14.2. Purpose of the Chapter

  1. The Array EIA Report provides the Scottish Ministers, statutory and non-statutory stakeholders with adequate information to determine the LSE1 of the Array on the receiving environment. This is further outlined in volume 1, chapter 1.
  2. The purpose of this Aviation, Military and Communications Array EIA Report chapter is to:
  • present the existing environmental baseline established from desk studies, modelling studies, and engagement with stakeholders;
  • identify any assumptions and limitations encountered in compiling the environmental information;
  • present the impacts on aviation, military and communications arising from the Array and reach a conclusion on the LSE1 on aviation, military and communications, based on the information gathered and the analysis and assessments undertaken; and
  • highlight any necessary monitoring and/or mitigation measures which are recommended to prevent, minimise, reduce or offset the likely significant adverse effects of the Array on aviation, military and communications.

14.3.   Study Area

14.3. Study Area

  1. The aviation, military and communications study area is driven by the Zone of Influence (ZoI), a defined term in the EIA. To identify and characterise aviation, military and communications receptors, a broad aviation, military and communications study area has been defined, based on recommendations provided by the Civil Aviation Authority (CAA) Civil Aviation Publication (CAP) 764 Policy and Guidelines on Wind Turbines (CAA, 2016a). Whilst not definitive, CAP 764 (CAA, 2016a) provides criteria for assessing whether any offshore wind development might have an impact on aerodrome and radar related operations. Consideration of the Array’s potential to impact on aviation, military and communications receptors has been undertaken in accordance with the recommended consultation distance of within 30 km of an aerodrome with a surveillance radar facility, as stated in CAP 764 (CAA, 2016a). However, CAP 764 (CAA, 2016a) states that the operational range of a radar system is dependent on the type of radar used and its operational requirement.
  2. Although CAP 764 (CAA, 2016a) provides a guide of 30 km for assessment of radar impact, impact to aviation radar is dependent on radar detectability of operational wind turbines, the radar’s operational range and the use of airspace in which the development sits, therefore, in this chapter, the operational range of individual radar, particularly Ministry of Defence (MOD) Air Defence Radar (ADR) with operational ranges in excess of 200 km, has been taken into account in defining the aviation, military and communications study area, rather than the CAP 764 30 km guideline only. The identification of the aviation, military and communications study area and assessment of potential operational impact has considered physical safeguarding of flight, airspace characteristics and procedures as published in the CAA CAP 032, United Kingdom (UK) Integrated Aeronautical Information Package (IAIP) (CAA, 2023a) and the Ministry of Defence (MOD) Military Aeronautical Information Publication (Mil AIP) (MOD, 2023a).
  3. Figure 14.1   Open ▸ illustrates the aviation, military and communications study area encompassing:
  • the aviation radar systems that potentially detect the Array maximum (highest) wind turbine blade tip height of 399 m above Lowest Astronomical Tide (LAT); and
  • the Array and applicable airspace between the Array and the UK east coast from the location of the NATS En-route Limited (NERL) operated Allanshill Primary Surveillance Radar (PSR) to the north and the Brizlee Wood Remote Radar Head (RRH) ADR to the south.

Figure 14.1:
Aviation, Military and Communications Study Area

Figure 14.1: Aviation, Military and Communications Study Area


14.4.   Policy and Legislative Context

14.4. Policy and Legislative Context

  1. Volume 1, chapter 2 of the Array EIA Report presents the policy and legislation of relevance to renewable energy infrastructure. Policy and guidance specifically in relation to aviation, military and communications is contained in CAP 393 The Air Navigation Order (ANO) (CAA, 2016b as amended 2022) which sets out the provisions of the ANO as amended together with the legislation made under the Order. Table 14.1   Open ▸ presents a summary of the legislation provisions relevant to aviation, military and communications, with the other revlevant policy and guidance set out in Table 14.2   Open ▸ and Table 14.3   Open ▸ .
  2. Further detail is presented in volume 1, chapter 2.

 

Table 14.1:
Summary of UK Legislation Relevant to Aviation, Military and Communications

Table 14.1: Summary of UK Legislation Relevant to Aviation, Military and Communications

 

Table 14.2:
Summary of National Policy Provisions Relevant to Aviation, Military and Communications

Table 14.2: Summary of National Policy Provisions Relevant to Aviation, Military and Communications

 

Table 14.3:
Summary of National Guidance Relevant to Aviation, Military and Communications

Table 14.3: Summary of National Guidance Relevant to Aviation, Military and Communications

 

14.5.   Consultation

14.5. Consultation

  1. Table 14.4   Open ▸ presents a summary of the key issues raised during consultation activities undertaken to date specific to aviation, military and communications for the Array and in the Ossian Array Scoping Opinion (Marine Directorate – Licensing and Operations Team (MD-LOT), 2023) along with how these have been considered in the development of this aviation, military and communications Array EIA Report chapter. Further detail is presented within volume 1, chapter 5.

 

Table 14.4:
Summary of Issues Raised During Consultation and Scoping Opinion Representations Relevant to Aviation, Military and Communications

Table 14.4: Summary of Issues Raised During Consultation and Scoping Opinion Representations Relevant to Aviation, Military and Communications

14.6.   Methodology to Inform Baseline

14.6. Methodology to Inform Baseline

  1. Aviation, military and communications guidance and airspace publications have been reviewed and analysed to inform this aviation, military and communications baseline. In addition, engagement with aviation, military and communications stakeholders has been carried out to aid the collection of baseline information. Data have also been provided through engagement with the stakeholders as detailed in Table 14.4   Open ▸ .

14.6.1.              Desktop Study

14.6.1. Desktop Study

  1. Information on airspace within the aviation, military and communications study area was collected through a detailed desktop review of existing datasets which are summarised in Table 14.5   Open ▸ .
  2. The literature review of the datasets was used to characterise the aviation, military and communications baseline. Volume 3, appendix 14.1 and volume 3, appendix 14.1, annex A include full details of the radar Line of Sight (LoS) and IFP analyses undertaken to develop the aviation, military and communications baseline.

 

Table 14.5:
Summary of Data Sets for Aviation, Military and Communications

Table 14.5: Summary of Data Sets for Aviation, Military and Communications

 

14.6.2.              Identification of Designated Sites

14.6.2. Identification of Designated Sites

  1. A three-step process was used to identify all designated sites within the aviation, military and communications study area and qualifying interest features that could be affected by the construction, operation and maintenance, and decommissioning phases of the Array. This process is described below:
  • Step 1: All airspace constructs of national and local importance within the aviation, military and communications study area were identified using the sources listed in Table 14.5   Open ▸ .
  • Step 2: Information was compiled on the relevant use and features for each of these construct as follows:

           stakeholder controlling authority;

           stakeholder Air Traffic Service (ATS) provider;

           stakeholder (operator) user; and

           volume of airspace within the aviation, military and communications study area.

  • Step 3: Using the above information and expert judgement, constructs were included for further consideration if:

           a construct directly overlaps with the Array and therefore has the potential to be directly affected by the Array; or

           construct and associated features were located within the aviation, military and communications study area for impacts associated with the Array.

  1. Identified designated sites within the aviation, military and communications study area are shown in Figure 14.2   Open ▸ . These include PSR locations, PEXAs, controlled airspace, PEXA Temporary Reserved Areas, and HMRIs, and are further discussed in section 14.7.

14.6.3.              Site-Specific Surveys

14.7. Baseline Environment

14.7.1.              Overview of Baseline Environment

14.7.2. Existing Baseline Scenario

  1. In aviation and airspace terms, the world is divided into Flight Information Regions (FIR2) for the allocation of responsibility for the provision of an ATS to aircraft. The airspace above and around the Array is used by both civil and military aircraft, which are tracked by radar systems operated by both NATS and the MOD. The Array will be located within the Scottish FIR2 in an area of Class G[1] uncontrolled airspace, which is established from surface up to FL 195 (approximately 19,500 ft). Above this Class G Airspace is Class C[2] Controlled Airspace (CAS).
  2. Aircraft operating within CAS must be in receipt of an ATS from NATS, military air traffic controllers located at a NATS ACC or under the control of military air defence controllers.

                        Civil aviation

  1. The UK civil airport nearest to the Array is Aberdeen International Airport, which is located approximately 50 nm north-west of the site on a bearing of 292°.
  2. Airports with published IFPs have associated Minimum Sector Altitudes (MSA). A MSA defines the minimum safe altitude an aircraft can descend to within a sector of radius 25 nm (approximately 46 km). These sectors provide obstacle clearance protection of at least 1,000 ft to aircraft within that area. This allows pilots of aircraft flying under Instrument Flight Rules (IFR)[3] the reassurance of properly designated obstacle and terrain clearance protection whilst making an approach and landing at an airport in poor weather.
  3. Volume 3, appendix 14.1, annex A, includes full details of the IFP analysis undertaken to develop the aviation baseline. This concluded that the Array will not have an effect on the Obstacle Limitation Surfaces (OLS) and IFP that serve Aberdeen International Airport.
  4. Volume 3, appendix 14.1, includes full details of the radar LoS analysis undertaken to develop the aviation baseline.
  5. The radar LoS analysis indicates that the Perwinnes PSR will theoretically detect operational wind turbines at a maximum height of 399 m, which is likely to create a detrimental effect to the operation of the PSR. The Allanshill PSR will theoretically detect, intermittently, operational wind turbines located within the northern quarter of the Array (the closest to the radar location) (see volume 3, appendix 14.1, Figure 3.2). However, NATS have confirmed that the Allanshill PSR will not be effected. The potential impacts wind turbines may have on radar systems through radar detection of operational wind turbines may include the following:
  • Twinkling appearance/blade flash effect can distract the air traffic controller from their primary task.
  • Masking of real aircraft targets caused by increased clutter being displayed on the radar data display screen.
  • Increase in unwanted targets or false aircraft tracks.
  • Receiver saturation.
  • Target desensitisation causing loss of valid aircraft targets that are of a small Radar Cross Section (RCS).
  • Shadowing behind the wind turbines caused by physical obstruction (blocking of radar transmitted signal).
  • Degradation of target processing capability and processing overload.
  • Degradation of tracking capabilities including track seduction.
  1. The CAA advises that effects on Secondary Surveillance Radar (SSR) are only relevant for consideration when wind turbines are located less than 10 km from the SSR CAP 764 (CAA, 2016a). The Array lies outside the area of interaction with any aviation related SSR systems therefore, as agreed in via consultation on the Array EIA Scoping Report, aviation SSR systems are scoped-out and not considered further in the Array EIA Report.

                        Military aviation

  1. The MOD through the Air Surveillance and Control System (ASACS) is responsible for compiling a Recognised Air Picture (RAP) to monitor the airspace in and around the UK to launch a response to any potential airborne threat. This is achieved through the utilisation of a network of long-range ADR systems, some of which are located along the east coast of the UK. ADR systems are similarly impacted by the detection of operational wind turbines as listed in paragraph 25. Due to their role in the defence of UK airspace; any identified impact of wind turbines on the ASACS Radar Systems that serve the airspace above the Array may potentially reduce the capability of the ASACS Force.
  2. The nearest ADR to the Array is the TPS-77 (Type 92) ADR located at RRH Buchan, Aberdeenshire, which is located approximately 48 nm north-west of the site on a bearing of 316° from the closest Array boundary. RRH Brizlee Wood in Northumberland operates a TPS 77 type ADR and is located approximately 80 nm south-west of the site on a bearing of 215° from the closest Array boundary.
  3. Radar LoS analysis predicts that the operation of the Buchan ADR may be affected by the detection of operational wind turbines placed within the Array (see volume 3, appendix 14.1, Figure 3.3). The Brizlee Wood ADR will theoretically not detect operational wind turbines placed within the Array at a blade tip height of 399 m; however, occasional detection cannot be ruled out in the southernmost part of the Array (the closest to the radar location) (see volume 3, appendix 14.1, Figure 3.5).
  4. Leuchars Station PSR is located approximately 73 nm south-west of the site on a bearing of 245° from the closest Array boundary. Although there is potential for this PSR to detect the operational wind turbines of the Array, it is not envisaged that Leuchars air traffic controllers will be providing a radar ATS in the close (less than 10 nm) vicinity of the Array as this will be located outside of Leuchars Area of Responsibility (AoR), which is expected to extend around a 40 nm radius from the Leuchars Station PSR position. Within Class G airspace an ATS may be provided by NATS, or military controllers located at an ACC or air defence controllers subject to suitable radar and radio coverage being available to them.
  5. Military low flying activities take place in uncontrolled airspace below 2,000 ft Above Mean Sea Level (AMSL) within defined LFA. The Array is adjacent to LFA 14; however, low flying activity also extends offshore therefore, military low flying is likely to take place above and around the Array. The MOD DIO (who safeguard MOD infrastructure) commonly request aviation obstruction lighting to be fitted to wind turbines in accordance with CAP 393 (CAA 2016, as amended 2022a). The fitment of aviation obstruction lighting will be detailed within a Lighting and Marking Plan (LMP), in line with CAP 764 (CAA, 2016a), which will be produced and consulted on post-consent. The outline LMP for the Array can be found in volume 4, appendix 26.
  6. UK En Route Low Altitude North Sea West Offshore Installations (UK (L) 5 OIL) (MOD, 2023b) chart provides the location of military PEXA. The Array does not lie within any military aeronautical PEXA, however, it does lie beneath D613, a managed high intensity manoeuvring area ( Figure 14.2   Open ▸ ). The MOD have confirmed through engagement (21 November 2023) that no effect will be created to D613; therefore, D613 has been scoped out from further assessment.

                        Helicopter operations

  1. Commercial offshore helicopter operations in the North Sea encompass support to offshore oil and gas exploitation and SAR operations. Bristow Helicopters Ltd hold the UK Government national contract to deliver SAR operations on behalf of the MCA.
  2. SAR are not constrained by Commercial Air Transport (CAT) Regulations as these flights are generally flown by His Majesty’s Coastguard (HMCG) SAR aircraft operating under CAP 999 (CAA, 2023b). The Coastguard helicopters are operated as State Aircraft under National Regulations and are not constrained by the higher weather limits in CAT Regulations (CAA, 2023b)[4]. The closest MCA SAR helicopter base[5] to the Array is Inverness Airport, approximately 114 nm north-west of the Array. SAR operations often involve flying at low level.
  3. Helicopters supporting offshore oil and gas, in the northern North Sea, use Helicopter Main Route Indicators (HMRI), radiating from Aberdeen International Airport (the main support base) on a hub/spoke radial pattern (see Figure 14.2   Open ▸ ). These HMRIs lie to the north of the Array; the closest being 4 nm to the north of the north-eastern boundary of the Array on a bearing of 21. The CAA recommend within CAP 764 (CAA, 2016a) that there should be no obstacles within 2 nm either side of the centreline of a HMRI; the Array is located outside of the CAA recommended obstacle free distance. Moreover, the CAA also recommend that dependent on radar low level coverage required and the type of radar service required, it may be necessary to maintain a greater buffer than 2 nm.

                        Other radar and communications

  1. The Met Office safeguards its weather radar and provides site-specific (radar) pre-planning advice for proposals sited in Met Office consultation zones; these zones extend to a 20 km (11 nm) radius of Met Office radar sites (OPERA, 2009). The Array is located outside of the consultation zone, at approximately 96 km from the nearest Met Office radar at Hill of Dudwick, Aberdeenshire. The Met Office have confirmed in response to engagement that the Array will not impact Met Office radar operations; therefore, Met Office radar is not considered further in the Array EIA Report.

                        Summary of baseline environment

  1. A description of the aviation baseline environment is provided within the Aviation, Military and Communications Technical Report volume 3, appendix 14.1. The key sensitivities identified as part of the baseline assessment are as follows:
  • aviation and radar systems; civil and military; and
  • civil and military low flying including HMRIs and SAR.

Figure 14.2:
Aviation, Military and Communications Study Area Airspace Construct

Figure 14.2: Aviation, Military and Communications Study Area Airspace Construct


14.7.3.              Future Baseline Scenario

14.7.3. Future Baseline Scenario

  1. The EIA Regulations require that “a description of the relevant aspects of the current state of the environment (baseline scenario) and an outline of the likely evolution thereof without implementation of the project 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 Array EIA Report.
  2. If the Array does not come forward, an assessment of the ‘without development’ future baseline conditions has also been carried out and is described within this section.
  3. The North Sea Transition Authority (NSTA) Oil and Gas Authority (OGA) Annual Report and Accounts 2022-2023 (NSTA, 2023) reported a predicted decline in gas production and usage in following years. Oil and gas operators continue to find it difficult to predict production accurately as older fields mature and their reliability reduces. The Prime Minister’s Office (PMO) and the Department for Energy Security and Net Zero (DESNZ) reported during July 2023 that the Prime Minister has committed to future oil and gas licensing rounds with two areas in the North Sea chosen as locations for carbon capture usage and storage clusters. The independent Climate Change Committee predicted around a quarter of the UK’s energy demand will still be met by oil and gas when the UK reaches net zero in 2050, the UK Government states that it is taking steps to slow the rapid decline in domestic production of oil and gas, which will secure UK domestic energy supply and reduce reliance on hostile states.
  4. North Sea Natural Resources Ltd undertook previous works to drill an appraisal well in hydrocarbon licence Block 27/5 which is located 19 km north-east of the Array. This work was completed in November 2023 and the permit for drilling works expired at the end of January 2024. However, as old oil and gas fields are decommissioned it is considered that helicopter use to oil and gas platforms associated with these fields will eventually decline; however, as helicopter support to offshore wind increases it is expected that there may be increased aviation activity as new offshore areas are developed to support net zero targets.
  5. Based on the timings of the development of the Array, the baseline environment for the aviation, military and communications assessment is not expected to change. The present airspace construct or usage, civil and military aviation, above and around the Array is not expected to change significantly.

14.7.4.              Data Limitations and Assumptions

14.7.4. Data Limitations and Assumptions

  1. The data used in this chapter is the most up to date publicly available information which can be obtained from the data sources as cited. Data have also been provided through engagement with the stakeholders detailed in Table 14.4   Open ▸ . For the purposes of the aviation, military and communications assessment, it should be noted that the results of the radar LoS analysis (volume 3, appendix 14.1) are theoretical, and considered to be conservative. These results are provided in order to establish the reasonable worst-case possibility of impact to aviation, military and communications stakeholders.  

14.8.   Key Parameters for Assessment

14.8. Key Parameters for Assessment

14.8.1.              Maximum Design Scenario

14.8.1. Maximum Design Scenario

  1. The maximum design scenarios identified in Table 14.6   Open ▸ are those expected to have 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 Array EIA Report. Effects of greater adverse significance are not predicted to arise should any other development scenario, based on details within the Project Description (volume 1, chapter 3) (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 Potential Impact as Part of the Assessment of LSE1 on Aviation, Military and Communications

Table 14.6: Maximum Design Scenario Considered for Each Potential Impact as Part of the Assessment of LSE1 on Aviation, Military and Communications

14.8.2.              Impacts Scoped Out of the Assessment

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 Array EIA Report, a number of impacts are proposed to be scoped out of the assessment for aviation, military and communications. This was either agreed with key stakeholders through consultation as discussed in volume 1, chapter 5, or otherwise, the impact was proposed to be scoped out in the Ossian Array EIA Scoping Report (Ossian OWFL, 2023) and no concerns were raised by key consultees within the Scoping Opinion (MD-LOT, 2023).
  2. These impacts are outlined, together with a justification for scoping out, in Table 14.7   Open ▸ .

 

Table 14.7:
Impacts Scoped Out of the Assessment for Aviation, Military and Communications

Table 14.7: Impacts Scoped Out of the Assessment for Aviation, Military and Communications

 

14.9.   Methodology for Assessment of Effects

14.9. Methodology for Assessment of Effects

14.9.1.              Overview

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 Array EIA Report. Specific to the aviation, military and communications Array EIA chapter, the guidance documents in Table 14.3   Open ▸ have been considered.
  2. In addition to the overarching policy and legislation as described in volume 1, chapter 2 of this Array EIA Report, the legislative framework relevant to this aviation, military and communications impact assessment within CAP 393 (CAA, 2016b, as amended 2022) has been considered.

14.9.2.              Criteria for Assessment of Effects

14.9.2. Criteria for Assessment of Effects

  1. When determining the significance of effects, a two-stage process is used which 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 Array EIA Report.
  2. The criteria for defining magnitude in this chapter are outlined in Table 14.8   Open ▸ and are based upon the technical expert’s experience and judgement. Each assessment considered the spatial extent, duration, frequency and reversibility of impact when determining magnitude which are outlined within the magnitude section of each impact assessment (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 ▸ and are based upon the technical expert’s experience and judgement.

 

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 magnitude of the impact and the sensitivity of the receptor are combined when determining the significance of the effect upon aviation, military and communications stakeholders (operators). The particular method employed for this assessment is presented in Table 14.10   Open ▸ .
  2. Where a range is suggested for the significance of effect, for example, minor to moderate, it is possible that this may span the significance threshold. The technical specialist’s professional judgement was applied to determine which outcome defines the most likely effect, which takes into account the sensitivity of the receptor and the magnitude of impact. Where professional judgement was applied to quantify final significance from a range, the assessment has 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 Array

14.10. Measures Adopted as Part of the Array

  1. As part of the Array design process, a number of designed in measures have been proposed to reduce the potential for impacts on aviation, military and communications (see Table 14.11   Open ▸ ). They are considered inherently part of the design of the Array and, as there is a commitment to implementing these measures, these have 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 designed in measures are considered standard industry practice for this type of development.

Table 14.11:
Designed In Measures Adopted as Part of the Array

Table 14.11: Designed In Measures Adopted as Part of the Array

 

  1. As provided in the Institute of Environmental Management and Assessment (IEMA) Guide to Delivering Quality Development (IEMA, 2016), where significant effects have been identified, further mitigation measures adopted (referred to as secondary mitigation, that are not "designed in") have been identified to reduce the significance of effect to acceptable levels following the initial assessment. These are measures that could further prevent, reduce and, where possible, offset any adverse effects on the environment. These measures are set out in section 14.11 below in the sections on “Secondary Mitigation and Residual effect” and “Future Monitoring”.

14.11.            Assessment of Significance

14.11. Assessment of Significance

  1. Table 14.6   Open ▸ summarises the potential impacts arising from the construction, operation and maintenance and decommissioning phases of the Array, as well as the MDS against which each impact has been assessed. An assessment of the likely significance of the effects of the Array on the aviation, military and communications receptors caused by each identified impact is given below.

Creation of physical obstacle to aircraft operations (including airborne search and rescue (SAR) operations and low flying aircraft)

  1. The construction, operation and maintenance, and decommissioning phases of the Array will lead to the creation of a physical obstacle to aircraft operations. The MDS in regard to aviation, is represented by the 130 floating wind turbines with a maximum blade tip height of 399 m above LAT and is summarised in Table 14.6   Open ▸ .

                        Construction phase

                        Magnitude of impact
  1. Wind turbine construction infrastructure above LAT could pose a physical obstruction to flight operations in the vicinity of the Array and specifically to military and other low flying operations including fisheries protection, pollution control and helicopters operating in the support of the renewable and hydrocarbon industries. Helicopter operators, the MOD and ATC service providers have been consulted with regard to the potential for the Array to create an obstruction to aviation, military and communications activities conducted in the vicinity of the floating wind turbines and OSPs. Construction infrastructure, OSPs and erected wind turbines can be difficult to see from the air, particularly in poor meteorological conditions leading to potential increased obstacle collision risk. Furthermore, during the construction phase, the presence and movement of associated infrastructure may present a potential obstacle collision risk to aircraft flight operations.
  2. A range of designed in measures, in the form of appropriate notification to aviation, military and communications stakeholders, regularity of layout, and lighting and marking to minimise effects to aviation flight operations would apply to the development of the Array. These will comply with current guidelines where appropriate and be agreed with the appropriate stakeholders as outlined in Table 14.11   Open ▸ . Pilots are obliged to plan their flying activities in advance and to be familiar with any enroute obstacles they may encounter; however, during flight, weather conditions or operational requirements may necessitate route adjustments. In Visual Meteorological Conditions (VMC), pilots are ultimately responsible for seeing and avoiding obstructions such as wind turbines and will be aware through notification procedures of the Array. Furthermore, when flying in Instrument Meteorological Conditions (IMC), pilots may be under the control of ATC with an appropriate level of radar service and flying at an altitude which provides the required separation from obstacles below them.
  3. Volume 3, appendix 14.1, annex A includes full details of the IFP analysis undertaken to develop the aviation, military and communications baseline and assesses those Aberdeen International Airport IFPs which are within 50 nm of the Array. The IFP assessment was completed at a maximum blade tip height of 399 m LAT and has concluded that the Array will not breach the MSA or IFPs of Aberdeen International Airport. These areas provide an altitude at which a minimum of 1,000 ft above the highest obstacle is required for IFR flights.
  4. The impact is predicted to be of regional spatial extent, short term (construction phase) duration, continuous with low reversibility (once construction has started). It is predicted that the impact will affect the receptor (low flying operations) directly. The magnitude is therefore considered to be low.
                        Sensitivity of the receptor
  1. Low flying operations are deemed to be of high vulnerability, high recoverability, and high value. The sensitivity of the receptor is therefore, considered to be medium.
                        Significance of the effect
  1. Overall, the magnitude of the impact is deemed to be low, and the sensitivity of the receptor is considered to be medium. 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 focussed secondary mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in section 14.10) is not significant in EIA terms.

                        Operation and maintenance phase

                        Magnitude of impact
  1. During the operations and maintenance phase of the Array, floating wind turbines and OSPs could pose a physical obstruction to the flight of aircraft operating in the vicinity of the Array, specifically to aircraft operating at low level. Helicopter operators, the MOD and ATC service providers have been consulted with regard to the potential for the Array to create an obstruction to aviation, military and communications activities conducted in the vicinity of the floating wind turbines and OSPs.
  2. A range of designed in measures, in the form of appropriate notification to aviation, military and communications stakeholders, lighting and marking to minimise effects to aviation flight operations would apply to the development of the Array, as included in the commitments set out in Table 14.11   Open ▸ . These commitments will comply with current guidelines and be agreed with the appropriate receptor aviation stakeholders.
  3. 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 VMC conditions, pilots are ultimately responsible for seeing and avoiding obstructions such as wind turbines and will be aware through notification procedures of the Array. When operating IMC pilots should be under the control of ATC with an appropriate level of radar service and flying at an altitude which provides the required separation from obstacles below them.
  4. The impact is predicted to be of regional spatial extent, long-term duration, continuous and not reversible. It is predicted that the impact will affect the receptor (low flying operations) directly. However, with the designed in measures outlined in section 14.10, the magnitude is therefore considered to be low.
                        Sensitivity of the receptor
  1. Low flying operations are deemed to be of high vulnerability, high recoverability, and high value. The sensitivity of the receptor is therefore, considered to be medium.
                        Significance of the effect
  1. Overall, the magnitude of the impact is deemed to be low, and the sensitivity of the receptor is considered to be medium. 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 focussed secondary mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in section 14.10) is not significant in EIA terms.

                        Decommissioning phase

                        Magnitude of impact
  1. During the decommissioning phase, the presence and movement of decommissioning infrastructure may present a potential collision risk to aircraft in the vicinity of the Array and specifically to low flying aircraft. Helicopter operators, the MOD and ATC service providers have been consulted with regard to the potential for the Array to create an obstruction to aviation, military and communications activities conducted in the vicinity of the wind turbines and OSPs.
  2. A range of designed in measures, in the form of appropriate notification to aviation, military and communications stakeholders, lighting and marking to minimise effects to aviation flight operations would apply to the development of the Array, as included in the commitments set out under Table 14.11   Open ▸ . These commitments will comply with current guidelines and be agreed with the appropriate aviation, military and communications stakeholders.
  3. 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 VMC conditions, pilots are ultimately responsible for seeing and avoiding obstructions such as wind turbines and will be aware through notification procedures of the Array. When operating IMC pilots should be under the control of ATC with an appropriate level of radar service and flying at an altitude which provides the required separation from obstacles below them. It is expected that any mitigation implemented will remain in place until the last wind turbine has been removed.
  4. The impact is predicted to be of regional spatial extent, short term duration, continuous and reversible. It is predicted that the impact will affect the receptor (low flying operations) directly. The magnitude is therefore considered to be low.
                        Sensitivity of the receptor
  1. Low flying operations are deemed to be of high vulnerability, high recoverability, and high value. The sensitivity of the receptor is therefore, considered to be medium.
                        Significance of the effect
  1. Overall, the magnitude of the impact is deemed to be low, and the sensitivity of the receptor is considered to be medium. 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 focussed secondary mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in section 14.10) is not significant in EIA terms.

Wind turbines causing interference to aviation radar systems

  1. The operational floating wind turbines in the Array would be theoretically detectable by the NATS Perwinnes PSR systems (also used by air traffic controllers at Aberdeen International Airport to provide an ATS).
  2. The operational floating wind turbines in the Array would also be theoretically detectable by the RRH Buchan ADR, and occasional detection cannot be ruled out in the southernmost part of the Array by the RRH Brizlee Wood ADR.
  3. Wind turbines detectable by a PSR system might degrade the system by creating false targets, reduce system sensitivity, create radar shadowing behind the wind turbines and saturate the radar receiver leading to clutter potentially concealing real aircraft targets (paragraph 25).

                        Operation and maintenance phase

                        Magnitude of impact
  1. Radar LoS modelling results indicate that, due to the location of the Array and the maximum blade tip height of the floating wind turbines, theoretical radar detectability is likely to affect the operations associated of the MOD and NATS. The impact is predicted to be of regional spatial extent, long term duration, continuous and low reversibility. It is predicted that the impact will affect the receptors (NATS, MOD and Aberdeen International Airport) directly. The magnitude is therefore considered to be high.
                        Sensitivity of the receptor
  1. The ability of NATS, airport authorities and MOD operators of aviation PSR systems to accurately use their respective radar systems for the provision of an ATS, could be impacted by the presence of wind turbine interference and the production of radar clutter on radar displays. All aviation PSR receptors aim to ensure ‘clutter free’ radar to continue to deliver a safe and effective ATS and to securely monitor UK airspace. NATS operations (including those at Aberdeen International Airport) are deemed to be of high vulnerability, medium recoverability, and high value. The sensitivity of the receptor is therefore, considered to be very high.
  2. MOD ADR operations are deemed to be of high vulnerability, low recoverability, and high value. The sensitivity of the receptor is therefore, considered to be very high.
                        Significance of the effect
  1. For NATS operations, the magnitude of the impact is deemed to be high, and the sensitivity of the receptor is considered to be very high. The effect will, therefore, be of major adverse significance, which is significant in EIA terms.
  2. For the MOD ADR operations, the magnitude of the impact is deemed to be high, and the sensitivity of the receptor is considered to be very high. The effect will, therefore, be of major adverse significance, which is significant in EIA terms.
                        Secondary mitigation and residual effect
NATS
  1. In the airspace in which the Array is located, operational acceptance of the effect created is unlikely to be acceptable to all ATC providers without technical PSR mitigation, as portions of airspace may be more important to some ATC establishments than others, due to the role and responsibility of ATC provision allocated to them.
  2. In the case of the NATS PSR system impacted (Perwinnes), previous acceptable mitigation of wind turbine impact to this system has been achieved through agreement by NATS of radar blanking and infill. However, there are no other suitable radar systems that do not theoretically detect the Array and would provide suitable infill data to be operationally effective.
  3. Any technical ATS PSR mitigation decided upon will be subject to commercial agreement between the Applicant and NATS and will be implemented by radar blanking of the affected areas of the Perwinnes PSR which will selectively remove all wind turbine radar returns. However, all other radar returns in the blanked area will also be removed.
  4. To resolve the removal of radar returns through radar blanking, an application to the CAA for an airspace change and the provision of a Transponder Mandatory Zone (TMZ) will remove impact created by the Array to the effected NATS PSR. A TMZ is a defined piece of airspace in which the carriage and operation of a pressure-altitude transponder is mandatory within an aircraft. The creation of a TMZ allows the airspace within and above the development to retain its original classification, yet also allows for enhanced situational awareness for all users and for air traffic controllers. Provision can be made for non-compliant aircraft to gain access to the TMZ; the creation of the TMZ will require regulatory approval by the CAA through an airspace change proposal.
  5. This impact is one that industry has substantial experience of resolving and there is no known reason why suitable mitigation will not be agreed for the Array.
  6. The MOD, DESNZ, The Crown Estate (TCE) and the Offshore Wind Industry Council (OWIC) workstream ‘Programme B’ has been established working with the Department for Transport (DfT), DESNZ the CAA, and NATS, looking to establish a strategic solution around offshore TMZ and future requirements for offshore aviation Communication, Navigation and Surveillance (CNS). Overall, following application of the proposed secondary mitigation, 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.
MOD
  1. In the case of RRH Buchan ADR, previous acceptable secondary mitigation of wind turbine impact to the MOD ADR systems has been achieved through agreement by MOD of the use of a Non-Auto Initiation Zones (NAIZ). Employment of this mitigation solution will require agreement from the MOD that the air defence task can be maintained with this mitigation in place. Commercial agreement between the Applicant and MOD will be required and once implemented the NAIZ mitigation solutions will be implemented over the Array. If a NAIZ is not suitable to mitigate effect, it is the intention of the Applicant to follow the direction provided in the jointly signed Strategy and Implementation Plan Issue 1 dated September 2021, the output of the MOD’s air defence radar mitigation procurement programme (Programme NJORD) and the opportunity to employ the acceptable mitigation(s). The aim of this Programme is to deliver an enduring technical mitigation(s) across the UK in which the Applicant would seek to potentially use in due course, removing the need for interim mitigations such as NAIZ.
  2. The UK Defence and Security Accelerator (DASA) has launched a competition seeking proposals that can provide future offshore wind farm mitigation for UK ADR. The MOD, DESNZ, TCE and the OWIC have formed a Joint Task Force (JTF) whose aim is to enable co-existence of air defence and offshore wind. In September 2021, the task force published a strategy document entitled Air Defence and Offshore Wind, Working Together Towards Net Zero (JTF, 2021)[9] which sets out the process of the development of future technical radar mitigation schemes to mitigate ADR from the impact created by the radar detectability of operational wind turbines. Potential technical radar mitigation solutions have been identified and these systems have demonstrated that they could potentially support wind farm development, the JTF are working towards the procurement of an ADR technical mitigation solution which once deployed will provide an enduring solution.

Engagement with MOD continues with the expectation that, if required, an enduring technical mitigation solution will be agreed, which will reduce the magnitude of the impact; therefore, and when secondary mitigation is in place the residual effect to the impacted MOD ADR systems will be of minor adverse significance, which is not significant in EIA terms.

Future monitoring
  1. No aviation, military and communications monitoring to test the predictions made within the impact assessment is considered necessary.

14.12.            Cumulative Effects Assessment

14.12. Cumulative Effects Assessment

14.12.1.         Methodology

14.12.1. Methodology

  1. The Cumulative Effects Assessment (CEA) assesses the impact associated with the Array together with other relevant plans, projects and activities. Cumulative effects are defined as the combined effect of the Array in combination with the effects from a number of different projects, on the same receptor or resource. Further details on CEA methodology are provided in volume 1, chapter 6.
  2. The projects and plans selected as relevant to the CEA presented within this chapter are based upon the results of a screening exercise (see volume 3, appendix 6.4 of the Array EIA Report). Volume 3, appendix 6.4 further provides information regarding how information pertaining to other plans and projects is gained and applied to the assessment. Each project or plan has been considered on a case-by-case basis for screening in or out of this chapter’s assessment based upon data confidence, impact-receptor pathways and the spatial/temporal scales involved.
  3. In undertaking the CEA for the Array, it should be noted that other projects and plans under consideration will have differing potential for proceeding to an operational stage and hence a differing potential to ultimately contribute to a cumulative impact alongside the Array. Therefore, a tiered approach has been adopted which provides a framework for placing relative weight upon the potential for each project/plan to be included in the CEA to ultimately be realised, based upon the project/plan’s current stage of maturity and certainty in the projects’ parameters. The tiered approach which will be utilised within the Array CEA employs the following tiers:
  • Tier 1 assessment – Array with Proposed offshore export cable corridor(s) and Proposed onshore transmission infrastructure, and projects which became operational since baseline characterisation, those under construction and those with consent application(s) submitted but not yet determined;
  • Tier 2 assessment – All plans/projects assessed under Tier 1, plus those projects with a Scoping Report;
  • Tier 3 assessment – All plans/projects assessed under Tier 2, which are reasonably foreseeable, plus those projects likely to come forward where an Agreement for Lease (AfL) has been granted.
  1. For the purposes of the EIA process in the assessment of the creation of a physical obstacle to aircraft operations , the cumulative effect to aviation, military and communications has been assessed within 40 km from the Array, which is considered to be the maximum range where the creation of an aviation obstacle to fixed wing and rotary aircraft operating offshore may occur although some impacts are likely to be localised to the Array.
  2. For the purposes of this chapter, the assessment of wind turbines causing interference on aviation radar systems (including PSR and ADR), the cumulative effect to aviation, military and communications has been assessed within 100 km from the Array, which is considered to be the maximum range where aviation, military and communications cumulative effects may occur although some impacts are likely to be localised to the Array due to the unmitigated effect created by the detection of operational wind turbines.
  3. It should be noted that the Proposed offshore export cable corridor(s) and Proposed onshore transmission infrastructure have been scoped out of the CEA for aviation, military and communications as there is no pathway for cumulative effect.
  4. The specific projects scoped into the CEA for aviation, military and communications are outlined in Table 14.12   Open ▸ .
Table 14.12:
List of Other Projects and Plans Considered within the CEA for Aviation

Table 14.12: List of Other Projects and Plans Considered within the CEA for Aviation

 

14.12.2.         Maximum Design Scenario

14.12.2. Maximum Design Scenario

Table 14.13:
Maximum Design Scenario Considered for Each Impact as part of the Assessment of Likely Significant Cumulative Effects on Aviation, Military and Communications

Table 14.13: Maximum Design Scenario Considered for Each Impact as part of the Assessment of Likely Significant Cumulative Effects on Aviation, Military and Communications

 

14.12.3.         Cumulative Effects Assessment

14.12.3. Cumulative Effects Assessment

  1. An assessment of the likely significance of the cumulative effects of the Array upon aviation, military and communications receptors arising from each identified impact is given below. Certain impacts assessed for the Array alone are not considered in the cumulative assessment due to:
  • The highly localised nature of the impacts (i.e. they occur entirely within the Array).
  • Management measures in place for the Array will also be in place on other projects reducing their risk of occurring.
  • Where the potential significance of the impact from the Array alone has been assessed as negligible.
  • A lack of data or confidence in data preventing meaningful assessment (i.e. Tier 3).
  1. The MDSs identified in Table 14.13   Open ▸ have been selected as those having the potential to result in the greatest effect on an identified receptor or receptor group. The cumulative effects presented and assessed in this section have been selected from the details provided in volume 1, chapter 3 of the Array EIA Report as well as the information available on other projects, plans and activities (see volume 3, appendix 6.4), to inform the MDS. Effects of greater adverse significance are not predicted to arise should any other development scenario, based on details within the PDE (e.g. different wind turbine layout), to that assessed here, be taken forward in the final design scheme.

CREATION OF PHYSICAL OBSTACLE TO AIRCRAFT OPERATIONS (including Airborne Search and Rescue (SAR) operations and Low Flying aircraft

  1. The construction, operation and maintenance, and decommissioning phases of the Array floating wind turbines, and Tier 1, 2 and 3 projects/plans in Table 14.12   Open ▸ , will lead to the creation of a physical obstacle to aircraft operations. The MDS is represented by the 130 floating wind turbines with a maximum blade tip height of 399 m above LAT and is summarised in Table 14.13   Open ▸ .
  2. A range of designed in measures, in the form of appropriate notification to aviation, military and communications stakeholders, regularity of layout and lighting and marking to minimise effects to aviation flight operations would apply to the development of the Array. These will comply with current guidelines where appropriate and be agreed with the appropriate stakeholders and are outlined in paragraph 61 explains pilots’ obligations for route planning and avoidance of enroute obstructions.
  3. For the purposes of this Array EIA Report chapter, this cumulative impact has been assessed within 40 km from the Array, which is considered to be the maximum range where the creation of an aviation obstacle to fixed wing and rotary aircraft operating offshore may occur although some impacts are likely to be localised to the Array. Tier 1, 2 and 3 projects/plans are listed in Table 14.12   Open ▸ .

                        Tiers 1/2/3

                        Construction phase
Magnitude of impact
  1. There is potential for cumulative effect as a result of construction activities associated with the Array.
  2. Aviation operations in the UK are highly regulated. The Array will be located in airspace where the provision of an ATS is routine. The same rules of the air which maintain a safe operating environment in the current baseline will apply in the northern North Sea off the coast of Angus, Kincardineshire and Aberdeenshire during all phases of the Array and other projects considered in the cumulative assessment; the provision of an ATS will not be affected.
  3. The cumulative impact is predicted to be of regional spatial extent, short term duration, continuous (temporal overlapping developments) with low reversibility once construction has started. It is predicted that the impact will affect the receptor directly. The magnitude is therefore, considered to be low.
Sensitivity of receptor
  1. At times of sufficient visibility VMC pilots are ultimately responsible for seeing and avoiding obstructions such as wind turbines and other infrastructure and will be aware through notification procedures of the projects. When flying in low visibility IMC pilots will be operating above the MSA and utilising on board systems which detects obstructions and be under the control of ATC with an appropriate level of radar service.
  2. Helicopter operators, the MOD and ATC service providers have been consulted with regard to the potential for the Array to create an obstruction to aviation activities conducted in the vicinity of the floating wind turbines and OSPs.
  3. Low level flight operators’ ability to continue using the northern North Sea airspace is deemed to be of high vulnerability, high recoverability and high value. The sensitivity of the receptor is therefore, considered to be medium.
Significance of effect
  1. Overall, the magnitude of the cumulative effect is deemed to be low, and the sensitivity of the receptor is considered to be medium. The cumulative effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.
Further mitigation and residual effect
  1. No further aviation, military and communications mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in section 14.10) is not significant in EIA terms.
                        Operation and maintenance phase
Magnitude of impact
  1. The cumulative impact is predicted to be of regional spatial extent, long term duration, continuous (temporal overlapping developments) and low reversibility. It is predicted that the impact will affect the receptor (low flying operations) directly and consented offshore wind farms considered in the CEA ( Table 14.12   Open ▸ ) will incorporate/adopt similar warning/notification designed-in measures ( Table 14.11   Open ▸ ). The magnitude is therefore, considered to be low.
Sensitivity of receptor
  1. As discussed in paragraphs 114 and 115, low level flight operators’ ability to continue using the northern North Sea airspace is deemed to be of high vulnerability, high recoverability and high value. The sensitivity of the receptor is therefore, considered to be medium.
Significance of effect
  1. Overall, the magnitude of the cumulative impact is deemed to be low, and the sensitivity of the receptor is considered to be medium. The cumulative effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.
Further mitigation and residual effect
  1. No further aviation mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in section 14.10) is not significant in EIA terms.
                        Decommissioning phase
Magnitude of impact
  1. The cumulative impact is predicted to be of regional spatial extent, short term duration, continuous (temporal overlapping developments) and low reversibility once the decommissioning process has commenced. It is predicted that the impact will affect the receptor (low flying operations) directly. The magnitude is therefore, considered to be low.
Sensitivity of receptor
  1. As discussed in paragraphs 114 and 115, low level flight operators’ ability to continue using the northern North Sea airspace is deemed to be of high vulnerability, high recoverability and high value. The sensitivity of the receptor is therefore, considered to be medium.
Significance of effect
  1. Overall, the magnitude of the cumulative impact is deemed to be low, and the sensitivity of the receptor is considered to be medium. The cumulative effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.

Further mitigation and residual effect

  1. No further aviation, military and communications mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in section 14.10) is not significant in EIA terms.

WIND TURBINES CAUSING INTERFERENCE to aviation radar systems

  1. The operational floating wind turbines in the Array and the majority of the Tier 1, 2 and 3 projects/plans in Table 14.12   Open ▸ would be theoretically detectable to some degree by the NATS Perwinnes PSR system (also used by air traffic controllers at Aberdeen International Airport to provide an ATS).
  2. In addition, the operational floating wind turbines in the Array and the majority of the Tier 1, 2 and 3 projects/plans in Table 14.12   Open ▸ would be theoretically detectable to some degree by the RRH Buchan ADR; and occasional detection cannot be ruled out from the RRH Brizlee Wood ADR.
  3. Wind turbines detectable by a PSR system might degrade the system by creating false targets, reduce system sensitivity, create radar shadowing behind the wind turbines and saturate the radar receiver leading to clutter potentially concealing real aircraft targets (paragraph 25).
  4. The ability of NATS, airport authorities and MOD operators of aviation PSR and ADR systems to accurately use their respective radar systems for the provision of an ATS, could be impacted by the presence of wind turbine interference and the production of radar clutter on radar displays. All aviation PSR receptors aim to ensure ‘clutter free’ radar to continue to deliver a safe and effective ATS and to securely monitor UK airspace.
  5. For the purposes of this Array EIA Report chapter, this cumulative impact to aviation radar has been assessed within 100 km from the Array, which is considered to be the maximum range where radar cumulative effects may occur although some impacts are likely to be localised to the Array due to the unmitigated effect created by the detection of operational floating wind turbines. The Tier 1, 2 and 3 projects/plans are listed in Table 14.12   Open ▸ .
                        Operation and maintenance phase
Magnitude of impact

NATS

  1. The cumulative impact to NATS is predicted to be of limited regional spatial extent (due to maximum range coverage restriction of the NATS Perwinnes PSR), long-term duration, continuous (with extensive temporal overlapping developments) and low reversibility. It is predicted that the impact will affect the receptors (NATS and Aberdeen International Airport) directly. The magnitude is therefore considered to be high.

MOD

  1. The cumulative impact to the MOD is predicted to be of regional spatial extent (due to wide-ranging maximum range coverage), long term duration, continuous (with extensive temporal overlapping developments) and low reversibility. It is predicted that the impact will affect the receptor (MOD) directly. The magnitude is therefore considered to be high.
Sensitivity of receptor
  1. Theoretical radar LoS analysis for the NATS Perwinnes PSR together with theoretical detection of the operational floating wind turbines by the MOD ADR systems at Buchan and to a lesser extent Brizlee Wood indicates that the operational Array floating wind turbines with a tip height of 399 m above LAT would be considered to be detectable (by varying degrees) to the PSR and ADR systems. It is likely that those consented and operational wind farms included in the CEA are already mitigated against the effect to aviation radar through non-objection or agreements with NATS and/or the MOD leading to a withdrawal of objection. Unmitigated, the potential cumulative effect created by the detection of operational Array floating wind turbines will be to potentially add to radar screen clutter that presently may be operationally managed by the aviation stakeholder, potentially leading to an increase in the individual signal processing demands of the predicted affected aviation radar systems.
NATS
  1. NATS operations are deemed to be of medium vulnerability, medium recoverability, and high value. The sensitivity of the receptor is therefore, considered to be very high.
MOD
  1. MOD ADR operations are deemed to be of high vulnerability, low recoverability, and high value. The sensitivity of the receptor is therefore, considered to be very high.
Significance of effect
NATS
  1. Overall, the magnitude of the cumulative impact to NATS is deemed to be high, and the sensitivity of the receptor (NATS and Aberdeen International Airport) is considered to be very high. The cumulative effect will, therefore be of major adverse significance, which is significant in EIA terms.
MOD
  1. Overall, for the MOD the magnitude of the cumulative impact is deemed to be high, and the sensitivity of the receptor is considered to be very high. The effect will, therefore, be of major adverse significance, which is significant in EIA terms.
Further mitigation and residual effect
  1. If a NAIZ is not suitable to mitigate effect, it is the intention of the Applicant to follow the direction provided in the jointly signed Strategy and Implementation Plan Issue 1 dated September 2021, the output of the MOD’s air defence radar mitigation procurement programme (Programme NJORD) and the opportunity to employ the acceptable mitigation(s). The aim of this Programme, as part of OWIC Programme A, is to deliver an enduring technical mitigation(s) across the UK in which the Applicant would seek to potentially use in due course, removing the need for interim mitigations such as NAIZ.
NATS
  1. The airspace in which the Array is located, operational acceptance of the effect created is unlikely to be acceptable to all ATC providers within the whole regional airspace environment, without technical PSR mitigation, as portions of airspace may be more important to some ATC establishments than others, due to the role and responsibility of ATC provision allocated to them.
  2. In the case of NATS PSR systems impacted (Perwinnes) the secondary mitigation described in paragraphs 89 to 94 will be agreed with NATS to reach a mutually agreeable technical solution (reducing the magnitude of the impact), and it is expected that similar measures would be agreed in regard to other project/plans in Table 14.12   Open ▸ adversely affecting NATS PSR assets, along with modified process and procedures in the provision of the ATS in the region.
  3. Overall, following application of secondary mitigation, the magnitude of the impact is deemed to be negligible, and the sensitivity of the receptor is considered to be very high. The effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.
MOD
  1. In the case of MOD ADR systems impacted (RRH Buchan and to a degree, in the south of the region, RRH Brizlee Wood) the mitigation described in paragraphs 95 to 96 will be agreed with relevant impacted aviation stakeholders (reducing the magnitude of the impact), and it is expected that similar measures would be agreed in regard to other project/plans in Table 14.12   Open ▸ adversely affecting MOD ADR assets, along with modified procedures in the provision of the ATS in the region.
  2. Overall, following application of secondary mitigation, the magnitude of the impact is deemed to be negligible, and the sensitivity of the receptor is considered to be very high. The effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.

14.13.            Proposed Monitoring

14.13. Proposed Monitoring

  1. No aviation monitoring to test the predictions made within the assessment of LSE1 on aviation is considered necessary.
  2. No monitoring as a result of the CEA is proposed as mitigation will have been required for those receptors which are affected by operational and planned projects, a much-reduced obstacle and radar (if any in some areas of the region) cumulative effect will be apparent and therefore with mitigation in place the residual effect will be minor which is not significant in EIA terms for all scenarios. No monitoring is therefore considered necessary.

14.14.            Transboundary Effects

14.14. Transboundary Effects

  1. Paragraph 19 to 20 explains that the Array is fully contained within the Scottish FIR2. Each FIR2 is managed by a controlling authority that has responsibility for ensuring that air traffic services are provided to the aircraft flying within it. The UK CAA is the controlling authority for the UK. The Scottish FIR2 covers Scotland and Northern Ireland. A screening of transboundary impacts has been carried out (volume 3, appendix 6.6) and has identified that there were no likely significant transboundary effects with regard to aviation from the Array upon the interests of European Economic Area (EEA) states.

14.16. Summary of Impacts, Mitigation, Likely Significant Effects and Monitoring

  1. Information on aviation, military and communications within the aviation, military and communications study area was collected through desktop review and stakeholder engagement. This information is summarised in Table 14.15   Open ▸ and Table 14.16   Open ▸ .
  2. Table 14.15   Open ▸ presents a summary of the potential impacts, designed in measures and the conclusion of LSE1 in EIA terms in respect to aviation, military and communications. The impacts assessed include:
  • creation of physical obstacle to aircraft operations (including airborne SAR operations and low flying aircraft); and
  • wind turbines causing interference on aviation radar systems (including PSR and ADR).
  1. Overall, it is concluded that there will be the following LSE1 arising from the Array during the construction, operation and maintenance or decommissioning phases prior to further mitigation:
  • wind turbines causing interference to aviation radar systems (including PSR and ADR).
  1. Table 14.16   Open ▸ presents a summary of the potential impacts, designed in measures and the conclusion of likely significant cumulative effects on aviation, military and communications in EIA terms. The cumulative effects assessed include:
  • creation of physical obstacle to aircraft operations (including airborne SAR operations and low flying aircraft); and
  • wind turbines causing interference on aviation radar systems (including PSR and ADR).
  1. Overall, it is concluded that there will be the following likely significant cumulative effects from the Array alongside other projects/plans:
  • wind turbines causing interference to aviation radar systems (including PSR and ADR).
  1. No likely significant transboundary effects have been identified in regard to effects of the Array.
Table 14.15:
Summary of Likely Significant Environmental Effects, Secondary Mitigation and Monitoring

Table 14.15: Summary of Likely Significant Environmental Effects, Secondary Mitigation and Monitoring

 

Table 14.16:
Summary of Likely Significant Cumulative Environment Effects, Mitigation and Monitoring

Table 14.16: Summary of Likely Significant Cumulative Environment Effects, Mitigation and Monitoring

14.17.            References

14.17. References

CAA (2016a). CAP 764 Policy and Guidelines on Wind Turbines. Available at: http://publicapps.aa.co.uk/modalapplication.aspx?catid=33&pagetype=65&appid=11&mode=detail&id=5609 Accessed on: 23 August 2023

CAA (2016b, as amended 2022). CAP 393 The Air Navigation Order. Available at: https://publicapps.caa.co.uk/modalapplication.aspx?appid=11&mode=detail&id=7523. Accessed on: 24 November 2023.

CAA (2019). CAP 670 Air Traffic Services Safety Requirements. Available at: https://publicapps.caa.co.uk/modalapplication.aspx?catid=1&pagetype=65&appid=11&mode=detail&id=9124 Accessed on: 23 August 2023.

CAA (2020). CAP 738 Safeguarding of Aerodromes. Available at: https://publicapps.caa.co.uk/modalapplication.aspx?appid=11&mode=detail&id=576 Accessed on: 24 November 2023

CAA (2021). CAP 774 The UK Flight Information Services. Available at: https://publicapps.caa.co.uk/modalapplication.aspx?catid=1&pagetype=65&appid=11&mode=detail&id=11032 Accessed on: 24 November 2023

CAA (2022a). CAP 168 Licensing of Aerodromes. Available at: https://publicapps.caa.co.uk/modalapplication.aspx?appid=11&mode=detail&id=6114. Accessed on: 25 August 2023.

CAA (2022b). CAP 785B Implementation and Safeguarding of Instrument Flight Procedures (IFP) in the UK.

CAA (2023a). CAP 032 UK Integrated Aeronautical Information Package (IAIP). Available at: https://publicapps.caa.co.uk/modalapplication.aspx?catid=1andpagetype=65andappid=11andmode=detailandid=223. Accessed on: 25 November 2023.

CAA (2023b). CAP 999 Helicopter Search and Rescue (SAR) in the UK National Approval Guidance. Available at: https://publicapps.caa.co.uk/modalapplication.aspx?appid=11&mode=detail&id=4092. Accessed on: 26 October 2023.

CAA (2023c) The CAA, Statutory Regulator. Available at: https://www.caa.co.uk/. Accessed on: 24 November 2023.

ICAO (2009). Document 8168 Ops/611 Procedures for Air Navigation Services - Aircraft Operations (PANS-Ops)

ICAO (2022). Annex 14 Aerodromes Design and Operations contains Standards and Recommended Procedures (SARPs)

IEMA (2016). Guide to Delivering Quality Developments.

JTF (2021). Air Defence and Offshore Wind Working Together Towards Net Zero. Available at: https://www.gov.uk/government/publications/air-defence-and-offshore-wind-working-together-towards-net-zero/air-defence-and-offshore-wind-working-together-towards-net-zero. Accessed on: 15 December 2023.

MCA (2021). Marine Guidance Note (MGN) 654: Safety of Navigation Offshore Renewable Energy Installations (OREIs). Available at: https://www.gov.uk/government/publications/mgn-654-mf-offshore-renewable-energy-installations-orei-safety-response. Accessed on: 14 April 2023.

MD-LOT (2023). Scoping opinion for Ossian Array. Marine Directorate – Licensing Operations Team, Edinburgh

Ministry of Defence (MOD) (2023a). Military Aeronautical Information Publication (Mil AIP).

MOD (2016). Obstruction Lighting Guidance. Available at: https://cdn.ymaws.com/www.renewableuk.com/resource/collection/0B792CF1-8B8A-474B-95B6-17886BF724A7/20190002-Windfarm_lighting_review__002_.pdf. Accessed on: 24 September 2023.

MOD (2023b). UK En Route Low Altitude North Sea West Offshore Installations Chart - UK (Low) 5 OIL.

NSTA (2023). Oil and Gas Annual Report and Accounts. Available at: https://www.gov.uk/government/publications/ogansta-annual-report-and-accounts-2022-to-2023. Accessed on: 22 October 2023.

Operational Programme for the Exchange of Weather Radar Information (OPERA) (2009). Statement on the cohabitation between weather radars and wind.

Ossian OWFL (2023). Ossian Array Scoping Report. Available at: https://ossian-eia.com/offshore-scoping/. Accessed on: 15 December 2023

Scottish Government (2015). Scottish National Marine Plan (NMP). Available at: https://www.gov.scot/publications/scotlands-national-marine-plan/. Accessed on: 24 November 2023.

Scottish Government (2020). Sectoral Marine Plan for Offshore Wind Energy (SMP). Available at: https://www.gov.scot/publications/sectoral-marine-plan-offshore-wind-energy/. Accessed on: 24 November 2023.

Trinity (2016). Guidelines on the Provision and Maintenance of Local Aids to Navigation. Available at: https://www.trinityhouse.co.uk/asset/2425. Accessed on: 24 November 2023.

 

[1] Class G airspace is uncontrolled, pilots may enter the airspace subject to a set of simple rules. Pilots are not obliged to contact air traffic control agencies, but many do for other traffic information, pilots remain responsible for their own safety. 

[2] Class C airspace is controlled airspace in which instructions provided to pilots are mandatory. Subject to the flight conditions and type of flight, aircrafts are separated from each other within this class of airspace.

[3] Instrument Flight Rules (IFR) are rules which allow properly equipped aircraft to be flown under Instrument Meteorological Conditions (IMC).

[4] CAP 999 defines the SAR operating minima as: “Operating minima for the dispatch and continuation of a SAR operational flight are at the discretion of the aircraft commander. However, he is to consider the urgency of the task, crew and aircraft capability and the requirement to recover the aircraft safely” (CAA, 2023b).

[5] Babcock Group Int also operates two specialist SAR aircraft to support the Oil and Gas industry from Aberdeen International Airport: the Integrated Search and Rescue (ISAR) Consortium (formerly Jigsaw Aviation).

[6] C = Construction, O = Operation and maintenance, D = Decommissioning

[7] C = Construction, O = Operation and maintenance, D = Decommissioning

[8] In aviation terms, “rarity” refers to the state or quality of being rare to the aviation user or service provider, e.g. resilience of radar, availability of a hub/node of operation, or the overall airspace.

[9] Policy paper: Air defence and offshore wind - working together towards Net Zero (29 September 2021)

[10] C = Construction, O = Operation and maintenance, D = Decommissioning

[11] C = Construction, O = Operation and maintenance, D = Decommissioning