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Legislation, notification and Civil Aviation Authority (CAA) Airspace Regulation output

Different legislation/notification requirements and output methods apply for the various types of balloons. Please refer to the relevant section below.

Captive/tethered unmanned gas balloons

Captive balloon flying in UK airspace is subject to the requirements of Article 92 of the Air Navigation Order (ANO) 2016 (as amended) and the CAA policy for operation of tethered balloons in UK airspace.

In accordance with ANO Article 92, CAA Airspace Regulation issues permissions for captive balloon flights where the top of the balloon will exceed 60 metres (above ground level). Within an Aerodrome Traffic Zone, CAA (or Air Traffic Control/Aerodrome operator) permission is required at any height. The ANO defines a captive balloon as "a balloon which when in flight is attached by a restraining device to the surface". All applications for permission should be submitted using the notification form.

If it is a recurring event/activity, please quote the previous CAA activity reference number (if known) when completing the notification form.

We request a minimum of 28 days' notice. During periods of high workload, we may be unable to process notifications made with less than the stated minimum notice.

After you submit the notification form, you will receive an automated email confirmation that the details have been received.

In addition to the ANO, the following legislation applies to captive/tethered balloons:

For some events/activities of this type, we issue Notice to Aviation (NOTAM) to notify other airspace users. NOTAM are notices containing information concerning the establishment, condition or change in any aeronautical facility, service, procedure or hazard, the timely knowledge of which is essential to personnel concerned with flight operations. Further details of the NOTAM system are in the UK Aeronautical Information Publication (AIP) section GEN 3.1 (available on the NATS Aeronautical Information Service (AIS) website) and in the UK NOTAM Guidance Material.

Close Captive/tethered unmanned gas balloons

Hot air balloons

Hot air balloons are regulated by our General Aviation Unit. Please refer to their guidance for balloon operators.

CAA Airspace Regulation will usually only be involved in the co-ordination and notification of events that have mass "flyouts" of balloons. For those types of event, please complete and submit the notification form.

If it is a recurring event/activity, please quote the previous CAA activity reference number (if known) when completing the notification form.

We request a minimum of 28 days' notice. During periods of high workload, we may be unable to process notifications made with less than the stated minimum notice.

Event organisers should co-ordinate directly with ATC Units, aerodromes or other sites of aviation activity, as necessary. Details of any co-ordination that has taken place should be stated in the notification form.

After you submit the notification form, you will receive an automated email confirmation that the details have been received.

We will usually issue Notice to Aviation (NOTAM) for this type of event/activity.

Close Hot air balloons

High altitude unmanned meteorological or research balloons

High altitude unmanned balloon activities are defined as “unmanned free balloons”, the regulations for which are within the Standardised European Rules of the Air Regulation (EU) No. 923/2012 as retained (and amended in UK domestic law) under the European Union (Withdrawal) Act 2018. One of the requirements is that “the State from which the launch is made” must authorise all unmanned free balloons. Therefore, an organiser/operator needs to obtain CAA Airspace Regulation exemption/permission for any such launches in the UK, regardless of the balloon/payload size and weight. All applications should be submitted using the notification form.

If it is a recurring event/activity, please quote the previous CAA activity reference number (if known) when completing the notification form.

We request a minimum of 28 days' notice. During periods of high workload, we may be unable to process notifications made with less than the stated minimum notice.

As this type of activity is very weather-dependent, applicants are encouraged to specify a “window” of at least one week in their notification, to give them more flexibility in selecting a suitable launch day/time. In most cases, it is possible for an exemption/permission to be valid for the duration of the launch "window", with the organiser/operator then giving advance notice (usually a minimum of 72 hours) to the CAA of their proposed launch date/time, so that Notice to Aviation (NOTAM) action can be taken to forewarn other airspace users.

After you submit the notification form, you will receive an automated email confirmation that the details have been received.

Locations of known permanent high altitude unmanned balloon launch sites are detailed in the UK AIP section ENR 5.3 (available on the NATS AIS website). Proposed additions or changes to the UK AIP list of sites should follow the process detailed in CAP 1618: Airspace Design: Unusual aerial activities published in the UK AIP.

For proposed launches of “rockoons” (high altitude unmanned balloon and rocket combination), please initially contact Airspace Regulation for advice and guidance.

Close High altitude unmanned meteorological or research balloons

Toy balloon releases

Guidance on releases of helium-filled small (toy) balloons can be found in CAP 736: Operation of Directed Light, Fireworks, Toy Balloons and Sky Lanterns within UK Airspace.

The release of small balloons in UK airspace is subject to the requirements of Article 93 of the ANO 2016 (as amended). Outwith the legal requirements, CAA Airspace Regulation may consider it necessary to impose restrictions in order to ensure flight safety, particularly for mass releases within 10 nautical miles of an active aerodrome. All applications should be submitted using the notification form.

If it is a recurring event/activity, please quote the previous CAA activity reference number (if known) when completing the notification form.

We request a minimum of 28 days' notice. During periods of high workload, we may be unable to process notifications made with less than the stated minimum notice.

After you submit the notification form, you will receive an automated email confirmation that the details have been received.

We may issue Notice to Aviation (NOTAM) for this type of event/activity.

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CAA Airspace Regulation response

When the notification is received, the details are checked to ensure all required information has been provided in line with regulatory/policy requirements. The event/activity is then compared against other known activity where we would support the co-ordination and deconfliction of any conflicting activities. If clarification of the details is required, we will contact you via the email address that was provided in the notification form.

We will endeavour to respond (to the address that was provided in the notification form) at least 7 days prior to the proposed start of the event/activity. When enquiring about the status of an outstanding notification, please always quote the reference number that you received in the automated email confirmation. The email response will explain whether or not the notification has been successfully processed. Additional advice/guidance may be included. If a formal CAA permission or exemption is issued, it will be attached to the email message.

CAA Airspace Regulation do not currently charge for this work. For costs relating to the regulation of hot air balloon events/activities, please seek advice from our General Aviation Unit. Full details of our charges can be found in the Scheme of Charges.

Changes and cancellations



If your event/activity is changed or cancelled, please inform Airspace Regulation as soon as possible. If Airspace Regulation have already completed the assessment of the event/activity and provided you with a detailed response, please quote the activity reference number that was used in our email to you.

For changes, appropriate re-assessment and notification action will be undertaken. For cancellations, we will take action to cancel any output already published.

However, please bear in mind that, during periods of high workload, we may be unable to action changes/cancellations made at short notice.

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Responsibilities of the event/activity sponsor

The CAA’s response to the sponsor does not constitute permission to disregard the legitimate interests of site landowners, other statutory bodies such as the Police and Emergency Services, the Highway Agency, local authorities (and their agents) or any other statutory body. It is the sponsor/operator’s responsibility to ensure that those interests are taken into consideration before going ahead with the event/activity.

The event/activity sponsor/operator is ultimately responsible for flight safety and must comply with the Air Navigation Order (ANO) 2016 (as amended) articles relating to endangerment:

  • Article 240 - Endangering safety of an aircraft

    A person must not recklessly or negligently act in a manner likely to endanger an aircraft, or any person in an aircraft.
  • Article 241 - Endangering safety of any person or property

    A person must not recklessly or negligently cause or permit an aircraft to endanger any person or property.

ANO Article 265 provides that it is a criminal offence to contravene EC Regulations as retained (and amended in UK domestic law) under the European Union (Withdrawal) Act 2018, the ANO or Regulations made under the Order. Further information can be found in CAP 1422: Code of Practice for the Investigations and Enforcement Team.

The sponsor/operator is responsible for the event/activity complying with all relevant national regulations.

Please refer to the relevant event/activity page for more specific guidance.

Contact us

If you have any questions, please contact Airspace Regulation between the hours of 08:30 and 16:30 Monday to Friday (excluding Public Holidays).  It may not be possible to action messages/notifications submitted after 16:00 until the next working day.

Planned periods of extended closure of the Airspace Regulation section will be notified here:

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