14. Aviation, Military and Communications

14.1. Introduction

  1. This chapter of the Offshore Environmental Impact Assessment (EIA) Report presents the assessment of the likely significant effects (as per the “EIA Regulations”) on the environment of the Berwick Bank Wind Farm offshore infrastructure which is the subject of this application (hereafter referred to as “the Proposed Development”) on aviation, military and communications. Specifically, this chapter considers the potential impacts of the Proposed Development seaward of Mean High Water Springs (MHWS) during the construction, operation and maintenance, and decommissioning phases.
  2. Likely significant effect is a term used in both the “EIA Regulations” and the Habitat Regulations. Reference to likely significant effect in this Offshore EIA Report refers to “likely significant effect” as used by the “EIA Regulations”. This Offshore EIA Report is accompanied by a Report to Inform Appropriate Assessment (RIAA) which uses the term as defined by the Habitats Regulations Appraisal (HRA) Regulations.
  3. This chapter also assesses the likely significant effects of the Proposed Development on onshore receptors (landward of Mean High Water Springs (MHWS)) during the construction, operation and maintenance, and decommissioning phases.
  4. This chapter summarises information contained within volume 3, appendix 14.1.

14.2. Purpose of this Chapter

  1. The primary purpose of the Offshore EIA Report is outlined in volume 1, chapter 1. It is intended that the Offshore EIA Report will provide the Scottish Ministers, statutory and non-statutory stakeholders with sufficient information to determine the likely significant effects of the Proposed Development on the receiving environment.
  2. In particular, this Aviation, Military and Communications EIA Report chapter:
  • presents the existing environmental baseline established from desk studies and consultation with stakeholders;
  • identifies any assumptions and limitations encountered in compiling the environmental information;
  • presents the likely significant environmental impacts on aviation, military and communications arising from the Proposed Development and reaches a conclusion on the likely significant effects on aviation, military and communications, based on the information gathered and the analysis and assessments undertaken; and;
  • highlights any necessary monitoring and/or mitigation measures which could avoid, prevent, minimise, reduce or offset the likely significant adverse environmental effects of the Proposed Development on aviation, military and communications.
    1. There are considered to be no likely significant additional effects on forms of telecommunication such as interference with cellular telephone service coverage, television scanning telemetry or non-aviation radar, satellite communications (e.g. with offshore oil and gas), maritime communications, Very High Frequency (VHF) radio and/or microwave links or any other forms of cabling (telecommunications and interlinks).
    2. This has been supported by the findings of the Infrastructure and Other Users Chapter of the Offshore EIA Report (volume 2, chapter 17) which reports there are no subsea telecommunications cables within the infrastructure and other users study area and no additional communications receptors have been highlighted by stakeholders. During consultation, British Telecom (BT) advised that the Proposed Development would not cause interference to BT’s current and presently planned radio network (See Berwick Bank Wind Farm Scoping Opinion (Marine Scotland Licensing and Operations Team (MS-LOT, 2022).
    3. Further, reference has been made to other Environmental Statements for other offshore windfarms in the area submitted within the past 11 years (for example, Seagreen (formally known as Alpha and Seagreen Bravo) (Seagreen Wind Energy, 2012 and 2018), Inch Cape (Inch Cape Offshore, 2011 and 2018/2019) and Neart na Gaoithe (NnG) (EMU, 2019). The findings of these assessments also indicate that the Proposed Development would have no likely significant effects on communication infrastructure or services.

14.3. Study Area

  1. The aviation, military and communications study area is defined by the range within which aviation receptors; in particular, Air Traffic Control (ATC) and Air Defence (AD) Primary Surveillance Radars (PSRs) could be affected by the Proposed Development. The operating range of these radars can be up to 200 nm (370 km). However, radars were identified for assessment within the aviation, military and communications study area on the basis the Proposed Development could realistically interfere with the base-level coverage of the radar (as this is the determining factor relating to aircraft safety). The extent of the aviation, military and communications study area is limited by the location of the most distant potential aviation receptor.
  2. An area of 9 nm around the Proposed Development was also searched to ascertain the potential for interference with helicopters procedures into oil and gas platforms (of which there are none within the aviation, military and communications study area). The aviation, military and communications study area covers airspace designations including low flying areas and military practice areas in the immediate vicinity of the Proposed Development; and, airspace, as necessary, used by fixed-wing aircraft and helicopters on routes which may cross the Proposed Development.
  3. The Proposed Development is located approximately 47.4 nm (87.9 km) to the south-east of Aberdeen Airport and 30.9 nm (57.2 km) to the north-east of Ministry of Defence (MoD) Leuchars Station, an active military aerodrome. The aviation, military and communications study area therefore incorporates radar on the north-east coast of England and east coast of Scotland that could potentially detect wind turbines within the Proposed Development array area.
  4. The locations of relevant aviation receptors in the surrounding region of the Proposed Development are depicted on an aviation chart at Figure 14.1   Open ▸ .
  5. To confirm the validity of the aviation, military and communications study area, reference was made to the findings reported for offshore wind farms in close proximity to the Proposed Development, which are listed in Table 14.5   Open ▸ . This body of literature assisted in identifying the relevant radars and stakeholders that may be affected. The 2020 Berwick Bank Scoping Opinion (MS-LOT, 2021) and the Berwick Bank Wind Farm Scoping Opinion (MS-LOT, 2022) are considered to further support the appropriateness of the aviation, military and communications study area. 
  6. The cumulative aviation, military and communications study area includes the area within 50 km of the Proposed Development. 

Figure 14.1:
Relevant Aviation, Military and Communications Receptors Identified

Figure 14.1: Relevant Aviation, Military and Communications Receptors Identified

14.4. Policy and Legislative Context

  1. Policy and legislation on renewable energy infrastructure is presented in volume 1, chapter 2 of the Offshore EIA Report. Policy and legislation specifically in relation to aviation, military and communications, is contained in the Scottish Planning Policy (SPP) (Scottish Government, 2014) and Scotland’s National Marine Plan (Scottish Government, 2015). A summary of the policy provisions relevant to aviation, military and communications are provided in Table 14.1   Open ▸ and Table 14.2   Open ▸ , with other relevant legislative provisions set out in Table: These are summarised here with further detail presented in volume 3, appendix 14.1.

 

Table 14.1:
Summary of SPP (Published June 2014) Relevant to Aviation, Military and Communications

Table 14.1: Summary of SPP (Published June 2014) Relevant to Aviation, Military and Communications

 

Table 14.2:
Summary of Scotland’s National Marine Plan (Published March 2015) Relevant to Aviation, Military and Communications.

Table 14.2: Summary of Scotland’s National Marine Plan (Published March 2015) Relevant to Aviation, Military and Communications.

 

Table 14.3:
Summary of Civil Aviation Act 1982 Relevant to Aviation, Military and Communications

Table 14.3: Summary of Civil Aviation Act 1982 Relevant to Aviation, Military and Communications

 

14.5. Consultation

  1. A summary of the key issues raised during consultation activities undertaken to date specific to aviation, military and communications is presented in Table 14.5   Open ▸ , together with how these issues have been considered in the production of this Aviation, Military and Communications EIA Report chapter. Further detail is presented within volume 1, chapter 5 Where assessments have departed from scoping advice, or further communications with consultees took place after the publication of the Berwick Bank Wind Farm Scoping Opinion (MS-LOT, 2022), these communications are audited in the Audit Document for Post-Scoping Discussions (volume 3, appendix 5.1) that accompanies the Application. The Audit Document provides the Applicant’s reasoning for any deviation from scoping advice.

 

Table 14.4:
Summary of Consultation of Relevance to Aviation, Military and Communications

Table 14.4: Summary of Consultation of Relevance to Aviation, Military and Communications

 

14.6. Methodology to Inform Baseline

14.6.1.    Desktop Study

  1. Information on aviation, military and communications within the aviation, military and communications study area was collected through a detailed desktop review of existing studies and datasets. These are summarised in Table 14.5   Open ▸ .
  2. The desktop review was conducted using comprehensive aviation documentation and charts to identify potential aviation receptors during the construction, operation and maintenance, and decommissioning phases of the Proposed Development (section 14.16). Supporting information was also drawn from a review of data sources; in particular, the UK Integrated Aeronautical Information Package (UK IAIP) and consultee responses and data sources as outlined in Table 14.4   Open ▸ : and Table 14.5   Open ▸ .

 

Table 14.5:
Summary of Key Desktop Reports

Table 14.5: Summary of Key Desktop Reports

 

  1. The desktop study provided the baseline characterisation to enable the assessment of potential impacts on the following aviation receptors:
  • Civil Airport Patterns and Procedures;
  • Military Aerodrome Patterns and Procedures;
  • Civil ATC Radar;
  • Military ATC Radar;
  • Military AD Radar;
  • Low Flying (including Search and Rescue (SAR) operations);
  • Helicopter Main Routes (HMRs);
  • Offshore Helicopter Installations (oil and gas platforms); and
  • Met Office Radar.

14.6.2.    Site-Specific Surveys

  1. No site-specific surveys have been undertaken to inform the EIA for aviation, military and communications. No radar modelling has been carried out on the basis the data collected from existing data sources coupled with ongoing consultation and mitigation discussions with relevant stakeholders are considered appropriate and sufficient to inform the assessment of likely significant effects for the Proposed Development.

14.7. Baseline Environment

14.7.1.    Overview of Baseline Environment

  1. The desktop review was undertaken to characterise the existing baseline conditions within the aviation, military, and communications study area. In terms of aviation, the baseline environment is influenced by the airspace, within which it is important to identify the locations of relevant radar receptors, such as ATC radar and AD systems, as well as any potential aviation stakeholders. A summary of the current baseline environment for aviation, military and communications follows and should be read in conjunction with Figure 14.1   Open ▸ .

Airspace structure

  1. In the UK Flight Information Region, airspace is classified as A to G in accordance with International Civil Aviation Organisation (ICAO) standards (there is no airspace designated as Class B or Class F in the UK). Airspace Classes A, C, D and E are variants of controlled airspace within which aircraft generically require an ATC clearance to operate. The Proposed Development is situated in an area of Class G uncontrolled airspace which is established from the surface up to Flight Level (FL) 115 (11,500 ft) which is the base of Airway P18 which is Class D controlled airspace.
  2. Airway P18 is primarily used by commercial aircraft routing to, and from, Aberdeen Airport. The airway is active from FL 115 (11,500 ft) to FL 195 (19,500 ft) in the north-west section of the Proposed Development and from FL 155 (15,500 ft) to FL 195 (19,500 ft) in the south-west section. The north-eastern portion of the Proposed Development overlaps the lateral boundaries of Danger Areas D613C and D613D. These Danger Areas are activated periodically from FL 100 (10,000 ft) to FL 660 (66,000 ft) for military air combat training and supersonic flight. Within Class G and D airspace, the following ATC rules apply:
  • Class G airspace - any aircraft can operate in this area of uncontrolled airspace without any mandatory requirement to be in communication with, or receive a radar service from, any ATC unit. Pilots of aircraft operating under Visual Flight Rules (VFR) in Class G airspace are ultimately responsible for seeing and avoiding other aircraft and obstructions; and
  • Class D airspace is established from FL 115 (11,500 ft) to FL 195 (19,500 ft). All aircraft operating in this airspace must be in receipt of an air traffic service from National Air Traffic Services En-Route PLC (NERL) or military controllers located at the NERL Area Control Centre.

Aviation operations

  1. Within the airspace environment described above, military and civilian aviation operations take place as described in paragraphs 26 to 29.
Military aviation
  1. In terms of military aviation, MoD Leuchars Station is located approximately 30.9 nm (57.22 km) to the south-west of the Proposed Development. Located at Leuchars Station is an ATC radar which is used to provide navigational services to aircraft inbound to and outbound from the aerodrome. In addition, Leuchars Station is responsible for navigational services to transitory military and civil aircraft operating within a 40 nm radius of the aerodrome, up to 9,500 ft, from Monday to Friday between 0900 and 1700 hrs. RAF Spadeadam is an Electronic Warfare Training Facility operated by MoD to provide training to aircrew in detecting and countering hostile radar threats associated with surface to air guided weapon systems. Located The Deadwater Fell ATC radar is located at Spadeadam is approximately 59.6 nm (110.5 km) to the south-west of the Proposed Development.
  2. MoD also operate two AD radars at Remote Radar Head (RRH) Buchan, approximately 60.0 nm (111.1 km) to the north of the Proposed Development, and at RRH Brizlee Wood, located 44.2 nm (82.0 km) to the south of the Proposed Development. These radars are used in support of training exercises on an almost daily basis. AD units, using radar data supplied from Buchan and Brizlee Wood, are also responsible for navigation services and support to aircraft activity within restricted airspace involving air combat training and supersonic flight, as well as providing radar data to intercept aircraft illegally infringing UK airspace.
Civil aviation
  1. Regarding civil aviation, NERL operate two ATC radars to the north north-west of the Proposed Development; Perwinnes ATC radar at approximately 46 nm (85 km) and Allanshill ATC radar at approximately 74 nm (137 km). These radars are used to support civilian ATC radar and en route operations for aircraft operating on civilian air routes and for aircraft arriving and departing to/from Aberdeen Airport.
  2. The airspace is also used by helicopters transiting to/from Aberdeen Airport and oil and gas installations in the North Sea. Navigational services for helicopters operating from Aberdeen Airport are provided using radar feeds from the Allanshill and Perwinnes ATC radar. These helicopters normally fly at 1,500 ft or above; however, depending on weather conditions, they may fly at less than 1,500 ft.

14.7.2.    Future Baseline Scenario

  1. The EIA Regulations ((The Electricity Works (Environmental Impact Assessment) (Scotland) Regulations 2017, The Marine Works (Environmental Impact Assessment) (Scotland) Regulations 2017 and The Town and Country Planning (Environmental Impact Assessment) (Scotland) Regulations 2017)), require that a “a description of the relevant aspects of the current state of the environment (baseline scenario) and an outline of the likely evolution thereof without development as far as natural changes from the baseline scenario can be assessed with reasonable effort, on the basis of the availability of environmental information and scientific knowledge” is included within the Offshore EIA Report.
  2. An assessment of the future baseline conditions has been carried out assuming that the Proposed Development does not come forward. As aviation stakeholders assess impacts on a case-by-case basis and in chronological order, for aviation, military and communications, there are no future baseline environment changes expected to affect the Proposed Development.

14.7.3.    Data Limitations and Assumptions

  1. The data used in this chapter are detailed in section 14.6. The data used are the most up to date publicly available information which can be obtained from the applicable data sources as cited. Data has also been provided through consultation as detailed in section 14.5. It is considered that the data employed in the assessment are robust and sufficient for the purposes of the assessment of effects presented.

14.8. Key Parameters for Assessment

14.8.1.    Maximum Design Scenario

  1. The maximum design scenarios identified in Table 14.6   Open ▸ have been selected as those having the potential to result in the greatest effect on an identified receptor or receptor group. These scenarios have been selected from the details provided in volume 1, chapter 3 of the Offshore EIA Report. Effects of greater adverse significance are not predicted to arise should any other development scenario, based on details within the Project Design Envelope (e.g. different infrastructure layout), to that assessed here, be taken forward in the final design scheme.


 

Table 14.6:
Maximum Design Scenario Considered for Each Impact as Part of the Assessment of Likely Significant Effects on Aviation, Military and Communications

Table 14.6: Maximum Design Scenario Considered for Each Impact as Part of the Assessment of Likely Significant Effects on Aviation, Military and Communications

 

14.8.2.    Impacts Scoped out of the Assessment

  1. On the basis of the baseline environment and the project description outlined in volume 1, chapter 3 of the Offshore EIA Report, a number of impacts are proposed to be scoped out of the assessment for aviation, military and communications. These have been agreed with key stakeholders through consultation as discussed in volume 1, chapter 5. Otherwise these impacts were proposed to be scoped-out in the Berwick Bank Wind Farm Offshore Scoping Report (SSER, 2021a) and no concerns were raised by key consultees. Where discussions with consultees took place after the publication of the Berwick Bank Wind Farm Scoping Opinion (MS-LOT, 2022), these are audited in the Audit Document for Post-Scoping Discussion (volume 3, appendix 5.1).
  2. These impacts are outlined, together with a justification for scoping them out, in Table 14.7   Open ▸

 

Table 14.7:
Impacts Scoped Out of the Assessment for Aviation, Military and Communications (tick confirms the impact is scoped out)

Table 14.7: Impacts Scoped Out of the Assessment for Aviation, Military and Communications (tick confirms the impact is scoped out)

14.9. Methodology for Assessment of Effects

14.9.1.    Overview

  1. The aviation, military and communications assessment of effects has followed the methodology set out in volume 1, chapter 6 of the Offshore EIA Report. Specific to this Aviation, Military and Communications EIA chapter, the following guidance documents have also been considered and referenced in section 14.16:
  • CAA (2019). CAP 670, Air Traffic Services Safety Requirements (Issue 3, 7 June 2019);
  • CAA (2016). CAP 764 - CAA Policy and Guidelines on Wind Turbines (Version 6, February 2016);
  • CAA (2017). CAP 774 - The UK Flight Information Services (Version 3, 25 May 2017);
  • CAA (2021). CAP 032 - UK Integrated Aeronautical Information Package (2021);
  • Military Aviation Authority (MAA) (2018). MAA Regulatory Publication 3000 Series: Air Traffic Management Regulations (21 September 2018);
  • MAA (2019). Manual of Military Air Traffic Management (30 September 2019);
  • MoD (2021). UK Military Aeronautical Information Publication (2021);
  • UK Government (2016). Marine Guidance Note 543: Offshore Renewable Energy Installations - Guidance on UK Navigational Practice, Safety and Emergency Response Issues (19 August 2016); and
  • CAA (2021). Visual Flight Rules Chart (CAA, 2021).
    1. In addition, the aviation, military, and communications assessment of effects has considered the legislative and policy framework set out in volume 1, chapter 3.

14.9.2.    Criteria for Assessment of Effects

  1. The process for determining the significance of effects is a two-stage process that involves defining the magnitude of the potential impacts and the sensitivity of the receptors. This section describes the criteria applied in this chapter to assign values to the magnitude of potential impacts and the sensitivity of the receptors. The terms used to define magnitude and sensitivity are based on those which are described in further detail in volume 1, chapter 6 of the Offshore EIA Report.
  2. The criteria for defining magnitude in this chapter are outlined in Table 14.8   Open ▸ . In determining magnitude within this chapter, each assessment considered the spatial extent, duration, frequency and reversibility of impact and these are outlined within the magnitude section of each assessment of effects (e.g. a duration of hours or days would be considered for most receptors to be of short term duration, which is likely to result in a low magnitude of impact).

 

Table 14.8:
Definition of Terms Relating to the Magnitude of an Impact

Table 14.8: Definition of Terms Relating to the Magnitude of an Impact

 

  1. The criteria for defining sensitivity in this chapter are outlined in Table 14.9   Open ▸ .

 

Table 14.9:
Definition of Terms Relating to the Sensitivity of the Receptor

Table 14.9: Definition of Terms Relating to the Sensitivity of the Receptor

 

  1. The significance of the effect upon aviation, military and communications is determined by correlating the magnitude of the impact and the sensitivity of the receptor. The particular method employed for this assessment is presented in Table 14.10   Open ▸ .
  2. In cases where a range is suggested for the significance of effect, there remains the possibility that this may span the significance threshold (i.e. the range is given as minor to moderate). In such cases the final significance is based upon the author’s professional judgement as to which outcome delineates the most likely effect. Where professional judgement is applied to quantify final significance from a range, the assessment will set out the factors that result in the final assessment of significance. These factors may include the likelihood that an effect will occur, data certainty and relevant information about the wider environmental context.
  3. For the purposes of this assessment:
  • a level of residual effect of moderate or more will be considered a ‘significant’ effect in terms of the EIA Regulations; and
  • a level of residual effect of minor or less will be considered ‘not significant’ in terms of the EIA Regulations.
    1. Effects of moderate significance or above are therefore considered important in the decision-making process, whilst effects of minor significance or less warrant little, if any, weight in the decision-making process.

 

Table 14.10:
Matrix Used for the Assessment of the Significance of the Effect

Table 14.10: Matrix Used for the Assessment of the Significance of the Effect

 

14.10. Measures Adopted as Part of the Proposed Development

  1. As part of the project design process, a number of measures have been proposed to reduce the potential for impacts on aviation, military and communications (see Table 14.11   Open ▸ ). As there is a commitment to implementing these measures, they are considered inherently part of the design of the Proposed Development and have therefore been considered in the assessment presented in section 14.11 (i.e. the determination of magnitude and therefore significance assumes implementation of these measures). These measures are considered standard industry practice for this type of development.

 

Table 14.11:
Designed in Measures Adopted as Part of the Proposed Development

Table 14.11: Designed in Measures Adopted as Part of the Proposed Development

 

14.11. Assessment of Significance

  1. The potential effects arising from the construction, operation and maintenance and decommissioning phases of the Proposed Development are listed in Table 14.6   Open ▸ , along with the maximum design scenario against which each effect has been assessed. An assessment of the likely significance of the effects of the Proposed Development on aviation, military and communications receptors caused by each identified impact is given below.

Potential Impact on Low Flying (Including SAR Helicopter Operations) Due to Presence of Obstacles (Cranes, Stationary Wind Turbines and OSPs/Offshore convertor station platform).

  1. The installation and presence of wind turbines pose physical obstructions to aviation operations carried out in the vicinity of wind farms. Wind turbines can be difficult to see from the air, particularly in poor meteorological conditions, leading to a potential increase in obstacle collision risk. Furthermore, during the construction phase, the presence and movement of installation vessels (with onboard cranes) may also present a potential obstacle collision risk to aircraft operations. In the case of the Proposed Development however, the cranes used during the construction phase are expected to have a maximum operating height of less than 355 m above LAT which is in line with the maximum design scenario in Table 14.6   Open ▸ .

Construction Phase

Magnitude of Impact
  1. The presence of construction infrastructure, such as installation vessels with cranes, will be alerted to pilots under the NOTAM system (see Table 14.11   Open ▸ ). The NOTAM will provide details of potential hazards along a flight route, or at a location, that could affect the safety of flight. The cranes will also have appropriate aviation lighting installed.
  2. In terms of wind turbines creating physical obstacles, aircraft operating at low levels are required to set a Minimum Safe Altitude (MSA); this is the lowest altitude set in areas to ensure safe separation between aircraft and known obstacles. The MSA for aircraft operating in Instrument Meteorological Conditions (IMC) (i.e. poor weather conditions), enables aircraft to maintain a minimum of 1,000 ft (305 m) clearance between aircraft and known obstacles. The anticipated maximum tip height of the proposed wind turbines is 355 m (1,165 ft) (above LAT). Therefore, the MSA in the area of the Proposed Development will need to be 2,200 ft (1,165 ft + 1,000 ft rounded to the next 100 ft) in order to maintain at least 1,000 ft (305 m) vertical separation between the wind turbines and aircraft.
  3. As detailed in Table 14.11   Open ▸ , potential impacts to low flying aircraft operating in the vicinity of the Proposed Development will be managed through the agreement of a LMP with key aviation stakeholders, and notification of the locations, heights and lighting status of the wind turbines to aviation stakeholders for inclusion in appropriate aviation documentation and charts. This will enable aviation operators to set an appropriate MSA over the Proposed Development. If required, the LMP will also cover the lighting and marking details for any construction infrastructure (e.g. cranes and OSPs/Offshore convertor station platform). An outline LMP is provided with the Application (see volume 4, appendix 22).
  4. The impact is predicted to be of local spatial extent, short to medium term duration, intermittent and low reversibility. It is predicted that the impact will affect the receptor directly. The magnitude is therefore, considered to be negligible.
Sensitivity of the Receptor
  1. Pilots are obliged to plan their flying activities in advance and to be familiar with any en-route obstacles they may encounter; however, during flight, weather conditions or operational requirements may necessitate route adjustments. In Visual Meteorological Conditions (VMC) (i.e. good weather conditions), pilots are ultimately responsible for seeing and avoiding obstructions such as wind turbines and will be aware of their presence through the notification procedures set out in Table 14.11   Open ▸ .
  2. In terms of potential impacts on military low flying operations, MoD recognised as part of relevant consultation to date that the Applicant was committed to lighting and charting the wind turbines and confirmed that, in the interests of air safety, the Proposed Development should be fitted with MoD accredited aviation safety lighting in accordance with the CAA, Air Navigation Order 2016; as set out in  Table 14.10   Open ▸ . An outline LMP is provided with the Application (see volume 4, appendix 22).
  3. In terms of SAR operations, MCA during relevant consultation to date indicated that they would welcome early discussion on the lighting and marking arrangements; furthermore, they requested that MCA should be consulted on the specific layout of the wind turbines with the aim of seeking compatibility with SAR helicopter operations in the event of rescue missions within the Proposed Development; as set out in Table 14.11   Open ▸ . Consultation will be carried out with MCA on their requirements in relation to wind turbine layout design and SAR lighting and marking and this will continue as wind turbine layout plans are refined prior to construction.
  4. Military low flying and SAR helicopter operations are deemed to be of high vulnerability, high recoverability and high value. The sensitivity of the receptor is therefore, considered to be high.
Significance of the Effect
  1. Overall, the magnitude of the impact is deemed to be negligible and the sensitivity of the receptor is considered to be high. The effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.
Secondary Mitigation and Residual Effect
  1. No aviation, military and communications mitigation are considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in section 14.10) is considered necessary because the likely effect in the absence of mitigation is of minor adverse significance, which is not significant in EIA terms.

Operation and Maintenance Phase

Magnitude of Impact
  1. The magnitude of impact is considered to be low, as described in paragraphs 48 to 51.
  2. During maintenance periods, it may be necessary to use surface vessels with crane capabilities for replacement of component parts (e.g. wind turbine blades). These temporary obstacles will be addressed under the NOTAM system as discussed in Table 14.11   Open ▸ .
  3. The impact is predicted to be of local spatial extent, short term duration and low reversibility. It is predicted that the impact will affect the receptor directly. The magnitude is therefore, considered to be negligible.
Sensitivity of the Receptor
  1. The sensitivity of this receptor is considered to be high as described in paragraphs 52 to 55.
  2. All aviation operations are deemed to be of high vulnerability, high recoverability and high value. The sensitivity of the receptor is therefore, considered to be high.
Significance of the Effect
  1. Overall, the magnitude of the impact is deemed to be negligible and the sensitivity of the receptor is considered to be high. The effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.
Secondary Mitigation and Residual Effect
  1. No aviation, military and communications mitigation are considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in section 14.10) is considered necessary because the likely effect in the absence of mitigation is of minor adverse significance, which is not significant in EIA terms.

Decommissioning Phase

  1. The effects of decommissioning activities are expected to be the same or similar to the effects from construction. The significance of effect is therefore minor adverse, which is not significant in EIA terms
  2. No aviation, military and communications mitigation are considered necessary because the likely effect in the absence of mitigation is not significant in EIA terms.

Potential impact on NERL ATC radars due to presence of wind turbines

  1. Adverse effects on ATC radar are only possible if the wind turbine blades are moving, therefore this impact is applicable to the operation and maintenance phase only.
  2. Wind turbines have been shown to have detrimental effects on the performance of ATC radar and have the potential to affect the provision of radar based air traffic services (ATS). These effects include the desensitisation of radar in the vicinity of the wind turbines, shadowing and the creation of unwanted returns which air traffic controllers must treat as aircraft returns. Unwanted radar clutter can affect the provision of ATS to pilots. Radar clutter (or false radar returns) can confuse air traffic controllers making it difficult to differentiate between aircraft and those radar returns resulting from the detection of wind turbines. Furthermore, the appearance of multiple false targets in close proximity can generate false aircraft tracks and seduce those returns from real aircraft away from the true aircraft position.

Operation and Maintenance Phase

Magnitude of Impact
  1. NERL uses ATC radar to support their provision of navigational services to aircraft operating between the UK and mainland Europe and to those overflying the UK FIR. Surveillance data from NERL’s Perwinnes ATC radar is used by other air traffic service providers such as Aberdeen Airport who are responsible for the provision of navigational services to aircraft operating on Airway P18.
  2. Air traffic controllers are responsible for maintaining typically 5 nm lateral separation between aircraft. Where line of sight to an ATC radar exists, wind turbines may appear as genuine aircraft targets and could mask genuine aircraft responses. The radar may also be desensitised by its clutter processing within the sector containing wind turbines meaning that real aircraft targets may disappear from radar. 
  3. The impact is predicted to be of local spatial extent, long term duration, continuous and low reversibility. It is predicted that the impact will affect the receptor directly. The magnitude is therefore, considered to be high.
Sensitivity of the Receptor
  1. Desensitisation of ATC radar could result in aircraft not being detected by the radar and therefore aircraft returns not presented to air traffic controllers. Controllers use the radar to separate and sequence aircraft; therefore, maintaining situational awareness of all aircraft movements within the airspace is crucial to achieving a safe and efficient ATS, and the integrity of radar data is central to this process. The creation of unwanted returns displayed on the radar leads to increased workload for both controllers and aircrews. Furthermore, real aircraft returns can be obscured by a wind turbine's radar return, making the tracking of both conflicting unknown aircraft and the controllers’ own traffic much more difficult.
  2. In their response to relevant consultation to date, NERL confirmed that false primary plots are likely to be generated on the Perwinnes ATC radar which would create a reduction in the radar’s probability of detection for real aircraft. Consequently, NERL considered that the impact on the Perwinnes ATC radar would be unacceptable. This was also confirmed by NERL in their response to the Berwick Bank Wind Farm Offshore Scoping Report (SSER, 2021a), see Table 14.4   Open ▸ .
  3. The impact on NERL’s ATC radar systems is deemed to be of high vulnerability, high recoverability and high value. The sensitivity of the receptor is therefore, considered to be high.
Significance of the Effect
  1. Overall, the magnitude of the impact is deemed to be high and the sensitivity of the receptor is considered to be high. The effect will, therefore, be major adverse, which is significant in EIA terms.
Secondary Mitigation and Residual Effect
  1. NERL has proven processes and techniques to mitigate the adverse impact of wind turbines on their ATC radars. The Applicant has commenced discussions with NERL about potential mitigation solutions and is likely that the proposed solution will be to use Multi-Radar Tracker (MRT) blanking, which is a technical mitigation solution routinely offered by NERL that removes wind turbines returns from the ATC radar display. However, in combination, NERL are likely to request that the MRT blanking is accompanied by a Transponder Mandatory Zone (TMZ). This provides an added layer of mitigation by ensuring that all aircraft transiting overhead the ‘blanked’ area carry a serviceable transponder which enables them to be tracked by means of Secondary Surveillance Radar (SSR) without reliance on ATC radar. Implementation of a TMZ requires developers to submit an Airspace Change Proposal (ACP) to the CAA for which a formal airspace change process has to be followed.
  2. The Applicant intends to continue negotiations with NERL with the aim of delivering a suitable ATC radar mitigation solution prior to the operation and maintenance phase of the Proposed Development.
  3. Once a mitigation solution is implemented, the magnitude of the impact is deemed to be negligible and the sensitivity of the receptor is considered to be high. The effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.

Potential impact on Military ATC radars due to presence of wind turbines

  1. As explained in paragraph 67, the impact of wind turbines on ATC radar is only applicable to the operation and maintenance phase. The detrimental effect of wind turbines on ATC radar is also explained in paragraph 68.

Operation and Maintenance Phase

Magnitude of Impact
  1. RAF ATC units not only provide navigational services to aircraft approaching and departing the aerodrome, but they are also responsible for the provision of such services to any aircraft operating within 40 nm (and sometimes 60 nm). If an offshore wind farm is within the operating range of a military ATC unit, it is possible that the wind turbines will be detectable on ATC radar displays. This direct, permanent effect could hamper the ATC operators’ ability to distinguish actual aircraft returns from those created by the wind turbines and degrade the safety and efficiency of the ATS being provided. Air traffic controllers’ responsibilities are as described in paragraph 70.
  2. The impact is predicted to be of local spatial extent, long term duration, continuous and low reversibility. It is predicted that the impact will affect the receptor directly. The magnitude is therefore, considered to be high.
Sensitivity of the Receptor
  1. Wind turbines within the Proposed Development are highly likely to be visible to the Leuchars Station ATC radar and adversely impact ATC operations. The Proposed Development is also considered to have the potential to affect the operation of the ATC radar at RAF Spadeadam Deadwater Fell. The sensitivity of this receptor is high as described in paragraph 74.
  2. In their response to relevant consultation to date, MoD confirmed that it is likely to affect and be detectable to, the ATC radar at Leuchars Station and that this impact would need to be taken into account and mitigated. This was also confirmed by MoD in their response to the Berwick Bank Wind Farm Offshore Scoping Report (SSER, 2021a); see Table 14.4   Open ▸ .
  3. Military ATC radar systems are deemed to be of high vulnerability, high recoverability and high value. The sensitivity of the receptor is therefore, considered to be high.
Significance of the Effect
  1. Overall, the magnitude of the impact is deemed to be high and the sensitivity of the receptor is considered to be high. The effect will, therefore, be of major adverse significance, which is significant in EIA terms.
Secondary Mitigation and Residual Effect
  1. The MoD has a recognised process for entering into agreement for ATC radar mitigation. Currently, no enduring radar mitigation solution has been accepted into service by MoD however, an interim solution has previously been negotiated for Seagreen. The Applicant has commenced discussions with MoD regarding the Proposed Development and it is expected that an interim solution will also be acceptable to MoD pending development of an enduring radar mitigation solution. The interim solution is expected to take the form of blanking and TMZ as outlined in paragraph 76 for mitigation of impacts on NERL’s ATC radar.
  2. The Applicant intends to continue negotiations with MoD with the aim of delivering a suitable ATC radar mitigation solution prior to the operation and maintenance phase of the Proposed Development.
  3. Once a mitigation solution is implemented, the magnitude of the impact is deemed to be negligible and the sensitivity of the receptor is considered to be high. The effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.

Potential impact on Military AD radars due to presence of wind turbines

  1. As explained in paragraph 67, the impact of wind turbines on ATC radar is only applicable to the operation and maintenance phase. The detrimental effect of wind turbines on ATC radar is also explained in paragraph 68.