Masterplan FAQs
Below are some of the most commonly asked questions about the Airspace Masterplan and the airspace change process.
What is the UK Airspace Change Masterplan?
The Airspace Masterplan is a high-level coordinated implementation plan that will identify what airspace changes need to be developed to achieve the range of benefits that modernisation can deliver. The Masterplan will draw on information from the constituent Airspace Change Proposals (ACPs) led by the airports and NATS (as the Airspace Change Sponsors) to consider potential interdependencies between the various proposals, potential conflicts, the concepts that might be used to resolve conflicts and the trade-offs that may be needed to deliver modernisation. The Masterplan does not show the detail of individual airspace designs included within each ACP but will include a programme plan for their development and implementation.

Who is responsible for developing the Masterplan?
The CAA and Department for Transport, as co-sponsors of airspace modernisation in the UK, commissioned NATS to set up an impartial body, the Airspace Change Organising Group (ACOG), to develop the Masterplan.
How is the Masterplan being developed?
Airspace modernisation is a long and complex process. The co-sponsors have agreed that ACOG will develop the Masterplan through a series of iterations over the next few years. This reflects the fact that different information and levels of detail will be available at different points as the constituent ACPs sponsored by the airports and NATS are developed. It also means that the Masterplan can be kept flexible to accommodate the evolving context for airspace modernisation, such as any changes in policy or additions to co-sponsor commissions to produce new elements of the Masterplan, or unanticipated external events.
How will trade-offs be decided when resolving interdependencies between ACPs?
The ACP sponsors (Airports and NATS) are responsible for agreeing how proposed trade-offs are made between themselves. ACOG may help facilitate these discussions. Explaining how proposed trade-off decisions have been made must be included in the public consultation materials that sponsors produce on their individual ACPs. It is in these consultations that stakeholders will be able to influence trade-off decisions which may impact them.
ACOG will ensure this process is transparent and applied consistently across the ACPs and that sponsors explain the methodology to stakeholders in an accessible way that will enable them to provide feedback on how the decisions were reached.
How will airports be consulting with communities affected by more than one ACPs? Will those airports be required to consult at the same time?
The approach to consultation with stakeholders affected by more than one ACP will be considered as part of the next iteration of the Masterplan (Iteration 3) and ACOG will be seeking stakeholders’ feedback on this. As part of our public engagement exercise, ACOG will set out and seek views on how the sponsors of interdependent ACPs will consult on their proposals in a coordinated manner, so that stakeholders are presented with a coherent view of the proposed system-wide changes and a full description of the cumulative impacts of the proposals.
ACOG will also seek views from stakeholders on how proposed airspace design trade-offs are presented by airspace change sponsors, the outcome of which will inform individual sponsors’ consultations.
Sponsors of interdependent changes will be required to publicly consult at a similar time and should align the relevant gateways of the CAA’s airspace change process (CAP 1616) in order to enable the CAA to assess interdependent ACPs consultation strategies and materials as a whole.

Why are only some UK airports included in the Airspace Masterplan?
There are currently 21 UK airports included in the Airspace Masterplan. These are mostly airports that share interdependencies with other nearby airports and therefore airspace changes need to be undertaken and consulted on in a coordinated way. They may also be airports that NATS have identified that need to make changes at lower levels in order to optimise changes to upper airspace.
Iteration 3 of the Masterplan will consider feedback received from stakeholders through a public engagement exercise. This will include seeking views about other airports that are not currently part of the Programme, and also ask whether there are any potential gaps (including other airports undertaking ACPs) in the Masterplan.
Will the participating airports be making changes to their airspace in the same timeframe?
Due to the complexity of the changes involved, the Airspace Change Programme is expected to take a number of years to complete. As part of Iteration 2 of the Airspace Masterplan (PDF), ACOG set out a ‘clustered’ approach to the delivery of the programme.
This will allow changes within geographical clusters of airports, once approved, to be deployed and the benefits realised, without waiting for all airports to complete the ACP process.
The Masterplan will play an important role in the sequencing of airspace changes. ACPs will be held at the relevant stage of CAP1616 process based on the approach set out in the Masterplan. This will ensure that Sponsors’ options development and public consultations are delivered in a coordinated, joined up manner.
The CAA will require a version of the Masterplan to inform their decision making about constituent ACPs at the relevant gateways in the CAP 1616 process.
How will the impact of aircraft noise be taken into account in the Airspace Masterplan?
In the Government’s key environmental objectives set out in the Air Navigation Guidance (2017), it stated that airspace changes are to ‘limit and, where possible, reduce the number of people in the UK significantly affected by adverse impacts from aircraft noise’.
This objective was further broken down in the Altitude Based Priorities section of the ANG
To limit and, where possible, reduce noise below 4000ft; and to minimise noise providing there is no significant CO2 cost between 4000ft and 7000ft’
The Masterplan and the constituent ACPs that the airports are responsible for, must demonstrate how this objective will be achieved.
What are the future engagement opportunities for stakeholders?
ACOG will engage extensively with a range of stakeholders as it develops the Masterplan. During 2023, ACOG will run a public engagement exercise on the content of Iteration 3 before it is submitted to the co-sponsors for assessment and subsequent acceptance by the CAA into the Airspace Modernisation Strategy. Through this engagement, ACOG will make stakeholders aware of the later consultations on airspace change proposals that will take place under the CAP 1616 process, how they are linked together, and how stakeholders can feed back on trade-off decisions that may affect them.
ACOG will also continue to keep this resource library fully updated so that stakeholders can find relevant and up to date information about the Masterplan and its development.