Windfarms
Policy and guidance relating to wind turbines and aviation.
The Government is committed to reducing greenhouse gas emissions within the UK and, in turn, this means there is now a shift towards economically viable renewable energy sources rather than carbon fuels. It is anticipated that wind energy will provide a significant contribution to renewable energy targets.
In order to harness this energy supply, both on- and offshore wind turbine developments are being constructed, which range from single structures to developments encompassing over one hundred wind turbines and which range in size from less than 30 metres to over 150 metres tall. The physical characteristics of wind turbines coupled with the size and siting of the developments can result in effects which impact on aviation.
Under the Civil Aviation Act, the CAA is responsible for providing advice about aviation safety. Our Safety and Airspace Regulation Group has the lead responsibility within the CAA for all wind turbine-related issues.
CAA policy
Our policy on wind turbine developments is summarised below:
- wind turbine developments and aviation need to co-exist in order for the UK to achieve its binding European targets and enhance energy security, whilst meeting national and international transport policies. However, safety of the air is paramount and will not be compromised. As the independent aviation regulator, the CAA is well placed to provide support to both the aviation industry and the wind energy industry.
- due to the complex nature of aviation operations, and the impact of local environmental constraints, all instances of potential negative impact of proposed wind turbine developments on aviation operations must be considered on a case-by-case basis.
- to provide the best and most timely advice to aviation and wider wind development stakeholders through consultation, the publication of CAP 764 (CAA Policy and Guidelines on wind Turbines) and its associated web pages on the CAA web site.
Developers needing to notify the NOTAM section of the UK Aeronautical Information Service of windfarm lighting outages, in accordance with the requirements stipulated in CAP 764, should contact 01489 61 2488 / 2489.
CAA representation
The CAA represents civil aviation interests on the Department of Energy Security and Net Zero chaired Aviation and Defence Management Board.
The Ministry of Defence advises on all matters affecting military aviation.
We recommend that pre-planning consultation establishes both civil and military aviation related issues as early as possible.
We do not formally participate in the pre-planning processes, however, when a planning application is submitted to a Local Planning Authority the CAA will respond to any consultation sent by the council in question.
As with any development, related decision-making responsibility rests with the appropriate planning authorities who will take into account the potential impact upon local aviation activities.
The CAA has no role in assessing the purely environmental implications of any project and has no power of veto over any proposed wind turbine development.
The CAA has no responsibilities for safeguarding sites other than its own property: aerodrome operators are responsible for safeguarding their own sites. Councils are reminded of their obligations to consult in accordance with ODPM/DfT Circular 1/2003 or Scottish Government Circular 2/2003, and in particular to consult with NATS and the Ministry of Defence as well as any officially safeguarded aerodromes listed in the above documents.
It is published government advice that the operators of licensed aerodromes which are not officially safeguarded, and operators of unlicensed aerodromes and sites for other aviation activities (for example gliding or parachuting) should take steps to protect their locations from the effects of possible adverse development by establishing an agreed consultation procedure between themselves and the local planning authority or authorities.
Further information is available in:
The CAA requires notification of a change to aviation obstacles if it or they are 100 metres or more above ground level, in accordance with Article 225A of the Air Navigation Order (2016). The obstacle height of a wind turbine is measured to the blade tips not the hub or nacelle. Proposed changes to any existing en-route obstacles which (or will) attain or exceed a height of 100 m must also be notified. Additional consideration of the aviation obstacle environment may be required during the initial build phase and the temporary use of cranes that may extend above a height of 100 metres.
Such structures should be notified at least 8 weeks prior to the start of construction. We will require the:
- accurate location of the turbines / meteorological masts,
- accurate maximum heights,
- the lighting status of the turbines / meteorological masts and the estimated start / end dates for construction,
- the estimate of when the turbines are scheduled to be removed.
In order to ensure that aviation stakeholders are aware of the turbines / meteorological masts while aviation charts are in the process of being updated, developments should be notified through the means of a Notice to Aviation (NOTAM).
To arrange an associated NOTAM, a developer should contact CAA Airspace Regulation (AROps@caa.co.uk) at least 14 days prior to the start of construction.
The CAA works closely with NATS Aeronautical Information Services (providing the relevant information to inform the required publication of UK en-route obstacles in the Aeronautical Information Publication) and the MoD Defence Geographic Centre (obstacle data that the CAA receives is shared and vice versa).
Notification of new or existing obstacles, changes to existing obstacles and failures of aviation lighting is made through our Airspace Coordination and Obstacle Management Service (ACOMS) via the CAA customer portal. Further information is available at:
Obstacle notification | UK Civil Aviation Authority
https://www.caa.co.uk/Commercial-industry/Airspace/Event-and-obstacle-notification/Obstacle-notification/Obstacle-notification/
Aeronautical Obstacle Lighting and Marking
For obstacles that are not in the vicinity of a licensed aerodrome, in accordance with Article 222 of the Air Navigation Order (2016) aeronautical obstacle lighting is legally mandated for structures of a height of 150 metres (m) above ground level.
Impacts on civil aviation monitoring systems
Wind turbines can impact aeronautical safety systems (in particular, primary surveillance systems) through clutter and interference leading to potential performance degradation. This aspect should be considered within the Environmental Impact Assessment and Report.
Our regulatory powers ensure that air navigation service providers undertake appropriate safeguarding activities in respect of their systems and equipment used for the provision of services, that changes to the operating environment are fully considered within their Safety Management Systems and that the operational systems and equipment are functional and being used safely.
We recommend that engagement with all potentially affected aviation stakeholders is undertaken and appropriate mitigation schemes developed, if required.
Aviation Stakeholders
There are a number of officially safeguarded aerodromes which are defined in government circulars. Such aerodromes should have lodged safeguarding maps with planning authorities identifying the areas in which they need to be consulted. These aerodromes will consider the impacts of the proposed development on their operations
In terms of charting, there is an international civil aviation requirement for all structures of 300 feet (91.4 metres) or more to be charted on aeronautical charts. Please note the maximum height of a wind turbine is measured to the blade tips not the hub or nacelle.
Structures with a maximum height below 100 m above ground level
On behalf of other non-regulatory aviation stakeholders, and in the interest of aviation safety, the CAA also requests that any feature/structure 70 ft. (21.3m) in height, or greater, above ground level is reported to the Defence Geographic Centre (DGC) via dvof@mod.gov.uk to allow for the appropriate notification to the relevant aviation communities. It should be noted that NOTAMs would not routinely be required for structures under 100 m unless specifically requested by an aviation stakeholder.
Aeronautical Obstacle Lighting and Marking
For obstacles that are not in the vicinity of a licensed aerodrome, in accordance with Article 222 of the Air Navigation Order (2016) aeronautical obstacle lighting is legally mandated for structures of a height of 150 metres (m) above ground level.
Additional information is contained within CAP 764.
Impacts on civil aviation monitoring systems
Wind turbines can impact aeronautical safety systems (in particular, primary surveillance systems) through clutter and interference leading to potential performance degradation. This aspect should be considered within the Environmental Impact Assessment and Report.
Our regulatory powers ensure that air navigation service providers undertake appropriate safeguarding activities in respect of their systems and equipment used for the provision of services, that changes to the operating environment are fully considered within their Safety Management Systems and that the operational systems and equipment are functional and being used safely.
We recommend that engagement with all potentially affected aviation stakeholders is undertaken and appropriate mitigation schemes developed, if required.
Aviation Stakeholders
There are a number of officially safeguarded aerodromes which are defined in government circulars. Such aerodromes should have lodged safeguarding maps with planning authorities identifying the areas in which they need to be consulted. These aerodromes will consider the impacts of the proposed development on their operations.
Related Information
- Department of Energy and Climate Change Aviation Management Board
- Scottish Government Renewable Energy
- Planning Inspectorate
- Scottish Government Energy Consents Unit
- NATS windfarms
- Renewable UK
- Airport Operators Association
- General Aviation Awareness Council
- Maritime and Coastguard Agency
- National Police Air Service (England and Wales)
- Send details of obstructions to nas.obstructions@npas.pnn.police.uk