20140513-MOD Written Statement-U

Town and Country Planning (Scotland) Act 1997

Town and Country Planning (Development Management Procedure) (Scotland) Regulations 2013

• Proposed erection of wind turbine at land adjacent to Dark Island Hotel, Liniclate, Benbecula

• Proposed erection of 2 wind turbines, 2 anemometer masts and site container at 7 Bornish, South Uist

• Proposed erection of 2 wind turbines at Locheport, North Uist

WRITTEN STATEMENT

ON BEHALF OF THE SECRETARY OF STATE FOR DEFENCE

Dated 15th May 2014

Directorate for Planning and Environmental Appeals Refs:

• CIN-CES-001 (Dark Island Hotel) • CIN-CES-002 (7 Bornish) • AIR-CES-001 (Locheport)

Executive Summary

The MOD maintains its objection to the Dark Island Hotel; 7 Bornish; and Locheport turbine proposals due to the unacceptable interference the turbines will have on military radars situated in the Hebrides.

Scottish Planning Policy acknowledges that defence interests should be recognised by local planning authorities as areas of potential constraint on wind turbine development.

The Scottish Government published guidance states that developers should initiate the process of identifying or developing a solution. The guidance also identifies that the use of mitigation conditions where there is no identified mitigation to deal with an aviation objection could have an impact on the likelihood of other developments being consented.

The Applicants have not adequately addressed issues of defence and aviation safety as they are required to do in terms of national and local planning policy.

It has been shown that where wind turbines are within radar line of sight and/or radar field strength detection occurs, wind turbines can have detrimental effects on the performance of the radar. These effects include the desensitisation of radar in the vicinity of the turbines, the creation of “false” aircraft returns, and obscuration of real aircraft targets.

Aviation safety and military operations should not be compromised by the proposed turbines.

The MOD would respectfully request that the Scottish Ministers refuse each of the applications on the basis of unacceptable adverse impact on aviation and defence interests.

1 Introduction

Defence Infrastructure Organisation

1.1 Defence Infrastructure Organisation (DIO) was formed on 1 April 2011, when the former Defence Estates organisation was brought together with other infrastructure functions in the Ministry of Defence (MOD) to form a single organisation.

1.2 DIO manages the military estate, including accommodation for Service personnel and their families, on behalf of the MOD. DIO Safeguarding manages, on behalf of the MOD, the formal consultation process through which the MOD is engaged on development proposals, including those for wind turbines. It ensures operational facilities such as aerodromes, explosive stores, radar facilities and range areas are not compromised by development either on or offshore. This safeguarding responsibility includes maintaining the effective operation of military radars.

1.3 DIO Safeguarding receives consultations from Local Planning Authorities and consenting authorities on behalf of the MOD. DIO Safeguarding then consults a range of technical experts across the Department and a response is provided to the Local Planning Authority or consenting authority that addresses all MOD interests, including defence radars.

2 MOD approach to wind turbine planning applications

2.1 Flight trials and research has proved that wind turbines have detrimental effects on radar. This is accepted by the Wind Energy industry, planning and consenting authorities, aviation stakeholders and radar stakeholders.

2.2 The MOD, has since 1994, conducted a number of trials to determine the impact of wind turbines upon air traffic control and air defence radars. These along with trials carried out by other nations have shown that wind turbines have a number of specific effects on radar systems. These are: on screen false target returns (also referred to as clutter); desensitisation of the radar's detection capability over and around wind turbines; obscuration of aircraft returns above the wind turbines; and the creation of a radar ‘shadow’ beyond the turbines. The appearance of returns from wind turbines on operators' screens also leads to distraction and increased workloads.

2.3 The MOD signed up to the Memorandum of Understanding (MOU) (August 2011 update): wind turbines and aviation radar (mitigation issues) – Department of Energy and Climate Change – Pub 2 August 2011) – see Reference 39 - and is committed to aviation solutions. Recognising the urgency to develop solutions to mitigate the impact of wind turbines on Air Traffic Control Primary Surveillance Radar (ATC PSR), MOD and Department of Energy and Climate Change (DECC) Ministers, with the support from the Aviation Investment Fund Company Limited (AIFCL), made a public commitment in the 2012 Autumn Statement that MOD would facilitate a technical demonstration during the summer of 2013.

2.4 The aim of that technology demonstration was to assess the relative maturity of existing mitigation solutions in comparison with the MOD requirement for ATC PSR in the presence of wind farms in accordance with MOD User Requirements. The technology demonstration took place at MOD Eskmeals in summer 2013 and six companies were selected via open competition to participate. The technology demonstration assessed the ability of the mitigation solutions to achieve the required performance in the vicinity of a wind farm and whilst more than one technology showed improvement over the baseline performance, none of them fully met MOD’s assessment criteria during the demonstration. MOD continues to proactively seek a solution and further details for the next steps after the technology demonstration will be articulated in MOD’s response to the March 2014 milestone in the National Infrastructure Plan.

2.5 MOD is proposing to continue its proactive approach and aims to run a pilot project that would take the recommendations of the technology assessment forward. The aim of the pilot would be to work with fewer mitigation solution provider(s) over a longer period in order to prove a technical solution that meets MOD requirements for mitigating wind turbines on ATC radars. Once proven, this solution can be subsequently implemented at a number of sites. The wind farm developers are considering this proposal and are in discussions with MOD on how the pilot and any subsequent implementation might be funded.

2.6 The MOD should be consulted on planning applications for wind turbines that are 11m or above in height to blade tip and/or 2m rotor diameter or above and this is readily accepted by Local Planning Authorities and consenting authorities across the UK. In 2013 MOD received in the order of 3500 wind turbine planning application consultations from Local Planning Authorities and consenting authorities. Each planning application is subjected to an individual assessment which considers technical and operational factors.

2.7 Where a proposed wind turbine is found to be within the coverage of, and detectable by a military radar, an operational assessment determines if the potential impact is manageable or not. The relevant operational subject matter expert conducting the operational assessment will give consideration as to what reasonable operational measures may be put in place to mitigate the effects of the wind turbine development. Where the potential impact is not manageable, MOD will object. Where the potential impact is manageable, the MOD will not object.

2.8 Following a MOD objection, it is the responsibility of the applicant to propose mitigation to MOD to overcome the radar issue(s). Should MOD consider that the mitigation is acceptable, MOD would then be willing to consider wording of a prospective planning condition. If no acceptable mitigation is submitted, MOD will maintain its objection.

2.9 MOD requires acceptable mitigation to have been proposed by the applicant before discussing planning conditions. Proposing mitigation demonstrates that the applicant has given due consideration to the impact of the proposal on MOD radars/aviation safety and how this can be addressed. This approach has been consistently applied by the MOD in other Hearings and Planning Inquiries.

3 Background

3.1 This Hearing is in respect of three planning applications which have been called in for determination by the Scottish Ministers. The MOD's position in respect of each of these is as follows:

3.2 Locheport - DPEA Ref AIR-CES-001 This planning application was lodged on behalf of the North Uist Community Council on 1 April 2013 for the erection of 2 wind turbines and associated infrastructure on existing croft land at Criongrabhal, By Clachan, Isle of North Uist (otherwise known as Locheport).

The MOD objected to this application in May 2013 stating that the turbines would be detectable by and cause unacceptable interference to the Range Control radar at South Uist and also the radar at St Kilda. Additionally, as the proposed turbines were within 5 nautical miles of the Air Defence Radar (ADR) at Remote Radar Head (RRH) Benbecula, MOD objected on the grounds that they would be a physical obstruction, which would be likely to cause disruption to the transmitted and received radar signals which ultimately would result in reduced radar detection performance at range. MOD's ultimate position is that this would compromise the capability of Air Defence operational staff to detect threats to the UK airspace and control aircraft at range.

Further information in support of MOD's objection was supplied by email dated 22 July 2013, at which time it was confirmed that the objection previously intimated was being maintained.

A Report by the Comhairle's Director of Development dated 24 July 2013 recommended refusal of this application on the basis of the MOD objection. It was noted that, at this time, the MOD's objection was made partially in their capacity as a statutory consultee, due to the proximity of the proposed turbines to the ADR at RRH Benbecula.

The application was considered further by the Comhairle Environment & Protective Services Committee ("the Committee") on 3 September 2013, at which time a further Report from the Director of Development continued to recommend refusal

of the application of the basis of the MOD objection, and non-compliance with the Outer Hebrides Local Development Plan.

In advance of that meeting, MOD provided the Comhairle with a further letter confirming that MOD's objection was maintained and that mitigation measures proffered were neither applicable, nor appropriate, to allow MOD to withdraw its objection.

On 19 November 2013, the Committee met again to consider this matter. At that time they resolved to approve the application, despite a further recommendation to refuse from their Director of Development. The Committee's decision was that the application should be approved on socio-economic grounds and that MOD had not demonstrated to their satisfaction that the proposal would have an adverse effect upon defence. As this decision was proposed to be taken in the face of an objection from MOD in its capacity as statutory consultee, this application required to be notified to the Scottish Ministers.

The current situation in respect of this application is that the MOD's objection as statutory consultee in respect of the ADR at RRH Benbecula has been withdrawn. The MOD does however maintain its objection to this proposed development on the basis of unacceptable interference with the range control radar at St Kilda. It remains appropriate for this application to be considered by the Scottish Ministers as a called-in application.

3.3 The Dark Island Hotel - DPEA Ref CIN-CES-001 This planning application was lodged on behalf of the Manager of the Dark Island Hotel on 31 May 2013 for the erection of 1 wind turbine on land adjacent to the Dark Island Hotel.

The MOD objected to this application on 24 June 2013 stating that the turbine would be detectable by and cause unacceptable interference with the Hebrides Range Control radar and the ADR at RRH Benbecula.

The application was considered by the Comhairle's Environment & Protective Services Committee on 24 July 2013, at which time a further Report from the

Director of Development recommended that a decision in this matter be delegated to the Director of Development.

The application was further considered by the Committee on 3 September 2013, at which time the Director of Development recommended refusal of the application on the grounds that the proposed turbine would be detectable by and cause unacceptable interference to the ADR at South Clettraval (RRH Benbecula), the Range Control radar on South Uist and Danger Area 701C. Accordingly, the proposal was in contravention of local planning policy. In advance of that meeting, further information substantiating MOD's objection was provided to the Comhairle by email dated 19 August 2013.

The Committee continued consideration of this application to its meeting on 19 November 2013, at which time a further report from the Director of Development recommended refusal having regard to the MOD objection. At that time, the Committee determined, by majority, to approve the application on the basis that MOD had not demonstrated to the Committee's satisfaction that this development would have an adverse impact upon defence. The application was not formally granted at this stage as the applicant was still required to submit a cumulative noise impact assessment to the satisfaction of the Director of Development.

Accordingly, on the basis of the following reasons:-

1) that the Committee was minded to grant this application, in the face of a recommendation to refuse from its own Director of Development; 2) having regard to the calling in of the Locheport application for determination by the Scottish Ministers; 3) and having regard to the grant of three other similar applications for planning permission, despite MOD objections and recommendations for refusal by the Comhairle's Director of Development (see section 3.5 hereof)

MOD requested that the application made on behalf of the Manager of the Dark Island Hotel be called in for determination by the Scottish Ministers. This request was made on behalf of MOD by letter dated 27 January 2014.

The current situation in respect of this application is that the MOD's objection is maintained on the basis that the proposed development will be detectable by and

cause unacceptable interference with the range control radar at St Kilda and the ADR at RRH Benbecula.

The primary role of the ADR at RRH Benbecula is to monitor the United Kingdom airspace and its approaches and its purposes are air surveillance; tactical control; and air traffic services. In addition to this primary role, the ADR at RRH Benbecula picture is fed to and used by the Hebrides Range operators as a means of detecting aircraft in the Range Danger Area during trials. In the instance of the Dark Island Hotel proposal, the proposed turbine will impact upon the range control radar at St Kilda and also the ADR at RRH Benbecula. As such, it will subsequently impact upon the ADR picture fed to and used by the Hebrides Range operators and affect the weapons trials. (See sections 5.8 and 5.9 hereof, for further details on the AD radar feed to the Range.)

3.4 7 Bornish - DPEA Ref CIN-CES-002 This planning application was lodged by Callum MacMillan of 7 Bornish, South Uist on 19 September 2013 for the erection of 2 wind turbines and associated infrastructure on croft land at 7 Bornish.

The MOD objected to this application on 29 October 2013 on the basis that the turbines would be detectable by and cause unacceptable interference with the ADR at RRH Benbecula.

The Committee considered this application at its meeting on 19 November 2013, at which time a report from the Director of Development recommended refusal, having regard to the MOD objection, which led to a conclusion that the proposal was in contravention to Polices 19 and 20 of The Outer Hebrides Local Development Plan. At that time, the Committee determined to defer consideration of this application, and requested the applicant to submit a noise impact assessment, the application to be considered further at the February 2014 meeting of the Committee.

Accordingly, on the basis of the following reasons:-

1) that the Committee was being minded to grant the Dark Island Hotel application, in the face of a recommendation to refuse from its own Director of Development;

2) having regard to the calling in of the Locheport application for determination by the Scottish Ministers; 3) and having regard to the grant of three other similar applications for planning permission, despite MOD objections and recommendations for refusal by the Comhairle's Director of Development,

MOD requested that the application made by Mr MacMillan, be called in for determination by the Scottish Ministers. This request was made on behalf of MOD by letter dated 27 January 2014.

The current situation in respect of this application is that the MOD's objection is maintained on the basis that the turbines would be detectable by and cause unacceptable interference with the ADR at RRH Benbecula.

On 15 April 2014, MOD received correspondence from the Comhairle advising that the two wind turbines which are the subject of this planning application, had been erected by the developer. The MOD was advised that the Comhairle had previously issued a Temporary Stop Notice in respect of this site, but that that had expired. As these works constituted unauthorised development, the Comhairle advised the developer verbally and in writing that the turbines constituted unauthorised development and that, unless they were removed by 3 p.m. on Tuesday 15 April, formal enforcement proceedings would be commenced. The developer did not remove the two turbines and MOD was advised that it was the Comhairle's intention to commence Enforcement Notice procedure on 17 April 2014. MOD supports such enforcement action being taken in respect of this unauthorised development in light of its particular concern as to the significant impact these turbines will have on the detection capabilities of its radar facilities. MOD understands that an Enforcement Notice was served on 17 April 2014, and that a Temporary Stop Notice was served on 24 April 2014, requiring the blades of the two turbines to cease turning.

3.5 By way of additional background, at its meeting on 19 November 2013, the Committee granted three applications for the erection of various wind turbines at 11 Bornish, 13 Bornish and 2 Frobost, respectively. In respect of each of these applications, MOD had lodged relevant objections citing interference with either, or both, of the ADR at RRH Benbecula and the Range Radars at South Uist and St Kilda. All of these applications had been recommended for refusal by the

Comhairle's Director of Development having regard to the MOD's objections and contravention with the Outer Hebrides Local Development Plan and Supplementary Guidance for Wind Energy Development.

In respect of each of these decisions to grant planning permission, proceedings have been brought by the MOD seeking Judicial Review thereof on the grounds that the Committee's decision to grant planning permission was irrational and unlawful. These cases are currently pending before the Court of Session, but the Comhairle has confirmed that it is not seeking to oppose any of the three Petitions for Judicial Review.

Procedure Notice dated 16 April 2014

The Reporter issued a procedure notice dated 16 April 2014, stating that the matters to be considered at hearing session are as follows:

• Matter 1: Details of the operation of the air defence radar system at South Clettraval, North Uist.

• Matter 2: Details of the operation of the range control radar systems at South Uist and St Kilda.

• Matter 3: Details of the impact that the erection and operation of wind turbines proposed for erection at the above addresses could potentially have on the operation of one or both of the above radar systems.

• Matter 4: The availability and effectiveness of potential mitigation systems to address any adverse impact the turbines may have on the radar operating systems.

• Matter 5: Clarification of why the council is dissatisfied with the Ministry of Defence’s explanation about the adverse impact and mitigation.

• Matter 6: Reasons why any possible adverse impacts are considered to be over-ridden by the potential benefits of the proposed turbines.

This written statement sets out the MOD's position on each of the above matters.

4 MOD radar assets on the Western Isles: introductory remarks

4.1 MOD radar assets on the Western Isles:

Benbecula • Long Range Air Defence Radar Lockheed Martin Type 92 (ADR at RRH Benbecula) • Air Defence Secondary Surveillance Radar.

St Kilda • Watchman Air Traffic Control Radar (Air Watch) • Watchman Air Traffic Control Radar (Sea Watch) • Cardion Secondary Surveillance Radar

South Uist (Hebrides Range) • Marine Surveillance Radar

Figure 1: Overview map showing the locations of the MOD radars, proposed turbine locations, and the Range Danger Area

4.2 The data sheet for Type 92 Lockheed Martin ADR at Benbecula (also known as FPS- 117) is at Reference 36.

Matter 1: Details of the operation of the air defence radar system at South Clettraval, North Uist.

5.1 The primary role for the Royal Air force (RAF) is air defence of the United Kingdom. The RAF’s air defence capability to detect and deter aircraft approaching UK sovereign airspace is just one layer of a multi-layered approach that the UK Government takes to protect UK and NATO-monitored airspace. The Air Surveillance and Control System (ASACS) Force is responsible for compiling a Recognised Air Picture, with radars monitoring the airspace around the UK, and also for providing tactical control of the Quick Reaction Alert (QRA) force.1 The ADR at RRH Benbecula radar is one of six dedicated static and permanently sited AD radars within the UK and forms part of the ASACS. All ASACS radars are used 24 hours per day, 365 days per year by the MOD to monitor the United Kingdom airspace and its approaches2. The purposes of the radars are three-fold: air surveillance; tactical control; and air traffic services for both the national homeland defence task and to support NATO collective defence. The picture detected and produced at each radar location is sent to the two UK Control and Reporting Centres (CRC) located at RAF Boulmer, Northumberland and RAF Scampton, Lincolnshire. At the CRC, the radar plot data from all six AD radars (as well as from other sources) is fused and operators then assess the behaviour of airborne objects (most usually aircraft) to produce a timely consolidated recognised air picture.

5.2 To supplement the ASACS radar coverage, a number of NATS3 long range radars are integrated into ASACS. Also, the feed from a number of local airfield radars around the UK is displayed on a separate screen within the CRC to supplement low level detection. In addition to these ground-based radar sensors, data from other ground- based air defence radars, airborne radars, intelligence sources and the AD systems of adjacent NATO partners are also fed into ASACS.

5.3 The recognised air picture produced by operators within the CRC identifies all aircraft movements within UK sovereign airspace and its approaches, and thus allows timely, effective and accurate air surveillance of the whole area. The ASACS radars and other contributory sensors are designed to detect aircraft which range from small up to large in size, operating at speeds from slow to fast, both low and high altitude, over water and over land. The data from the ADR at RRH Benbecula, as with all ASACS

1 http://www.raf.mod.uk/currentoperations/opaukair.cfm 2 http://www.raf.mod.uk/rafboulmer/ 3 NATS is the UK air traffic service provider: http://www.nats.aero

radars, is vital to contribute to the UK’s Air Operations Centre mission and NATO’s Combined Air Operations Centre mission to produce an accurate, timely and relevant recognised air picture across the whole of northern Europe.

5.4 The RAF operators within the CRC also provide both tactical control of military aircraft on air defence operations, (including interceptor fast jets and any supporting assets) and Air Traffic Services to military aircraft on operations, training or exercise sorties within UK airspace.

5.5 It is vital that the integrity of the sensors which enable detection surveillance and control services over the UK airspace and its approaches is maintained. Any potential interference from developments such as wind turbine proposals which could degrade the performance of the air defence radars must therefore be analysed and the impact must be continually assessed.

5.6 The ADR at RRH Benbecula is of particular strategic importance due to its location. The other five ASACS radars4 are in close proximity to the ADR of the UK’s NATO partners in northern Europe and therefore have adjacent coverage and an established early warning system is in place to warn the UK of potential threats approaching from mainland Europe. The ADR at RRH Benbecula is adjacent only to the AD system of Iceland and therefore there is a large portion of the North Atlantic Ocean adjacent to the UK for which the radar coverage of RRH Benbecula (and RRH Portreath in the south west of the UK) is vitally important. A key characteristic of an ASACS radar is that it can calculate the 3D radar height of an aircraft without needing a co-operative Secondary Surveillance Radar5 (SSR) response from the aircraft. This feature is particularly important when dealing with un-cooperative targets such as those aircraft which could potentially be a threat to the UK. If a QRA fast jet needs to be directed towards a potential threat aircraft that is uncooperative, the 3D radar height of the target gained from the ASACS radar is vital in ensuring a safe and appropriate approach.

5.7 The provision of data from the ADR at RRH Benbecula is integral to the recognised air picture at all times. As a particular example, the airspace above the North Atlantic

4 The other five ASACS radars in addition to RRH Benbecula are: RRH Buchan in Aberdeenshire, RRH Brizlee Wood in Northumberland, RRH Staxton Wold in Lincolnshire, RRH Trimingham in Norfolk and RRH Portreath, Cornwall. 5 SSR is a co-operative radar surveillance system that employs ground-based interrogators and airborne transponders which in Mode 3/A and 3/C provides additional information about an aircraft’s identity and position. Mode S is the recent upgrade to SSR which provides improved surveillance capability required to overcome limitations of the existing SSR and which meet future traffic demands. – Manual of Military Air Traffic Management – Military Aviation Authority – Chapter 35 - http://www.maa.mod.uk/linkedfiles/regulation/mmatm.pdf

Ocean approach to the UK and within the detection range of the ADR at Benbecula is extremely busy every morning with civilian flights from USA and Canada heading east towards mainland Europe. This daily surge of aircraft is detected, monitored and identified by ASACS personnel and this task relies on the integrity of data from the ADR at RRH Benbecula, as for all ASACS radars, in order to deliver the UK Homeland Defence Mission.

5.8 In addition to the primary role of the ADR at RRH Benbecula, which is detailed in the paragraphs above, data from the radar is also fed into the Hebrides Range Control Building on South Uist in order to provide visibility and detection of aircraft within the Danger Area EG D701.6 At the Hebrides Range the data is displayed on dedicated ‘Stand alone’ displays and is also merged with other radar sensor information and displays to provide a consolidated Range Safety Picture. The ADR data feed is inline with an Internal Business Agreement between ASACS Force Command (the Provider Organisation) and D Weapons TEST PT7 (the User organisation)8. The details of this Agreement are at OFFICIAL classification and so cannot be released to this forum.

5.9 With regards to any scheduled maintenance or interference to the routine operation of the range, QinetiQ, are made aware of any planned maintenance or outages through a formal process in advance. Any short notice outages are informed by RAF personnel on site at the RRH to relevant QinetiQ personnel. Any future anticipated long-term impact on the integrity of the ADR at RRH Benbecula such as those from windfarm developments, would be assessed by ASACS Force Command as part of the routine Safeguarding process, who would then, if necessary, enter discussion with TEST PT and/or QinetiQ to anticipate any resulting secondary effects on Range operations. This process would also include the assessment of anticipated impact of any potential mitigation solutions.

6 Map indicating position of D701 is at Figure 1 7 Trials, Evaluation Services & Targets Project Team

8 Internal Business Agreement between ASACS Force Command, RAF Boulmer and DE&S Director Weapons TEST PT, V 1.1 dated 1 March 2012. Classification: RESTRICTED – therefore cannot be released to this forum.

Matter 2: Details of the operation of the range control radar systems at South Uist and St Kilda.

6.1 The MOD Hebrides Range was formed in 1957 to allow the development and practice of long range tactical battlefield artillery, and ground based air defence. It has since developed as a valuable internal MOD UK tri-service asset and is also used by many other nations. The Range provides about 100 direct full time jobs on the southern isles and has provided seven Engineering apprenticeship roles over the last three years. In employment terms it is the second largest employer in the Western Isles, second only to the Council. The Hebrides Range, like many other MOD ranges, is operated by QinetiQ. QinetiQ provides Test and Evaluation (T&E) and Training Support services to MOD under a 25-year contract – known as the Long Term Partnering Agreement (LTPA).

6.2 The Hebrides range consists of a Deep Range, for complex weapons trials and in- service firings; and an Inner Range, for ground-based air defence campaigns. The Range occupies a large sanitised airspace with unlimited altitude and it can be extended to 57,000 km² for specific trials. This large area and its nearby airfield make it ideal for air-launched weapons operations. This fully instrumented controlled environment enables the evaluation of land, air and sea weapons, systems and training.

6.3 Under the LTPA, the development, test and training of complex weapons systems and military platforms including both fixed and rotary wing aircraft, land and sea platforms is supported. The controlled environments are suitable for testing a wide range of systems within this valued UK strategic asset. The enforced integrity of the Danger Area, by radar observation, ensures the following activities can be conducted safely.

6.4 Fixed wing capabilities include fast jets and larger aircraft supporting air-to-air and air-to-surface attacks against specially designed target systems, store drops and the exercising of defensive aid suites.

6.5 Proving trials are conducted on new rotary wing aircraft, including the latest Lynx Wildcat, before they go into service. This activity involves a complete spectrum of activities from the trial releases of sonar buoys and testing defensive aid suites to strafing against remote-controlled targets as part of training exercises.

6.6 Land platforms, such as Starstreak and Rapier, use the LTPA ranges for T&E and training. A variety of airborne and surface targets, including fixed structures, are provided within the Range to support these activities.

6.7 Sea platforms, such as the new Type 45, use the ranges to exercise modern systems such as Sea Viper and various calibres of ordnances.

6.8 The Range is suitable for testing and training with the MOD’s numerous navigational systems, radar and optical sensors.

6.9 The Ground Based Air Defence (GBAD) capability offers the MOD a range of facilities for operator and weapon system evaluation for their accuracy in protecting against air attack and the Range is used by GBAD prior to their operational deployment.

6.10 Fire units can be fired under tactical conditions or fully instrumented for near real- time or post event analysis using multiple or mixed weapon platform engagements and laser designation pods.

6.11 The MOD uses aerial targets capable of supporting basic and advanced profiles and Fighter Ground Attack manoeuvres. Targets can be flown as singletons, as matched pairs or as mixed formations thus allowing for the tactical evaluation of operators, weapon commanders and threat assessment. Synthetic target facilities also exist for Rapier engagements using real or simulated missiles. The Range can also facilitate engagements in Electronic Warfare conditions using standoff airborne jammers.

6.12 Training is one of the most important factors for achieving success in theatre. The Hebrides Range offers the MOD the space and realism to provide training to the highest levels and can accommodate national and international joint training utilizing the vast Danger Area for sea and air assets. Training can include: Hands-on live weapon releases to maintain currency, live and synthetic training bringing the joint battlespace to the individual unit and recording training events to improve value and effectiveness.

6.13 The Range provides aerial targets, instrumented barges and land targets for T&E, research and development, and training purposes.

6.14 The Combined Aerial Targets Service (CATS) is a 20-year contract to satisfy the UK MOD with a worldwide service of subsonic aerial targets for training and testing weapons systems. Aerial target systems include Banshee, Voodoo, Mirach and Pop- ups. In addition sea target barges (static or mobile) and other sea targets for countermeasure deployment, Infrared sources, threat emitters or target faces, as well as the provision of passive and active radar augmentation are also available.

6.15 The MOD uses unmanned aerial systems (UAS) which are seen as an increasingly important enabler in surveillance, security and defence. The Range provides a controlled

and sanitised environment for development, testing and training with UAS and facilitates take-off and landing sites, targets of opportunity and specially deployed targets for sensor trials.

6.16 Range Danger Area. The physical size of the Range Danger Area (an area known to be free of non- participating aircraft or shipping) is unique to the Hebrides Range. This is invaluable when developing, testing, and practising, the use of long range high energy military weapons in realistic situations and target scenarios. The Range Danger Area is shown below in figure 2.

Figure 2: Hebrides Range Danger Area (EGD701 Complex)

6.17 The firing of live weapons, as carried out at the Range, is dangerous. To mitigate for safety, a layered approach to the production of the Range Danger Area is used. The integrity of the Range Danger Area is assured by the coverage of the surveillance radars (and land based manned lookout points for aerial target launch and recovery). The location of the radar on St Kilda allows coverage over the Range Danger Area and aircraft approaches to the area (up to 60nm). For some trials, a larger area (beyond the Range Danger Area) is required. In these instances an agreement is sought from Airspace Regulators to ‘clear’ it so as it can be used as part of the Range.

6.18 Even with all the control measures in place to ensure trials/operations are conducted safely, infringements by intruders still breach the Range boundaries during active periods. There have been 29 recorded infringements since April 2000. The Range operators are legally and contractually bound to keep all risks ‘As Low As Reasonably Practicable’ (ALARP). Infringements detrimentally affect the Range in terms of trial time and delays caused by investigations.

6.19 The land based radars and how they are used to assure the integrity of the Range Danger Area:

(a) Air Defence Radar at RRH Benbecula

This radar situated on Clettraval on North Uist (referred to above) is used, insofar as the Range is concerned, for the principal means of detecting 'airborne' intruders and potential intruders9 to the Range Danger Area. The MOD is contractually obliged to provide the ADR feed, i.e. the radar picture, to the Hebrides Range operators. The Range operators are reliant upon the ADR feed to provide early warning surveillance during weapons trials. The Range therefore has an interest in any activities or developments which would impact the data provided to them from the ADR at RRH Benbecula.

The ADR at RRH Benbecula has long range 360o coverage and in particular can provide coverage at low level down the back of the South Uist hills. It has 'small target' detection capability and can give a non-cooperative 3D height for each of the targets that it detects. This is why it is sometimes referred to as a '3D radar'. Particularly important for range operations, the ADR at RRH Benbecula gives coverage of aircraft movements in and out of Benbecula airport and can detect helicopter movements throughout the Southern isles.

It is important that the current ADR radar coverage is maintained in order to provide early warning of aircraft movements close to the edge of the Range Danger Area. As an example, there have been instances of aircraft taking off from Benbecula airport and transiting into the Range Danger Area when the area is ‘active’ i.e. when MOD firing operations have been taking place. There have also been instances of unscheduled helicopter flights incurring in the Range’s area active airspace. There have been four

9 An ‘intruder’ is considered to be a non participating aircraft i.e. an aircraft not involved in the MOD operation/trial but is within the Range’s Safety Assured Area whilst the firing operation is taking place.)

incursions in the last six years, three of which were by fixed wing aircraft and one by helicopter. Early detection and swift reaction to these incursion events by the operators involved, or destruction of the UAV targets, have thus far prevented any serious air incidents by inhibiting the firing activity taking place.

Any loss of UAV targets as a result of incursion events can cost from tens to hundreds of thousands of pounds.

6.20 The integrity of the data from the ADR at RRH Benbecula is vital to the safe operation of the Hebrides Range and its trials/operations.

(a) Watchman Air Traffic Control Radar – the Range radar

6.21 This radar is situated on St Kilda and the displays are remotely operated by the Range control staff at the Range Control Building (RCB) on South Uist. It is used as the 'Trusted' display for the control of trials participating aircraft and aerial targets. The Air Watchman is an airfield approach radar with a display range of 60 nautical miles (nm). In addition to controlling participating aircraft and UAV targets, the radar is also used for intruder detection. In the past it has detected incursions which would have otherwise not been observed. Such undetected incursions are a direct threat to flight safety.

(b) Marine Surveillance radar

6.22 This radar is situated at the Range Control Building on South Uist and is used to detect marine shipping to its horizon in the Range Danger area. It is a Harbour Radar with a sea coverage out to approximately 12nm.

The proposed onshore turbines will not cause an unacceptable impact on the Marine Surveillance radar and therefore is not included in the reasoning for the MOD objections to the proposed turbines.

6.23 This radar is also situated on St Kilda and the displays are remotely operated by the Range control staff at the Range Control Building (RCB) on South Uist. Whilst this radar is essentially the same type of radar as the Air Watchman it has been modified to allow it to see and output sea borne targets. Because of its height advantage on St Kilda

it can detect surface objects on the sea and movement surface to a range of approximately 30 nm.

The proposed onshore turbines will not cause an unacceptable impact on the Marine Surveillance radar and therefore is not included in the reasoning for the MOD objections to the proposed turbines.

Matter 3: Details of the impact that the erection and operation of wind turbines proposed for erection at the above addresses could potentially have on the operation of one or both of the above radar systems.

7.1 Where a proposed wind turbine is found to be within the coverage of, and detectable by a military radar, an operational assessment determines if the potential impact is manageable or not. Where the potential impact is not manageable, MOD will object.

7.2 The ADATS RSP technical assessment provides an indication of whether a proposal is within radar coverage and which facilities are likely to be affected.

(a) The technical assessment for Locheport determined that the proposed development was within radar coverage and consequently likely to be detected by the Hebrides Range radar.

(b) The technical assessment for Dark Island Hotel determined that the proposed development was within radar coverage and consequently likely to be detected by both the Hebrides Range radar and the ADR at RRH Benbecula.

(c) The technical assessment for 7 Bornish determined that the proposed development was within radar coverage and consequently likely to be detected by the ADR at RRH Benbecula.

7.3 The potential impact that a wind farm has on radar systems varies considerably depending on the characteristics of the wind turbines in question, differences in equipment performance depending on location and on the relevance of the area in question to the MOD mission. Local topography can mask turbines thereby reducing the impact on the radar; on the other hand the local terrain may be such that the turbines are clearly visible on radar and will therefore influence the radar system performance.

7.4 Where the technical assessment indicated that the proposal was within the coverage of, and detectable by a military radar, the proposal is then subjected to an operational assessment by an appropriate Subject Matter Expert (SME). The SME determines whether the technical impacts are operationally manageable.

7.5 Merrill Skolnik in “The Radar Handbook” states: “The basic concept of radar is relatively simple even though in many instances its practical implementation is not. A radar operates by radiating electromagnetic energy and detecting the echo returned from reflecting objects (targets).” The amount of electromagnetic energy reflected back to the transmitting antenna by an object is determined by the objects radar cross section (RCS). The formal definition of RCS is a relatively complex mathematical equation but in simple terms it can be explained as the proportion of transmitted energy scattered (reflected) back to the receiver (called backscattering) from an object. This constitutes the radar echo of the object, and the intensity of the echo is proportional to the radar cross section.

7.6 To reduce the likelihood of unwanted returns being displayed a number of techniques can be used. One technique is Moving Target Detection (MTD): this reduces the probability of returns which have no relative velocity being displayed on the screen. A feature of MTD processing is the exploitation of the Doppler Effect to determine relative motion. The Doppler Effect is the apparent change in frequency of an electromagnetic wave when there is relative motion between the transmitter and receiver. If the receiver is moving away from the transmitter the frequency appears to decrease and if moving towards, increase. In radar there are effectively two transmitters and two receivers, the radar transmits and receives while any reflecting object effectively receives and transmits. Due to the size and rotation speeds of wind turbines blades, they generate a significant Doppler-shift in the frequency of the returned signal so wind turbines will therefore be visible as moving and therefore valid targets on radar displays so long as sufficient energy is reflected by the wind turbine. The energy reflected will be a factor of the distances involved, terrain path and RCS of the wind turbines. The detection and identification of aircraft targets in and around regions of a wind turbine/turbines is therefore likely to become difficult, as there may be nothing to differentiate them on the screen from a turbine.

7.7 The proposed two turbines at Locheport are located 43.2 nautical miles (80.1km) from the Hebrides Range radar at St Kilda with a turbine RCS of 119.8m² and are likely to be detected by the radar. The turbines, at 77 metres in height to blade tip, are therefore likely to appear on the operator's screen as a re-occurring return in the area.

7.8 The proposed turbine at Dark Island Hotel is located 46.2 nautical miles (85.7km) from the Hebrides Range radar at St Kilda and 12.1 nautical miles (22.5km) from the Air Defence radar Benbecula with a turbine RCS of 7.1m² and is likely to be detected by the

radar. The turbine, at 29.95 metres in height to blade tip, is therefore likely to appear on the operator's screen as a re-occurring return in the area.

7.9 The two turbines at 7 Bornish are located 22.7 nautical miles (42.1km) from the Air Defence radar Benbecula with an RCS of 2.4m² and are likely to be detected by the radar. The turbines, at 16.8 metres in height to blade tip, are therefore likely to appear on the operators screen as a re-occurring return in the area.

7.10 The Locheport technical assessment report entitled ‘DIO 10179B – AIR DEFENCE (AD) RADARS, MAA RADARS, RANGES – ASSESSMENT OF THE DEVELOPERS PROPOSAL TO ESTABLISH A WINDFARM AT LOCH EUPHORT, ISLE OF NORTH UIST’ can be found at Reference 17.

7.11 The Dark Island Hotel assessment reports entitled ‘DIO 18459 – AIR DEFENCE (AD) RADARS, RANGES – ASSESSMENT OF THE DEVELOPERS PROPOSAL TO ESTABLISH A WINDFARM AT DARK ISLAND HOTEL, NEAR LINICLATE, BENBECULA’ can be found at References 14 and 15.

7.12 The 7 Bornish assessment report entitled ‘DIO 19203 – AIR TRAFFIC CONTROL (ATC) RADARS, AIR DEFENCE (AD) RADARS – ASSESSMENT OF THE DEVELOPERS PROPOSAL TO ESTABLISH A WINDFARM AT 7 BORNISH(EXT) ON THE ISLE OF SOUTH UIST’ can be found at Reference 16.

8 Operational evidence

AIR DEFENCE (AD) OPERATIONAL ASSESSMENT

8.1 The operational assessment undertaken by the AD SME takes into account the predicted operational effects on the ADR of interest. The operational assessment is carried out on initial receipt of the planning application and at any point along the way when turbine characteristics or locations are amended. Also, an additional assessment might be carried out if a review of certain cases or certain locations is required (which could be due to a number of reasons). The operational assessment considers the increase of the effects on the ADR as detailed at paragraph 8.7 below (Constant False Alarm Rate, clutter, tracking anomalies and shadowing) due to the proposed developments. The assessment then considers the combined level of these effects. Finally, the operational assessment also considers the level of existing impact due to wind turbine developments already in the area, based on observations and operational experience from the ASACS operators working within the CRCs. In an area where the effects are already seen or known of from existing turbine developments, an increase in such effects can only be accepted up to a certain level. Above this level, further interference on the ADR will not be operationally tolerated and in such a situation, the proposed development would be objected to, on grounds of cumulative effect.

8.2 The proposed developments at 7 Bornish and The Dark Island Hotel were assessed and re-assessed at numerous stages in their consideration. The operational assessment for 7 Bornish was carried out at the beginning of October 2013. The operational assessment for The Dark Island Hotel was carried out in June 2013 and again in February 2014. The 2 developments above were assessed again in November 2013 and also in January 2014 as part of the hearing process preparation.

IMPACT ON AIR DEFENCE RADAR

8.3 The impact of wind turbines on the primary radar signal in AD radars has been documented since at least 2004. The RAF conducted trials in July 2004 to assess the impact of wind turbines on Air Defence Radars10. This trial proved that primary radar

10 The Effects of Wind Turbine Farms on Air Defence Radars, Ministry of Defence unclassified report published 6 Jan 05 (AWC/WAD/72/652/TRIALS)

returns from low radar cross section aircraft are lost when flying over wind turbines, regardless of the aircraft’s height. The report recommended that personnel using Air Defence radars in support of provision of Air Traffic Services be informed that they are likely to lose primary radar returns over wind turbines and should consider limiting the radar services that they offer accordingly. Clutter due to wind turbines was displayed throughout the trial. Although the effect of clutter was not operationally significant on this trial (due to the many variables such as radar type, turbine parameters, location, weather) this observation does not necessarily apply to other situations. A further effect was the observation of a shadow region immediately behind the wind turbine farm similar to the conventional shadow observed when a radiating light is placed in front of a physical obstruction. This is believed to be due to the direct interference of large physical objects on the propagation of the radar beam. The report recommends that ATS should not be provided by AD controllers to aircraft inside the shadow region and that there is deterioration on the detection of low-level targets within the shadow region.

8.4 Further work was carried out in March-April of 2005 on air defence radars to validate the work from 2004 detailed above. The unclassified report published on 12 August 200511 noted the impact of wind turbines on detection between the locations of the turbines and how radar processing or clutter maps could be employed to help minimise this impact. However, the report also noted that such processing techniques must be applied carefully to ensure that detections in one beam do not affect the sensitivity of other beams. The report highlights how the side-effects of potential mitigation methods must be carefully monitored to reduce any impact across the rest of the detection area of the radar. The report also details how large RCS objects (such as wind turbines) in one area will increase the value of averaged background levels and thus reduce sensitivity of the radar across its full area of detection.

8.5 Supplementary to the studies on AD radars, the RAF also conducted trials on ATC radar in November 200412. This study into the effect of wind turbine farms on airfield primary surveillance radar showed that the previously observed effect on AD radars of a shadow region was also seen in the case of the ATC Watchman radar. As well as the shadow effect behind the wind turbines, a further effect was observed which showed that aircraft returns faded in front of the turbines. Additionally, the level of clutter displayed to

11 Further Evidence of the Effects of Wind Turbine Farms on AD Radar, Ministry of Defence unclassified report published 12 August 2005 12 The Effects of Wind Turbine Farms on ATC Radar Ministry of Defence unclassified report published 10 May 05 (AWC/WAD/72/665/TRIALS)

the operator as a result of the motion of the wind turbines was assessed as highly detrimental to the safe provision of air traffic services. The operator was likely to be unable to differentiate between returns from wind turbine blades and those from real aircraft. The probability of detection of aircraft by the Watchman radar was considerably reduced when aircraft were overhead or in close proximity to the wind turbines. All of these effects reduce the detection probability of aircraft in the vicinity of wind turbines and affect an operator’s confidence that the displayed returns are aircraft and not wind turbine detections.

8.6 The unclassified DSTL literature survey13, which reviews reports and observations of wind turbine interference on MOD missions from 1994 to 2008, summarises the principal adverse effects measured or observed during the above trials and also includes observations from operational environments. Some of the reported effects on radars include; a Constant False Alarm Rate (CFAR), clutter, track creation, track seduction and loss of target and tower shadowing. The DSTL survey shows how numerous sources have come to similar conclusions about the negative impact that wind turbines can have on the AD task.

8.7 Detail on these effects is provided below:

a. Constant False Alarm Rate (CFAR). During every scan, a radar transmits and receives thousands of pulses. This then forms a map of the average level of radar reflections surrounding the radar head. During each pulse, the radar signal processor looks for targets by comparing every point in that pulse with the local average. This is the essence of CFAR processing. CFAR processing raises the local amplitude threshold to a level equal to the average of the area around the position of a suspected target. In the presence of a number of geographically small but very large amplitude echoes, such as those from wind turbines, the threshold over a large area can be unduly raised. This raises the detection threshold of the area and subsequently reduces the detection probability of target detection.

13 Mitigation Of the Impact Of Wind Farms On MOD Missions, Selected Literature Survey published by DSTL on 21 Oct 2008 (DSTL/TR31992 V1.0 21 Oct 08)

This effect is of concern now in the area of the proposed wind turbines at The Dark Island Hotel and 7 Bornish where a number of turbines have not been objected to and the acceptable threshold has already been reached.

Any subsequent turbines, such as those at The Dark Island Hotel and 7 Bornish, are likely to cause a cumulative increase in CFAR processing to an unacceptable level which potentially would reduce the probability of detection and ultimately degrade the radar picture. This amounts to an unacceptable adverse impact on aviation and defence, and affects the safe use of defence service operation.

b. Clutter. The rotating blades of wind turbines can induce a Doppler shift on the radar returns and allow the returns to pass into the Moving Target Indicator (MTI) filters of radar processors. The result is the display of unwanted returns (either clutter of false alarms). Such clutter can prove misleading, inducing the operator to treat the clutter as though it were an aircraft. Additionally, the radar returns from a real aircraft can be lost amongst the additional clutter returns. Both outcomes can lead to some or all of a number of effects: confusion for the operator; a delay in reaction to a situation or decision making when having to separate out false and real returns; an incorrect indication or assumption of an aircraft position; loss of an aircraft position; and the unsafe provision of ATS. Existing developments within the vicinity of the proposed developments are already producing clutter due to detection by the ADR at RRH Benbecula.

The following figure is a recording of primary surveillance returns from the ADR at RRH Benbecula14 over a 14 hour period, overlaid onto an Ordnance Survey map to show the radar returns from at least two known turbine developments (Loch Carnan and Dark Island Hotel) and demonstrates the visible effect of clutter at these locations.

Returns from Dark Island Hotel wind turbine

Returns from Loch Carnan Wind Farm

Returns from 7 Bornish (Extension) turbines

Figure 3 – 14 hour DREAM recording from the ADR at RRH Benbecula showing primary surveillance returns exported onto geographical mapping.

14 Excerpt from study conducted by 56(R) Sqn at RAF Waddington on “The Effect of Wind Turbines on the Remote Radar Head (RRH) Benbecula – dated 5 May 2014

The additional clutter from the proposed developments will increase the level of existing clutter on the ADR at RRH Benbecula in the locality of said developments above an operationally acceptable level. This will have an unacceptable adverse impact on aviation and defence, and will affect the safe use of defence service operation.

c. Tracking Anomalies. Plot information detected by the network of surveillance sensors around the UK, including the ADR at RRH Benbecula, is converted to track data and displayed at the Control and Reporting Centres (CRC) within the UK. As part of the 24/7 UK Homeland Defence Task, ASACS operators within the CRCs assess the behaviour and characteristics of the tracks and make a threat assessment on every single track over UK airspace and approach waters in order to apply an identification category. The resulting Recognised Air Picture is used by the UK Air Operations Centre and NATO’s Combined Air Operations Centre to contribute to the recognised air picture across northern Europe. The impact of any factors which confuse or slow down the operators’ ability to conduct this threat assessment must be minimised. There are a number of ways that the track displayed on the operator screen can be affected. These are detailed below:

i. Track Creation. The signal processor that is inherent in and unique to any radar system creates a spatial pattern of detections (called plots) which changes from scan to scan. The track creation software specific to the radar system looks at how this pattern changes between each scan. The software effectively joins up the plot data to create a track on the radar screen. This track will have position, velocity and heading characteristics. Wind turbines can move at similar speeds to aircraft such that false plots are created that will move from scan to scan and can therefore create false tracks. The 2004 trial15 observed that “numerous false tracks were produced by the [radar’s] integral tracking system during the trial”. Although during the trial, a radar operator was present at the radar screen and cancelled the tracks out manually, within the ASACS system a radar operator might not be present at all times in front of the screen to cancel out such tracks and indeed, would not always necessarily know which were false and which were “real” tracks. An automatic tracker could not be added to the ASACS system as it could

15 The Effects of Wind Turbine Farms on Air Defence Radars, Ministry of Defence unclassified report pub 6 Jan 05 (AWC/WAD/72/652/TRIALS)

not be relied upon to intelligently cancel out the “correct” tracks at all times. In the area specific to the ADR at RRH Benbecula, where the open terrain means that the radar has clear radar line of sight to many existing and proposed wind turbines, an increase in wind turbine density above the current level could create a number of false tracks for the ASACS operators which would cause potential distractions from true aircraft or targets of interest in their execution of the Homeland Defence Task.

It is also important to consider the proposed turbines relative to existing structures.

The proposed turbine at the Dark Island Hotel would be so close to the existing 200m turbine at Liniclate that when both sets of blades are turning, it is possible that returns from the radar could fit the profile of an aircraft due to the regularity of the returns and the height above ground level. Thus, the radar would recognise the returns as an aircraft and display a track on the radar screen. This track would cause confusion to radar operators if QRA jets were vectored onto an aircraft of interest in that location and could either vector the jets onto the returns from the turbines (instead of the target aircraft) or could cause the operator wrongly to dismiss the real target aircraft returns as those from the turbine and thus unsafely direct the QRA jets too close past the aircraft of interest towards the (false) target of the wind turbines.

This amounts to an unacceptable adverse impact on aviation and defence, and affects the safe use of defence service operation.

ii. Track Seduction. Track seduction occurs when a real track alters its heading based on false plot information. As detailed above, the RAF trials proved that the track of an aircraft which is flying over a wind turbine has been observed to alter. If the aircraft travels within a region of low probability of detection, the tracking software may assume that the returns from the wind turbine blades or towers are that of the target. This may result in the position and velocity of the target aircraft being misreported and there is a possibility that two tracks will form, one of which will eventually disappear.

Track Seduction was observed during RAF Trials conducted in 200416. Seduction occurred during Stage 1 of the Trial when no corresponding Secondary Surveillance Radar (SSR) data was available for the participating aircraft. Although there is a requirement for any aircraft crossing into UK territorial waters to display a transponder SSR code, and therefore this Track Seduction effect is unlikely for the majority of air traffic within the detectable range of the ADR at RRH Benbecula, any un-cooperative targets, i.e. those not displaying a transponder code, are highly likely to be subject to Track Seduction. The un-cooperative targets are of the highest interest to the UK Homeland Defence Mission due to their potentially unknown intentions. The impact of Track Seduction on an uncooperative target could result in the lack of ability of the radar and/or the operators to know the location of the target at any one time. In addition, if fast jets from the UK QRA force were scrambled to look at an uncooperative target, Track Seduction could make it very difficult to ensure the safe and accurate vector of the QRA jets close alongside an aircraft of interest. This is of particular importance with regards to the ADR at RRH Benbecula, as due to its location there is limited advanced warning to react to an inbound potential threat.

iii. Loss of Target. A more severe effect than Track Seduction is the inaccurate information on an aircraft track with regard to position, heading or altitude or complete loss of the aircraft position. This is of particular concern when there is no transponder code. During the 2004 RAF Trials17, without SSR interrogation “significant degradation of tracking performance was observed. Where a target aircraft does not squawk SSR it is highly likely that the associated track would drift when the aircraft overflies a wind turbine farm or flies through the shadow area. Provided that the aircraft does not manoeuvre and the track is not seduced then the system should resume tracking as soon as primary radar returns are available.”18. This unpredictability and erratic nature of track behaviour in the vicinity of wind farm developments is of major concern to the MOD mission.

16 The Effects of Wind Turbine Farms on Air Defence Radars, Ministry of Defence unclassified report pub 6 Jan 05 (AWC/WAD/72/652/TRIALS) 17 The Effects of Wind Turbine Farms on Air Defence Radars, Ministry of Defence unclassified report pub 6 Jan 05 (AWC/WAD/72/652/TRIALS) 18 The Effects of Wind Turbine Farms on Air Defence Radars, Ministry of Defence unclassified report pub 6 Jan 05 (AWC/WAD/72/652/TRIALS

Figure 4 - A plan position view of several minutes of radar data taken during RAF trials. The zig-zag aircraft track, shown by the orange dashes is missing over a region surrounding the wind farm (shown by the green dashes) in range (left and right of the windfarm) and cross range. (DSTL report19 – page 11 – image from The Effects of Wind Turbine Farms on ATC Radar – 10 May 2005)

The image above was obtained from trials involving a wind farm. Although the proposals being considered within this Statement are single turbines or small numbers of wind turbines, the MOD concern is that with the proliferation of turbines in the areas of concern, small numbers of wind turbines within a close proximity will cumulatively cause the effect similar to that of a larger development.

d. Tower Shadowing. The physical presence of a wind turbine tower creates a shadowed region, from the perspective of the radar head itself. The presence of a physical obstruction with a large RCS in the path of the radar beam creates a region behind the wind turbine in which objects would not be detected. This results in a loss of detection of a small area (up to approximately 1km per single turbine) behind the tower. Objects that lie

19 Mitigation Of The Impact Of Wind Farms On MOD Missions, Selected Literature Survey, published by DSTL on 21 Oct 2008 (DSTL/TR31992 V1.0 21 Oct 08)

‘behind’ the turbine, relative to the radar, might be in the shadow of the turbine and their detection will be partially obscured. Although this is not a major effect, the effect on the ADR at RRH Benbecula is likely to be greater than for the other AD radars, due to the flat and open nature of the local terrain. However, the accumulation of wind turbine developments could potentially lead to larger shadow areas, as was noted within the RAF Trials of 200420.

8.8 All of the above reported effects on radar data can cause misleading and inaccurate information to be displayed on a radar operator’s screen. This inaccurate radar data information can confuse and deceive the operator, increasing their workload and potentially causing them to make incorrect decisions or in the least, delaying an assessment. As a result of the reported effects, there is therefore a potential for inaccurate data to be assessed by radar operators, resulting in an incorrect recognised air picture being produced, potentially leading to the threat surveillance assessment of the UK airspace being incorrect. Having regard to providing air traffic services, flight safety can be directly affected if the exact and continually accurate location of an aircraft is not certain. There is the potential for aviation and defence interests to be adversely impacted upon to an unacceptable degree.

8.9 In order to allow safe execution of the AD task and to protect national security, therefore, the MOD has a duty to safeguard critical infrastructure, including ensuring the best possible radar coverage from all AD radars including the ADR at RRH Benbecula. It is for this reason that the MOD intervene in planning applications where potential wind turbine developments are likely to impact upon radar assets.

8.10 Within the CAA Policy and Guidelines on Wind Turbines (CAP76421), produced by the Civil Aviation Authority, Chapter 2 summarises the impact of wind turbines on aviation, including the following issues; twinkling appearance, masking of true targets due to increased clutter, increased false tracks, receiver desensitisation, shadowing behind the turbines and tracking anomalies. The CAA recognises that effects from wind turbines can have a negative impact on aviation and in particular, surveillance systems.

20 The Effects of Wind Turbine Farms on Air Defence Radars, AWC/WAD/72/652/Trials, dated 6 Jan 05. 21 CAP 764 – CAA Policy and Guidelines on Wind Turbines, amendment 1 to 5th edition, dated 1 Jun 13

CUMULATIVE EFFECT

8.11 As will have been noted from comments made above, the cumulative impact of wind turbine developments is of material concern to the MOD. The MOD assesses all wind farm applications on a case by case basis, taking into account the cumulative effects of pre-existing and consented developments within the surrounding area. The area local to the proposed developments at both 7 Bornish and the Dark Island Hotel has already received a number of planning applications to which the MOD has not objected. Despite these previous wind farm proposals being radar line of sight (RLOS) to the ADR at RRH Benbecula and therefore detectable, the reason for “nil objections” by the MOD is that it was considered that the level of interference to MOD operations from the wind turbines within the localised area was notable but was within an acceptable level.

8.12 However, by the time the application for 7 Bornish was received in October 2013 and that of Dark Island Hotel in June 2013, the number of RLOS developments in the area which the MOD did not object to during the planning consultation phase (and which have subsequently been consented to be built) had increased to a level which was of concern to the MOD. This level of wind turbines in the local area had reached such a number that the maximum permissible impact on AD operations was assessed as having been attained. Any additional wind turbines in the area are assessed as having an unacceptable level of detrimental effect on the ADR at RRH Benbecula and would be objected to on AD reasons. Thus, the 7 Bornish and Dark Island Hotel proposals were objected to by the MOD. This collective impact on the ADR at RRH Benbecula of a number of turbines within a localised area is known as the “Cumulative Effect”. It is due to this cumulative effect on the ADR at RRH Benbecula that the two named developments are being objected to by the MOD.

8.13 The CAA publication, CAP 764: Policy and Guidelines on Wind Turbines22 clearly highlights the issue due to proliferation of developments and the resulting cumulative effect, which can be of far more significant concern. It states how the combined effect of ‘numerous individual turbines…can be hard if not impossible to mitigate.’ The CAP recognises that due to this effect, objections might be lodged in areas where previously there were none.

22 Civil Aviation Publication CAP 764 - Policy and Guidelines on Wind Turbines – Edition 5 - published June 2013 – Section 2.39, page 33

Figure 5 Map showing all wind turbine(s) planning applications in Outer Hebrides (source: MOD WIND database)

8.14 For all of the above reasons, the impact of the proposed wind turbines at 7 Bornish and Dark Island Hotel on the ADR at Benbecula is assessed as being unacceptably

adverse. The MOD has considered whether the cumulative impact could be manageable but has assessed that for all of the above reasons, it is not. The MOD has already not objected to a number of developments in the area which despite being line of sight to the ADR at RRH Benbecula and therefore detectable, overall produce a level of operational impact which has been assessed as manageable. The 2 proposed developments elevate the operational impact above the manageable level. It should be stressed that MOD's objection to both applications stands irrespective of whether one of the applications is granted, and one refused. This Cumulative Effect with existing and consented wind turbines is the main reason for objection, and irrespective of whether the three pending petitions for Judicial Review are successful or not. It should be noted that the strategic importance of the ADR at RRH Benbecula is such that any further degradation to the radar picture would severely reduce the confidence of aircraft returns and therefore impact the MOD’s ability to protect the integrity of the UK airspace.

HEBRIDES RANGE OPERATIONAL ASSESSMENT

8.15 From an Air Safety perspective, the radars that are considered are the ADR at RRH Benbecula and the Air Watchman Range Control radar on St Kilda.

8.16 In order to minimise repetition in what is already a lengthy written statement, the general impacts of wind turbines on radar will not be repeated at length here. The following is therefore a summary of the operational considerations which were taken into account by MOD when deciding to object to the proposed developments on the basis of interference with the Hebrides Range Radar.

Factors considered by the Range operators include:

§ The proximity of the proposed turbine to the boundary of the Air Danger Areas. This was a consideration in both the Dark Island Hotel and Locheport cases.

The wind turbine at the Dark Island Hotel is only 1.3 nm from the Range Danger Area which gives the operators less than a minute to react to helicopter incursions from this area as has happened previously. The danger is that the wind turbine may appear as an aircraft, and have to be treated as such. This increases the risk of a 'genuine' incursion being missed.

The Locheport installations will look like an un-scheduled aircraft coming in to land or just taken off from Benbecula airport. This airport is sometimes used to practise “touch and go” (Rollers) manoeuvres particularly during Joint NATO exercises. The fast jets (usually) need to practise putting their wheels on the runway and then immediately taking off again. They can do multiple attempts at this manoeuvre to maintain currency. Any aircraft practising such ‘bounces’ coming into Benbecula is almost certain to incur the Range Danger Area.

The danger with both applications is that radar operator workload will increase which, in turn, increases the risk of an error so the more likely it becomes that air safety will be severely compromised.

§ The position of the proposed turbine in relation to inshore shipping activity.

Though considered for all applications, this did not form part of MOD's objection to either the Dark Island Hotel or Locheport installations as they cannot form any ‘shadows’ into the Danger Area.

§ The position of the proposed turbine in relation to known air routes, fish farm helicopter operating areas, approach and departure tracks for Benbecula and Barra airfields and known local landing areas out with the establish airfields (guest houses, hotels and beaches). The Range has experienced incursions from the Dark Island Hotel, so there is a history of potential intruders from this area; this was a consideration when assessing this application. Similarly for Locheport, there has been a history for manoeuvres as described in the ”touch and go” bullet point above. The danger with both proposed developments is that, if consented and constructed, radar operator workload will increase which, in turn, increases the risk of an error so the more likely it becomes that air safety will be severely compromised.

§ Interaction with existing turbines or know points of electronic interference or radar clutter.

This was a feature of the objection to the Dark Island. The existing turbine will come through as a separate ‘paint’ from the new application and will form what will look much more like a moving aircraft than would a single false alarm.

The Locheport turbines were considered for whether they would impinge on the line of sight to the remote Clettraval site from the Range Control Building, but this did not form part of the objection.

§ The risk of break-through of the false return as a credible blip on the operators' display or as a credible return for automatic plot extraction systems.

This was a consideration in both the Dark Island and Locheport objections. The installations are large enough to simulate radar returns from real aircraft on the Air Watchman range control radar, with enough regularity to form credible looking ‘tracks’.

§ The proximity of the development to remotely piloted air vehicle launch and recovery areas.

The recovery and launch of Unmanned Air Vehicles such as aerial targets are nearly as lethal to manned aircraft as missiles, should there be a collision. This was a feature in both objections as described under “proximity…to Range Danger Area” above.

§ Increases in workload for operational staff carrying out safety related tasks.

This was a consideration in our objection to both the Dark Island Hotel and Locheport applications. The more false alarms have to be investigated to ascertain if they are aircraft or turbines, the more likely the radar operator is to be distracted from real incursions from other areas.

§ The risk of terminating range activity as a result of false radar returns.

This was a consideration in the objection to both the Dark Island and Locheport applications.

The radar operators will take action to stop a trial or firing if there is any doubt as to whether a credible track that looks like it is about to enter the Range Danger Area is generated by a wind turbine or a real aircraft.

The needless waste of time, effort and ultimately cost both to the trial sponsors and the Range’s reputation for not being able to ‘deliver’ was part of the consideration to object to both applications. Operators consider how much time is available to consider the return (potentially caused by a turbine); how likely it is that the clutter will be displayed; how likely it is to form a false track on each of the radars; how much clutter is in that area already; and how much, if any, 'shadow' is cast into the marine area.

In undertaking this operational assessment, MOD considered whether the proposed developments would have an unacceptable adverse impact on aviation and defence, and would affect the safe use of defence service operation. For the above reasons, MOD's assessment was that the proposed developments were both unacceptable.

IMPACT ON RANGE RADAR

8.17 Wind turbines generate intermittent clutter to radar. This clutter varies with the number of turbines (cumulative effect) and distances between turbines. The effects of wind turbines on radar as detailed at section 8.7 of this written statement are applicable to the Air Watchman radar at St Kilda. Aircraft returns will be de-sensitised in the vicinity of Wind Turbines. This is because the false alarms they generate build up in the ‘clutter memory’ of the radar so the radar automatically desensitises itself in that region. This makes it less likely to see smaller aircraft in this area.

8.18 The figure below shows the clutter generated by a wind farm on the Air Watchman Range radar display.

Figure 6 Turbine clutter on Air Watchman Range radar 4th May 2014

The returns from the 3 turbines shown on Figure 3 above look like an aircraft flying to the South East away from the Range Danger Area. The Dark Island Hotel turbine return in addition to the false return above appears like an aircraft that did not paint on the last radar sweep; it cannot just be dismissed by the controller as just a false alarm.

Figure 7 Turbine clutter and real aircraft track on Air Watchman Range radar

Figure 8 Turbine clutter and real aircraft on Air Watchman Range radar

Figures 6, 7 and 8 show that the returns from turbine clutter is similar to that of real aircraft.

8.19 The danger emanating from the impact of wind turbines on the Hebrides Range comes principally from operator loading and distraction e.g. an operator could decide clutter is a wind turbine when actually it is a micro light or a helicopter. The more wind turbines there are, the more clutter is generated which increases the workload on the operators which, in turn, increases the risk of an error so the more likely it becomes that air safety will be severely compromised.

8.20 In Aug 2010, 2 incursions of the helicopter taking off and landing at the Dark Island Hotel occurred during a UAV trial. When the incursions were spotted, the radar operator diverted the UAV from the direction of the helicopter to avoid potential collision. The reaction time for the controller to take the avoiding action would have been less than a minute. It is therefore essential that operators can see incursions as they happen and are not overly hampered/impacted by turbine clutter.

8.21 Radar operators are able to ‘Pan’ and Zoom’ within their radar displays. Every time a pan or zoom function is conducted by an operator the radar picture including returns and historic returns e.g. trails, are momentarily lost until the radar picture is refreshed by the next radar rotation. Several radar rotations are then required to verify and understand what it the operator is now seeing. This all takes time and operator effort. Clutter can distract the operator from areas of potential real incursions – this is known as ‘operator distraction’. The additional burden of turbine clutter and its investigation increases the ‘load’ (i.e. what the operator needs to consider) on an operator and can lead to a reduction in air safety. With this distraction, there is a material risk that the operator could miss a real incursion. An error could lead to a trial being abandoned resulting in wasted time/effort/cost or, the worst case scenario, a collision.

8.22 To assist with controller alertness and concentration, the controller personnel are changed at regular intervals and there is a change over process that is followed. This involves briefing the relieving controller on what is happening and where, with regard to the radar picture. Depending on the wind speed and direction the returns from the wind turbines vary throughout the day. This in itself complicates and extends the handover briefings. An increase in turbine numbers increases the complication of and time taken for the handovers.

8.23 The MOD technical assessments of Locheport and the Dark Island Hotel proposals have determined that the proposed turbines will be visible to the Air Watchman radar at St Kilda. The turbines could therefore present themselves on the radar picture in a similar fashion to the 3 turbines in the above figure. The proposed turbines would have an unacceptable adverse impact on air safety.

8.24 Again, as noted above when commenting on Air Defence Radar, cumulative effects are of concern to the operators of the Range. Interaction with existing turbines or known points of electronic interference or radar clutter increase false radar returns. The Operational SME considered that the area around the 7 Bornish location contained existing clutter (most probably due to road traffic) and consequently the additional clutter generated by the 7 Bornish turbines would only worsen an already degraded part of the radar picture. This has a direct impact on aviation safety and the safe operation of the Range.

8.25 The Dark Island Hotel development is only 3.2 nm from the weapons engagement zone at Launch Area 1 and only about 1.3 nm from the Range Area itself. This is where operational army regiments come up to practise shooting down planes. The Range also often launches aerial targets from this site. The Dark Island Hotel regularly hosts helicopters and their pilots and the Range has suffered incursions from this site before. The helicopters often operate under their own visual flying rules so their intentions may not even be made known to the operator of the Range.

8.26 In the event that a false track is created that looks like it will incur on the Range Danger Area then all trials activity is stopped. The MOD and its contractor, QinetiQ, have a duty for safety which everyone involved in trials work takes very seriously.

Applicants' reports

DARK ISLAND HOTEL

• On the 1st August 2013, the Comhairle provided the MOD with a report (“the report”) entitled ‘DARK ISLAND HOTEL TURBINE BENBECULA AIR DEFENCE RADAR AND S UIST RANGE CONTROL RADAR MITIGTAION ASSESSMENT‘ (Author: Buccaneer Consulting Limited). The Comhairle stated that the report was submitted in response to the MOD objection to the Dark Island Hotel turbine proposal and invited MOD comments.

• The MOD response to the Comhairle dated 19th August 2013 can be found at Reference 42

• Further to that response, the MOD considers that the report is speculative; makes sweeping assumptions; lacks technical accuracy; and provides no evidence to support its conclusion.

• Section 3 of the report refers to Line of Sight assessment; the radar at Benbecula having Line of Sight to the moon; and shipping radar. It is unclear how this relates to the 3 cases being considered in the Hearing. For clarity, the MOD radar line of sight assessment uses 4/3rds true earth radius because radio waves are ducted by the atmosphere beyond the visual horizon and follow the curvature of the earth. The MOD carries out a radar coverage analysis which checks for the probability of detection of the turbine, this is much more accurate than a radar LOS.

• In Section 4 the author states ‘…AD radars are designed to detect moving targets…the turbine itself will not move over the ground.’ The first part of this is true, but the second part of the statement does not draw the correct conclusions. The turbine blades will move relative to the stationary ground and this movement has the potential to appear as a target to the radar, which can confuse radar operators, as explained in detail above at paragraph 8.8.

• The author states “It is most likely that the TB will be filtered from the radar display by software processing”. There are many factors which will affect whether

the turbine is detected by the radar. The wind direction will affect the angle that the turbine is presented to the radar head, which will determine the radar cross sectional (RCS) area and therefore the size of reflective surface. The larger the RCS, the stronger or more likely a return to the radar. Wind speed will determine the blade tip speed which will impact the likelihood of the rotating turbine appearing as a potential moving target. It is therefore a sweeping statement to say that the turbine is likely to be filtered. The variety and accumulation of so many factors cannot give certainty of this filtering occurring. It is this uncertainty of the degree of interference that the MOD is concerned with.

• The author mentions that ‘…a derivative of the T92 radar at Benbecula…[is used] ‘against’ the very large wind farms off the E Coast of England!’ The radars being referred to on the East Coast of England are Lockheed Martin TPS77 models and makes use of the in built limited Non Auto Initiation Zone (NAIZ) function to alleviate the effects of the east coast wind farms. (This NAIZ function is referred to by MOD at paragraph 9.6 below).

• The author mentions ‘…the radar operator will treat it like any other transitory target…’ A number of turbines have not been objected to by MOD in the area and the level of operational interference expected from these has been assessed as manageable. The effect from the proposed Dark Island Hotel turbine crosses above this manageable threshold. Therefore this turbine will not be able to be treated "in the same way" as other targets.

• Further in section 4, the author states ‘…it is certain that a new TB will appear in the same resolution cell as the existing large one.’ The author does not provide any evidence for this. Just because two turbines are very close geographically does not mean they are in the same cell; a dividing line could be between the two turbines. The author makes some sweeping statements about the radar’s resolution cells without offering any evidence.

• The author also states that the ‘…radar is largely focussed over the sea and as such targets overland are of less concern.’ This is erroneous and misleading. The AD radar is not focussed over the sea, in fact it is set up to give 360° coverage over land and sea to meet the air defence task. The site of the radar will have been surveyed and carefully selected to ensure the radar provides optimum

coverage. The ASACS Force provides surveillance coverage of the airspace over the UK and her surrounding territorial and approach waters 24/7, 365 days a year. The 9/11 scenario in America is an example of how threats can be posed from within a country. The Benbecula radar, as per other AD radars, are designed to provide 360° coverage as airborne threats are likely from any direction. Therefore targets on land are of a concern which has been factored into the AD radar element of the MOD objection to the Dark Island Hotel proposal.

• The author states ‘…even if detected the turbine will be of little or no concern.’ and ‘…the TB is most unlikely to be detected and displayed, and will have no operational impact on the Benbecula AD radar.’ but offers no evidence to support this statement. The MOD’s assessment, as explained in detail above, has determined that the proposed turbine will be within radar coverage and the impact will be unmanageable as to the AD operations.

• In section 5 the author states ‘The RCR [Range Control Radar] is a standard radar used to control oversea ranges to the NW’ The ADR at RRH Benbecula and the Air Watchman Range Control radar at St Kilda is used to monitor the approaches to the Range Danger Area for unauthorised aircraft. The radar at the Range Control Building on South Uist is a Marine Surveillance radar used to monitor the marine area.

• The author states that ‘ATC radars are specifically specified and designed to detect aircraft….not at low level, and to reduce a minimum any ground based/very low level radar returns.’ The Watchman ATC radar at St Kilda is essentially an airport approach radar designed to see aircraft from flight level to the ground.

• The author states ‘One detail of the radar is not known and this MIGHT affect its effectiveness ‘against’ the TB. However the radar’s location…strongly indicates that the radar is designed to ‘look’ only oversea and not overland at all.’ It is the ATC radar at St Kilda and the ADR at RRH Benbecula which form the basis of the MOD objection. The author has seems to have focussed on the Marine Surveillance radar.

• The author states ‘…the TB will appear in the same resolution cell as the larger one nearby and will not be separately detected.’ This is not the case. The resolution of the radar is such that they will show up as two separate returns.

• The author states ‘Overall, the TB is most unlikely to be detected and displayed, and will have no operational impact on the s Uist Range Control Radar’ The MOD assessment has determined that the turbine will be within radar coverage and likely to be detected by the ATC Range Control radar and the ADR at RRH Benbecula and that the impact is operationally unmanageable.

• In section 6 the author refers to the 3km distance from the Range being irrelevant. The Range radar operators need to consider reaction time to suspend firing or target launches in the event of an unauthorised incursion of an aircraft into the active Range Danger Area.

• The author states that ‘…it appears that the TB will be close to the edge of D701 not D701C. This must further diminish the validity of the MOD’s objection…’ This is not correct. The Dark Island Hotel turbine proposal location and the Range are shown in a map at figure 1. However, it is likely that any time D701C is activated, D701 will also be active.

• In section 7 the author states ‘The turbine does not meet the MOD’s published criteria of complete obscuration of the turbine tip from the radar.’ It is not clear what is meant so the MOD cannot comment. The author goes on to state that ‘…neither radar’s operations will suffer.’ This in incorrect. As previously stated, the turbine will impact unmanageably upon operations.

• The author states ‘the AD radar will not detect/display the turbine, which will also be obscured by the much larger TB nearby. While the RCR is probably not set up to look overland at all.’ This is incorrect. The existing turbine is detected by the ADR and ATC radar and the proposed turbine will be detected as determined by the MOD assessment. The existing and proposed turbines are at different heights and therefore will be detected separately on the radars.

• The author then states that ‘The MOD will accept NO technical mitigation of any of its radars…’ This is not true. The MOD will consider mitigation as per the process as set out in sections 9.1-9.7 hereof.

• In section 8 the author states that ‘…the MOD’s objection is not fully considered; it is absolutely standard…’ This is incorrect. Each wind turbine planning application is considered on a case by case basis and on its merits. Each application is subjected to a technical and operational assessment based on information known at that time.

• The author then refers to ‘…the MOD’s many objections…those it withdraws.’ There are certain circumstances when the MOD considers it appropriate to review and or conduct reassessments, for instance, in light of new information. This may result in a change of MOD position and demonstrates that the MOD is not intransigent and is willing to ensure each application is given due consideration.

• The author states ‘The AD radar will not detect and display the TB and therefore none of the ill-effects will be experienced.’ This is incorrect and has been addressed in the points above. The author then likens the proposed turbine to a mobile phone mast. This is misleading as turbines and masts are not comparable. The rotating blades of a turbine appear as moving targets to a radar. This is not the case with mobile phone masts.

• The author states ‘…ATC radars are specified/designed so that they do not detect/display very low level, static targets.’ This is not correct. ATC radars are designed to see targets from high level to the ground.

LOCHEPORT

• Wind Farm Aviation Consultants Ltd (WFAC) wrote a letter to North Uist Development Company dated 18th November 2013 entitled ‘Re: Ministry of Defence objection to turbine development on Locheport North Uist (Planning Application Number 13/00155)’.

• The letter states that ’we [WFAC] would not accept the MOD justification for the objection on either the Range Control Radar or the Air Defence Radar.’ The letter provides WFAC’s reasoning behind their statement and argues against the MOD’s objection. The AD objection to the Locheport proposal was withdrawn so the comments below relate to the authors comments relating to the Hebrides Range.

• In the ‘Background’ section the author states ‘Aircraft operating…inside the Danger Area complex are provided with a Range Air Control Service’. Aircraft operating in the Range Danger Area are provided with an appropriate air traffic service to conduct a Range Air Control task.

• The author states ‘…aircraft…can overfly the Danger Areas at any time’. This is a problem insomuch as any aircraft could infringe the Range Danger Area air space. The Range operators have a duty of care for their safety, which is why they have to be vigilant with the surveillance assets.

• The author states ‘The radar will only display wind turbines as clutter when turbine blades rotate...that the radar is deceived into treating the echo as if it is a moving aircraft; this is not a constant effect.’ The in-constancy of the return (or clutter) generated by the turbines is an issue. Each report from certain known areas of incursions has to be investigated. This adds workload to the radar operators and can delay or hinder trials.

• The author states ‘It should not be disputed that, in the case of the Benbecula Watchman, the turbine will be detected by the radar, there will be occasions when the turbine will show on the radar as clutter.’ This point is in agreement with the MOD. It should be noted that areas of false alarms, such as turbines, do de- sensitise the radar in the vicinity of the turbine.

• The author states ‘…the key phrase is “situational awareness of all aircraft movements within the airspace”...i.e. within the boundary of Benbecula Danger Area complex.’ The operators also need to have situational awareness outwith the Range Danger Area so as to detect aircraft that may infringe the Range Danger Area when active.

• The author states ‘The turbines are more than 5 nm from the boundary of D701C.’ This is considered as less than one minute flying time by a fast jet. Radar operators need sufficient time to take appropriate action so as to avoid collisions.

• The author states ‘Flight safety should not be jeopardised in the area…’ An increase in turbine clutter will cause operator distraction and de-sensitise the radar. The effects caused by turbines on radar are covered in Section 8.7 hereof.

• The author states ‘The claim that radar is the only sure way of operating in uncontrolled [airspace] is not only inaccurate and misleading…’ The aim of the operators is to keep people safe from hazardous activity. Surveillance radars help to achieve this.

• The author states ‘The radar is not being used as an air traffic control radar….is more likely being used as an aid for clear range procedures.’ The Air Watchman radar is an Air Traffic Control radar and is licensed as such. It is the radar that allows the control of participating air traffic within the Range Danger Area airspace. It is also used by the radar operators to ensure non-participating aircraft do not infringe the Range Danger Area.

• The author states ‘…the range operators are unsure as to the extent of the potential impact…’ The MOD technical and operational assessment has determined that the impact of the 2 proposed turbines will be operationally unmanageable.

• The author states ‘It is unlikely that normal Watchman radar filtering techniques….will remove these unwanted returns.’ The Range operators are aware of existing turbine installations of similar size that appear as clutter on the radar display.

• The author states ‘Pilots…are expected and required to remain clear of the Danger Area…when…active.’ Whilst this is a true statement, the Range operators have experienced pilots incurring the Danger Area when active. The instances of unnecessary interruptions to MOD activities within the Danger area will increase due to false infringement indications.

• The author states ‘…”buffer” does not improve the ability to detect aircraft nor is required to…detect aircraft’ The buffer does allow the Range Control staff to inhibit the firing of weapons and launch of UAV targets. It is intended to improve air safety.

• In the ‘Summary’ section, the author states ‘…clutter on the radar screens is accepted…what is not accepted is…that the turbines existence would result in any significant impact on the operation of the Ranges.’ The MOD disagrees with this statement. The MOD operational assessment has determined that the impact of the Locheport proposal will be unmanageable.

• Finally, the author refers to the ‘Technical Demonstration’. The Technology Demonstration is explained in Section 2.5 hereof.

Matter 4: The availability and effectiveness of potential mitigation systems to address any adverse impact the turbines may have on the radar operating systems.

9.1 Mitigation

The MOD assesses each wind turbine planning application on its merits and on a case by case basis. When the MOD is consulted on planning applications for wind turbines, each planning application is subjected to an assessment which considers technical and operational factors.

9.2 Where a proposed wind turbine is found to be within the coverage of, and detectable by a military radar, an operational assessment determines if the potential impact is manageable or not. The relevant operational subject matter expert conducting the operational assessment will give consideration to what reasonable measures may be put in place to mitigate the effects of the wind turbine development. Where the potential impact is not manageable, MOD will object. Where the potential impact is manageable, the MOD will not object.

9.3 Process

If a proposed development is objected to by the MOD, the developer might propose a form of technical mitigation to the MOD to try to reduce or remove the predicted interference on the MOD assets. Any mitigation proposal should be submitted prior to the determination of the planning application and should be of a sufficient detail to allow the MOD to make a fully informed assessment on the detailed technical impact on the MOD asset in question.

9.4 Technical Mitigation Assessment.

A technical analysis is conducted on the mitigation proposal which will determine if it is acceptable from a technical perspective to the MOD. In other words, there may be technical reasons which the proposed mitigation is unacceptable.

9.5 Operational Mitigation Assessment.

The detailed mitigation report along with the technical analysis is considered by the operational SME. The exact location of the area proposed for mitigation is carefully considered with regard to (and not limited to) the following: Sensitive Air Defence areas of interest; any local points of interest around which air traffic would need to be routed and thus could impact on the mitigation area; the presence of any military training areas or transit to and from military training areas; the presence of any other interference which already obstructs the radar detection which will determine if further reduction in detection should be accepted (as this can be the impact of proposed technical mitigation). From the Range perspective, an operational SME will consider several factors including, but not limited to, the location of the proposed turbine in relation to the Range Danger Area boundary; operations; existing turbines; clutter; likelihood of a false alarm; and increase in operator workload.

9.6 The Type 92 ADR at RRH Benbecula is to be upgraded to a Lockheed Martin TPS- 77 standard in 2015. This upgraded radar type has the potential to mitigate specific wind farms through a characteristic known as a 3-dimensional Non Automated Initiation Zone (NAIZ) subject to the MOD’s mitigation assessment process. The NAIZ permits a specified volume of airspace within which the returns from a wind turbine can be filtered out. A windfarm developer can, through a sufficiently detailed Mitigation Report provide a detailed proposal of a NAIZ solution specific to the area which will be affected by the returns from the wind turbine. This mitigation proposal will be provided by the developer to DIO. As per MOD’s approach to the assessment of applications, MOD will follow a two stage approach to the assessment of mitigation proposals covering both technical and operational assessments, which will in general terms consider the type of mitigation proposed, the level of technical information provided within the proposal, the location of the wind turbine and the associated airspace and operations. The considerations will vary depending on the type of mitigation proposed and the location of the wind turbine. The possibility of a NAIZ solution of course only potentially applies to the ADR and not the Range radar.

9.7 No inference should be taken as to the acceptability of a mitigation proposal based on the outcome of MOD’s consideration of a mitigation proposal for another wind turbine.

Matter 5: Clarification of why the council is dissatisfied with the Ministry of Defence’s explanation about the adverse impact and mitigation.

10.1 MOD reserves the right to respond to the Council's comments on this matter.

10.2 In summary, MOD's position is that MOD has explained its concerns regarding adverse impact and mitigation. Greater weight should be attached to the MOD's concerns than to policy promoting renewable energy development.

10.3 Over the last 18 months or so the MOD has engaged with the Comhairle regarding the safeguarding requirements of its assets and operations in the Western Isles. When the Comhairle made the MOD aware of the difficulties faced when considering wind turbine planning applications that have MOD objections lodged against them it became necessary for both parties to engage so as to understand the issue.

10.4 In November 2012, the MOD held a teleconference with the Comhairle primarily to explain Air Defence safeguarding requirements.

10.5 In January 2013 the MOD AD subject matter experts visited the Comhairle to provide further information as to the AD safeguarding requirements.

10.6 In August 2013, in depth discussions regarding the Locheport case took place between the MOD and the Comhairle. A record of the discussion should be before the Reporter (provided by the Comhairle when they passed the determination of the Locheport turbines application to the Scottish Government). The in depth discussion focussed mainly on the Hebrides Range and the impact of the proposed turbines. Several mitigation options were discussed and found to be unacceptable.

10.7 The Range operators also engage with the local community and are represented in the Hebrides Range Task Force. The community are also represented on the Task Force.

10.8 Section 3.5 hereof refers to the wind turbine planning applications at Judicial Review. The Comhairle did ask for further information as to the reasoning behind the MOD objections for these applications. As such the MOD was scheduled to meet with the Comhairle to discuss these cases. Unfortunately the meeting was postponed. The Comhairle have also accepted an offer from the MOD to present the MOD safeguarding

issues to the Committee members. It has not yet been possible to re-schedule the meeting and presentation but the MOD remains committed to engaging with the Comhairle and the Committee.

10.9 The above demonstrates the MOD’s willingness to engage with the Comhairle.

Matter 6: Reasons why any possible adverse impacts are considered to be over-ridden by the potential benefits of the proposed turbines.

11.1 In dealing with each of these applications, there is a conflict between the policy to encourage renewable energy development in the UK as a whole, and the need to protect defence and military interests and installations. It is for the decision maker to balance these competing interests, taking into account material considerations.

11.2 The legal context in which the decision maker determines whether or not to grant planning permission is provided for in section 25 of the Town and Country Planning (Scotland) Act 1997 (as amended) (the '1997 Act'), which provides, among other things:

'(1) Where, in making any determination under the planning Acts, regard is to be had to the development plan, the determination is, unless material considerations indicate otherwise -

a) to be made in accordance with that plan...'

11.3 In respect of each of the proposed developments, Reports by the Comhairle's Director of Development to the Environmental and Protective Services Committee recommended refusal of each application on the grounds that they do not comply with planning policy.

11.4 The planning context within which the impact of each of these proposed developments has to be assessed includes national policy and advice, the Local Development Plan and other material considerations.

11.5 The relevant points in national policy and advice are: a) Scottish Planning Policy, paragraphs 187 to 191, deal with Wind Farm developments. Paragraph 187 thereof details aviation as one of the criteria that will be considered by planning authorities in deciding applications for wind farm developments. Further, paragraph 190 goes on to state that "when identifying areas with potential constraints on wind farm development, planning authorities should consider the…impact on aviation and defence interests, particularly airport and aerodrome operation, flight activity, tactical training areas, aviation and defence radar

b) Further guidance is contained in the Scottish Government's online advice on Onshore Wind Turbines which was last updated on 12 December 2013. The online advice provides guidance to local planning authorities in determining onshore wind turbine applications. The online advice highlights "Aviation Matters" and "Military Aviation and Other Defence Matters" as typical planning considerations for local authorities in determining planning applications for onshore wind turbines.

11.6 In respect of Aviation Matters, the online advice provides as follows:-

"UK Airspace is important for both civilian and military aviation interests. It is essential that the safety of UK aerodromes, aircraft and airspace is not adversely affected by new wind power infrastructure." The guidance then goes on, "Depending on the wind turbine and anemometers’ size, shape, construction materials and location, together with the amount of electromagnetic interference, there may be implications for airport radar and communications systems. Planning authorities should consult the MOD and NERL who have a statutory duty to safeguard certain communication, navigation and surveillance (CNS) sites (including radars) from interference to signals caused by wind turbines in the interests of national security, and the continued safe operation of passenger and military aviation."

11.7 In respect of Military Aviation and Other Defence Matters, the online advice goes on to state that, " ….military aviation may be over extensive areas of the UK in airspace outside "controlled airspace". The approaches and flight patterns to military aerodromes are not necessarily routine and can be irregular owing to the performance characteristics of military aircraft…….The MOD also operates military training areas, military danger zones (offshore Danger and Exercise areas), military explosives storage areas and Tactical Training Areas. There are extensive Danger and Exercise Areas across the UK Continental Shelf Area (UKCS) for military firing…….The MOD also operates Air Defence Radars and Meteorological radars which have wide coverage over the UK (onshore and offshore). It is important that new energy infrastructure does not significantly impede or compromise the safe and effective use of any defence assets…… The MOD is a statutory consultee for some of the operations/facilities mentioned above. For wind energy, MOD should be

consulted if a proposed wind turbine is 11metres to blade tip or taller, and / or has a rotor diameter of 2m or more… The MOD has committed to work with developers to identify mitigation where possible…."

11.8 The Scottish Government published guidance in January 2012, namely Guidance on Dealing with Aviation Objections and Associated Negative Conditions on Wind Turbine Consents. This guidance states that developers should initiate the process of identifying or developing a solution. The guidance also identifies that the use of mitigation conditions where there is no identified mitigation to deal with an aviation objection could have an impact on the likelihood of other developments being consented.

11.9 At the time of the various reports by the Comhairle's Director of Development recommending refusal of each of these applications, the development plan for all three sites comprised the Outer Hebrides Local Development Plan (Adopted in November 2012) ("the LDP"), together with the Outer Hebrides Local Development Plan Supplementary Guidance for Wind Energy Development ("the Supplementary Guidance"). Relevant policies were cited from both of these documents in the various reports prepared by the Comhairle's Director of Development, recommending refusal of each of these planning applications

11.10 For present purposes, the relevant Development Plan policies are as follows:-

LDP Policy 19: Energy Resources "Proposals for onshore renewable energy projects…..will be assessed against the details below and be required to demonstrate…… (2) no unacceptable adverse impact (including cumulative) on…aviation, defence and telecommunications transmitting and receiving systems"

LDP Policy 20: Small and Micro Renewables "...In addition to satisfying the criteria for Policy 19, micro generation renewable energy proposals will be required to meet all the following criteria: 1. the proposal does not have an unacceptable direct=, indirect or cumulative impact on residential amenity; 2. colour, form, finish and height are appropriate to the setting and are designed to minimise visual impact and distraction;

3. sufficient information is provided to enable a balances assessment of any other likely effects of the development."

Supplementary Guidance DC6 - Aviation & Defence Developers will be expected to demonstrate that wind energy proposals…will not affect the safe use of airport, defence or emergency service operation. This includes flight activity, navigation and surveillance systems; and associated infrastructure.

Full consultation with the…..Ministry of Defence….should take place at the relevant stages.

When designing and siting proposals developers should pay particular regard to:

• MOD "Safeguarding Extents Hebrides";

• Health & Safety Executive Safeguarding Zones;

• NATS En Route plc Safeguarding Maps;

• Department of Trade & Industry "Wind Energy and Aviation Interest - Interim Guidance

• CAP 764 - CAA Policy and Guidance on Wind Turbines; Civil Aviation Authority July 2011

• CAP 393 - Air Navigation: The Oder and the Regulations Civil Aviation Authority April 2010

• CAP 670 - Air Traffic Services Requirements Part B en 01 Wind Farms Civil Aviation Authority February 2010

A footnote to this section of the Supplementary Guidance provides that for all applications in Uist pre-application discussion with the Comhairle Planning Service is advised to identify any potential aviation and/or defence constraint arising in relation to radar.

Further, Appendix 3 to the Supplementary Guidance provides a specific advice note in respect of micro generation on shore wind turbines. Section 3.2 thereof specifically highlights the problems which can be caused by wind turbines in so far as radar signals is concerned, and make specific reference to MOD's long

standing presence in the Outer Hebrides. This advice note goes on to state that "Defence is a national interest and a material planning consideration."

Accordingly, in these circumstances, it is MOD's position that local planning policy places the onus on developers to show that their proposals do not produce any unacceptable adverse impact (including cumulative) of aviation and defence interests. Further, guidance to developers provided by the Comhairle stresses the importance of consideration of aviation and defence interests which are specifically stated to be a material planning consideration.

11.11 MOD's position is that, for the reasons set out in this written statement, each of the proposed developments would have an adverse effect upon defence interests.

11.12 In each of the applications with which this Hearing is concerned, MOD has lodged a relevant objection citing unacceptable interference with its radar operations. In each of these applications, Reports prepared by the Comhairle's Director of Development recommended refusal of each of the development proposals as they do not comply with the Outer Hebrides local Development Plan. In each of these Reports, the Director of Development concluded that there were no material considerations to indicate that the Comhairle's Development Plan should not be accorded priority.

11.13 In each of these applications, the reports prepared by the Comhairle's Director of Development recommended refusal having regard to compliance with local planning policy.

11.14 In respect of the Locheport and the Dark Island Hotel applications the Committee did not consider that MOD had demonstrated to its satisfaction that the proposals would have an adverse impact upon defence. In MOD's submission, this is an error on the part of the Committee as local planning policy of itself places the onus of this upon developers. In the present applications, none of the developers have shown that there is no adverse effect upon defence interests. MOD is uniquely placed to assess such impacts and any such objection lodged should not be dismissed lightly, particularly where there is no evidence of any material consideration which is said to outweigh defence considerations.

11.15 In the Locheport decision, the Committee also cited socio-economic reasons as justifying the grant of planning permission, despite these having been assessed by the Director of development in his report, and found not to outweigh the MOD objection.

11.16 Scottish Planning Policy identifies the generic impacts that arise from the development of any types of energy infrastructure. Such impacts include military aviation and defence interests. SPP requires that the decision maker should be satisfied that the effects on civil and military aerodromes, aviation technical sites and other defence interests have been addressed by the applicant. Aviation safety and military operations should not be compromised by proposed turbines.

13 Conclusion

13.1 The MOD maintains its objection to the proposals due to the unacceptable interference to the Air Traffic Control radar at the Hebrides Range and the Air Defence radar at Remote Radar Head Benbecula. The MOD does not consider that the applicants have addressed the requirements of national or local planning policy. The MOD has not received site specific mitigation proposals for consideration from the applicants to address the outstanding radar issues.

13.2 The MOD respectfully request that the Scottish Ministers give full consideration to aviation safety and national security, and attach greater weight to MOD's objection than to any potential benefits of the proposed turbines. In the current circumstances, the MOD considers that a planning condition on any of the three applications would not be appropriate to address the MOD concerns.

13.3 The MOD respectfully requests that the Scottish Ministers refuse each of the applications.

Annexes

Names, occupations and qualifications, if any, of those who will be participating in the hearing on behalf of the Secretary of State for Defence:

Douglas Milne LL.B (Hons), Dip.LP, LARTPI, WS Partner, Morton Fraser LLP

Desmond Egan Senior Safeguarding Officer, Defence Infrastructure Organisation

Flight Lieutenant Hayley Adamson, BSc Hons, RAF, Headquarters 1 Group, Air Defence Safeguarding Safeguarding Officer for the MOD regarding Air Defence interests

Kenny MacDonald Tracking Radar Supervisor, Hebrides Range

Steve Speke Wind farm Subject Matter Expert, Air Defence and Air Traffic Systems.

Jane Rymell Defence Equipment and Support Weapons TEST Dep Ops Del Mgr

Estimate of how long it will take MOD to give evidence

Two hours

GLOSSARY OF DEFINED TERMS

AD Air Defence ADATS Air Defence Air Traffic Systems ADR Air Defence Radar AGL Above Ground Level ASACS Air Surveillance and Control System ATC Air Traffic Control ATS Air Traffic Services CFAR Constant False Alarm Rate DIO Defence Infrastructure Organisation FAR False Alarm Rate km Kilometre nm Nautical Mile m Metre MOD Ministry of Defence MOU Memorandum of Understanding MTI/MTD Moving Target Indication/Detection NATO North Atlantic Treaty Organisation PD Probability of Detection RAF Royal Air Force RCS Radar Cross Section RLOS Radar Line of Sight RRH Remote Radar Head RSP Radio Site Protection SME Subject Matter Expert

Preliminary inventory of productions

1 Application for Planning Permission for two Wind Turbines at Locheport dated 1st April 2013

2 Letter from Defence Infrastructure Organisation to Comhairle Nan Eilean Siar dated 14th March 2013

3 Report by Director of Development to Environment and Protective Services Committee dated 19th November 2013 (with relevant appendices)

4 Comhairle Nan Eilean Siar Environment and Protective Services Committee Minute of Meeting held on 19th November 2013.

5 Application for Planning Permission in respect of installation of Wind Turbine on land adjacent to the Dark Island Hotel dated 31st May 2013.

6 Letter from Defence Infrastructure Organisation to Comhairle nan Eilean Siar dated 24th June 2013.

7 Email from Defence Infrastructure Organisation to Hannah Morrison dated 19th August 2013

8 Report by Director of Development to Environment and a Protective Services Committee dated 19th November 2013 (with relevant appendices).

9 Application for Planning Permission for installation of two micro wind turbines at 7 Bornish dated 19th September 2013

10 Letter from Defence Infrastructure Organisation to Comhairle nan Eilean Siar dated 29th October 2013

11 Report by Director of Development to Environment and Protective Services Committee dated 19th November 2013 – 7 Bornish

12 Letter from Morton Fraser to Directorate for Local Government and Communities Planning and Architecture dated 27th January 2014 (without appendices)

13 Email exchange between Keith Bray and Desmond Egan dated 15th/16th April 2014

14 Air Defence and Air Traffic Systems Radio Site Protection Technical Support ("ADATS Report 1") on Dark Island Hotel WR80026/01 dated 13th June 2013

15 Air Defence and Air Traffic Systems Radio Site Protection Technical Report ("Report") on Dark Island Hotel WR80026/01 dated 5th February 2014

16 Air Defence and Air Traffic Systems Radio Site Protection Technical Report ("Report") on 7 Bornish (Extension) WR80026/01 dated 5th October 2013

17 Air Defence and Air Traffic Systems Radio Site Protection Technical Report ("Report") on Locheport WR80026/01 dated 23rd April 2013

18 CAP 764 Civil Aviation Authority Policy and Guidelines on the Wind Turbine dated 1st June 2013, 5th Version

19 Mitigation of the Impact of Wind Farms on MOD Missions - Selected Literature Survey - DSTL-DSTL/TR31992V1.0 21st October 2008

20 Report to the Congressional Defence Committees - the effect of Windmill Farms on Military Readiness (2006) - US Department of Defense, Office of the Director of Defense and Engineering

21 Memorandum of Understanding (August 2011 update:) Wind Turbines and Aviation Radar (Mitigation Issues)

22 Guidelines on how to assess the potential impact of Wind Turbines on Surveillance Sensors - Euro Control - Edition 1.1 dated 9th June 2010

23 Wind Farms Impact on Radar Aviation interest - final Report - Qinetiq dated September 2003

24 The effects of Wind Turbine Farms on Air Defence Radars - Ministry of Defence - dated 6th January 2005 (AWC/WAD/72/652/Trials)

25 Further evidence of the effects of Wind Turbine Farms on Air Defence Radar - Ministry of Defence dated 12th August 2005

26 The effects of Wind Turbine Farms on ATC Radar - Ministry of Defence - dated 10th May 2005

27 Location Overview Map of Proposed Developments

28 Overview Map and Status of All Proposed and Consented Developments on North and South Uist

29 Data Sheet for Type 92 Lockheed Martin ADR at Benbecula (also known as FPS-117)

30 Scottish Planning Policy Paragraphs 187 to 191

31 Scottish Government Online Advice on Onshore Wind Turbines (updated 12th December 20130

32 Scottish Government Guidance on Dealing with Aviation Objections and Associated Negative Conditions on Wind Turbine Consents (January 2012)

33 Outer Hebrides Local Development Plan Policy 19 Energy Resources

34 Outer Hebrides Local Development Plan Policy 20

35 Outer Hebrides Local Development Plan Supplementary Guidance for Wind Energy Development

36 Lockheed Martin Data Sheet for FPS-117 Long Range Solid State Radar [another name for Type 92] http://www.lockheedmartin.co.uk/content/dam/lockheed/data/ms2/documents/ground- based-air-surveillance/FPS117_brochure.pdf

37 Email exchange between Morag Ferguson and Desmond Egan dated 22nd 11th 3rd and 2nd July 2013

38 Email exchange between Calum Iain MacIver and Desmond Egan dated 30th and 26th July 2013

39 Letter from Defence Infrastructure Organisation to DPEA dated 9th December 2013

40 Letter from Defence Infrastructure Organisation to Comhairle nan Eilean Siar dated 28th February 2014

41 Letter from Defence Infrastructure Organisation to Comhairle nan Eilean Siar dated 30th August 2013 (with Meeting Minutes 28th August 2013)

42 Email from MOD to Comhairle ‘RE: 20130801 18459 From LPA To SSpeke Dark Island Hotel’ dated 19 August 2013.