• In line with long-standing international agreements, the UK has a well-established system for notifying blocks of airspace where particular limitations are placed on the flight of all aircraft (manned and unmanned).  Such areas are typically either: Prohibited Areas, Restricted Areas or Danger Areas (military ranges etc).  Other airspace may have temporary restrictions imposed at specific times, either as a result of a longer term pre-planned event, or in reaction to a short notice occurrence, such as an emergency incident.  Further details can be found in the UK Aeronautical Information Package (UK AIP) at the NATS Aeronautical Information Service (AIS) website.  General airspace Rules and Procedures can be found at section ENR 1.1, and specific ‘Navigation Warnings’ can be found at section and ENR 5.

    Permanent Prohibited, Restricted or Danger areas are marked on aviation ‘Visual Flight Rules’ (VFR) flight charts (maps) which are readily available for purchase online or at local flight schools/clubs.  In addition, proprietary VFR flight-planning and navigation software and apps contain such information in their mapping databases.  A free, limited, version of such software is available here: www.skydemonlight.com.  Other Apps are also available, such as the ‘Drone Assist’ App which can be accessed through the Dronesafe website.

    It is occasionally necessary to institute temporary restrictions of airspace (‘Restricted Area – Temporary’).  These are usually shared via Aeronautical Information Circulars or, if done at very short notice, via the Notice to Airmen (NOTAM) system.  These temporary restrictions are also listed on the AIS website.  It is important to note that these restricted areas apply to all aircraft including drones, regardless of weight or height of operation.

    Flight restrictions around aerodromes

    Flights of drones around airfields or airports that are designated as ‘protected aerodromes’ are tightly restricted.  Drones must not be flown closer than 1km from the boundary of a protected aerodrome without first checking that you have permission to do so.  Further details on the precise aspects of the restrictions, how they apply and at which aerodromes can be found within CAP 1687

    Controlled Airspace and Aerodrome Traffic Zones (ATZ)

    UK airspace is divided into separate airspace 'classes' for Air Traffic Management purposes - these are classified by the letters 'A' to 'G, with Class A being the most tightly regulated, down to Class G being the least restrictive.  Classes A to E are known as Controlled Airspace (CAS).  In addition, licensed aerodromes have an Aerodrome Traffic Zone (ATZ) established around them, within which some additional rules for aircraft operations apply.  Controlled airspace and ATZs are established in busier airspace, where the density of air traffic is likely to be high, and so the potential for a conflict with a manned aircraft will therefore be much greater. Unmanned aircraft weighing more than 7kg are not permitted to be flown in controlled airspace or within an ATZ without the permission of the Air Traffic Control unit responsible for the airspace.

    Although operators of drones weighing 7 kg or less are not required to have the permission of Air Traffic Control (even when flying within Controlled Airspace or within an ATZ), the Air Navigation Order requires that any person in charge of a small drone:

    • may only fly the aircraft if reasonably satisfied that the flight can safely be made
    • must maintain direct, unaided visual contact with the aircraft …for the purpose of avoiding collisions.  Note: The use of normal corrective spectacles is acceptable within the term ‘unaided’

    In practical terms, drones of any weight could present a particular hazard when operating near an aerodrome or other landing site due to the presence of manned aircraft.  Operators of small drones are therefore strongly advised to remain clear of charted aerodromes by at least a distance of 5 km, whether or not the aerodrome is in controlled airspace or has an associated Aerodrome Traffic Zone (ATZ).

    The CAA will not advise on post codes and locations where drones can be flown, as this covered by the Air Navigation Order i.e. classes of Airspace. The responsibility lies with the operator to determine if the area he has chosen to fly in is suitable.

    Royal helicopter flight airspace

    When royal flights in helicopters take place airspace known as a Royal Low-Level Corridor (RLLC) is established between the departure and arrival sites; the details of the flights, including the route and timings, are published by NOTAM and so will also be depicted on airspace mapping apps.  

    A RLLC encompasses the airspace five nautical miles either side of the intended track of the Royal helicopter, a five nautical mile ‘circle’ around the departure and arrival sites, and extends from the surface up to 1,000ft above the royal helicopter’s highest planned transit altitude.  RLLCs are also divided into 20 minute ‘sectors’, with checkpoint locations nominated at the start and end of each sector.  

    The key requirements for operators of small unmanned aircraft are to be aware of the flight, keep a good look out and maintain adequate separation from the royal helicopter; however, small unmanned aircraft operators are strongly advised to keep their aircraft at least one nautical mile horizontally clear of the departure and arrival sites during the published active periods (15 minutes before until 30 minutes after the planned departure/arrival time detailed in the NOTAM).  

    Other considerations to take into account before operating

    The role of statutory bodies

    The aviation regulations only address the flight safety aspects of the flight and they do not constitute permission to disregard the legitimate interests of other statutory bodies such as the Police and Emergency Services, the Highway Agency, local authorities or any other statutory body.  As the range and scale of drone operations continues to grow, statutory bodies are increasingly aware of how drone operations will affect their areas of responsibility and are developing specific policy and guidelines.

    In addition to aviation-specific legislation, it is already apparent that drone use, or the effects of drone use, may be construed to be encompassed within the remit of existing national and local legislation (e.g. public-order offences, ensuring pedestrian and vehicle rights-of-way, security and safety in public places and at schools, limits on recreational activities in public parks etc). 

    Any camera equipped drone operator who does not have an additional permission from the CAA, is restricted to remaining at least 150 metres from congested areas or any organised, open-air assembly of more than 1,000 people.  Drone operators must not fly camera fitted drones within a distance of 50 metres of any person, vessel, vehicle or structure that is not under the control of the person in charge of the said aircraft (during take-off and landing this distance may be reduced to 30 metres).  This means that each flight will carry a ground ‘footprint’ below the aircraft, within which there should be no uninvolved members of the public.  This is difficult to achieve in a busy urban environment and will likely involve the drone operator making formal arrangements with the relevant authority to temporarily restrict pedestrian and vehicular access or to restrict access to shops, dwellings and other property.

    A congested area means, ‘in relation to a city, town or settlement, any area which is substantially used for residential, commercial, industrial or recreational purposes’.

    Drone operators should also be mindful of the requirements of Section 76(1) of the Civil Aviation Act 1982 in relation to trespass and nuisance, noting that they must comply, at all times, with the requirements of the Air Navigation Order.  

    Drones should be flown at a height over the property of another person which is ‘reasonable’ in all circumstances. Failure to do so could amount to trespass if the flight interferes with another person’s ordinary use and enjoyment of land and the structures upon it.