What is an Airspace Change Proposal (ACP)?

It is a formal UK Civil Aviation Authority (CAA) process that is being undertaken by TAG Farnborough Airport in order to introduce a new airspace design to benefit airport operations. The standard published process is outlined in CAA guideline documents CAP724 and CAP725.

What do you mean by airspace?

Airspace is the vertical and lateral extent within which fixed wing aircraft, helicopters and other types of aircraft fly. Airspace is categorised by the CAA in a number of ways, which determine the rules governing its operation and the requirements placed on pilots and air traffic controllers.

How is airspace currently managed at the airport?

TAG Farnborough Airport currently operates within Class G airspace (uncontrolled airspace), which is shared with other airports, gliding sites and general aviation activities. Presently, while controlling airport traffic, TAG Farnborough radar controllers have to observe and take account of non-airport traffic, which can result in longer, less direct routings, less predictable climb or descent profiles for aircraft flying out of or into the airport and an increase in cockpit and air traffic control workload during take-offs and landings.

While TAG Farnborough Airport operates to the highest safety standards within the current airspace environment, Class G airspace is less able to efficiently support predictable and structured arrivals and departures that are required to maintain an efficient operation as the number of air transport movements (ATMs) increases at the airport. TAG Farnborough Airport currently handles approximately 25,000 ATMs per annum and has approval to increase the number of ATMs up to 50,000 per annum by 2019.

Why does TAG Farnborough Airport propose to change its airspace?

The objective of the proposed airspace change is to create a new operating environment with elements of ‘controlled’ airspace, which would offer all airspace users predictability and consistency of operation. Creating a known air traffic control environment would assist the airport in catering for an increasing number of air transport movements and do so in a way which benefits efficiency and safety for many airspace users, and the environment.

What is controlled airspace?

Controlled airspace is a defined area of airspace within which all aircraft must be in communication with air traffic control and follow its instructions. Other types of airspace have other requirements, for example, a Radio Mandatory Zone is not ‘controlled airspace’ but no aircraft are allowed therein without speaking to a controller first.

What are the benefits of the proposed airspace change?

The proposed airspace change aims to create a more predictable flow of air traffic to and from TAG Farnborough Airport, which has a number of advantages.

Overall airspace efficiency

A new airspace environment with controlled airspace would create more predictability in planning and managing operations, and also enable the introduction of routes based on advanced navigation standards. This could result in the following benefits:

  • More precise and efficient inbound and outbound flight paths
  • Fewer flights at low altitudes as arriving aircraft will remain higher for longer and departing aircraft will climb higher more quickly
  • Net reduction in people overflown
  • Reduced delays (both on the ground and in the air)

Creating more efficient airspace at TAG Farnborough Airport would benefit airport traffic, other airspace users and the environment.

Other general aviation airspace users would maintain the ability to cross the airspace with permission from air traffic control or to fly around the airspace.


While the current Class G airspace is managed in accordance with the highest safety standards, TAG Farnborough Airport is committed to continually identifying ways to advance safety standards. By changing to a new airspace environment, which includes controlled airspace, the airport will be able to create a known and more predictable environment.


With improvements in efficiency and safety, a new airspace environment could achieve reductions in noise around the airport as well as reduced fuel usage and emissions over time (including CO2), compared with doing nothing.

However, in developing design options, there is a balance to be struck between competing benefits. For example, low-level altitude routings may prioritise the avoidance of areas of population to reduce the impact of noise but could lead to an increase in track miles, thereby potentially negating the fuel-saving benefits. The consultation sought to explain this balance and asked for feedback.

If implemented, how will the ACP affect local people in and around TAG Farnborough Airport?

The impact on local residents and stakeholders has been of primary importance throughout. Noise is an important consideration for local people and the ultimate proposed design option will aim to further reduce the impact of noise; for instance, by optimising arrival and departure routes.

Will it lead to an increase in noise for local people?

Overall, the proposed airspace design should lead to less noise as new arrival and departure routes will be optimised to further reduce the overall noise impact.

The proposed design will aim to minimise delays for arriving aircraft, resulting in fewer people being overflown at low altitudes, as well as reducing delays to aircraft on the ground waiting to depart.

Will the Airspace Change Proposal affect the hours of operation?

No. The existing published hours will not change. Any aircraft movements that you see or hear outside of the published hours will not be operating from TAG Farnborough Airport.

The hours of operation of TAG Farnborough airport are, in local time:
7am to 10pm weekdays
8am to 8pm weekends and public holidays
Closed Christmas Day and Boxing Day

Is this proposal about increasing movements beyond the current allowed maximum at Farnborough?

No. TAG Farnborough Airport already has approval to operate up to a maximum of 50,000 movements per year, with incremental annual increases until 2019. The 2014 limit is 43,000 annual movements. There is no proposal to increase this number, which is limited by local authority planning consent.

Current movements are approximately 25,000 per year. The airport has the capacity to operate at 50,000 per year but the inefficiencies in the current airspace are such that any increase in movements by any operator/airport/airspace user would increase delays and holding in the region for all airspace users. The airspace change proposal therefore addresses this and is set to improve the efficiency of the airspace for all users.

Who will prepare the Airspace Change Proposal?

The proposal will be prepared by TAG Farnborough Airport; the ‘sponsor’ of the proposal as defined by the CAA. The airport has also contracted NATS, the UK air navigation service provider, which has considerable experience in carrying out airspace changes, to assist in technical and operational aspects.

Who will review the Airspace Change Proposal and how will a final decision be made?

Airspace Change Proposals follow a series of prescriptive steps outlined in CAA document CAP725. Before the proposal is submitted, there is comprehensive engagement with stakeholders and a formal consultation phase of at least 12 weeks, when anyone is welcome to respond, including members of the public. This consultation phase is now complete.

After the analysis and consideration of all the feedback gathered during consultation, we have produced a report detailing our findings. A first document, Feedback Report Part A, which provides a summary analysis of the numbers and types of responses received, is available for download here.

A second document, Feedback Report Part B, provides more detail on the final airspace design (and how we reached that design), is available to download here. After Feedback Report Part B is published, we will submit an Airspace Change Proposal (ACP) to the CAA.

Once submitted, the ACP will be reviewed by the CAA’s Safety and Airspace Regulation Group (SARG), which is legally obligated to ensure that airspace changes are undertaken fairly, properly and with demonstrable high levels of engagement and consultation. SARG will make a decision on whether to approve the proposal and can add conditions that it deems appropriate. SARG is required to make its decisions in accordance with its remit as outlined in CAP724 and CAP725.

What is the purpose of consultation?

CAA Airspace Change guidance document CAP725 states: “Consultation is the only way to ensure that the proposal has taken account of the interests of all airspace users and the society.”

Consultation is a way in which interested parties can raise considerations to ensure the design option is balanced between competing needs.

Please read the additional consultation document which can be found here.

What has happened so far?

The initial airspace design phase began in October 2012. This has involved continued engagement with key aviation stakeholders to help develop preliminary design options. A number of these options have been simulated and analysed for operational integrity which resulted in a single option being developed.

TAG Farnborough Airport took this proposed design to formal consultation, where both aviation stakeholders and members of the public along with other interested parties were encouraged to formally submit feedback.

TAG Farnborough Airport and NATS air traffic control experts have held meetings, discussions and workshops with aviation stakeholders in order to inform the airspace design options. Other non-aviation agencies have also been briefed on progress, for example the Farnborough Aerodrome Consultative Committee (FACC).

Public representatives (including MPs, district and borough councils), statutory bodies, the military and environmental groups have also been consulted.

All feedback from both aviation and non-aviation stakeholders is being considered and used to refine the proposed design option.

A consultation document outlining the proposed airspace changes was released at the start of the consultation on 3 February 2014, and consultation closed on 12 May 2014. All the consultation material is available under the Consultation Documents section of this website.

All feedback gathered during public consultation was analysed. TAG Farnborough Airport published an initial document on 29 August 2014, Feedback Report Part A, which provides a summary analysis of the numbers and types of responses received.

TAG Farnborough Airport published a second document on 3 July 2015, Feedback Report Part B, which describes how the main points raised have been taken into account in the design refinement process. It describes the airspace design and routes that we seek to submit to the CAA for its consideration under its CAP725 airspace change process.

From 10 August 2016 to 2 November 2016, TAG Farnborough Airport held an additional consultation following the identification of opportunities to refine the Proposal submitted to the CAA in July 2015. This consultation was limited in scope and area, details of which can be found on the Consultation Document page.

Which stakeholders were contacted regarding the Additional Consultation?

2Excel Engineering Lasham Goodwood Airport
Adventure Balloons Guild of Air Traffic Control Officers (GATCO)
Aircraft Owners and Pilots Association (AOPA) Harting Parish Council
Airport Operator’s Association (AOA) Heavy Airlines
ARPAS UK Helicopter Club of Great Britain (HCGB)
Aviation Environment Federation Heyshott Parish Council
BAE Systems Honourable Company of Air Pilots
Bepton Parish Council Lasham Gliding Society
Blackbushe Airport Lavant Parish Council
Bramshott and Liphook Parish Council Light Aircraft Association (LAA)
Brimpton Airfield Light Airlines
British Air Transport Association (BATA) Linch Parish Council
British Airline Pilot’s Association (BALPA) Low Fares Airlines
British Airways Lynchmere Parish Council
British Balloon & Airship Club (BBAC) Marden Parish Council
British Business & General Aviation Association (BBGA) Midhurst Town Council
British Gliding Association (BGA) Milland Parish Council
British Hang Gliding & Paragliding Association (BHPA) MoD DAATM
British Helicopter Association (BHA) NATS
British Microlight Aircraft Association (BMAA) Popham Airfield
British Model Flying Association (BMFA) PPL/IR Europe
British Parachute Association (BPA) Rogate Parish Council
British School of Ballooning Scotland Farm
Campaign for Rural England (CPRE) Singleton Parish Council
Mr Andrew Tyrie, MP for Chichester South Downs National Park Authority
Chichester District Council Southdown Gliding Club
Cocking Parish Council Stedham with Iping Parish Council
Compton Parish Council Stoughton Parish Council
Denham Airfield Tongham Airfield
Dunsfold Aerodrome Trotton with Chithurst Parish Council
Easebourne Parish Council Valentine Farm
Mr Damian Hinds, MP for East Hampshire Virgin Balloons
East Hampshire District Council & Havant Borough Council West Dean Parish Council
Elsted and Treyford Parish Council West Lavington Parish Council
European UAV Systems Centre Ltd West London Aero Club at White Waltham
Fairoaks Airport West Sussex County Council
Fernhurst Parish Council Wishanger Frensham Ponds
Funtington Parish Council Woolbeding with Redford Parish Council
General Aviation Alliance (GAA) Wycombe Air Park (Booker Aviation)
General Aviation Safety Council (GASCo)

Will there be any change in the size or types of aircraft operating at TAG Farnborough airport as a result of this proposal?

No. The existing planning restrictions in place limit the maximum size of aircraft allowed to operate at TAG Farnborough Airport to aircraft like Airbus A319 and Boeing 737. In addition, the planning restrictions limit the number of movements of these aircraft to a maximum of 1,500 per year.

Will there be any change to the types of flight operations at TAG Farnborough Airport as a result of this proposal? For example, could charter or scheduled airlines operate out of the airport?

No. Operations at TAG Farnborough Airport are restricted to Business Aviation operations by the local planning authority, Rushmoor Borough Council. Recreational flying is limited to the incumbent small Flying Club and no bulk freight services, scheduled passenger services or “inclusive tour” charter flying is permitted.

Are the dimensions of airspace in the proposal unusually large in comparison to other airports?

No. We are required by the CAA airspace change process to keep the controlled airspace to the minimum necessary to achieve the aims of the proposal.

Is the proposed controlled airspace for the exclusive use of Farnborough traffic?

No. Regardless of any airspace design refinements, it is a fundamental requirement that access to this airspace is granted to all users whenever possible.

Will this proposal lead to a reduction in the number of air traffic controllers available at Farnborough?

No. Farnborough approach radar services will continue at the present level of service, indeed, an increase of one air traffic controller has been approved and implemented to increase flexibility and coordination in the area.

TAG Farnborough Airport remains committed to maintaining the current provision of the Lower Airspace Radar Services in the vicinity of Farnborough (“LARS West”) as part of the free London-wide LARS services. In 2013, Farnborough LARS provided services to 115,000 flights in the London region at no cost to the airspace user. This is in addition to the 27,000 Farnborough movements and 2,500 airway flights handled on behalf of nearby airfields (Lasham, Blackbushe, Dunsfold and Fairoaks are known as the “Farnborough Group of Airfields”).

You say that Farnborough aircraft will often be higher than at present – if that is true, why are you looking to lower the controlled airspace?

Farnborough aircraft currently fly below controlled airspace near the airport.

Lowering the airspace would encompass these flights and provide a small airspace buffer beneath. Primarily this lowering would encompass inbound traffic. With new connections to the wider airspace system, it would be easier for aircraft to climb departures higher and quicker. The consultation provided a great deal of useful data that was considered during the airspace redesign process.