Policy paper

Benefits of airspace modernisation

Published 22 October 2024

The airspace modernisation programme will harness the latest technology and airspace design expertise to enable aircraft to fly more direct routes. This will result in:

• quicker journeys
• reducing CO2 emissions per flight
• future-proofing airspace structures and procedures for current and new users

A wide range of stakeholders will benefit from the programme.

Local environment and communities

Airspace modernisation is expected to result in a further reduction in the average noise levels per flight, as aircraft climbs and descents become quicker and quieter. 

The current guidance is that below 4,000ft airspace design should prioritise minimising noise impacts, and above 7,000ft reducing carbon emissions should be prioritised. Between 4,000 and 7,000ft, the priority is to continue minimising the impact of aviation noise, unless there is evidence this would disproportionately increase CO2 emissions.

Performance based navigation (PBN) technology offers the opportunity to accurately address the positioning and precise routing flight paths, for example, by moving them from their historic positions to narrower routes which avoid more people. Airspace modernisation creates opportunities for airports to better manage how noise impacts local communities, including ‘planned breaks’ for noise respite.

However, noise impacts will also depend on other factors like planning decisions, traffic growth or airline route networks. In some locations, the redistribution of noise between different areas may lead to disruption for communities living under new flight paths.

The CAA’s airspace change process and government guidance to the CAA ensure that those impacted by changes in flightpaths are properly consulted on any changes proposed.

Carbon savings

Airspace modernisation can reduce aviation’s carbon emissions, helping the UK to achieve net zero by 2050.

Through airspace redesign and operational changes, modernisation can deliver system improvements that help to reduce fuel burn and emissions per flight.

These include:

• enabling aircraft to fly optimal routes, shortening the distance of travel
• facilitating more frequent continuous climbs and descents when flights are transitioning between the take-off/landing phase and cruising in upper airspace, thereby requiring less engine power
• reducing delays, which in turn lessens the need for aircraft to be held in holding stacks, where air traffic burns extra fuel circling in lower airspace

Airspace efficiency improvements offer substantial opportunities for short-to-medium term emission reductions, although the scale of these reductions is subject to ongoing research.

In one instance, the Free Route Airspace deployment over Scotland, the North Sea, the North Atlantic, Northern Ireland and parts of northern England in December 2021 enabled a reduction of 12,000 tonnes of CO2/year.

Passengers and the wider economy

Airspace modernisation aims to benefit passengers by providing more choice and value for the consumer and shippers, while enhancing the likelihood that services can run to schedule.

By optimising flight paths, the modernisation of airspace will deliver a reduction in delays enabling passengers to experience quicker journey times and greater reliability, boosting customer satisfaction.

Passengers may be less likely to have to rearrange plans due to flight cancellations and diversions at short notice, as airspace modernisation can enable airlines to be more dynamic and flexible during inclement weather.

Furthermore, increased airspace efficiency can help to address congestion ‘hotspots’ and reduce the need for holding stacks, where aircraft join circular queues to land at busy airports.

In addition, passengers may see a greater frequency of connections to some destinations as the higher expected level of resilience will reduce the need for airlines to build buffers into flight schedules.

Modernised airspace also makes it feasible to deliver the high safety standards that passengers require. For example, as traffic grows, some of the innovative solutions that may be needed to maintain safety levels include new designs of route separation and new technologies that automate controller tasks.

Airspace users

By using airspace as efficiently as possible, more direct and efficient flightpaths will reduce costs for operators due to fuel savings and enhanced aircraft utilisation.

Modernisation will improve flight efficiency, punctuality and reduce costs per flight, enabling airlines to take advantage of the performance capabilities of their modern aircraft fleets.

Airspace modernisation will ensure that airspace design is proportionate and flexible to meet the needs of all current and future users, including General Aviation (GA), spaceflight and the military.

It also plays a key role in encouraging the innovative opportunities that new and emerging technologies, such as aerial taxis and remotely piloted aircraft, can provide through safe integration (rather than segregation) in busy air environments.

These newer technologies can help to provide new services to businesses and the public, alongside current medical or search and rescue flights.

The implementation of new technologies such as electronic conspicuity, which enable airspace users to be seen and detected, improve safety through the potential reduction of mid-air collisions.

Airspace modernisation will continue to ensure that military operators can access suitably sized and sited areas of airspace to fulfil defence and national security objectives, recognising that military aircraft often require large volumes of airspace to train and maintain operational readiness.

Airports and air navigation service providers

The sharing of accurate flight information about traffic using UK airspace is expected to improve airport productivity and resilience to disruption from bad weather.

Additional airspace capacity gives airports the scope to develop operations in line with their business plans (subject to planning considerations).

Reduced delays will benefit airports and airlines who incur additional fuelling and operational costs when delays occur. Pre-departure delays on the ground caused by capacity constraints in airspace will be reduced.

Implementing modern technology combined with updated airspace design enables safe, expeditious and efficient management of increased traffic.

Cost efficiencies are expected to be reflected in improvements in air navigation services productivity.

Potential challenges

When airspace design changes occur, the redistribution of noise between different areas may lead to disruption for some communities living under new flight paths or existing paths with more intense activity, whereas other communities might hear less noise. People living under a PBN route may experience an increase in noise.

It may not be possible to distribute the benefits of modernisation of airspace designs evenly. For example, regions with multiple overlapping airspace designs are inherently complex and therefore may have more to gain from modernisation than less complicated regions.

At lower altitudes in particular, it may be difficult to realise the benefits of both reduced emissions and lower noise levels in full, as there are likely to be some trade-offs required between the two.

Airspace improvements benefit both arriving and departing flights, but only emissions on flights departing the UK are accounted for as UK aviation emissions.

Research from airlines, trade bodies and other industry stakeholders to quantify the emissions savings that airspace modernisation could deliver is currently ongoing.

Further benefits from airspace modernisation, including enabling the use of electric autonomous vehicles such as drones and electric vertical take-off and landing (eVTOL) aircraft, to replace road transport and traditional aircraft operation, are unquantified.

Policy developments

The Department for Transport is working with the Civil Aviation Authority and others to modernise UK airspace.

Read more about why we need to modernise our airspace and what we are doing.