CHAPTER 15 15.0 AVIATION... 1 15.1 Introduction... 1 15.2 Methodology... 3 15.3 Baseline... 8 15.4 Assessment of Effects... 12 15.5 Mitigation... 15 15.6 Residual Effects and Conclusions... 18 15.7 References... 19 Appendices Appendix 15.1 (Volume 3 Bound Separately) Loch Urr Aviation Impact Assessment LOCH URR WIND FARM 15 - i
15.0 AVIATION 15.1 Introduction 15.1.1 This Chapter has been prepared by Osprey Consulting Services Ltd (Osprey), a technical consultancy providing aviation expertise to the wind industry. It identifies and assesses the potential effects that the Proposed Development, as described in Chapter 5.0 Scheme Description and Construction Methods, may have on aviation and air safeguarding, and the mitigation measures to be implemented to prevent, reduce or offset potential adverse effects, where required. 15.1.2 The potential effects of wind turbines on aviation interests have been widely publicised. There are two dominant scenarios: Physical obstruction: turbines can present a physical obstruction at, or close to, an aerodrome or other aviation activity site; and Radar/Air Traffic Services (ATS): turbine clutter appearing on a radar display can affect the safe provision of air traffic services as it can mask unidentified aircraft from the air traffic controller and/or prevent him from accurately identifying aircraft under his control. In some cases, radar reflections from the turbines can affect the performance of the radar itself. 15.1.3 This chapter presents a summary of the results of the Aviation Impact Assessment (AIA) undertaken by Osprey (Appendix 15.1). The AIA identifies potential effects on aviation receptor groups in the area of the Proposed Development and provides an objective assessment of the effects and any necessary mitigation measures. Osprey considered the potential for the Proposed Development to have an effect on the aviation interests, either in terms of operations or Air Traffic Control (ATC) radar or flight operations, of National Air Traffic Services (NATS) and the Ministry of Defence (MOD). There are no other potentially affected aviation stakeholders. 15.1.4 The assessment considers all radar systems within operational range of the Site and has been informed by the results of a desktop baseline study and with reference to the existing evidence base regarding effects of onshore wind farm development. This chapter is supported by the following document: LOCH URR WIND FARM 15-1
Technical Appendix 15.1; Loch Urr Aviation Impact Assessment, Issue 2 (Osprey, 2014). LOCH URR WIND FARM 15-2
15.2 Methodology Scope of Assessment 15.2.1 The AIA was conducted in accordance with Civil Aviation Authority (CAA) Civil Air Publication (CAP) 764, Policy and Guidelines on Wind Turbines (CAA, 2013). Potential aviation stakeholders were identified for each receptor, the physical obstruction and/or radar effect, and the operational effects were subsequently evaluated. Any impact to operations pays heed to, but is not limited to, consideration of the orientation of approach and departure flight paths, physical safeguarding of flight, airspace characteristics and flight procedures as published in the NATS UK Integrated Aeronautical Information Package (UK IAIP) (NATS, 2014). 15.2.2 Radar performance and propagation modelling has been undertaken to determine the theoretical detection of the proposed turbines by the regions radar infrastructure. Osprey utilised the ATDI ICS LT V3.7.7 1 tool to model the terrain elevation profile between the identified Primary Surveillance Radars (PSRs) and each wind turbine blade tip height, to provide a graphical representation of the intervening terrain and theoretical direct Line of Sight (LoS), in order to determine the affected radar systems within the baseline. 15.2.3 The AIA considers the potential solutions that would mitigate the effects of the Proposed Development on the operations of identified aviation receptors. This chapter summarises the results of the AIA which are contained in full in the Technical Appendix 15.1. Assessment Guidelines 15.2.4 The aviation industry and the provision of Air Navigation Services are regulated through extensive legislation, with the mechanism for wind development enabled through the consenting system and in accordance with regulatory guidance. The following policy and guidance documents were considered during the baseline definition and assessment activities: (CAA, 2014(a)) CAA, CAP 393 Air Navigation: The Order and the Regulations (known as the Air Navigation Order (ANO)); 1 Advanced Topographic Development and Images Ltd ICS Lite Version 3.3.7 LOCH URR WIND FARM 15-3
(CAA, 2014(b)) CAA, CAP 670 Air Traffic Services Safety Requirements; (CAA, 2013) CAA, CAP 764 Policy and Guidance on Wind Turbines; (MOD, 2012) MOD Specification for IR and Low Intensity Red Vertical Obstruction Lighting; and (RenewableUK, 2012) Renewable UK Guidance on Low Flying Activity and Onshore Tall Structures Including Anemometer Masts and Wind Turbines. Other data sources and guidance considered under desktop review of the definition of the baseline environment include the following: (MOD, 2011(a)) MOD UK Low-Flying System (UKLFS) Priority Areas map; (MOD, 2014) Military Aeronautical Information Publication (Mil AIP); (NATS, 2012) NATS Project RM: Wind Turbine Mitigation Briefing note for developers; (NATS, 2013(b)) Visual Flight Rules chart; and (NATS, 2014) CAA, CAP 32 UK Integrated Aeronautical Information Publication. UK IAIP is the main resource for information and flight procedures at all licensed UK airports as well as airspace, en-route procedures, charts and other air navigation information. Impact Assessment Methodology Magnitude 15.2.5 The magnitude criterion of the potential effects on aviation and radar receptors is assessed using the following method and terminology: Table 15.1 Magnitude Criteria Descriptor or Criteria High Magnitude Medium Magnitude Low Magnitude Description Receptor unable to continue safe operations or safe provision of air navigation services (radar) in the presence of the turbines. Technical and/or operational mitigation of the effect is required. Receptor able to continue safe operations but with some restrictions or non-standard mitigation measures in place. Receptor able to continue operations with standard LOCH URR WIND FARM 15-4
Descriptor or Criteria Description mitigation in place. Negligible Magnitude No effect on this Receptor. Sensitivity 15.2.6 The sensitivity of a receptor is subjective in aviation terms and therefore difficult to quantify. Whereas an Air Defence Radar installation would be an obvious high value and high sensitivity receptor to most (due to its role in UK national security), the sensitivity of a local aerodrome can often be rated high if the Planning Authority considers the receptor to be significant asset to the local area. The identified receptors in this analysis are considered to have a high sensitivity to effects, given their safety critical function. Significance 15.2.7 Significance criteria for aviation effects are difficult to establish as they are not strictly based on the sensitivity of the receptor or magnitude of change but on whether the industry regulations for safe obstacle avoidance or radar separation (from radar clutter) can be maintained in the presence of the turbines. However, where practicable the following matrix has been used to assist in determining the likelihood of a significant effect arising from the Proposed Development. Table 15.2 Significance Criteria Magnitude of Effect Sensitivity of Receptors High Medium Low Negligible High Significant Significant Significant Not Significant Medium Significant Significant Not Significant Not Significant Low Significant Not Significant Not Significant Not Significant Negligible Not Significant Not Significant Not Significant Not Significant LOCH URR WIND FARM 15-5
Approach to the Assessment 15.2.8 Potential aviation stakeholders were identified in accordance with CAA guidance (CAA, 2013). The guidance states that any wind turbine development within 30 km of an aerodrome with a surveillance radar facility might have an effect upon civil aerodrome related operations. The guidance goes on to say that the distance can, however, be far greater than 30 km depending upon a number of factors, including the type and coverage of the radar and the particular operation at the aerodrome. 15.2.9 Consideration was given to any ATC, Air Defence or other radar systems that are within operational range of the Proposed Development. Operational range varies by radar and by using a database of all ATC and air defence radars in the UK, the study areas can be defined on a case-by-case basis in this respect. 15.2.10 Definition of the baseline environment for aviation can often be a subjective process. For this reason, at least one ATC expert, and one safeguarding and regulatory expert are involved in the selection of the study area. 15.2.11 The AIA (Osprey, 2014) is a desk-based study involving a systematic review of the charts and data available through the UK IAIP (NATS, 2014) as well as utilisation of Visual Flight Rules charts (NATS, 2013(b)). The review seeks to identify all potential aviation receptors. Summary of Consultation 15.2.12 The approach to the assessment has identified those radars or systems and practices that have the potential to interact with the Proposed Development. Those with no identifiable interaction are not taken through to the assessment phase. Table 15.3 highlights those systems and aviation receptors which are considered to be potentially effected and hence, whom the Applicant has sought to engage through consultation. Table 15.3 summarises the response received from aviation receptors. LOCH URR WIND FARM 15-6
Table 15.3 Summary of Consultation Receptor Type Assessment Terms NATS Technical and Operational Assessment (TOPA) W(F)11396 dated July 2011 The Proposed Development would conflict with NATS Safeguarding criteria, causing false primary plots to be generated on the Lowther Hill and Great Dun Fell radar (NATS, 2011). NATS has indicated that the effects of the Proposed Development would be technically mitigated by the implementation of a Project Raytheon Modification (Project RM) upgrade to the Great Dun Fell PSR (NATS, 2013(a)) as discussed further below in para 15.5.4. In addition, Osprey analysis has concluded that a similar upgrade to the NATS Lowther Hill PSR would also mitigate the effect of the Proposed Development on this radar system (Osprey, 2014). Further consultation will follow to conclude NATS mitigation requirements. MOD Pre-application assessment (DE/C/SUT/43/10/1/12311) The MOD stated that they had no concerns with the Proposed Development and provided their lighting requirements based on the original site design, noting at the point of consultation the Proposed Development comprised 28 turbines. Further consultation will follow to ascertain the MOD lighting requirements based on the finalised development parameters. LOCH URR WIND FARM 15-7
15.3 Baseline NATS En-Route 15.3.1 NATS is the UK civil en-route Air Navigation Service Provider (ANSP). NATS operate a number of long-range radars positioned to provide maximum coverage of UK airspace, which are important for the safe provision of air traffic services to civil and military, national and international air traffic. 15.3.2 The Proposed Development is located within operational range of the NATS Lowther Hill and Great Dun Fell PSR systems. The Lowther Hill PSR is sited at a distance of approximately 28 km and on a bearing of 205 from the Proposed Development and the Great Dun Fell PSR is sited at a distance of approximately 107 km and on a bearing of 300 from the Proposed Development. These radar systems contribute to the network of en-route radars providing vital coverage of UK airspace; the sensitivity of the receptor is determined to be high. In addition, surveillance data from these systems are also used by other air navigation service providers. Military ATC Units are based in NATS Control Centres to facilitate the control of aircraft that require ATC services outside or crossing the civil airspace structure. NATS have a contracted responsibility to provide appropriate PSR coverage to support this task. United Kingdom Low Flying System 15.3.3 Low flying is a demanding but essential skill for military aircrew, gained through progressive training and continuous practice within the United Kingdom Low Flying System (UKLFS). The ability to operate effectively at low level by day and night is vital to fast jets, transport aircraft and helicopter operations as they support forces on the ground, and hence the UKFLS is a high sensitivity receptor. The Proposed Development is located within the UKLFS Low Flying Area (LFA) 16 and within Tactical Training Area (TTA) 20T, when this area is active. 15.3.4 Height in the UKLFS can be referred to in terms of minimum separation distance (MSD). This is the distance that must be maintained between any part of an aircraft in flight and the ground, the water or any other object. In an LFA aircraft can operate down to 250 feet (ft) MSD; however, in a TTA fast LOCH URR WIND FARM 15-8
jets can fly at 100 ft MSD and helicopters can fly down to 100 ft above ground level (agl) or down to ground level in support of troops on the ground. Airspace 15.3.5 The airspace above the Proposed Development is categorised as follows, this is illustrated below on Diagram 15.1: Class G uncontrolled airspace up to Flight Level (FL) 85 (approximately 8,500 ft above mean sea level (amsl)); any aircraft can operate in this area of uncontrolled airspace without any requirement to be in communication with any ATC Unit. Pilots of aircraft operating in Class G airspace are ultimately responsible for seeing and avoiding other aircraft or obstacles; Class A Controlled Airspace (CAS) established from FL 85 up to FL 195; aircraft operating within this airspace must be in receipt of an air traffic service (ATS) from NATS Prestwick Area Control Centre (ACC). The air traffic controller is responsible for maintaining typically 5 nautical mile lateral separation between aircraft; Class C CAS established from FL 195 up to FL 245; all aircraft operating in this airspace must be in receipt of an ATS from NATS or Military controllers located at a NATS control centre; and Class C CAS established above FL 245; again all aircraft operating in this airspace must be in receipt of an ATS from NATS or Military controllers located at a NATS ACC. LOCH URR WIND FARM 15-9
Diagram 15.1 Cross Sectional View of Airspace Structure Other Aviation Stakeholders 15.3.6 No other aviation stakeholders (i.e. small airfields, glider sites, etc.) were identified as likely to be affected during the assessment of the baseline environment. Potential Receptors 15.3.7 The approach to the assessment has identified those radar or systems and practices which have the potential to interact with the Proposed Development. Those with no identifiable interaction are not taken forward to the assessment phase e.g. Glenswinton Airstrip. The following Table 15.4 highlights those systems which are considered in the assessment. Table 15.4 Summary of Receptors taken forward to the Assessment Receptor Type To Assessment Phase NATS Lowther Hill PSR En-Route Radar Yes NATS Great Dun Fell PSR En-Route Radar Yes LOCH URR WIND FARM 15-10
Receptor Type To Assessment Phase MOD UKLFS LFA 16 and TTA 20T Yes LOCH URR WIND FARM 15-11
15.4 Assessment of Effects NATS Lowther Hill and Great Dun Fell PSR Systems Construction Phase 15.4.1 The infrastructure required in the process of the construction of the Proposed Development would have no significant effect on either of the NATS Lowther Hill or Great Dun Fell PSR systems. The static nature of the infrastructure is such that it would not be processed and presented onto ATC display screens by the PSR system. No significant effect on radars and operations is expected ahead of the turbines commencing operation. Operational Phase 15.4.2 NATS uses the Lowther Hill and Great Dun Fell PSR systems to support their provision of navigational services to flights into and out of Edinburgh, Glasgow and Prestwick Airports, aircraft operating between UK airports and mainland Europe and also to those overflying the UK Flight Information Region (FIR). 15.4.3 Air Traffic Controllers are responsible for maintaining typically 5 nautical miles lateral separation between aircraft. Where turbines are detectable by a PSR system, they may appear as aircraft targets and could mask genuine aircraft responses. The radar may also be de-sensitised by clutter processing within the sector containing turbines, meaning that real aircraft targets may not be detected or may disappear from radar. At an anticipated maximum height of 127.5 metres (m) to blade tip, the Proposed Development is predicted to cause clutter to be presented on NATS ATC displays. 15.4.4 Radar propagation modelling has been undertaken and the interaction of radar with the proposed wind turbines is well understood (Osprey, 2014). Therefore, the magnitude of the effect is high. The sensitivity of the receptor is also high. This effect has therefore been assessed as Significant. Decommissioning Phase 15.4.5 Agreed mitigation is required to remain operational until the Site has been fully decommissioned; consequently, this phase would have no significant effect on the NATS Lowther Hill and Great Dun Fell PSR systems. LOCH URR WIND FARM 15-12
Micro-siting 15.4.6 No additional effect on this receptor is anticipated should the micro-siting of any individual turbine(s) be required. MOD Low Flying Construction Phase 15.4.7 The infrastructure required in the construction process of the Proposed Development may present a physical obstruction and effect operations of Military Low Flying aircraft. Operational Phase 15.4.8 The Proposed Development would be located within LFA 16 and when active, within TTA 20T. These areas are considered by the MOD to be of key importance for Military low flying training. 15.4.9 Pilots are obliged to plan their flying activities in advance and to be familiar with any en-route obstacles they may encounter. During the flight, weather conditions or military exercises may necessitate route adjustments. However, pilots are ultimately responsible for seeing and avoiding tall structures such as wind turbines. Despite this, it is acknowledged that there is an increased risk in low visibility conditions where pilots performing high energy manoeuvres could experience a delay in visually acquiring the turbines. 15.4.10 The airspace in the vicinity of the Proposed Development is considered to be of high priority in terms of the UKLFS, indicating an area where the MOD may raise objections to wind developments. However, during initial consultation in 2011, the MOD stated that they had no concerns with the layout provided. The consultation layout comprised 28 turbines, two more than now being proposed. On the basis of the consultation response the sensitivity of the receptor is considered to be low. The magnitude of effect is determined to be medium, resulting in the effect being Not Significant. LOCH URR WIND FARM 15-13
Decommissioning Phase 15.4.11 The infrastructure required in the process of the turbine decommissioning process may present a physical obstruction and effect operations of Military Low Flying aircraft. Micro-siting 15.4.12 No additional effect on this receptor is anticipated should the micro-siting of any individual turbine(s) be required. LOCH URR WIND FARM 15-14
15.5 Mitigation General 15.5.1 It is good practice to notify Aviation Stakeholders of the location and dimension of any wind energy development and the associated construction activities. Information regarding construction should be passed to the Defence Geographic Centre and the General Aviation Awareness Council at least 6 weeks in advance of the erection of the first turbine and to follow up on the day with a confirmation that the activity has taken place. The data should include: Location, height (of all structures over 150 ft, date of erection, date of removal and lighting type (none, infra-red or lighting brightness); and RenewableUK should be copied on the submission of all such information as an independent record and that they might share the information with other relevant official agencies. Appropriate information about the Site construction and any associated lighting (where applicable), for example the height and temporary location of construction cranes, should be provided to the UK Aeronautical Information Service (NATS AIS) for promulgation throughout the UK IAIP (NATS, 2014). NATS Lowther Hill and Great Dun Fell PSR Systems Construction Phase 15.5.2 As stated at above, the construction phase would have no significant effect on the NATS Lowther Hill and Great Dun Fell PSR systems; there is no requirement for mitigation. Operational Phase 15.5.3 NATS in conjunction with the supplier of their PSR systems, Raytheon, have developed a technical solution that allows clutter generated by wind turbines to be removed from a controllers display whilst ensuring that the current ability to detect, track and provide navigational assistance to aircraft is not degraded (Project Raytheon Modification (RM)). LOCH URR WIND FARM 15-15
15.5.4 NATS has indicated that the implementation of a Project RM upgrade mitigation solution to the Great Dun Fell PSR has the potential to be an acceptable option to resolve the impact of the Proposed Development on this system (NATS, 2013(a)). 15.5.5 Osprey analysis concludes that the potential base of PSR coverage that may exist when a Project RM upgrade to the Lowther Hill PSR is implemented by NATS would be approximately 3,620 ft amsl. The base of controlled airspace above the Proposed Development is 8,500 ft amsl. Therefore, it is concluded that approximately 4,880 ft of radar coverage is likely to be available below the base of the existing controlled airspace, which is considered sufficient to meet NATS operational task (Osprey, 2014). Further comprehensive consultation would follow the grant of consent to conclude NATS mitigation requirements. It is anticipated that this would be controlled by way of a suitably worded planning condition. Decommissioning Phase 15.5.6 Any agreed mitigation would remain operational until the Proposed Development has been fully decommissioned; as such this phase would have no significant effect on the Lowther Hill and Great Dun Fell PSR systems. MOD Low Flying Construction Phase 15.5.7 Construction of the Proposed Development, including turbines and the assembly infrastructure, may present a physical obstruction to Military Low Flying aircraft. Appropriate details regarding the site s construction, for example the height and temporary location of construction cranes, and any associated lighting (where applicable) should be provided to the Defence Geographic Centre (DGC) and UK Aeronautical Information Service (NATS AIS) for promulgation throughout the UK IAIP (NATS, 2014). Operational Phase 15.5.8 Pilots of Military Low Flying VFR aircraft are ultimately responsible for their own terrain and obstacle clearance. Pilots refer to aviation charts detailing the relevant terrain and any obstacles; this mapping would depict the location of LOCH URR WIND FARM 15-16
the Proposed Development and its parameters in the event of it being constructed. Details of the Proposed Development are required to be promulgated through the DGC and the UK AIS to enable the site s depiction on appropriate aviation charts and documentation as required. 15.5.9 The MOD stated in their original response a requirement in the interests of air safety, that the corner most turbines and 6 other turbines within the Proposed Development are fitted with a form of aviation obstruction lighting for day and night operations (MOD, 2011(b)). Although the layout has since been significantly reduced in terms of turbine numbers, it is considered that the MOD is unlikely to alter their position. 15.5.10 The requirement for aviation lighting is stipulated for structures which extend greater than 150 m agl. However, the CAA may further support the use of aviation obstruction lighting at the request of an aviation stakeholder for shorter structures, should this be deemed necessary. Consultation with the MOD through the Defence Infrastructure Organisation (DIO) would determine the finalised lighting requirements. It is anticipated that this would be controlled by way of a suitably worded planning condition. Decommissioning Phase 15.5.11 Decommissioning of the Proposed Development, including both the turbines and the associated infrastructure, may present a physical obstruction to Military Low Flying aircraft. In order to safeguard the general use of the area by military traffic, the Applicant would adhere to the notification requirements outlined at Paragraph 15.5.1 and any lighting requirements should this be deemed necessary. LOCH URR WIND FARM 15-17
15.6 Residual Effects and Conclusions 15.6.1 It is acknowledged that the Proposed Development is likely to have an effect on the NATS Lowther Hill and Great Dun Fell PSR systems. It has been identified that it is highly likely that technical mitigation solutions can be implemented to resolve the predicted significant effects of the Proposed Development on their radar and operations. Should consent be granted for the Proposed Development, it is considered that, with the collaboration of NATS, a technically and operationally acceptable mitigation solution can be implemented prior to the Proposed Development becoming operational. 15.6.2 The configuration of the aviation obstruction lighting requested by the MOD is anticipated to be sufficient in terms of the UKLFS, resulting in an insignificant residual effect. Comprehensive formal consultation would follow any grant of consent and would identify the finalised requirements for the fitting of aviation obstruction lighting to the Proposed Development. It is anticipated that this would be controlled by way of a suitably worded planning condition. Cumulative Effects 15.6.3 There are a number of operational and consented wind farms within the vicinity of the Proposed Development which may be considered by NATS and the MOD to result in an increasing cumulative effect on their individual operations within the region. 15.6.4 However, it has been demonstrated that there are technically feasible solutions available to avoid significant effects on aviation receptors from the Proposed Development and as such it is considered unlikely that the scheme would result in any significant cumulative effects with other operational, consented or proposed wind farm projects. 15.6.5 On this basis it is considered there would not be any significant aviation effects from the Proposed Development. LOCH URR WIND FARM 15-18
15.7 References CAA. (2013). CAP 764 - CAA Policy and Guidance on Wind Turbines. CAA. CAA. (2014(a)). CAP 393 Air Navigation: The Order and the Regulations. CAA. CAA. (2014(b)). CAP 670 Air Traffic Services Safety Requirements. CAA. MOD. (2011(a)). MOD UK Low-Flying System (UKLFS) Priority Areas map. MOD. (2011(b)). Pre-application Assessment DE/C/SUT/43/10/1/12311. MOD. MOD. (2012). MOD Specification for IR and Low Intensity Red Vertical Obstruction Lighting. MOD. MOD. (2014). Military Aeronatical Information Publication. MOD. NATS. (2011). Technical and Operational Assessment (TOPA) W(F)11396. NATS. NATS. (2012). NATS Project RM: Wind Turbine Mitigation Briefing note for developers. NATS. NATS. (2013(a)). NATS Project RM Mitigation Capability Correspondence. NATS. NATS. (2013(b)). Visual Flight Rules Chart Scotland Edition 28. NATS. NATS. (2014). CAP 32 UK Integrated Aeronautical Information Package. NATS. Osprey. (2014). Loch Urr Aviation Impact Assessment. Osprey. RenewableUK. (2012). Guidance on Low Flying Aircraft and Onshore Tall Structures Including Anemometer Masts and Wind Turbines. RenewableUK. LOCH URR WIND FARM 15-19