The CAA may request minor changes to the proposal. The CAA prepares assessment papers to inform and provide guidance to the airspace change decision-maker.

Step 5b - CAA Decision

During the CAA Decision Step, the CAA decides whether to approve or reject the airspace change proposal. For Level 1 changes, the CAA will normally seek views on a draft of the decision, or the Secretary of State may ‘call-in’ the proposal.

Decide Gateway

At the Decide Gateway, the CAA reviews and signs-off the documentation relating to Stage 5.

Stage 6 IMPLEMENT

Step 6 - Implement

During the Implement Step, the change sponsor implements the approved change, working with air navigation service providers as necessary.

Stage 7 Post Implementation Review

Step 7 - Post Implementation Review

At the Post-Implementation Review Step, the CAA reviews how the airspace change has performed, including whether anticipated impacts and benefits in the original proposal and decision have been delivered.

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Permanent Level 0

Proposals to change the nomenclature and/or qualifying remarks of the notified airspace design that do not have the potential to alter traffic patterns are classed as Level 0 airspace change proposals, and they follow a scaled airspace change process.

Stage 1 ASSESS REQUIREMENT

Step 1 – Assess Requirement

During the Assess Requirement Step, the change sponsor prepares a Statement of Need setting out what airspace issue it is seeking to address. Having reviewed the Statement of Need, the CAA meets with the change sponsor to agree whether an airspace change is a relevant option to consider, and to have a first discussion about the appropriate scale of the airspace change process.

Stage 5 DECIDE

Step 5: CAA Assessment and Decision

During the CAA Assessment and Decision Step, the CAA reviews and assesses the airspace change proposal. The CAA may request minor changes to the proposal. The CAA prepares assessment papers to inform and provide guidance to the airspace change decision-maker.  The CAA then decides whether to approve or reject the airspace change proposal.

Stage 6 IMPLEMENT

Step 6: Implement 

During the Implement Step, the change sponsor implements the approved change, working with air navigation service providers as necessary.

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Temporary Changes To The Notified Airspace Design

Specific events or operating conditions may sometimes require a temporary change to the notified airspace design.  A temporary change will usually apply for a period no longer than 90 days, except in extraordinary circumstances.  The airspace change process for temporary changes to the notified airspace design is summarised below.

Stage 1 - Assess Requirements

Step 1 - Assess Requirement

During the Assess Requirement Step, the change sponsor prepares a Statement of Need setting out what airspace issue it is seeking to address. Having reviewed the Statement of Need, the CAA meets with the change sponsor to agree whether an airspace change is a relevant option to consider, and to have a first discussion about the appropriate scale of the airspace change process.

Stage 4 - Submit Proposal to CAA

Step 4 - Update Design and Submit Proposal to CAA

During the Update Design and Submit Proposal to CAA Step, the change sponsor considers stakeholder feedback, identifies any consequent design changes, and formally submits the airspace change proposal to the CAA.

Stage 5 - Decision

Stage 5 - CAA Assessment and Decision

During the CAA Assessment and Decision Step, the CAA reviews and assesses the airspace change proposal. The CAA may request minor changes to the proposal. The CAA prepares assessment papers to inform and provide guidance to the airspace change decision-maker. The CAA then decides whether to approve or rejected the airspace change proposal.

Decide gateway

At the Decide Gateway, the CAA reviews and signs-off the documentation relating to Stage 5.

Stage 6 - Implement

Stage 6a - Implement

During the Implement Step, the change sponsor implements the approved change, working with air navigation service providers as necessary.

Stage 6b – Implement (Extension)

At Step 6b, the change sponsor may request an extension, which will be considered by the CAA.

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Temporary Danger Area

Danger Areas are defined as airspace of defined dimensions within which activities dangerous to the flight of aircraft may exist at specified times.  The airspace change process for a Temporary Danger Area is summarised below.

Stage 1 - Assess Requirements

Step 1 - Assess Requirement

During the Assess Requirement Step, the change sponsor prepares a Statement of Need setting out what airspace issue it is seeking to address. Having reviewed the Statement of Need, the CAA meets with the change sponsor to agree whether an airspace change is a relevant option to consider, and to have a first discussion about the appropriate scale of the airspace change process.

Stage 4 - Submit Proposal to CAA

Step 4 - Update Design and Submit Proposal to CAA

During the Update Design and Submit Proposal to CAA Step, the change sponsor considers stakeholder feedback, identifies any consequent design changes, and formally submits the airspace change proposal to the CAA.

Stage 5 - Decision

Step 5 - Decide

During the CAA Assessment and Decision Step, the CAA reviews and assesses the airspace change proposal. The CAA may request minor changes to the proposal. The CAA prepares assessment papers to inform and provide guidance to the airspace change decision-maker.  The CAA then decides whether to approve or reject the airspace change proposal.

Decide gateway

At the Decide Gateway, the CAA reviews and signs-off the documentation relating to Stage 5.

Stage 6 - Implement

Stage 6a - Implement

During the Implement Step, the change sponsor implements the approved change, working with air navigation service providers as necessary.

Stage 6b – Implement (Extension)

At Step 6b, the change sponsor may request an extension, which will be considered by the CAA.

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Airspace Trials

An airspace trial is defined as:

  • a change to the notified airspace design, or air traffic operational procedures, for the purpose of investigating the feasibility of, or validating proposals for, innovative airspace design, technology or air traffic control operational procedures; or
  • a test of an airspace design or an air traffic control operational practice, in order to assess its performance ad effect

Airspace Trials usually last no longer than six months, although the CAA may be prepared to extend this period.  The airspace change process for airspace trials is summarised below.

Stage 1 - Assess Requirements

Step 1 - Assessment Requirement

During the Assess Requirement Step, the change sponsor prepares a Statement of Need setting out what airspace issue it is seeking to address. Having reviewed the Statement of Need, the CAA meets with the change sponsor to agree whether an airspace change is a relevant option to consider, and to have a first discussion about the appropriate scale of the airspace change process.

Stage 4 - Update Design and Submit Proposal to CAA

Step 4: Update Design and Submit Proposal to CAA

During the Update Design and Submit Proposal to CAA Step, the change sponsor considers stakeholder feedback, identifies any consequent design changes, and formally submits the airspace change proposal to the CAA.

Stage 5 - Decision

Stage 5 - CAA Assessment and Decision

During the CAA Assessment and Decision Step, the CAA reviews and assesses the airspace change proposal. The CAA may request minor changes to the proposal. The CAA prepares assessment papers to inform and provide guidance to the airspace change decision-maker. The CAA then decides whether to approve or reject the airspace change proposal.

Decide Gateway

At the Decide Gateway, the CAA reviews and signs-off the documentation relating to Stage 5.

Stage 6 - Implement

Stage 6a - Implement

During the Implement Step, the change sponsor implements the approved change, working with air navigation service providers as necessary.

Stage 6b – Implement (Extension)

At Step 6b, the change sponsor may request an extension, which will be considered by the CAA.

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GNSS Instrument Approach Procedures Without Approach Control (GNSS IAP WAC)

Proposals to implement a GNSS Instrument Approach Procedure to aerodromes Without an Approach Control Service follow a scaled airspace change process in accordance with the requirements of CAP 1961.

Stage 1 - Define

Step 1 - Assessment Requirement

During the Assess Requirement Step, the change sponsor prepares a Statement of Need setting out what airspace issue it is seeking to address. Having reviewed the Statement of Need, the CAA meets with the change sponsor to agree whether an airspace change is a relevant option to consider, and to have a first discussion about the appropriate scale of the airspace change process.

Stage 2 - Develop & Assess

Step 2 - Options Development

During the Options Development Step, the change sponsor develops one or more design options that address the Statement of Need and align with the defined design principles.

Stage 3 - Engage

Step 3 - Engagement Activity

During the Engagement Activity Step, the sponsor plans its stakeholder engagement by developing an engagement strategy and associated engagement materials.  If the CAA is satisfied that the relevant process requirements and guidance have been followed up to that point, it will allow the change sponsor to proceed with their planned engagement activities.

Stage 4 - Update & Submit

Step 4a - Update Design

During the Update Design Step, the change sponsor considers the stakeholder feedback, produces an engagement summary report and identifies any consequent design changes.

Step 4b - Submit Proposal to CAA

During the Submit Proposal to CAA Step, the change sponsor prepares the formal airspace change proposal and submits it to the CAA.

Stage 5 - Decide

Step 5a - CAA Assessment

During the CAA Assessment Step, the CAA reviews and assesses the airspace change proposal. The CAA may request minor changes to the proposal. The CAA prepares assessment papers to inform and provide guidance to the airspace change decision-maker.

Step 5b - CAA Decision

During the CAA Decision Step, the CAA decides whether to approve or reject the airspace change proposal. The Secretary of State ‘call-in’ process applies to these proposals.

Decide Gateway

At the Decide Gateway, the CAA reviews and signs-off the documentation relating to Stage 5.

Stage 6 - Implement

Step 6 - Implement

During the Implement Step, the change sponsor implements the approved change, working with air navigation service providers as necessary.

Stage 7 - Post Implementation Review

Step 7 - Post-Implementation Review

At the Post-Implementation Review Step, the CAA reviews how the airspace change has performed, including whether anticipated impacts and benefits in the original proposal and decision have been delivered.

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Planned & Permanent Redistribution of Air Traffic (PPR)

Definition of a PPR

A category of airspace change where there is no change in airspace design, but there is a planned and permanent redistribution of air traffic through changes in air traffic control operational procedure. “Planned and permanent” means other than a day to-day or at the time decision taken by an air traffic controller or other decision-maker.

Definition of a relevant PPR - the type of PPR

An air navigation service provider must assess whether a proposal to amend air traffic control operational procedures might lead to a planned and permanent redistribution of air traffic, and if so whether it meets certain criteria set out in the Directions, in which case it is referred to as a ‘relevant PPR’. These criteria are that the proposed PPR falls within scope of one or more Types 1, 2, or 3.

  • Type 1. Lateral shift in flight track of more than a specified distance. 
  • Type 2. Redistribution between Standard Instrument Departures routes. 
  • Type 3. Change to Instrument Landing System joining point (on approach).

How a PPR differs from a proposed change to the notified airspace design.

A proposed change to the notified airspace design (such as blocks of controlled airspace and published flight procedures in the form of Standard Instrument Departure routes and Standard Arrival Routes)  requires a change to the Aeronautical Information Publication.

In contrast, a change to written air traffic control operational procedures involves no change to the notified airspace design. Prior to the introduction of the PPR process, such changes were (subject to the CAA’s safety oversight) determined solely by the relevant air navigation service provider. Nevertheless, changes to those procedures could cause a redistribution of the tracks taken by aircraft over the ground even though the notified airspace design itself has remained unchanged.

Planned & Permanent Redistribution of Air Traffic - (Permanent)

The airspace change process for a permanent PPR is summarised below.

Stage 1 DEFINE

Step 1a - Assess Requirements

During the Assess Requirement Step, the change sponsor uses an internal trigger process to identify if a proposed change to its air traffic control operational procedures is considered a relevant PPR. It then prepares a Statement of Need setting out what issue or opportunity it is seeking to address, including the rationale that it meets the relevant PPR criteria. Having reviewed the Statement of Need, the CAA meets with the change sponsor to agree whether the proposal is a relevant PPR, and to have an initial discussion about the appropriate Type and scale of the process.

Stage 2 DEVELOP & ASSESS

Step 2a – Options Development

During the Options Development Step, the change sponsor develops one or more design options that address the Statement of Need.

Step 2b - Options Appraisal

During the Options Appraisal Step, the change sponsor appraises each option to understand the impact, both positive and negative, including a qualitative assessment of the potential safety implications.

Stage 3 CONSULT

Step 3a - Consultation Preparation

During the Consultation Preparation Step, the sponsor plans its stakeholder consultation and associated engagement, and prepares consultation documents, including the second-phase Full options appraisal with more rigorous evidence for its chosen option(s).

Step 3b - Consultation Approval

During the Consultation Approval Step, the CAA reviews and where appropriate approves the consultation strategy.

Assess & Consult Gateway

At the Assess and Consult Gateway the CAA reviews and signs-off the documentation relating to Stages 1 and 2.

Step 3c - Commence Consultation

At the Commence Consultation Step, the change sponsor implements its consultation strategy and launches the consultation.

Step 3d - Collate & Review Responses

During the Collate & Review Responses Step, consultation responses are collated, reviewed and categorised.

Stage 4 UPDATE & SUBMIT

Step 4a - Update Proposal

During the Update Proposal Step the change sponsor considers the consultation responses, identifies any changes to the PPR proposal as a result of that feedback, and updates the options appraisal to take account of any revised impacts of those amendments, submitting these to the CAA for review.

Step 4b - Submit Proposal to CAA

During the Submit PPR Proposal Step the change sponsor prepares the formal proposal using a standard format drawing from the earlier outputs in the process. The air navigation service provider then submits its PPR proposal to the CAA.

Stage 5 DECIDE

Step 5a - CAA Assessment

During the CAA Assessment Step, the CAA reviews and assesses the PPR proposal. The CAA may request minor changes to the proposal.  The CAA prepares assessment papers to inform and provide guidance to the airspace change decision-maker.

Step 5b - CAA Decision

During the CAA Decision Step the CAA decides whether to approve or reject the PPR proposal.

Decide Gateway

At the Decide Gateway, the CAA reviews and signs-off the documentation relating to Stage 5.

Stage 6 IMPLEMENT

During the Implement Step, the change sponsor implements the approved change.

Stage 7 Post Implementation Review

At the Post-Implementation Review Step, the change sponsor reviews how the change has performed, including whether anticipated impacts and benefits in the original proposal and decision have been delivered.

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Planned & Permanent Redistribution of Air Traffic - (Temporary)

Specific events or operating conditions may sometimes require a temporary change to written air traffic control operating procedures. Temporary changes to airspace design are defined in the Government’s Air Navigation Guidance and Directions to the CAA as lasting not more than 90 days, other than in extraordinary circumstances.  The airspace change process for a temporary PPR is summarised below.

Stage 1 – Define

Stage 1 – Assess Requirements

During the Assess Requirement Step, the change sponsor uses an internal trigger process to identify if a proposed change to its air traffic control operational procedures is considered as a relevant PPR. It then prepares a Statement of Need setting out what issue or opportunity it is seeking to address, including the rationale that it meets the relevant criteria. Having reviewed the Statement of Need, the CAA meets with the change sponsor to agree whether the proposal is a relevant PPR, and to have an initial discussion about the appropriate Type and scale of the process.

Stage 4 – Submit Proposal to CAA

Stage 4 – Update Proposal  and Submit Proposal to CAA 

During the Update Proposal and Submit PPR Proposal to CAA Step, the change sponsor considers stakeholder feedback, identifies any consequent design changes, and formally submits the PPR proposal to the CAA.

Stage 5 – Decide

Step 5 – CAA Assessment and Decision

During the CAA Assessment and Decision Step, the CAA reviews and assesses the airspace change proposal. The CAA may request minor changes to the proposal. The CAA prepares assessment papers to inform and provide guidance to the airspace change decision-maker. The CAA then decides whether to approve or reject the airspace change proposal.

Decide gateway

At the Decide Gateway, the CAA reviews and signs-off the documentation relating to Stage 5.

Stage 6 IMPLEMENT

Step 6a: Implement

During the Implement Step, the change sponsor implements the approved change.

Step 6b: Implement (Extension)

At Step 6b, the change sponsor may request an extension, which will be considered by the CAA.

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Gateway Assessment Schedule

During the airspace change process, a proposal must pass a series of gateways. We hold monthly Gateway Assessment meetings to review and sign off documentation showing that the criteria to proceed have been met. For a proposal to be considered at a Gateway Assessment meeting, the change sponsor must have submitted all of the relevant material to the CAA at least two weeks in advance of the meeting.