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Airspace Change - For expansion and existing two runways

We want local communities to tell us what we should take into account when designing new flight paths – both for expansion, and to make better use of our existing runways.

In this consultation, we are presenting the geographic areas within which flight paths could be positioned. We are asking what local factors should be taken into account when developing new flight paths within these geographically defined areas known as ‘design envelopes’.

The design envelopes presented cover both:

  • Potential flight paths for an expanded Heathrow i.e. with a third runway; and
  • Potential new flight paths for some arrivals to make better use of our existing two runways i.e. prior to the operation of a third runway.

To develop detailed options for new flight paths we first define the broad areas within which they could feasibly be positioned. These are known as design envelopes (See below “What is a design envelope? In more detail…”). The wide areas do not mean that the final flight path or paths will be spread across the extent of the envelope.

New flight paths for Heathrow, both for expansion and for some arrivals on our existing two runways, will see the introduction of new air navigation technology, Performance-based Navigation (PBN), to modernise the way aircraft fly.

What is a design envelope? In more detail...

A design envelope is a geographical area within which it is technically possible to position one or more flight paths. It does not mean that final flight paths will be spread across the full width of the envelope.

The envelopes have been divided into sections to show the heights that aircraft could be flying at for that portion of the envelope. Given that the height (altitude) of an aircraft affects the noise level experienced on the ground, we have assumed the lowest potential heights for these design envelopes. In reality, we would expect aircraft will be flying higher (and should therefore be quieter when heard from the ground).

The design envelopes also show the number of aircraft which might fly through that envelope in a given day.

By providing information on the number, height and noise of potential flights over your area, our design envelopes aim to give you an understanding of the potential impact of flights and helps you to respond to this consultation.

What is Performance-based navigation?

The introduction of Performance-based navigation (PBN) is the key to achieving airspace modernisation. PBN improves the accuracy of where aircraft fly by moving away from outdated and conventional navigation using ground-based beacons, to modern satellite navigation. This is similar to the sat navs that most people have in their cars today.

As Heathrow’s airspace and the routes aircraft fly are redesigned to accommodate the expansion of the airport and a new runway, we will move to using PBN. Heathrow needs to introduce PBN to meet our commitments to the Government’s Airspace Modernisation Strategy.

PBN is being introduced across the world. This new technology allows more flexible positioning of routes and enables aircraft to fly them more accurately. This helps improve operational performance and reduce delays. It also provides opportunities to avoid noise sensitive areas.

PBN flight paths will be narrower and more concentrated than they are today and we understand that this may be a concern to some local communities. Heathrow is committed to working with residents, local stakeholders and the aviation industry to find ways to introduce PBN while seeking to limit negative effects from aircraft noise.

We have been discussing potential impacts of PBN with local stakeholders in Heathrow’s regular community engagement forums over the last few years, and considering options to “share” aircraft noise to reduce the potential impact of concentration of flight paths.

We also undertook a public consultation last year on Airspace Design Principles, where we asked for feedback on potential principles to guide how we design our future flight paths, including whether we should look to share flights across a wider area.

How can I find out information about flights today over my area?

The design envelopes presented in this consultation show the geographical area of where it is possible to locate future flight paths – therefore they are only used as part of our design process for future changes.

You can see how areas are currently overflown using our online flight tracking and analysis tools available here: https://www.heathrow.com/noise/what-you-can-do/track-flights-on-maps

Questions – Airspace Change

While looking through the information below please keep in mind that we are asking for your feedback on the following three questions: 

  1. What sites or local factors should we be aware of in your area (or other areas of interest to you), when designing flight paths for an expanded three-runway Heathrow? 
  2. What sites or local factors should we be aware of in your area (or other areas of interest to you), when designing new arrival flight paths to make better use of our existing two runways? 
  3. Any other comments you have relating to the airspace elements of the consultation

What is the process for airspace change - including flight paths?

The aviation industry is regulated by the Civil Aviation Authority (CAA) in the UK, and they ensure that the environmental impact of aviation on local communities is managed through efficient use of airspace. When changes to airspace are proposed, an airport is required to follow the CAA’s Airspace Change Proposal (ACP) process.

The process places great importance on engaging and consultation on airspace proposals throughout the process with a wide range of stakeholders, including potentially affected communities.

Although a formal consultation is only required at a later stage of the process, given the scale and complexity of Heathrow’s airspace changes, we have decided to carry out three phases of consultation.

These stages are:

  • The consultation on design principles which took place in 2018;
  • This consultation on design envelopes; and,
  • A future consultation on flight path options

This gives all stakeholders the best opportunity to be involved throughout the process to help shape the design and structure of Heathrow’s future airspace.

The first stage of the CAA’s airspace change process requires airports to engage on design principles. These are effectively a set of principles that could be used to design and structure future airspace. In 2018, Heathrow consulted and engaged with stakeholders, including local communities, on the design principles for both an expanded Heathrow and potential changes to some arrivals flight paths for our existing two runways.

Both sets of proposed design principles were submitted to and approved by the CAA in 2018.

This consultation on design envelopes gives you the opportunity to provide feedback that will help us to shape our flight path options for the future consultation. This means we do not have flight path options to consult on at this stage.

What are the airspace design principles for an expanded Heathrow?

1. Must be safe

2. Must meet Airports National Policy Statement requirements, including capacity

3. Must meet 3 Airports National Policy Statement noise policy tests

4. Must meet local air quality requirements

5. Must meet commitments to the government’s Airspace Modernisation Strategy

6. Should limit, and where possible reduce, local noise effects from flights by:

a. Using more noise efficient operational practices

b. Minimising number of people newly overflown

c. Maximising sharing through predictable respite

d. Avoiding overflying communities with multiple routes

e. Maximising sharing through managed dispersal

f. Minimising total population overflown

g. Designing flight paths over commercial and industrial areas

h. Where appropriate, prioritising routing flight paths over parks and open spaces (rather than over residential areas), but avoiding overflight of Areas of Outstanding Natural Beauty (AONB)

7. Should minimise fuel/CO2/greenhouse gasses per flight

8. Should ensure operational efficiency and resilience to maximise benefits to all stakeholders

9. Should base our airspace design on the latest navigation technology widely available

10. Should minimise impact on other airspace users

The third, and final stage, in the ACP will be a final consultation on flight path options, which will be developed following the feedback given in this consultation.

What are the design principles for changes to some arrivals flight paths for our existing two runways?

1. Must be safe

2. Must meet the three aims of the Noise Policy Statement for England (NPSE):

a. Avoid significant adverse impacts on health and quality of life

b. Mitigate and minimise adverse impacts on health and quality of life

c. Where possible, contribute to the improvement of health and quality of life

3. Must meet local air quality requirements

4. Must base our airspace design on the latest navigation technology widely available

5. Must meet Heathrow’s hourly landing rate requirements

6. Should limit, and where possible reduce, local noise effects from flights:

a. Use more noise efficient operational practices

b. Maximise sharing through predictable respite

c. Avoid overflying communities with multiple routes

d. Minimise the number of people newly overflown

e. Minimise total population overflown

f. Design flight paths over commercial and industrial areas (rather than residential areas)

g. Where appropriate, prioritise flight paths over parks and open spaces (rather than residential areas), but avoid
overflight of Areas of Outstanding Natural Beauty where possible

7. Should minimise impact on Heathrow’s existing traffic patterns and other airspace users

8. Should minimise fuel and CO2 greenhouse gases per flight

9. Should be simple and efficient flight paths for operational efficiency





Airspace change for an expanded Heathrow

The expansion of Heathrow is not just about the physical changes required on the ground. Building a new runway will also lead to changes to the flight paths planes follow. This is known as an “airspace change”.

The Government is driving plans to modernise the UK’s airspace to accommodate growing demand for air travel. The modernisation of UK airspace will happen regardless of the expansion of Heathrow, but combining the two provides Heathrow with a once in a generation opportunity to update and improve the way our airspace is used.

Changes that are made to accommodate a third runway at Heathrow will also need to fit in with the changing airspace of the UK and Europe. Heathrow is working closely with NATS (the UK’s leading provider of air traffic control services) and the other airports in the south-east of England to develop an integrated approach to airspace modernisation.

Feedback from this consultation, together with our design principles and technical requirements, will be used to develop flight path options. These will be the actual routes that aircraft will fly.

We will present these flight path options, and seek feedback on them, in a final consultation (likely to be in 2022). We will also provide evidence of all the technical work undertaken when designing flight paths, and full analysis of the flight path options, at this stage.

Making better use of our existing runways - Independent Parallel Approaches

As part of this consultation, Heathrow is also consulting on a proposed short-term change to the way that some aircraft arrive at Heathrow. This is known as Independent Parallel Approaches (or “IPA”) and involves some new arrival routes into Heathrow from the holding stacks. Some of these flight paths could overfly areas that are not affected by Heathrow arrivals today.

The introduction of IPA requires an airspace change to be approved by the CAA, and our current consultation on IPA will form part of our evidence of engagement with local communities and affected stakeholders.

IPA will make us more efficient and more resilient to disruption, reducing the chances of delays for passengers. Any airspace changes required would be replaced by our longer-term airspace design, if our third runway is approved.

How does IPA work?

A standard aircraft approach at Heathrow
With the introduction of IPA, aircraft landing on the arrival runway would continue to be directed as they are today. However, aircraft landing on the departure runway would follow new precise flight paths from the holding stacks to the final approach.
Current Dependent Parallel Approaches
Currently, an aircraft landing on the departure runway must be diagonally spaced by a specified distance from aircraft landing on the arrival runway. To achieve this, the spacing between aircraft landing on the arrival runway has to be increased compared to when only one runway is used for landing. This additional spacing means that fewer aircraft are able to land on the arrival runway in that hour. So even though both runways are being used for landings, there is only a small gain in the total number of arrivals.
Independent Parallel Approaches in action
As show in the diagram above - because the aircraft is following a very precise arrival flight path using Precision Based Navigation (PBN), the aircraft can be classed as operating independently. This is because PBN technology gives us certainty that aircraft will be safely separated when landing in parallel and removes the need for the diagonal spacing between arriving flights. This would prevent any reduction in the number of aircraft that can land on the arrival runway, resulting in a much more efficient use of the arrival process.

How to tell if you may be affected by airspace changes? Check your postcode

We’ve made it easy to check your postcode and see any potential flight path design envelopes in your area. Visit out online response tool and enter your postcode via the first question that appears.

Are there any limitations on using IPA?

Only aircraft certified to use this type of PBN approach required for IPA will be able to use the new flight paths. It is costly for older aircraft types to be upgraded with the required technology for IPA and so we expect the vast majority of aircraft that could use the IPA flight paths will be modern aircraft such as the Boeing 787, A320neo and the Airbus 350. Airline forecasts have demonstrated to us that there will be a sufficient number of certified aircraft to fly the IPA flight paths.

Use of the IPA flight paths would also not be possible in all weather conditions. For example, during fog, thunder storms and/or extremely windy conditions. In these circumstances, we will continue to land on the departure runway the way we do today using diagonal spacing.


What are the benefits of IPA?

The introduction of IPA has the potential to increase the efficiency and resilience of the airport. IPA will make our arrivals procedures more efficient which will reduce arrival delays. Typical savings are estimated to be up to 13 hours of arrival flight delay per day, which is a benefit to all passengers.

This will lead to further benefits including:

  • Reducing fuel burn from aircraft queuing in Heathrow’s holding stacks on arrival, leading to a reduction in carbon emissions;
  • Improving the punctuality of flights including a reduction in the number of late running flights and cancellations;
  • Enabling the airport to prevent and recover from arrival delays more quickly. This is expected to result in fewer flights departing in the night time period;
  • Reducing the number of aircraft that land on the departure runway which will improve periods of respite from aircraft noise via runway alternation for residents living under the final
    approach into Heathrow;
  • Supporting airline cost savings associated with delays;
  • Contributing to meeting the UK’s legal obligation to implement PBN flight paths at Heathrow.

In addition to the benefits we have already mentioned, by making more efficient use of our two runways, IPA could also be a step towards delivering a longer period at night without scheduled flights. However, Heathrow is not presently proposing or consulting on that change as part of the IPA airspace change proposal.

There are clear benefits to IPA and those are our rationale for the IPA proposal. However, IPA could also be used to facilitate additional capacity in advance of the third runway being brought into operation, should that be permitted as part of expansion (see Early Growth within Managing Heathrow’s growth within environmental limits). In that instance, it should be noted that the scale of some of the benefits set out on this page may vary.

Full details of the impacts of any additional capacity will be discussed in our June 2019 consultation and are not the subject of this consultation. Heathrow has stated that if we put forward proposals for additional capacity it would be only be implemented at the same time as a longer period at night without scheduled flights.

What could the introduction of IPA mean for local communities?

As well as improving the overall performance of the airport and reducing delays for Heathrow’s passengers, the introduction of IPA would mean a number of flights flying over areas that do not routinely see arriving aircraft today from 6am onwards. These new flight paths would use PBN which means aircraft using IPA would follow the flight paths with increased precision and consistency compared to existing flight operations.

What changes would IPA introduce?

  • The introduction of IPA would require new PBN arrival flight paths from Heathrow’s holding stacks to the departure runways;
  • When we are using both runways for landing, only those aircraft landing on the departure runway will use the new IPA flight paths;
  • Aircraft would fly these new flight paths precisely;
  • New IPA arrival flight paths would mean a number of flights going over some areas that do not routinely see arriving aircraft today. Please see “Making Better Use of our Existing Runways” for more information;
  • IPA aircraft will be joining the final approach closer than the 8 nautical miles that they do today (only for IPA arrivals to the departure runway). This is because the aircraft landing on the main landing runway must be established on their final approach before coming within 2.5nm of the aircraft following the IPA flight path.

What questions are you asking for feedback on in this section of the consultation? 

To help us design new flight paths we want to know whether there are any sites or locations that you think require special consideration by us in determining where future flight paths should be. 

Our interactive map, within the online feedback tool on this website, can be used to input the postcode of your business, property, residence or local site of interest to reveal the potential airspace Design Envelopes that may affect it. 

We are asking for your feedback on two questions: 

  1. What sites or local factors should we be aware of in your area (or other area of interest to you), when designing flight paths for an expanded three-runway Heathrow? 
  2. What sites or local factors should we be aware of in your area (or other area of interest to you), when designing new arrival flight paths to make better use of our existing two runways? 
  3. Any other comments you have relating to the airspace elements of the consultation