DONG Energy Walney Extension (UK) Ltd. Walney Extension Offshore Wind Farm Transponder Mandatory Zone (TMZ) Stakeholder Consultation
Walney Extension offshore wind farm DONG Energy Walney Extension (UK) Ltd. Prepared by: Richie Hinchcliffe (Osprey CSL) Checked by: Alan Price (Communications Manager, DONG Energy) Accepted by: Nikolaj Frimodt-Møller (Commercial Project Manager, DONG Energy) Approved by: Uffe K. Jørgensen (Programme Director, DONG Energy) Issue Amendment Date Issue 2 Web Links and Consultation end date 10 October 2014 2
Executive Summary DONG Energy Walney Extension Ltd (DONG Energy) plans to develop an extension to the existing operational Walney Offshore Wind Farms (1 and 2), located North West of Morecambe Bay in the Irish Sea. The Walney Extension Offshore Wind Farm will cover an area of 145 km 2 and have an estimated generating capacity of up to 750 Mega Watts (MW). The project development site will be located west of the operational wind farm, approximately 33 kilometres (km) (17.8 Nautical Miles (NM)) northwest from the Fleetwood and Blackpool coast, and 31 km (16.7 NM) east from the Isle of Man. The Walney Extension was awarded an agreement for lease by The Crown Estate, which was signed on 26 th November 2010, and following extensive planning development and local consultation, DONG Energy submitted an Application for Consent to the Planning Inspectorate on 28 th June 2013. The Planning Inspectorate conducted its examination during Spring 2014 and submitted its report to the Secretary of State on 7 th August 2014. The Secretary of State will make its decision on award of consent no later than 3 months from receipt of the report from the Planning Inspectorate, and the consent will be secured 6 weeks after issue of the SoS decision of award of consent, provided no credible challenge to the consent decision is made during that period. What is the issue? The presence of the Walney Extension turbines would affect BAE Systems Warton (Warton) Aerodrome flying and Air Traffic Service (ATS) operations and potentially those of BAE Systems at Barrow/Walney Island Aerodrome, with the most significant effect being the detection of the Walney Extension wind turbines by the Warton Primary Surveillance Radar (PSR). Wind turbines located within PSR coverage can present themselves as a large number of reflecting moving targets to the radar, which look very similar to aircraft radar returns. These false radar returns (also known as clutter ) displayed on the radar screen can be confusing to air traffic controllers, which has the potential to erode levels of effectiveness and efficiency for the control of aircraft flying in the area of the Walney Extension Offshore Wind Farm. DONG Energy are working with Warton to identify a mitigation to the effect of the turbines on the PSR which will enable the Walney Extension wind turbines to be built without affecting Warton flying operations. Proposed solution In developing the plans to resolve the issues described above, DONG Energy and Warton have considered a variety of options to determine how best to meet the needs of Warton as well as other aviation and non-aviation stakeholders. 3
Warton s preferred solution is to establish a Transponder Mandatory Zone (TMZ 1 ) around the Walney, West of Duddon Sands (WoDS), Ormonde and Barrow operational Wind Farms and Walney Extension up to Flight Level (FL)100, (10,000 ft) to be active during the Warton Lower Airspace Radar Service (LARS) provision times 2. The proposed TMZ (lined in green) is illustrated in Figure 1 below. The existing operational turbines of Walney, Ormonde and Barrow do not affect the Warton PSR and the recently operational WoDS turbines are expected to affect the Warton PSR to some degree. For the purposes of this document, these wind farms are therefore collectively referred to herein as the Morecambe Bay Offshore Wind Farms. It would be difficult for a pilot to make a visual distinction between the existing Morecambe Bay Offshore Wind Farm turbines and those of the planned Walney Extension Offshore Wind Farm. Therefore, from an airspace user s visual perspective, DONG Energy and Warton consider that if mitigation involves a change to local airspace arrangements, then it is simpler to encompass all wind turbines in the immediate area within an airspace boundary. Figure 1 Proposed TMZ Reproduced from CAA digital map data Crown copyright 2014. UK IAIP ENR 1 A TMZ is defined by the CAA as a volume of airspace where aircraft wishing to enter or fly within the defined area will be required to have and operate secondary surveillance radar equipment. TMZs are notified for the purposes of Article 39(2) of the Air Navigation Order 2010. 2 Monday to Thursday 07:30 19:00, Friday 07:30 17:00 (local time). 4
The proposed establishment of the TMZ is one element of a 3-part Mitigation Package aimed at negating the effect of the clutter from the Walney Extension wind turbines upon the Warton PSR. The three parts are: Element 1: Establishment of a TMZ; Element 2: Authorisation to control Secondary Surveillance Radar (SSR 3 )-only and; Element 3: Suppression of PSR returns within the boundary of the Walney Extension Offshore and WoDS Wind Farms. The authorisation to control using SSR-only would be determined by the UK Civil Aviation Authority (CAA) in parallel to the TMZ consultation activity. The PSR returns from the wind turbines can be supressed in a number of ways including blanking of the PSR, or a more sophisticated methods. This document outlines the proposal from DONG Energy to maintain the effectiveness and efficiency of the airspace surrounding the Morecambe Bay Offshore Wind Farms by mitigating the effects of the wind turbines on BAE Warton and Barrow/Walney Island Aerodromes flying operations and BAE Warton PSR-based ATS operations. Stakeholder consultation DONG Energy wishes to engage with all parties that might be affected by this proposed airspace change. We will take your relevant feedback and analyse it, balancing safety, operational requirements and constraints, benefits/disbenefits and competing feedback from other respondents. We will take into account guidance from the Government and the CAA to inform the development of the proposal, ensuring that any positive effect is enhanced and negative effects minimised. This consultation is being undertaken in accordance with the Civil Aviation Publication (CAP) 725, Guidance on the Application of the Airspace Change Process [Ref 1]. This consultation document will aim to provide all of the information required for stakeholders to make an informed decision on the effect of the proposed changes. The consultation runs from 6 th October 2014 to 11 th January 2015, a period of 14 weeks. Please make use of the feedback form on the webpage. 3 SSR is a radar system used in Air Traffic Control (ATC) that not only provides controllers with azimuth position information, but also requests additional information from the aircraft itself such as its altitude. 5
Table of Contents 1 Glossary... 9 2 Introduction... 13 2.1 General... 13 2.2 Purpose and objectives... 14 2.3 Document structure... 15 3 The Consultation Process... 16 3.1 Overview... 16 3.2 What is this consultation about?... 16 3.3 Why is this consultation being carried out?... 16 3.4 Who are the consultees?... 17 3.5 Method of consultation... 17 3.6 Consultation CAA oversight... 18 3.7 Confidentiality... 18 4 The Need for an Airspace Change Proposal... 19 4.1 Overview... 19 4.2 General flying operations at Warton Aerodrome... 19 4.3 Justification for an ACP... 20 5 Proposed Design Options... 23 5.1 Overview... 23 5.2 Option 0 Do nothing... 23 5.3 Option 1 A PSR solution... 24 5.4 Option 2 Radio Mandatory Zone (RMZ)... 24 5.5 Option 3 Secondary Surveillance Radar (SSR)-only... 24 5.6 Option 4 Primary Surveillance Radar (PSR) blanking or NAIZ only... 26 5.7 Option 5 A Transponder Mandatory Zone (TMZ) with associated PSR suppression techniques... 26 5.8 Conclusion... 27 6 Development of the Proposed TMZ... 29 6.1 Overview... 29 6.2 Aim... 29 6.3 TMZ boundary requirements and operation... 30 6.4 Impact of the TMZ on military operations... 32 6
6.5 Impact of the TMZ on light GA operations... 32 6.6 Impact of the TMZ on Offshore Helicopter Operations... 33 6.7 Impact of the TMZ on Advisory Route (ADR) W2D... 33 7 Environmental and Economic Considerations of a TMZ... 34 7.1 Overview... 34 7.2 Impact of noise... 34 7.3 Anticipated level of fuel burn/co 2 emissions... 34 7.4 Anticipated effect on local air quality... 35 7.5 Environmental implications... 35 7.6 Economic benefit... 35 8 Next Stages... 36 8.1 Overview... 36 8.2 Consultation summary... 36 8.3 Consultation results... 36 8.4 What happens next?... 37 9 References... 39 A1 Walney Extension Offshore Wind Farm Line of Sight Assessment... 40 A1.1 Overview... 40 A1.2 Boundary Details... 40 A1.3 Boundary Graphic... 41 A1.4 LoS Assessment Methodology... 41 A1.5 LoS Assessment Results... 42 A1.6 Conclusion... 43 A2 West of Duddon Sands Line of Sight Assessment... 44 A2.1 Overview... 44 A2.2 Boundary Details... 44 A2.3 Boundary Graphic... 45 A2.4 LoS Assessment Methodology... 45 A2.5 LoS Assessment Results... 45 A2.6 Conclusion... 46 A3 Proposed TMZ Co-ordinates... 47 A4 Stakeholder / Consultee List... 49 A4.1 Aviation Consultees... 49 A4.2 Aerodromes / Local Aviation Consultees... 50 A4.3 Non-Aviation Consultees: National Bodies... 51 A4.4 Non-Aviation Consultees: Regional Council Authorities... 51 A4.5 Non-Aviation Consultees: Council Wards / Local Authorities... 51 A4.6 Information Organisations: Members of Parliament... 53 7
A4.7 Information Organisations: Civil Aviation Authority... 53 Table of Figures Figure 1 Proposed TMZ... 4 Figure 2 Location of BAES Warton in relation to the proposed TMZ and AARA 13.... 20 Figure 3 Walney Potential TMZ including 3.71 km (2 NM) Buffer Zone... 31 Figure 4 Proposed TMZ ENR 6.1 Entry... 37 Figure 5 Illustration of the Walney Extension Boundary Points... 41 Figure 6 LoS Profile between Warton (PSR) and Point 5... 42 Figure 7 Illustration of the WoDS Boundary Points... 45 Figure 8 LoS Profile between Warton (PSR) and Point 4... 46 Table of Tables Table 1 Table of References... 39 Table 2 Summary of Turbine/Boundary Details for the Walney Extension LoS Assessment... 40 Table 3 Summary of Turbine/Boundary Details for WoDS LoS Assessment... 44 Table 4 Proposed TMZ Co-ordinates... 47 Table 5 TMZ Proximity to Military and Civilian Aerodromes... 48 8
1 Glossary Acronym AARA ACAS ACP AEF AGL AIP ANO AOA AOPA ARA AR AMSL ATC ATM ATSOCAS ATS ATSU ATZ BIA BAA BABO BAES Meaning Air to Air Refuelling Area Airborne Collision Avoidance System Airspace Change Process Air Experience Flight Above Ground Level Aeronautical Information Publication Air Navigation Order Airport Operators Association Aircraft Owners and Pilots Association Advisory Radio Area Airspace Regulation Above Mean Sea Level Air Traffic Control Air Traffic Management Air Traffic Service Outside Controlled Airspace Air Traffic Service Air Traffic Service Unit Aerodrome Traffic Zone Blackpool International Airport British Airports Association British Association of Balloon Operators British Aerospace Systems 9
BALPA BATA BBAC BBGA BGA BHA BHPA BMAA BMFA BPA CAA CAP CAS CAT CO 2 CTA CTR DAATM DfT DIO DS ELFAA FJ FL ft FUA British Airline Pilots Association British Air Transport Association British Balloon and Airship Club British Business and General Aviation Association British Gliding Association British Helicopter Association British Hand Gliding and Paragliding Association British Microlight Aircraft Association British Model Flying Association British Parachute Association Civil Aviation Authority Civil Aviation Authority Aeronautical Publication Controlled Airspace Commercial Air Transport Carbon Dioxide Control Area (Class D UK Airspace) Control Zone (Class D UK Airspace) Defence Airspace and Air Traffic Management Department for Transport Defence Infrastructure Organisation Deconfliction Service European Low Fares Airline Association Fast Jet Flight Level Feet Flexible Use of Airspace 10
GA GASCo GAT GAPAN GATCO HCGB HQ HQ DAAvn IAIP ICAO IFP IoMA km kts LAA LARS LACC LoA MAA MoD Morecambe Bay Offshore Wind Farms MTWA MW NAIZ NATMAC General Aviation General Aviation Safety Council General Air Traffic Guild of Air Pilots and Air Navigators Guild of Air Traffic Control Officers Helicopter Club of Great Britain Headquarters Headquarters Director Army Aviation Integrated Aeronautical Information Package International Civil Aviation Organisation Instrument Flight Procedure Isle of Man Airport Kilometre Knots Light Aircraft Association Lower Airspace Radar Service London Area Control Centre Letter of Agreement Military Aviation Authority Ministry of Defence Collectively refers to Walney 1 and 2, Walney Extension, West of Duddon Sands, Ormonde Offshore Windfarm, Barrow Offshore Windfarm Maximum Total Weight Authorised Mega Watt Non-Automatic Initiation Zone National Air Traffic Management Advisory Committee 11
NATS NERL NCHQ NM NO 2 NOTAM OAT PANS PIR PSR RAF RMZ SARG ScACC SSR TMZ UAS UAV UKFSC WoDS VGS The National Air Traffic Service Provider NATS En-Route Ltd Navy Command Head Quarters Nautical Mile Nitrogen Dioxide Notice to Airmen Operational (Military) Air Traffic Procedures for Air Navigation Services Post Implementation Review Primary Surveillance Radar Royal Air Force Radio Mandatory Zone CAA Safety and Airspace Regulation Group Scottish Area Control Centre Secondary Surveillance Radar Transponder (SSR) Mandatory Zone Unmanned Air Systems Unmanned Air Vehicles UK Flight Safety Committee West of Duddon Sands Wind Farm Volunteer Gliding Squadron 12
2 Introduction The presence of the Walney Extension Offshore Wind Farm would affect BAE Systems Warton Aerodrome flying and Air Traffic Service (ATS) operations, with the most significant effect being the detection of the wind turbines as unwanted clutter by the Warton Primary Surveillance Radar (PSR). DONG Energy and BAE Systems are working together to identify a suitable mitigation which will enable the Walney Extension wind turbines to be built without affecting Warton and Barrow/Walney Island flying operations. 2.1 General DONG Energy Walney Extension Ltd (DONG Energy) wishes to develop an extension to the existing Walney Wind Farms, referred to as the Walney Extension Offshore Wind Farm. The project development site will be located West of the operational Walney Wind Farms (1 and 2) and the operational offshore wind farms in the Irish Sea to the North West of Morecambe bay, approximately 33 kilometres (km) (17.8 Nautical Miles (NM)) northwest of Fleetwood and Blackpool coast, and 31 km (16.7 NM) from the Isle of Man. The presence of the Walney Extension wind turbines would affect BAE Systems Warton Aerodrome flying and Air Traffic Service (ATS) operations and potentially BAE Systems operations at Barrow/Walney Island Aerodrome; thereby requiring a change to the arrangements and procedures in the immediate airspace surrounding the wind farms. Wind turbines located within PSR coverage can present themselves as moving targets to the radar, which look similar to aircraft radar returns. These false radar returns ( clutter ) displayed on the radar screen can be confusing to air traffic controllers and has the potential to erode levels of effectiveness and efficiency for the control of aircraft flying in the area of the Morecambe Bay Offshore Wind Farms. False radar returns may cause disruption by forcing air traffic controllers to take unnecessary action in order to maintain radar separation in accordance with Civil Aviation Authority (CAA) regulations. Hence, any loss of radar performance in this area, along with any misleading or unnecessarily distracting displayed radar information, has the potential to erode the effective and efficient use of the airspace in the area of the Walney Extension Offshore Wind Farm as well as the wider area of the Morecambe Bay Offshore Wind Farms. Analysis completed (Annex A1) as part of the planning process for the Walney Extension concludes that it is highly likely that the Warton PSR will detect all turbines located within the planned Extension area. Annexes A1 and A2 provide example theoretical radar Line of Sight (LoS) profiles for the Warton PSR looking towards the Walney Extension Offshore and West of Duddon Sands (WoDS) Wind Farms which are expected to affect the Warton PSR. 13
The existing operational Walney 1 and 2, Ormonde and Barrow Wind Farms do not affect the Warton PSR, as the wind turbines are smaller than those planned for the extension. However, whilst the existing operational turbines do not affect the Warton PSR, from an airspace user s visual perspective DONG Energy and Warton consider that if mitigation involves a change to local airspace arrangements, then it is simpler to encompass all wind turbines in the immediate area. It would be difficult for a pilot to make a visual distinction between the existing Morecambe Bay Offshore Wind Farm turbines and those of the planned Walney Extension. The degradation in the detection and tracking capabilities of the Warton PSR in the area of the Walney Extension is of particular importance with regard to the flight test area in which the Wind Farm is centred. The airspace within the vicinity of the proposed site is Class G and is regularly used by aircraft from Warton, as it provides a sufficient volume of airspace away from airways and other Controlled Airspace (CAS), for the evaluation and testing of advanced air systems. Wind turbines located within PSR coverage can present themselves as a large number of reflecting moving targets to the radar, which look very similar to aircraft radar returns. These false radar returns ( clutter ) displayed on the radar screen can be confusing to air traffic controllers, when endeavouring to maintain the standard separation required between radar returns, in this complex volume of airspace. This confusion has the potential to erode levels of effectiveness and efficiency for the control of aircraft flying in the area of the Walney Extension Offshore Wind Farm. If there was a reduced ATS from Warton Air Traffic Control (ATC) in the area of the Walney Extension turbines, it would significantly restrict Warton s current operations in the Irish Sea. Other airspace users requiring a service from Warton ATC may also experience disruption due to unnecessary route deviation. Extensive work to determine a solution to mitigate the potential effect of the turbines on the ATS provided by Warton has been undertaken by DONG Energy and Warton. It has been determined that the introduction of a Transponder Mandatory Zone (TMZ) over the Morecambe Bay Offshore Wind Farms will mitigate the effects of the detection of wind turbines by the Warton PSR. Any change to airspace constructs requires adherence to CAP 725 [Ref 1] and the Airspace Change Process (ACP). DONG Energy is the sponsor of this airspace change and has engaged Osprey Consulting Services Ltd (Osprey) to manage the process on their behalf. 2.2 Purpose and objectives The purpose of this document is to provide information regarding the proposal to establish a Transponder Mandatory Zone (TMZ) over the Morecambe Bay Offshore Wind Farms to mitigate the effects of the detection of wind turbines by the Warton PSR, because of the presence of Walney Extension. Osprey, on behalf of DONG Energy and Warton and in accordance with CAP 725 [Ref 1], has prepared the document. The objectives of the document are to: Provide the background to the Airspace Change Proposal; Describe the operations at Warton Aerodrome and how these may be affected by the Walney Extension wind turbines; 14
Detail the proposed change to the airspace over the Morecambe Bay Offshore Wind Farms; and Describe the other options considered and explain why these options were considered insufficient mitigation for the effects of the detection of unwanted wind turbine radar returns by the Warton PSR. It is DONG Energy s responsibility, as Sponsor of the proposed change, to consult with all relevant stakeholders who may be directly or indirectly affected by the proposal. 2.3 Document structure This document contains nine main sections and four Annexes, outlined below for convenience: Section 1 provides a glossary; Section 2, this section, introduces the document; Section 3 outlines the consultation process; Section 4 explains the necessity for an Airspace Change Proposal; Section 5 gives the proposed design option; Section 6 describes the development of the proposed TMZ; Section 7 details the environmental and economic considerations; Section 8 provides an outline of the next stages following consultation; and Section 9 provides a list of references. There are four Annexes: Annex A1 details the radar Line of Site (LoS) assessment for the Walney Extension Offshore Wind Farm; Annex A2 details the radar Line of Site (LoS) assessment for the WoDS Wind Farm; Annex A3 provides the co-ordinates of the proposed TMZ; and Annex A4 lists the Consultees. 15
3 The Consultation Process It is a CAA requirement that the Sponsor of an Airspace Change Proposal must consult stakeholders prior to submission of the Proposal. 3.1 Overview The primary objective of this consultation process is to enable DONG Energy to engage with all parties that might be affected by its proposed airspace change, in order to ensure that the development of the proposal is informed by constructive feedback. This section provides an outline of the consultation process for DONG Energy s Airspace Change Proposal. It includes details of why a consultation is undertaken, details of who has been sought to engage in consultation, details on the method of consultation and CAA oversight of the consultation process. 3.2 What is this consultation about? This consultation concerns a proposal to establish a TMZ over the Walney Extension Offshore Wind Farm and the Morecambe Bay Offshore Wind Farms. The proposed establishment of the TMZ is one element of a 3-part Mitigation Package aimed at negating the effect of the clutter from the Walney Extension wind turbines upon the Warton PSR. The three parts are: Element 1: Establishment of a TMZ; Element 2: Authorisation to control SSR-only and; Element 3: Suppression of PSR returns within the boundary of the Walney Extension Offshore and WoDS Wind Farms. Such an airspace change is necessary in order to mitigate the effects of the Walney Extension and WoDS wind turbines on the Warton PSR. This will ensure a full suite of Air Traffic Services Outside Controlled Airspace (ATSOCAS) 4 can continue to be provided, whilst maintaining the current levels of airspace effectiveness and efficiency in this area. This consultation is not about facilitating change of routine air traffic procedures at local aerodromes. 3.3 Why is this consultation being carried out? It is a requirement of the CAA s Airspace Change Process (CAP 725) [Ref 1] that a Sponsor undertakes a public consultation process prior to the submission of a 4 Air Traffic Services Outside Controlled Airspace (ATSOCAS) are provided by a variety of air traffic units and used by a wide variety of users from General Aviation to commercial flights and military aircraft. 16
proposal. This ensures that all stakeholders who may be directly or indirectly affected by the proposed change are consulted, as well as highlighting any environmental effects that the proposed airspace change may have. The CAA lays down its regulatory requirements and process for consultation in CAP 725 [Ref 1]. The CAA Policy Statement for the development of a TMZ [Ref 2] requires that such airspace developments must be carried out in accordance with the ACP. DONG Energy will collate and distribute all consultation results to the CAA for their consideration during the regulatory decision process. We are not seeking feedback on the Planning Inspectorate s consent for the Walney Extension Offshore Wind Farm. 3.4 Who are the consultees? Consultees broadly fall into two categories: Aviation consultees; and Non-aviation consultees. Aviation consultees include aviation parties such as the Ministry of Defence (MoD), airlines, aircraft operators, adjacent aerodromes, all local airspace users and the national bodies representing all UK aviation interests who may be affected by the regulatory requirements within the TMZ. Non-aviation stakeholders for consultation include environmental and heritage organisations, local planning authorities and the general public. Although the proposed change to the airspace lies offshore, and there are no changes to the way aircraft operate over land, the neighbouring coastal districts and parish councils are being consulted. Fundamentally, the consultation will enable DONG to obtain or confirm views and opinions about the effect of the proposed airspace change. A full list of consultees, developed with the advice of the CAA, is given at Annex A4. Consultees have a crucial role in providing relevant and timely feedback to DONG Energy, giving their views and opinions on the effect of the proposed airspace change. Consequently, you are urged to participate fully in this important consultation. 3.5 Method of consultation The CAA requires that the consultation be conducted in accordance with the principles set out in the Cabinet Office Code of Practice on Consultation, as specified in CAP 725 [Ref 1]. This consultation document is made widely available and can be viewed on the DONG Energy website. If further clarification is required on this consultation, please address these to walney.tmz@ospreycsl.co.uk via email or by post to Osprey, The Forge, Bentley, Hampshire, GU10 5HY (marking your letter Walney Consultation ). 17
3.6 Consultation CAA oversight Osprey, in compliance with CAP 725 [Ref 1], manages the consultation process on behalf of DONG Energy for the Walney TMZ Airspace Change. Any complaints on the adherence of Osprey or DONG Energy to the consultation should be addressed to CAA Airspace Regulation (AR), using the contact details below: Airspace Business Coordinator Airspace, ATM and Aerodromes CAA House 45-59 Kingsway London WC2B 6TE Email: airspace.policy@caa.co.uk It should be noted that the CAA is responsible for overseeing the consultation process and will therefore not comment on the proposed changes. 3.7 Confidentiality The CAA requires that all consultation material, including copies of responses from consultees and others, are included in any formal Airspace Change submission to the CAA. Should you not wish to pass your personal details to the CAA, then please let DONG Energy know. However, the CAA is bound by the Data Protection Act and will protect all personal information where provided. DONG Energy undertakes that, apart from the necessary submission of material to the CAA and essential use by Osprey for analytical purposes, DONG Energy will not disclose personal details or content of responses and submissions to any third parties. 18
4 The Need for an Airspace Change Proposal Warton ATC operates under regulatory oversight of both the Military Aviation Authority (MAA) and CAA, providing essential ATS to military and civil aircraft in the area of the Morecambe Bay Offshore Wind Farms. 4.1 Overview This section describes the background relevant to this ACP by providing an overview of flying operations at Warton and by highlighting the primary areas of concern relating to the effects of the Walney Extension on Warton operations. In this case, there are three principal issues to be considered: Test flying operations in the Irish Sea; Services to aircraft under the Lower Airspace Radar Service (LARS) scheme; and Approach Control Service. These are further elaborated below. 4.2 General flying operations at Warton Aerodrome A range of military and civilian aircraft operate from Warton aerodrome. The airfield carries out, on average, around 1000 aircraft movements per month, 40% of which are military registered flights, in support of the following operational tasks: Flight development and test activities, predominantly on Typhoon, Tornado and Hawk aircraft, which can include civilian test support aircraft operations; Production test flying of brand new Typhoon (and soon to be Hawk) aircraft that are manufactured on site; Daily commercial passenger flying operations; Military and civilian transport operations; National Police Helicopter operations; and Flying training activity on civilian and military aircraft. Warton ATC provides aerodrome control and approach control services to a wide range of commercial, general aviation and military aircraft in the airspace over the Irish Sea and overland near Warton. In addition to these routine air traffic control tasks, Warton ATC is responsible for providing LARS cover to a radius of 74 km (40 NM) from Warton and a dedicated specialist service to aircraft conducting test and development flights up to (and occasionally beyond) 370 km (200 NM) from Warton. Warton ATC operates under regulatory oversight of both the MAA and the CAA. The standard ATS, the LARS and the dedicated test service combine to support the 19
required efficient and effective operations of a mix of aircraft in the local and extended operating areas. 4.3 Justification for an ACP As outlined above, the effect of the Walney Extension wind turbines on the Warton PSR, giving rise to false radar returns will have an effect on the provision of radar services in relation to the following three issues: Test flying control in the vicinity of the Walney Extension; Services to aircraft under the LARS scheme when aircraft are operating outside CAS; and Approach Control Service. These areas of concern have led to the requirement to mitigate the effects of the Walney Extension wind turbines. Figure 2 below shows the location of BAES Warton in relation to the proposed Walney TMZ, the Dark Blue (Walney Extension Offshore Wind Farm) and Red (WoDS) areas shows the theoretical extent of the related wind turbine generated clutter. The Yellow outline shows the Air-to-Air Refuelling Area (AARA) 13. Figure 2 Location of BAES Warton in relation to the proposed TMZ (Green) and AARA 13 (Yellow) depicting a 2NM buffer around the entire area occupied by the Morecambe Bay Offshore Wind Farms (various block colours). 20
Further detail is provided in the following paragraphs. 4.3.1 Flight test operations in the vicinity of the proposed TMZ Warton s coastal location, adjacent to extensive CAS and uncontrolled airspace, makes it an ideal site for testing, research and development of complex military aircraft. The majority of these operations take place offshore over Morecambe Bay and Liverpool Bay. The MoD, in support of front line military aviation operations, and other export customers rely on this operation for the delivery of high specification military capability. The fast jet (FJ) military aircraft conducting test and development sorties operate in accordance with predetermined schedules to ensure that appropriate test data is gathered; the test and development aircrew involved rely on Warton ATC to provide a mixture of air traffic services. In support of this, three high-speed routes have been established under a Letter of Agreement with NATS, London Area Traffic Control Centre (LACC) and Scottish Area Control Centre (ScACC). The preferred route used by Warton ATC is one that has the least effect on civil ATC operations, and therefore requires less coordination with external agencies. However, this preferred route tracks directly over the proposed TMZ area. Additionally, AARA 13 is within the vicinity of Walney as depicted at Figure 3, with Warton as one of the three possible controlling authorities, the others being LACC and ScACC. This adds to the complexity of the airspace and re-enforces the requirement for the TMZ to ensure accurate traffic information and/or avoiding action on unknown aircraft can be passed to aircraft within the refuelling area when under the control of Warton. The Warton Advisory Radio Area (ARA) incorporates the Morecambe and Liverpool Bay areas and is notified airspace extending from Flight Level (FL)95 (9,500 feet (ft)) to FL190 (19,000 ft). Within the Warton ARA all pilots are advised to make radio contact with Warton ATC in order to receive up to date information on other traffic, specifically test and evaluation aircraft, operating in the area. To support test-flying activities Warton ATC requires an unambiguous picture of its operational airspace, which allows efficient and flexible tactical freedom for aircraft manoeuvres close to Warton and in the airspace above the Morecambe Bay Offshore Wind Farms, the area of the proposed TMZ. Class G airspace is uncontrolled in that any aircraft may use the airspace under the Air Navigation Order and the Regulations (ANO) CAP 393 [Ref 3] and although an ATS may be available, it is not mandated; Military and General Aviation use large portions of Class G airspace below FL195 (19,500 ft) extensively. The service provided by Warton controllers to test and evaluation pilots in Class G airspace, aimed at achieving notified deconfliction minima from other traffic in Class G airspace, is a Deconfliction Service (DS). In Class G airspace, the avoidance of other traffic is ultimately the pilot s responsibility. However, under a DS the controller provides the pilot with specific surveillance-derived traffic information and issues advisory headings and/or levels aimed at achieving the required deconfliction minima. The deconfliction minima required against unknown or un-coordinated traffic, or unknown radar returns (like wind turbine generated returns) are: 9.27 km (5 NM) laterally (subject to surveillance capability and regulatory approval); or 3,000 ft vertically and, unless the SSR code indicates that the Mode C data has been verified, the surveillance returns, however presented, should not merge. 21
(Note: Mode C can be assumed to have been verified if it is associated with a deemed validated Mode A code. The Mode C data of aircraft transponding code 0000 is not to be utilised in assessing deconfliction minima). If the Warton radar clutter induced by the Walney Extension wind turbines is not addressed, Warton ATC will be required to apply 9.27 km (5 NM) separation between any aircraft in receipt of a DS and any unknown or false returns from the wind turbines, which could significantly restrict Warton s operations in this portion of airspace. In summary, degradation of detection and tracking capabilities of the Warton radar in the area of the Walney Extension is of importance. Habitually reduced DS from Warton ATC in the area of the Walney Extension would effectively render a large volume of the Class G airspace above the Irish Sea unusable unless pilots agree to a downgrade in service. This may not be acceptable to the pilot and under such circumstance; this would represent a significant reduction in the size of the Warton ARA airspace available for critical flight test activities. Other airspace users requiring a service from Warton ATC may also experience disruption due to unnecessary route deviation. 4.3.2 LARS provision Warton ATC provides a LARS for the purpose of ensuring participating pilots are aware of other nearby aircraft and/or flying activities, thereby enhancing flight safety in the area. This service is available to any aircraft operating outside CAS, from ground level up to 10,000 ft, within a 40 NM radius of Warton. The Warton LARS is active between the hours of 07:30 and 19:00 (Mon-Thu), 07:30 and 17:00 (Fri); which is coincidental with the operating hours of Warton Aerodrome. LARS is regarded as a very important scheme, which is sponsored by the Department for Transport (DfT) and is determined by the CAA Safety and Airspace Regulation Group (SARG) as key to enhancing the effectiveness, efficiency and safety of the airspace in an area that can be busy with a mixture of aviation activities. A recent LARS review by DfT recognised Warton s key role as a provider of LARS in the North West of England. The service would necessarily be reduced or terminated near the Morecambe Bay Offshore Wind Farms if the radar returns from the turbines were not mitigated. 4.3.3 Approach Control Service The airspace around Warton is considered to be of medium complexity in that it is surrounded by areas of open (Class G) airspace, particularly to west and northwest, but is bounded closely by CAS to the south and east. Warton ATC is responsible for providing services to aircraft arriving at and departing from Warton, as well as local air traffic and military aircraft involved in complex test and development flights. Warton ATC in accordance with CAP 393 [Ref 3] provides an approach control service. Warton is also the approach control unit for Barrow/Walney Island and has a Letter of Agreement (LoA) with Blackpool International Airport (BIA) to cater for seamless ATS provision in the event of BIA PSR failure. 22
5 Proposed Design Options Warton s preferred solution is to establish a TMZ with associated PSR suppression of returns. 5.1 Overview In developing the plans to resolve the issues detailed in Section 4, DONG Energy has considered a variety of design options in their aim to provide sufficient mitigation, whilst meeting the needs of Warton and all other aviation and non-aviation stakeholders. The following mitigation design options were considered: Do nothing; Implement a PSR solution; Implement a Radio Mandatory Zone (RMZ); Conduct SSR only operations; Implement PSR blanking or a Non-Automatic Initiation Zone (NAIZ) only; or Implement a TMZ with associated SSR-only operations and PSR suppression of returns. Extensive evaluation and consideration of all options was made as described in the following sections. Details of each of the design options considered are provided in the sections below. 5.2 Option 0 Do nothing If no mitigating actions are taken for the effect of the Walney Extension wind turbines on the Warton PSR, it is likely that the PSR service at Warton ATC would be impacted. Wind turbines located within PSR coverage can reduce the ability of the radar to detect aircraft, and ATC to differentiate between a wind turbine return and a radar return from an aircraft. The following effects have been well documented and are detailed within the CAA s CAP 764 CAA Policy and Guidelines on Wind Turbines [Ref 4]: Wind turbine generated returns leading to false target generation and track seduction; Loss of radar receiver sensitivity; Radar plot extractor or memory overload; Presenting an obstruction (shadow); and Receiver saturation. Each of these effects reduces the effectiveness of radar in detecting targets, which can result in misidentification of aircraft, temporary loss of aircraft track position and identity, and the generation of false radar returns. Any reduction in radar 23
performance and the consequential loss of situational awareness will result in, as a minimum, a less efficient use of the airspace If mitigation is not introduced, substantial changes would need to take place to the way in which Warton handles traffic in the vicinity in order to maintain service provision. These changes could potentially lead to greater overland routing, greater noise exposure by communities, and greater fuel burn, NO 2 and CO 2 emissions through extended routing to avoid the wind turbine clutter. This option has been rejected as DONG Energy and Warton have agreed that mitigation is required to minimise the effect of the Walney Extension on Warton operations. 5.3 Option 1 A PSR solution Warton operates a Selex ES ATCR-44 ATC PSR, complemented by a co-mounted Mode S SSR, and a combined SSR data feed from NATS radars at Clee Hill, Great Dunn Fell and Lowther Hill. DONG and Warton have held discussions with Selex ES, the PSR Design Authority, to investigate if there are approved methods in which the PSR could be modified to enable Warton to continue to provide an ATS using the PSR in the region of the Walney Extension wind turbines. Due to the large number of wind turbines planned for the Extension, simple radar modifications to provide mitigation are not possible with the existing technology. Modification to the PSR to mitigate for the turbine returns would therefore involve a gap filler radar to be integrated alongside the existing PSR system. Extensive discussion took place between Dong Energy and Warton on this option and Warton concluded that it entailed substantial technical complexity and risk and did not present a cost-effective solution. 5.4 Option 2 Radio Mandatory Zone (RMZ) A Radio Mandatory Zone (RMZ) would require aircraft to be in two-way communication with ATC and provide information pertinent to the flight prior to entering the designated airspace. Although ATC would be able to provide some level of service to traffic in the area, it would not prevent the Walney Extension wind turbine generated radar returns from being displayed on the radar display, with the effect of requiring a limited service provision as outlined previously. An RMZ alone also permits access to aircraft that are not transponder equipped. This makes it difficult to identify and maintain track identity on the non-transponding aircraft, in the presence of wind turbine generated clutter, for the purposes of providing traffic information and separation. This operational mitigation does not go far enough to reduce the effects of wind turbine generated tracks on Warton ATC displays. This option has been rejected by Warton as it provides insufficient mitigation. 5.5 Option 3 Secondary Surveillance Radar (SSR)-only SSR is a co-operative surveillance technique, which relies on the aircraft being equipped with a transponder. The target aircraft's transponder responds to interrogation by the ground station (SSR) by transmitting a coded reply signal. The sole reliance and use of this surveillance technique, without appropriate airspace use 24
rules in place, is not approved in the UK due to busy approach environments. However, due to the small area of the airspace requiring mitigation, it may be justifiable to use SSR-only to maintain the identity of an aircraft as it transits through the airspace above the Morecambe Bay Offshore Wind Farms. It should be noted that the circumstances when SSR may be used alone in the provision of ATS are limited. For the UK, the requirement is outlined in CAP 493 MATS Part 1 [Ref 5], Section 1, Chapter 3, paragraph 3.71 as follows: Use of SSR alone 3.71 Provided the pilots are made aware of the limitations of the service, SSR may be used to provide horizontal separation in the following circumstances: a) In accordance with MATS Part 2; b) To overcome temporary deficiencies within PSR cover, such as fading or clutter, the SSR return only of one aircraft may be used to provide separation from the PSR or SSR return of another aircraft provided the PSR and SSR situation displays are correctly aligned. In this context, unavailable for use due to maintenance does not constitute a temporary deficiency ; c) Immediately after PSR failure for the minimum time necessary to establish procedural separation. Once established, services normally provided using radar may be resumed when the PSR is serviceable. However, a permanent large area of clutter, such as that generated by a wind farm, is not considered a temporary deficiency in PSR cover. Thus, the principal requirement would be for CAA approval that, in turn, is dependent on fulfilling the International Civil Aviation Organisation (ICAO) 5 requirement 8.1.9: 8.1.9 SSR systems, especially those utilizing monopulse technique or having Mode S capability, may be used alone, including in the provision of separation between aircraft, provided: a) the carriage of SSR transponders is mandatory within the area; and b) identification is established and maintained. This option alone has been rejected by Warton as it does not solve the problem of being able to distinguish between primary radar returns created by the turbines and those created by non-transponding aircraft. Simply providing a service using SSR only does not prevent non-transponder equipped aircraft from entering the airspace and therefore safety could be compromised as a result of the inability to identify, track and provide separation from those aircraft. Thus, the potential for ambiguity and air traffic controller confusion in the area of the Walney Extension wind turbines 5 ICAO outlines the principles for airspace protection and procedure design to which all ICAO signatory states must adhere. 25
would not be removed. Hence, this option alone is rejected as it provides insufficient mitigation to the effects of the wind turbines on Warton radar. 5.6 Option 4 Primary Surveillance Radar (PSR) blanking or NAIZ only PSR blanking involves the deliberate masking of fixed areas on the radar display. This ensures that clutter caused by a wind turbine development is not presented to the controller. The potential drawback of this option is that in addition to wind turbine clutter, primary radar returns from legitimate aircraft are also blanked and therefore not presented to the air traffic controller. Clutter effects can be limited by establishing NAIZ 6 in which new tracks are prevented from initiating, whilst mature tracks are maintained and updated. A NAIZ placed over the location of a wind farm development ensures that turbine blades do not create false tracks, but established aircraft tracks entering the location continue to be updated. Despite turbine returns being inhibited, there is potential for the PSR processor to confuse the two returns, and switch the association of the established aircraft track from its real radar response to that of the turbine response. Switching of track association presents false information to the air traffic controller and may cause a risk to flight safety. Moreover, NAIZ cannot identify the source of new potential tracks within the zone, and so will not enable the initiation of a track on a radar response caused by an actual aircraft whose radar responses have only just begun to be received by the radar (i.e. climbing out of low level) before it enters the wind farm. Warton has rejected this option as it provides insufficient mitigation. 5.7 Option 5 A Transponder Mandatory Zone (TMZ) with associated PSR suppression techniques A TMZ is airspace of defined dimensions wherein aircraft wishing to enter or fly within the defined area will be required to have and operate SSR equipment or receive authorisation (approval) to enter, via radio, from the TMZ Controlling Authority. The concept of Transponder Mandatory Airspace, in the form of a TMZ, has been developed by the CAA to cater for overriding safety reasons where the airspace classification would not normally require aircraft to carry a transponder. This SSR equipment must include a pressure altitude reporting transponder capable of operating in Mode A and Mode C and have the capability and functionality prescribed for Mode S Elementary Surveillance. 6 Some plot extracted PSRs have the ability to create NAIZ. In their simplest form received radar signals are displayed on ATC displays as direct representations of the target's range, bearing and strength (known as video). By utilising advanced Digital Signal Processing techniques some radars analyse signals and provide them in the form of data messages instead (known as plot extraction). Amongst the many advantages of plot extraction is the ability to manipulate data from different systems in a Surveillance Data Processing system, however, significant difficulties may be encountered when combining information from plot extracted and video radars. 26
The proposed establishment of the TMZ is one element of a 3-part Mitigation Package aimed at negating the effect of the clutter from the Walney Extension wind turbines upon the Warton PSR. The three parts are: Element 1: Establishment of a TMZ; Element 2: Authorisation to control SSR-only; and Element 3: Suppression of PSR returns within the boundary of the Walney Extension Offshore and WoDS Wind Farms. The proposed solution provides Warton ATC with a known traffic environment where each aircraft can be identified and monitored for the purpose of providing separation and traffic information. Any unknown targets that are presented without a corresponding SSR return can be assumed to be either spurious or created by the turbines. This provides the assurance that any aircraft that are in receipt of a service within the TMZ can be positively identified and the appropriate separation can be provided between aircraft. This enhances safety since it removes any doubt that unknown primary only returns created by the turbines are assured to be turbine returns and not unknown aircraft. Furthermore, Commercial Air Traffic (CAT) operators will benefit from collision avoidance mitigation through the cooperative use of ACAS. Aircraft flying through the TMZ will be required to be equipped and operate SSR equipment or to have established two-way radio communications with Warton ATC, the TMZ Controlling Authority. The airspace classification of a TMZ would remain unchanged, Class G in this case. Hence, the ATS available within and around the TMZ would continue to be applied according to ATSOCAS through the assured provision of SSR data to the controller. Figure 2 (Section 4.3) illustrates a potential design for a TMZ around the Morecambe Bay Offshore Wind Farms including a 2 NM buffer zone. The primary determining features for the TMZ would be: 5.8 Conclusion The location of the current operational Walney 1 and 2 turbines; The location of the planned Walney Extension turbines; The location of the WoDS, Ormonde and Barrow turbines; The tracking characteristics of the Warton PSR; The base of CAS above the wind farms or the FL above which transponder carriage is mandated in the UK; The presentation of the TMZ to pilots (i.e. how it is portrayed on the charts); Proximity to the coastline; and Proximity to Barrow/Walney Island Aerodrome and BIA. DONG Energy and Warton have considered multiple options in depth. Warton deemed Option 5 to be the most feasible for the continued efficient provision of ATS by Warton. This solution is also a more cost-effective solution than option 1, which is deemed viable but entails significant technical complexity. The other options are not considered to provide sufficient mitigation, and could potentially have negative effects on the environment through greater overland routing, greater noise exposure by communities and increased emissions. 27
Warton s preferred solution therefore is to establish a TMZ, with associated suppression of PSR returns within the boundary of the Morecambe Bay Offshore Wind Farms (both existing and proposed), within the Warton LARS provision times. This will allow the removal of wind turbine generated clutter from the radar display and provide controllers with the ability to maintain track identity of aircraft within the vicinity and above the wind turbines, maintaining the current safe and efficient levels of ATS. 28
6 Development of the Proposed TMZ The overall aim of the Walney TMZ Airspace Change Proposal is to maintain airspace efficiency and effectiveness, for all users, and mitigate the effects of the Walney Extension Wind Farm on Warton flying and ATS operations. 6.1 Overview The CAA, in CAP 725 [Ref 1], lays down extensive regulatory requirements to be applied to the design of the airspace arrangements. However, most of these requirements, such as Instrument Flight Procedure (IFP) containment, are relevant to the development of CAS, which is not the case with this TMZ proposal. The regulatory requirements applicable to this proposal are that the: Dimensions of the proposed airspace should be the minimum practicable to meet the safety and operational requirements; and Configuration of the airspace should be as simple as practicable. Thus, the primary considerations in the development of the proposed TMZ are the lateral and vertical dimensions, including alignment with other, pre-existing, airspace boundaries and the impact on: 6.2 Aim Those aircraft wishing to use the airspace which are not and/or cannot be equipped with a transponder; and The operational impact on adjacent Air Traffic Service Units (ATSU) who may not be SSR equipped. A potential drawback of establishing a TMZ is that non-transponding aircraft may choose to take an alternative route in order to bypass the TMZ, resulting in a change in traffic patterns and ATC workload in this area. This would only reasonably occur when aircraft have been unable to establish two-way radio communications with Warton ATC, the TMZ Controlling Authority. The overall aim of the Walney TMZ Airspace Change Proposal is to maintain airspace efficiency, effectiveness and safety, for all users, and mitigate the effects of the Walney Extension on Warton flying and ATS operations. It is envisaged that this will be achieved through the establishment of a TMZ with suppression of Warton PSR returns within the boundary of the Walney Extension Offshore and WoDS Wind Farms. The secondary objective of the mitigation solution is to minimise any known airspace impacts by allowing continuity of a full suite of ATSOCAS provision in the vicinity of the Morecambe Bay Offshore Wind Farms. Consequently, the proposed TMZ design is intended to be sympathetic to existing airspace structure, traffic patterns and local ATC operational norms. 29
6.3 TMZ boundary requirements and operation 6.3.1 TMZ horizontal buffer zone It is not possible to remove only the radar returns from the wind turbines without also removing wanted radar returns from aircraft. This is why PSR Blanking in isolation is not considered a viable mitigation for the Walney Extension. The objective of establishing the TMZ is not to prevent aircraft from operating near the turbines, but to require that they operate a transponder, or are in two-way radio contact with Warton ATC, when so doing. Notwithstanding, there is always potential for a non-transponder-equipped aircraft to inadvertently enter the TMZ; once in this area, the aircraft radar return would not be clearly presented to the radar controller, and any opportunity to provide separation from other (transponding) aircraft in the area would be lost. In order to assure effective and expeditious ATS provision within and around the TMZ, it is considered that an additional lateral buffer for ATS purposes is necessary to mitigate the potential navigation error that might occur whenever pilots of nontransponding aircraft fly close to the TMZ and the area of PSR return suppression. Such a buffer zone would provide time for ATC to provide avoiding action to aircraft operating within the TMZ but close to its boundary, if required. This is particularly the case when unknown aircraft approach the proposed TMZ from the west where they may be operating close to the lateral and/or vertical limits of Warton PSR radar cover. Thus, it is concluded that an additional volume of airspace should be added to the surface footprint of the wind farms themselves to cater for TMZ infringements, allowing ATC the opportunity to spot a potential infringement as the aircraft approaches the airspace. The Warton PSR requires 30 seconds to establish and display an aircraft track (6s per sweep with the track displayed on the 5 th sweep). Considering the worst-case scenario, where in Class G airspace, General Air Traffic (GAT) can travel up to speeds of 250 knots (kts) (4 NM/min), the Warton radar would therefore require 3.71 km (2 NM) to create a coherent foreground track. It is therefore logical to implement a 3.71 km (2 NM) lateral buffer zone around the TMZ required directly over the wind farms, in order to ensure that tracks are well initiated and known to ATC as they may approach the zone. Due to the proximity of the existing Morecambe Bay Offshore Wind Farms to the Walney Extension, the TMZ would encompass all these wind farms. This would avoid issues with visual confusion from the air, difficulty in navigation chart interpretation and visual depiction on ATC video display screens. Figure 3 below illustrates the airspace at Morecambe Bay, and a potential TMZ including a 2 NM buffer zone around the Morecambe Bay Offshore Wind Farms. 30
Figure 3 Walney Potential TMZ including 3.71 km (2 NM) Buffer Zone Reproduced from CAA digital map data Crown copyright 2014. UK IAIP ENR By way of comparison to other offshore wind farm mitigations, the TMZ around the London Array, now administered by Southend ATC, also has a buffer zone of 2 NM (3.71 km). 6.3.2 Vertical extent of the TMZ It is proposed that the TMZ should extend from sea level up to FL100 (10,000 ft) above the turbines, since transponder carriage within the airspace above is already required 7. The co-ordinates for the nine corners of the proposed TMZ (with buffer zone) are given in Annex A3, together with the proximity of the TMZ to military and civilian aerodromes. 6.3.3 Hours of operation of the TMZ Under normal UK Integrated Aeronautical Information Package (IAIP) arrangements, the operating hours of a particular airspace segment established for ATS purposes are linked to the operating hours of the associated ATS Unit. Hence, DONG and Warton propose that Warton ATC is the TMZ Control Authority and TMZ activation coincides with the Warton LARS hours (Mon-Thu 07:30-19:00; Fri 07:30-17:00 Local Time). The information will be captured within the UK IAIP, noting the LARS frequency and timings as well as the boundary of the TMZ. Activation 24/7 is discounted as overly burdensome as 24/7 operation would require the employment of another Controlling Authority (when Warton is not operating). However, Warton sometimes operate outside these hours, and at weekends, thus Warton propose that 7 Gliders have notified exemptions to this requirement 31
Notices to Airmen (NOTAM) 8 promulgate associated exceptions to the TMZ activation. 6.4 Impact of the TMZ on military operations No impact on military operations has been identified since the majority of UK and European-based military aircraft carry and operate SSR transponders, and in most cases, these are Mode S compatible. The only UK military aircraft types that are not transponder equipped are gliders. It is considered that military gliders are unlikely to operate as far offshore as the proposed TMZ and so would be unaffected by the TMZ requirements. 6.5 Impact of the TMZ on light GA operations All aircraft operating on Public Transport flights within UK airspace are required to be equipped with, as a minimum, Mode S Elementary transponders. It can be assumed that the majority of General Aviation (GA) aircraft over 5,700 kg Maximum Total Weight Authorised (MTWA) are likely to be transponder equipped: such aircraft types, which can be used for public transport operations, are likely to operate from time to time within Class A, C or D CAS (where carriage of transponders is mandatory). Whilst not prohibited from operating over water, the majority of pilots of light aircraft (sports and recreation) prefer to minimise their over-water flight time. Warton ATC note that the majority of GA operating around the periphery of Morecambe Bay operate SSR transponders and follow the coastlines applying the Right-Hand Traffic Rule 19 9 (this has been confirmed by an on-going survey of traffic behaviour near the Morecambe Bay Offshore Wind Farms). A pilot following a line feature (a railway, road, river or coastline etc.) must fly so that the line feature is on his LEFT, unless the aircraft is flying in CAS and has been instructed otherwise by an Air Traffic Control Unit. This rule ensures separation between two aircraft following the same line feature but flying in opposite directions as both aircraft will be flying to the right of the line feature. Notwithstanding the transponder mandate within a TMZ, provision exists within the TMZ Rules for conditional access by non-equipped aircraft by prior arrangement with the appropriate ATSU (Controlling Authority), in this case Warton ATC, and the maintenance of two-way radio contact, It is recognised that the majority of locally based light aircraft are, or will be, transponder equipped. Conditional access to the TMZ airspace by non-transponder equipped aircraft is available by radio and it is anticipated that the impact of a TMZ on light GA operations, including glider, microlight and balloon operations, would be minimal as these types are unlikely to be operating far offshore. 8 NOTAMs cover short duration or temporary changes or short notice permanent changes. They contain information concerning the establishment, condition or change in any aeronautical facility, service, procedure or hazard, the timely knowledge of which is essential to personnel concerned with flight operations. 9 CAP 393 [Ref 3]. Air Navigation: The Order and the Regulations (ANO). 32
6.6 Impact of the TMZ on Offshore Helicopter Operations As outlined in Section 6.5 above, aircraft likely to be affected by the proposed TMZ are those with an MTWA of less than 5,700 kg, as above this weight the aircraft are likely to be used for public transport operations and therefore transponder equipped. Offshore helicopter types are categorised into the following MTWA groups: Extra Heavy Twin >20,000 kg (e.g. Chinook); Heavy Twin >5,700 kg (e.g. Bell 214ST, Super Puma, EC225, S61 and S92); Medium Twin 2,730 to 5,700 kg (e.g. Dauphin, EC155, S75 and AW139); and Light Twin <2,730 kg (e.g. Bo105). The helicopters operated by Bond Offshore Helicopters in the Morecambe Bay area are Medium Twin aircraft equipped with a transponder. 6.7 Impact of the TMZ on Advisory Route (ADR) W2D In line with the CAA s intention to remove Class F airspace within the UK, it is highly likely 10 that the ADR W2D will be removed and the Class F Advisory Route will revert to Class G airspace. Therefore, there will be little or no impact on traffic utilising W2D. 10 Civil Aviation Authority INFORMATION NOTICE Number: IN 2014/085: "Class F airspace is planned to be replaced on an AIRAC date no later than 13 November 2014 (AIRAC 12/2014), the target implementation date being 18 September 2014 (AIRAC 10/2014). The actual implementation date will be confirmed in the CAA s decision letter to industry." 33
7 Environmental and Economic Considerations of a TMZ Overall, it is anticipated that the environmental impact of the proposed TMZ will be neutral within the three major categories of noise, fuel burn and local air quality. 7.1 Overview This section discusses the effects of the proposed airspace change on the environment in terms of noise pollution, fuel burn and local air quality. In any airspace decision-making, the CAA must consider the environmental impact of aviation and the disturbance caused to the public. The airspace within which the introduction of a TMZ is proposed lies off shore within Class G airspace and lies greater than 1.85 km (1 NM) from the coastline. Notwithstanding that the proposed TMZ airspace is not CAS, and no aircraft operations are excluded from it, it is possible nonetheless that some GA operators might elect to route on or closer to shore to avoid the TMZ requirements rather than routing offshore through the TMZ. As airspace activity in Class G airspace is not routinely monitored, it is not possible to gauge or anticipate those flights that would elect to re-route simply because of the TMZ, even though a TMZ itself does not inhibit flight operations. However, it is understood that the large majority of transit GA in the area of the proposed TMZ remain close (within 1.85 km/1 NM) to the coastlines and has been confirmed by a survey of traffic behaviour near the existing Morecambe Bay Offshore Wind Farms. 7.2 Impact of noise It is expected that the noise impact immediately after implementation is not likely to be significantly different from the pre-implementation situation. 7.3 Anticipated level of fuel burn/co 2 emissions It is recognised that aircraft contribute to carbon dioxide (CO 2) emissions and this has an impact on climate change. A responsible approach to airspace planning is to balance the competing demands and ensure that the most direct routes possible are utilising optimal aircraft performance, as this will minimise fuel burn and emissions and therefore reduce the impact upon climate change. Access to the activated TMZ airspace (Mon-Thu 07:30-19:00 Local; Fri 07:30-17:00 Local Time) will be available whenever and wherever practicably possible; little displacement or re-routing is anticipated and any re-route taken is likely to be insignificant. No re-routing will be required outside the TMZ activation times. This airspace proposal ensures sustainability of the efficient routing of aircraft. 34
The very small amount of non-transponder, non-radio, equipped aircraft activity recently observed in the Walney area by a survey of traffic behaviour near the existing Walney Wind Farms (1 and 2) and the Walney Extension area, indicates that the TMZ would displace a very small amount of airborne traffic. 7.4 Anticipated effect on local air quality CAP 725 [Ref 1], Appendix B, Annex 8 identifies that local air quality at ground level remains largely unaffected by aircraft emissions that take place above 3,000 ft Above Ground Level (AGL) because dispersion reduces concentration levels for these emissions. It is understood that in the context of local air quality, the overall objective under CAP 725 is to determine whether the proposed airspace changes will exceed any statutory air quality standards, and if so, what contribution the airport operations make towards such departures. The proposed TMZ lies offshore and it is not anticipated that Air Quality Standards will be breached. 7.5 Environmental implications Overall, it is anticipated that the environmental impact of a proposed TMZ will be neutral within the three major categories of noise, fuel burn and local air quality. It is not anticipated that the proposed TMZ will reduce the environmental impact of aviation in the subject airspace; however, it is reasonable to expect that the environmental impact of aviation in the subject airspace will not worsen because of the change. Both tranquillity and visual intrusion are unlikely to be impacted by GA displacement and, in the worst case, the numbers of those negatively affected are not likely to increase significantly upon implementation. 7.6 Economic benefit The establishment of the TMZ is an efficiency measure to enable Warton PSR-based ATS to be sustained near the Morecambe Bay Offshore Farms. Any economic benefit is derived mainly from enabling the wind development to proceed and the avoidance of protracted re-routing of CAT, GAT and military aircraft operating to and from Warton, Barrow/Walney Island Aerodrome and BIA. 35
8 Next Stages Once the stakeholder consultation has been completed and any issues arising have been dealt with accordingly, DONG Energy will submit a formal Airspace Change Proposal to the Airspace Regulation (AR) of the CAA detailing the case for the proposed TMZ. 8.1 Overview This section summarises the consultation process and outlines the next steps to be taken following the consultation period, with a view to Airspace Change Proposal submission to the CAA. 8.2 Consultation summary This document has presented the plans proposed by DONG Energy to maintain efficient operations and to mitigate for the effects that the Walney Extension may have on Warton s flying activities and ATS services. It is proposed that this will be achieved through the establishment of a TMZ, with approval to operate SSR-only, and with Warton PSR suppression. The secondary objective of the mitigation solution is to minimise any known airspace impacts. Consequently, the proposed TMZ design is intended to be sympathetic to existing airspace structure, traffic patterns and local ATC operational norms. DONG Energy is consulting widely on its proposed solution in order to identify any unforeseen effects. It is anticipated that overall environmental impacts of the proposed airspace change will be neutral within the three major categories of noise, fuel burn and local air quality. Both tranquillity and visual intrusion are also unlikely to be impacted. It is considered that any economic benefit is derived mainly from enabling the wind development to proceed and the avoidance of protracted re-routing of CAT, GAT and military aircraft operating to and from Warton, Barrow/Walney Island and BIA. 8.3 Consultation results All consultee responses will be recorded and closely monitored as they are received. Individual responses will not be acknowledged unless the consultee requests an acknowledgement. However, if any clarifications are required, consultees may be contacted, or may contact Osprey, for further detail in order to provide an informed response. All objections to the proposal will be considered carefully and a response will be provided to the consultee. If further clarification is required on this consultation, please address these to walney.tmz@ospreycsl.co.uk via email. On closure of the consultation period, feedback will be provided to all consultees by means of a report that will highlight the key themes that arose and how DONG 36
Energy will incorporate those concerns into their plans. A Consultation Feedback Report will be published on the DONG Energy website. The records of consultation correspondence and the analysis of the results will be presented in the Consultation Report, which will be presented to the CAA as part of the overall airspace change submission. 8.4 What happens next? Once the stakeholder consultation has been completed modifications might have to be made in light of responses; DONG Energy will submit a formal Airspace Change Proposal to the AR of the CAA detailing the case for the proposed TMZ once analysis of all responses has been completed. It is a requirement of the consultation process that DONG Energy will provide the CAA with full details of the consultation (including copies of responses and correspondence) together with all documentation necessary for the promulgation of the proposed TMZ. The CAA requires a 16-week period to conduct its own internal analysis of the final proposal and consultation results, before arriving at a Regulatory Decision. Should the CAA, accept the Airspace Change Proposal, without the need for further design optimisation or analysis, DONG Energy suggest that the implementation of the TMZ would take place on a single date to coincide with the full operational date of the Walney Extension; this is expected to be late 2017. Figure 4 Proposed TMZ ENR 6.1 Entry Reproduced from CAA digital map data Crown copyright 2014. UK IAIP ENR 37
DONG Energy proposes to detail the TMZ within the UK Mil AIP Warton AD2 entry, in UK IAIP ENR GEN 1.5 (Aircraft Instruments, Equipment and Flight Documents) and ENR 6.1 (Morecambe Bay/Liverpool Bay Gas Field Helicopter Support Flights, Figure 4 above). This would serve the purpose of formally notifying the TMZ. 38
9 References Reference Name Origin 1 CAP 725 CAA Guidance on the Application of the Airspace Change Process Third Edition (corrected) April 2007 2 DAP Policy: Transponder Mandatory Zone (TMZs) 17 April 2009 3 CAP 393 Air Navigation: The Order and the Regulations Third Edition (incorporating amendments up to 1/2012) 10 August 2012 4 CAP 764 CAA Policy and Guidelines on Wind Turbines 5 CAP 493 Manual of Air Traffic Services Part 1 Fifth Edition (incorporating amendments up to 6 March 2014) CAA ISBN 978 0 11790 739 3 CAA CAA ISBN 978 0 11792 658 5 CAA ISBN 978 0 11792 634 9 CAA ISBN 978 0 11792 859 6 Table 1 Table of References 39
A1 Walney Extension Offshore Wind Farm Line of Sight Assessment A1.1 Overview This Annex contains the results of the radar Line of Sight (LoS) assessment for the Walney Extension Offshore Wind Farm wind turbines in respect of the PSR located at Warton Aerodrome (owned and operated by BAE Systems Ltd). The analysis was carried out on specific points (labelled 1-9) on the fringes of the Walney Extension boundary. An OS map showing the relative positions of these boundary points accompanies this assessment. A1.2 Boundary Details Boundary Point WGS84 Blade Tip Height (m) Latitude Longitude Point 1 N54 08 01.9 W003 54 57.2 223 Point 2 N56 06 38.7 W003 54 55.2 223 Point 3 N54 04 01.1 W003 46 29.9 223 Point 4 N54 00 05.1 W003 33 53.2 223 Point 5 N54 00 35.7 W003 31 22.5 223 Point 6 N54 03 25.8 W003 38 23.9 223 Point 7 N54 05 27.3 W003 39 59.4 223 Point 8 N54 06 11.2 W003 39 09.7 223 Point 9 N54 09 22.2 W003 49 24.1 223 Point 10 N54 07 54.5 W003 53 34.2 223 Table 2 Summary of Turbine/Boundary Details for the Walney Extension LoS Assessment 40
A1.3 Boundary Graphic Figure 5 Illustration of the Walney Extension Boundary Points A1.4 LoS Assessment Methodology Over the distance between a PSR and a wind turbine, radar signal will attenuate (lose power) and be refracted and diffracted (change direction). We have predicted likely radar performance characteristics for the assessed radar station to model the radar signal. The intervening terrain and signal path between the assessed radars and the Walney Extension boundary points have been modelled using ATDI ICS LT. For LoS analysis, the terrain path has been assessed to determine whether the intervening terrain is likely to be significant enough to prevent the turbines/boundary points being detectable by radar. We assess the direct LoS and the 1 st Fresnel zone, an elliptical zone around the direct LoS where the radio waves remain strong. Objects that infringe upon the Fresnel zone or the direct LoS will cause the signal to diffract and attenuate. The effect of diffraction means that the direct transmitted radio waves and those in the upper 1 st Fresnel zone can still reach the turbine and be returned to the radar receiver, hence why it is not always obvious that terrain shielding is sufficient. LoS diagrams are included with this briefing note to support our opinion on the likely detectability of the Walney Extension development by the assessed radar stations. Within the diagrams, the signal propagation is modelled from the radar (far most left) to the turbine blade tip (far most right). The black line in the diagram with area underneath filled in dark brown represents the terrain profile between the radar and the boundary point. The red line in the diagram represents the direct LoS between 41
the two locations. The orange ellipse around the direct line of sight represents the 1 st Fresnel zone. The light blue and magenta lines are not relevant to this assessment. Although every care is taken during the LoS modelling and analysis process, modelling limitations and assumptions obviously lead our conclusions to be based on theoretical results. The results are therefore indicative, and actual radar performance may differ from this analysis. A1.5 LoS Assessment Results The LoS assessment has been carried out based on nine boundary locations and a tip height of 223 m Above Mean Sea Level (AMSL) as requested. Osprey concludes one of four opinions following line of sight assessment on the potential detectability of a wind turbine/boundary point by radar: Yes the location is highly likely to be detected by the radar: direct line of sight exists between the radar and the wind turbine/boundary point; Likely the location is likely to be detected by the radar at least intermittently: direct line of sight skims terrain/only a small part of the 1 st Fresnel zone is blocked; Unlikely the location is unlikely to be detected by the radar but cannot rule out occasional detection: around 60% or more of the 1 st Fresnel zone upper limit is blocked; and No the location is unlikely to be detected by the radar as significant intervening terrain exists: entire 1 st Fresnel zone of signal is blocked. As all the boundary points for Walney Extension produce the same result and all are highly likely to be detected by the Warton PSR, the image for Point 5 only will be shown in this section to provide an indicative result of Osprey s findings for each point. A full set of LoS profiles for all the analysed points will be available on request. Figure 6 shows the LoS profile between the Warton PSR and Point 5, the closest point to the Warton PSR. This result is indicative of that for all Points assessed; all locations are highly likely to be detected by the Warton PSR at a height of 223 m amsl. The assessment result is Yes for all Points. A full set of LoS profiles is available on request. Figure 6 LoS Profile between Warton (PSR) and Point 5 42
A1.6 Conclusion In conclusion, with an assumed blade tip height of 223 m AMSL, the boundary points for the Walney Extension are highly likely to be detected by the PSR at Warton Aerodrome due to the lack of intervening terrain that exists between the radar and the proposed development. 43
A2 West of Duddon Sands Line of Sight Assessment A2.1 Overview This Annex contains the results of the radar LoS assessment for the West of Duddon Sands (WoDS) offshore wind farm in respect of the PSR located at Warton Aerodrome. The analysis was carried out on specified points (labelled 1-5) on the fringes of the WoDS wind farm boundary. An OS map showing the relative positions of these boundary points accompanies this assessment. A2.2 Boundary Details Boundary Point WGS84 Blade Tip Height (m) Latitude Longitude Point 1 N54 00 07.0 W003 33 25.6 175 Point 2 N53 56 40.9 W003 29 14.6 175 Point 3 N53 56 36.4 W003 25 17.2 175 Point 4 N53 58 18.6 W003 22 42.6 175 Point 5 N54 01 44.0 W003 26 34.3 175 Table 3 Summary of Turbine/Boundary Details for WoDS LoS Assessment 44
A2.3 Boundary Graphic Figure 7 Illustration of the WoDS Boundary Points A2.4 LoS Assessment Methodology As previously explained in Annex A1 for the Walney wind turbine development, the same methodology was applied to an assessment on the wind turbine development at WoDS. A2.5 LoS Assessment Results The LoS assessment has been carried out based on five boundary locations and a tip height of 175 m ASL as requested. Osprey concludes one of four opinions following LoS assessment on the potential detectability of a wind turbine/boundary point by radar: Yes the location is highly likely to be detected by the radar: direct LoS exists between the radar and the wind turbine/boundary point; Likely the location is likely to be detected by the radar at least intermittently: direct line of sight skims terrain/only a small part of the 1st Fresnel zone is blocked; Unlikely the location is unlikely to be detected by the radar but cannot rule out occasional detection: around 60% or more of the 1 st Fresnel zone upper limit is blocked; and No the location is unlikely to be detected by the radar as significant intervening terrain exists: entire 1 st Fresnel zone of signal is blocked. 45
Figure 10 shows the LoS profile between the Warton PSR and Point 4, the closest point to the Warton PSR. This result is indicative of that for all Points assessed; all locations are highly likely to be detected by the Warton PSR at a height of 175 m amsl. The assessment result is Yes for all Points. A full set of LoS profiles is available on request. Figure 8 LoS Profile between Warton (PSR) and Point 4 A2.6 Conclusion In conclusion, with an assumed blade tip height of 175 m AMSL, the boundary points for the WoDS wind farm are highly likely to be detected by the PSR at Warton Aerodrome due to the lack of intervening terrain that exists between the radar and the proposed development. 46