STANSTED AIRSPACE Proposal for Implementation of a Transponder Mandatory Zone STAKEHOLDER CONSULTATION

Transcription

1 STANSTED AIRSPACE Proposal for Implementation of a Transponder Mandatory Zone STAKEHOLDER CONSULTATION Reproduced by permission of CAA and Ordnance Survey Crown copyright All rights reserved NATS, , 2009 Reference: \StanstedTMZ\StanstedConsutationDocument Issue 1, published 12 January 2009

2 Executive Summary This document explains changes proposed by NATS to airspace surrounding Stansted. It contains information from which stakeholders identified as consultees in this process can gain an understanding of the proposal and hence give informed feedback. This proposal seeks to establish defined areas known as transponder mandatory zones (TMZ) under portions of the Stansted airspace. Aircraft flying within the TMZs will be required to have and operate a working altitude reporting transponder. This is a change to the requirement for equipment carriage and operation; there are no changes proposed to the dimensions of the airspace, and IFR (Instrument Flight Rules) air traffic using Stansted Airport would be unaffected. Aircraft not equipped with a transponder, would have to comply with locally agreed restrictions or avoid the airspace. This proposed change is not associated with the Terminal Control North (TCN) airspace development currently under review by NATS following consultation in Neither is it associated in any way with the BAA Stansted planning application for a second runway. If accepted, this airspace change will enhance safety, by providing a more informed air traffic control (ATC) environment below the Stansted Control Area (CTA), allowing ATC and airborne safety systems to see the altitude of aircraft operating there. This helps to reduce the possibility of infringements of controlled airspace and to ensure that safe separation is maintained. This consultation follows a process agreed by the Civil Aviation Authority (CAA) which gives consideration to the nature of this proposed airspace change. In accordance with the guidance (Ref.1), NATS is consulting with aviation stakeholders including representatives of General Aviation. The CAA guidance is that this proposed change does not require consultation with environmental stakeholders since it is limited to a change in the technical requirements for flying in the airspace. The period of consultation commences on 12 January 2009 and closes on 06 April 2009 (12 weeks). If the proposal is approved by the CAA, NATS will implement the airspace change at an appropriate opportunity. Please send any comments on the airspace change proposal to: Stansted TMZ Consultation Co-ordinator NATS, Corporate & Technical Centre Mailbox 5a 4000 Parkway, Whiteley, Fareham, Hampshire, PO15 7FL Or via to stanstedtmz@nats.co.uk Stansted TMZ Consultation - Issue 1 (12 January 2009) Page 2 of 29

3 Table of contents Executive Summary Introduction The purpose of consultation The scope of consultation What happens next? Development Objectives Proposed airspace changes in relation to existing airspace... 7 Figure 1: Existing airspace Justification Safety Rationale Necessitating the Change Design options Safety Improvement Environmental effects Impact on aviation stakeholders Table 3: Proposed change to the airspace rules Next steps References Glossary Appendix A: List of Stakeholders Appendix B: Overview of Structure and Operation of UK Airspace Appendix C: A Brief Outline of Air Traffic Control Principles Appendix D: ICAO Airspace Classification Appendix E: HM Government Code of Practice on Consultation Stansted TMZ Consultation - Issue 1 (12 January 2009) Page 3 of 29

4 1. Introduction 1.1 Air travel is integral to the success of the UK economy and has become an important part of modern life; for business or pleasure, more of us are flying more frequently than ever before. More flights mean busier skies, and how we use and manage our airspace is a matter of great responsibility. The passage of aircraft above us is managed by air traffic control. Air Traffic Control (ATC) ensures safety and keeps aircraft flowing efficiently. The more efficient the system can be made, the more we can reduce the impact of aviation on the environment, and make advances in safety. For these reasons, NATS undertakes constant reviews of UK airspace and, when necessary, recommends changes to how it should be managed. 1.2 This consultation document relates to a proposal to require the carriage and operation of altitude reporting transponders by establishing transponder mandatory zones (TMZs) in the Class G airspace below portions of the Stansted Control Area (CTA). As the sponsor of this change, NATS is seeking feedback on the proposal before submitting it to the UK airspace regulator, the Civil Aviation Authority (CAA), for consideration and decision. The feedback received during this consultation will influence the final design that is submitted to the CAA. The CAA will decide on the merits of the proposal, and whether or not the airspace change can be introduced. What is NATS? 1.3 NATS provides air traffic control services to aircraft flying through UK airspace, over the eastern part of the North Atlantic, and at 15 UK airports. Our responsibility is for the safe and efficient management of some of the most complex airspace in the world. In 2007 NATS handled almost 2.5 million flights carrying more than 235 million passengers. 1.4 Air traffic control services for aircraft travelling between airports are known as en route air traffic control services. NATS provides en route air traffic services under licence to the CAA. This licence requires us to ensure the provision of a safe service, make the most efficient use of airspace and be capable of meeting reasonable levels of future demand. 1.5 Whilst NATS is responsible for providing a safe and efficient service, we do not control the demand placed upon UK airspace, the numbers of flights or the times of flights. These are determined by the demand for air travel from businesses and the general public. The Government s aviation policy and the airspace policy set out by the Directorate of Airspace Policy at the CAA provide the framework for meeting anticipated future demand. 1.6 To find out more about NATS go to Why review the way airspace is managed? 1.7 There are a number of reasons for reviewing the way airspace is managed: Safety. Our overriding priority is to ensure the safe movement of aircraft. As the skies become busier we review the way airspace is managed to maintain or enhance our high safety standards. Delay. We are required under our licence from the CAA to be capable of meeting any reasonable level of overall demand. Busier, congested skies lead to flight delays which airspace change proposals are designed to address. Environment. We recognise the impact of aviation on the environment and a key aim of the airspace change process is to mitigate that impact wherever possible. Stansted TMZ Consultation - Issue 1 (12 January 2009) Page 4 of 29

5 2. The purpose of consultation 2.1 The primary purpose of the consultation exercise is to allow stakeholders to consider the proposal and provide NATS with feedback. 2.2 At the end of the consultation NATS must demonstrate to the CAA that the best balance possible has been achieved between conflicting demands and objectives. The CAA requires that changes are made only after consultation, when it is clear that an environmental benefit will accrue or where airspace management considerations and the overriding need for safety allow for no practical alternative (Ref. 1). It is on this basis that the CAA will decide whether or not to approve the proposed change. NATS first priority is safety and the establishment of TMZs seeks to provide a higher degree of safety assurance within this area of airspace. 2.3 This consultation has been carried out in accordance with guidance provided by the Government and the CAA. (See Appendix E.) 2.4 The details of this consultation exercise have been agreed in principle with the CAA and meet the requirements of their airspace change process (Ref 1). This includes the rationale for who should be involved in the consultation on this proposal. Appendix A lists the stakeholders identified to be involved in this consultation, although feedback is also welcomed from other interested parties. 2.5 Any matters raised during the consultation period that have not been adequately considered during the development of the proposed design may require NATS to make changes to the proposal. Any such changes may require further consultation. 3. The scope of consultation Environmental stakeholders 3.1 The proposal is limited to a change in the mandatory equipment required to be carried by aircraft operating in the Class G airspace beneath the Stansted CTA. This proposal would not change the patterns of flights (either IFR flights using Stansted Airport or recreational aircraft operating within the Class G airspace under the Stansted CTA). Hence the CAA has agreed that consultation with environmental groups is not required for this proposal. Aviation stakeholders 3.2 Groups representing airspace users such as the military, general aviation (such as recreational flyers) and commercial air transport are included in this consultation. A full list of stakeholders included in the consultation is given in Appendix A. 4. What happens next? 4.1 The period of consultation commences on 12 January 2009 and closes on 06 April 2009 which is a period of 12 weeks. 4.2 When responding, consultees must specify the grounds for supporting or objecting to the proposal. Feedback in favour of, or objecting to, the proposal without supporting reasons will be reported to the CAA but NATS will not be in a position to consider the merits of the feedback. NATS will analyse feedback received during the consultation. The feedback will be analysed by NATS and summarised in a post-consultation report which will be made publicly available. Stansted TMZ Consultation - Issue 1 (12 January 2009) Page 5 of 29

6 4.3 The post-consultation report will be made available via the NATS website and notification will be sent to the consultees identified in Appendix A. This report will also update stakeholders on subsequent phases of the development process such as any further consultation that may be required, the submission of a formal proposal to the CAA and its consideration of that proposal. 4.4 Details of the consultation exercise will form part of the airspace change proposal that NATS will submit to the CAA for consideration and decision. Copies of all responses will be provided to the CAA, including any personal information contained in them, except where the respondent requests otherwise. If the proposal is accepted by the CAA, NATS will implement the airspace change at an appropriate opportunity. 4.5 This implementation date may be affected by the following: the length of time taken by the CAA in reaching its decision; the need for any revision of the airspace change proposal identified by the consultation process and any further period of consultation required for such revisions and; operational constraints. 4.6 Responses should be sent to: Stansted TMZ Consultation Co-ordinator NATS, Corporate & Technical Centre Mailbox 5a 4000 Parkway, Whiteley, Fareham, Hampshire, PO15 7FL Or via to stanstedtmz@nats.co.uk Stansted TMZ Consultation - Issue 1 (12 January 2009) Page 6 of 29

7 5. Development Objectives Safety 5.1 The primary objective for this change is enhanced safety. The current airspace design in the vicinity of Stansted airport is such that IFR flights using the airport must fly through a volume of controlled airspace that overlies portions of uncontrolled (Class G) airspace. Radar returns seen by air traffic control within the lateral boundaries of the Stansted CTA which do not display an altitude via a transponder may be assumed by ATC to be flying below the controlled airspace 1. In cases where an aircraft without a transponder makes an unauthorised penetration of controlled airspace (controlled airspace infringement), ATC will not be aware of this unless the aircraft enters controlled airspace that is established from ground level. It is possible that such infringements may not be recognised for some considerable time (or at all). The potential for a loss of separation is therefore considerably higher than when aircraft are operating with altitude reporting (Mode-C) transponders. Hence at present, according to our safety database, this airspace carries a risk from infringements by nontransponding aircraft or those that do not display altitude information, which could lead to a loss of aircraft separation. As the ATC service provider for the airspace serving Stansted airport, NATS is therefore proposing that the portions of the Class G airspace in question be established as TMZs. 5.2 For IFR aircraft operating to/from Stansted airport, this airspace is used during the approach and departure phases of flight, during which time the pilots workload is at its highest. This proposal would not result in any change to the operation or routing of IFR aircraft using the airport. Delay 5.3 This change does not seek to improve capacity or reduce delay, and is not expected to have any impact on these. Environment 5.4 The proposed change would not affect the profiles of flights in the region. IFR flights would fly the same routes and vertical profiles as today. There is not expected to be any change in noise exposure, CO 2 emissions or local air quality. Other airspace users 5.5 Light aircraft/sport aviation would be permitted to fly through the airspace, but would be required to fit and operate altitude reporting transponders. NATS understands that this proposal may pose some difficulty for certain aircraft operators who are unable technically or financially to fit transponders to aircraft that do not currently have one. We would work with local airfields and national organisations to develop procedures and letters of agreement to accommodate such aircraft as far as is safe and practical. 6. Proposed airspace changes in relation to existing airspace 6.1 The areas labelled A-D in Figure 1 below, show the existing airspace where aircraft can fly without fitting or operating transponders. The areas labelled A-D are currently Class G airspace from the ground to the base of controlled airspace as indicated on the map. 6.2 The change proposes that these areas of airspace remain classified as Class G airspace, but are designated as Transponder Mandatory Zones. 1 CAP493: Manual of Air traffic Services Part 1. Section 1, Chapter 5 Stansted TMZ Consultation - Issue 1 (12 January 2009) Page 7 of 29

8 Figure 1: Existing airspace D A B C Reproduced by permission of CAA and Ordnance Survey Crown copyright All rights reserved NATS, , 2009 Subsequent text in this document refers to areas A-D in figure 1 above. Stansted TMZ Consultation - Issue 1 (12 January 2009) Page 8 of 29

9 7. Justification 7.1 The controlled airspace around the London area is complex and particularly vulnerable to infringements. Infringements by aircraft not displaying height information are a safety risk because they are not recognised by existing technical safety systems and the aircraft are often deemed to be outside controlled airspace. However, when aircraft are using a transponder with altitude readout, any infringement can be monitored, and systems which act as safety nets can alert ATC. This enables ATC to react immediately to mitigate the situation. 7.2 A number of activities and technical initiatives have been undertaken to reduce the number and mitigate the effects of controlled airspace infringements. However at present, air traffic controllers visual scan of the radar remains the only way of spotting infringements by non-transponding aircraft. This scan is however rendered ineffective since any tracks not showing altitude information may be assumed to be legitimately below controlled airspace, when in fact they may be infringing the airspace % of NATS highest risk incidents result from infringing aircraft which either have no transponder fitted or do not have one switched on. A further 25% have a transponder which displays Mode-A only (No altitude information). Without Mode-C (altitude information); Airborne safety nets such as Traffic Alert & Collision Avoidance System (TCAS) will not give any indication or offer any resolution to potential loss of separation if an infringement occurs. Like TCAS, the controllers Short Term Conflict Alert (STCA) will not highlight a risk of loss of separation without Mode-C. NATS Controlled Airspace Infringement Tool (CAIT) will not operate without altitude information below the base of controlled airspace. 7.4 If an unknown aircraft infringes controlled airspace and carries only a Mode-A transponder (no altitude information), or is visible only through a primary radar return, ATC must seek to achieve lateral separation. Because of the unpredictable trajectories of the uncontrolled traffic, there is an increased possibility that avoiding action may have to be issued to IFR traffic in order to ensure continued safe separation. This can lead to increased ATC and pilot workload in busy airspace and during a busy phase of flight, which in turn can result in the disruption of operations at the airport. 7.5 A defined area of airspace within which the carriage and operation of a Mode-C transponder is compulsory is known as a Transponder Mandatory Zone (TMZ). A TMZ around the most frequently infringed airspace would provide enhanced protection. This could be further enhanced by improvement to the CAIT to recognise primary only contacts. When an aircraft enters the TMZ without an altitude reporting transponder, the CAIT will highlight the radar return to the controller. This would give ATC an earlier indication of possible infringements and allow them to take appropriate action. 7.6 This proposal is aligned with the joint CAA/NATS/MoD Airspace & Safety Initiative which includes addressing airspace infringements, transponder carriage and the use of deemed separations. Stansted TMZ Consultation Issue 1 (12 January 2009) Page 9 of 29

10 8. Safety Rationale Necessitating the Change 8.1 The proposed transponder mandatory zones in the vicinity of Stansted are motivated solely on the basis of improving the safety levels for users of the airspace. 8.2 The airspace concerned is currently Class G within which flight is permitted without ATC knowledge. With the current risk from infringements (See paragraph 10.3), this environment is not considered to provide adequate protection to aircraft operating to and from Stansted airport, as ATC is unable to ascertain the altitude of aircraft flying in the region derived from primary radar contacts, or Mode-A only transponders. 8.3 Owing to the nature of airspace permissions, ATC assumes that all non Mode-C tracks are below the base of the Class D airspace. Hence they will only initiate avoiding action to flights in receipt of an ATC service if they have any other reason to believe that an aircraft is lost or making an unauthorised entry into controlled airspace. 8.4 Where ATC has information that an aircraft is lost or making an unauthorised entry into controlled airspace, they are required to ensure lateral separation of 5NM or more against primary-only radar tracks (i.e. no altitude information). For Mode-C derived tracks (displaying altitude information), that separation can be either 5NM laterally, or 5000ft above the unverified Mode-C readout. In cases where the pilot can be contacted and the aircraft altitude verified, ATC may reduce the separation between aircraft under their control and the infringing aircraft. 8.5 Where this avoiding action has to be issued to IFR aircraft, it will be during a high workload stage of the flight. ATC would be vectoring IFR arrival aircraft towards the final approach, and the pilots workload is at its highest. Infringements by non-transponding aircraft at this stage of approach are less likely to be visually acquired by pilots as they are busy configuring the aircraft towards achieving a stable final approach. 8.6 It is important to note that because they are difficult to detect, primary only infringements tend only to be detected when they result in a loss of separation. 8.7 The current situation can result in late detection of controlled airspace infringements by non-transponding aircraft. This in turn increases ATC workload and complexity through the need to issue avoiding action alerts, increased radio communications with the aircraft (or multiple aircraft), and the disruption and subsequent rearranging of the final approach spacing pattern. This disruption can, at times, lead to airborne holding of subsequent aircraft in the sequence. All airborne holding requires telephone coordination between the Stansted Radar Controller, the Essex Radar controller and appropriate London Terminal Centre Sector. 8.8 Whilst NATS is highly proactive in training controllers and developing systems to spot controlled airspace infringements, this cannot be guaranteed to be fully effective unless aircraft are suitably equipped. There are five levels of safety net, which the Stansted ATC radar controller can utilise (in decreasing order): Radar derived Mode-C activating the CAIT Radar derived Mode-C activating STCA to highlight a confliction with another aircraft. Stansted TMZ Consultation Issue 1 (12 January 2009) Page 10 of 29

11 The controller recognising that the combination of altitude and track of an aircraft outside controlled airspace is likely to enter controlled airspace without a clearance. Mode-A transponder equipped aircraft entering a portion of controlled airspace that extends from ground level upwards. Radar derived primary returns entering a portion of controlled airspace that extends from ground level upwards. 8.9 The construction of certain types of small aircraft makes them poorly visible to primary radar. Thus there could be aircraft within the airspace which, if not equipped with a transponder, are not currently visible on radar; hence ATC is not aware of them when vectoring IFR flights in the area There have been losses of separation between IFR flights and infringing aircraft in the Stansted CTA. Establishing a TMZ would prevent such losses of separation from happening in the future NATS Swanwick (Terminal Control), as the controlling authority for the Stansted CTA, believes that the risk posed from infringements by nontransponding aircraft is not acceptable when a technical solution in the form of mandated carriage and operation of mode-a and C transponders would significantly mitigate this risk Figures 2 to 7 below are taken from BAA Stansted s Track Keeping system and are indicative of the actual usage of controlled airspace established around Stansted. A numerical breakdown of traffic is shown in the subsequent table. Plots on Figures 2 to 7 all courtesy of BAA Stansted Ltd. Stansted TMZ Consultation Issue 1 (12 January 2009) Page 11 of 29

12 Figure 2. Plot of all Arrivals to Stansted Runway 23 for August 2007 Figure 3. Plot of Arrivals to Stansted Runway 05 for August 2007 Stansted TMZ Consultation Issue 1 (12 January 2009) Page 12 of 29

13 Figure 4. Plot of arrivals to Stansted runway 23 (31/08/07) Figure 5. Plot of Departures from Stansted runway 23 (31/08/07) Figure 6. Plot of Arrivals to Stansted Runway 05 (22/05/07) Figure 7. Plot of Departures from Stansted Runway 05 (22/05/07) Stansted TMZ Consultation Issue 1 (12 January 2009) Page 13 of 29

14 8.13 Table 1 below illustrates the volume of Stansted airport IFR flights during Table 1: Numbers of aircraft movements at Stansted airport Total Monthly Movements Busiest day Running monthly total January February March April May June July August September October November December Total Taking an August day as an example of a typical busy day, table 2 below illustrates the hourly movement rate for runway 23 during the core daylight hours; Table 2: Typical hourly movement rate, Stansted airport Friday 31 August 2007 (06:00 17:59 hours) Hour (UTC) 23 ARRIVALS 23 DEPARTURES TOTAL 06:00-06: :00-07: :00-08: :00-09: :00-10: :00-11: :00-12: :00-13: :00-14: :00-15: :00-16: :00-17: Stansted TMZ Consultation Issue 1 (12 January 2009) Page 14 of 29

15 9. Design options 9.1 This proposal is simply a change to the requirement for transponder carriage and operation; no alternative airspace design options are presented. However, as the CTA is in four sections, there are different combinations of TMZ that could be introduced as well as options to enable non-compliant aircraft to transit the airspace. It is therefore proposed that the following changes are made in the Stansted ATC region: Designation of portions of class G airspace beneath the Stansted CTA to be designated as Transponder Mandatory Zones Amendments to airspace charts to show clearly the areas where transponder use is mandatory. Option One - do nothing: This option relies on improvements in pilot navigation or on a general voluntary increase in transponder usage. For aircraft which are not fitted with a transponder, the controllers visual scan would still be unable to identify all infringers. Option Two - re-designate all the class G airspace sections (FIGURE 1 areas A,B,C & D) under the Stansted CTA as Transponder Mandatory Zones: This option provides the maximum protection from infringements and the greatest reduction in risk. An increase in the number of aircraft using transponders in the airspace would improve the effectiveness of CAIT and TCAS to augment controllers visual scan. Option Three - Create TMZs in the portions of class G airspace (FIGURE 1 areas B & D) under the Stansted CTA aligned with the airport runway configuration: This option provides some protection from infringements but a smaller risk reduction. An increase in the number of aircraft using transponders in the airspace would improve the effectiveness of CAIT and TCAS to augment controllers visual scan only in the areas described. Non compliant aircraft To provide options for pilots who cannot fit transponders to their aircraft, a crossing service could be established for radio equipped aircraft: In order to transit the airspace, pilots would be required to contact and receive prior approval from a designated air traffic service unit (ATSU). This option would help create a better informed environment and allow more aircraft access to the airspace. NATS accepts that this would increase controller workload For airfields within airspace re-designated as transponder mandatory zones, local operating procedures could be developed to allow continued operation supporting enhanced safety in the airspace. Letters of Agreement (LoA) would describe the procedures required to be followed by non-transponder equipped aircraft, and may require some additional restrictions. 9.3 These proposals are designed specifically to reduce the risk from infringements of the Stansted CTA by non-transponding aircraft. Any future proposals for other airspace would be considered on their own merits and would be subject to the CAA CAP725 process. 9.4 This proposed change is not associated with the Terminal Control North (TCN) airspace development currently under review by NATS following consultation in Neither is it associated in any way with the BAA Stansted planning application for a second runway. Stansted TMZ Consultation Issue 1 (12 January 2009) Page 15 of 29

16 10. Safety Improvement 10.1 NATS has defined an internal measure of safety performance, the Safety Significant Event (SSE) performance scheme. We use our SSE scheme to determine the severity of each event and as our top level indicator of safety performance as well as to help us understand the relative risk in the airspace Based on a safety benefit assessment of SSEs over a four and three quarter year period, NATS has calculated the reduction in risk that can be expected by the introduction of the options described in paragraph 9 above Using the SSE Risk index as a measure, 78% of the infringement risk at Stansted was made up of; 21.5% Primary only infringing aircraft and; 56.5% Mode-A only infringing aircraft. The remaining 22% of the risk was from Mode A & C aircraft It is important to note that because they are difficult to detect, primaryonly infringements tend to be reported only when they result in a loss of separation. Therefore the reporting of primary-only infringements not resulting in incidents is likely to be low, even though the risk from them remains high. Option 1 (no change) As this option offers no improvement in transponder carriage in the airspace, this option offers no reduction in risk. Option 2 (sections A-D in figure 1) This option would reduce the risk from Primary & Mode-A only infringing aircraft at Stansted by 85% and the total infringement risk at Stansted by 65%. Option 3 (sections B & D in figure 1) Option three would reduce the risk from Primary & Mode-A only infringing aircraft at Stansted by 70% and the total infringement risk at Stansted by 55%. However, associating only part of the Stansted CTA with transponder carriage may lead to pilots continuing not to fit or operate the equipment because they do not anticipate flying in the areas designated as TMZs. Therefore, it is probable that there would continue to be infringements from non-transponding aircraft that are detected late or not at all The benefits from Options 2 and 3 include: Enhancing the safety of the overall ATS provided in the vicinity of Stansted Airport by reducing the likelihood that infringements by nontransponding or Mode-A only aircraft go undetected. Removing the assumption that non-transponding or Mode-A only aircraft operating within the lateral boundaries of the Stansted CTA are outside controlled airspace. Stansted TMZ Consultation Issue 1 (12 January 2009) Page 16 of 29

17 11. Environmental effects 11.1 This proposed change is only to the rules for transponder carriage and operation of the airspace. No new routes are proposed. The change is based solely on improved safety, and is not designed to facilitate traffic growth or to increase capacity. There would be no changes to where aircraft fly as a result of the proposed change i.e. no change to routes, flight paths or concentration of aircraft. Some pilots who are unable to retro-fit transponders to their aircraft, or comply with other access procedures will avoid the airspace. However, any dispersed traffic will be free to route anywhere in the other portions of class G airspace. Flight patterns within controlled airspace would be unchanged. It is not expected that people living and working beneath and around the airspace would experience any difference in the over-flying air traffic as a result of this change. Exhaust emissions and fuel burn 11.2 NATS takes the environmental impact of exhaust emissions into consideration when evaluating airspace designs, and seeks to ensure that proposed designs meet the objective of reducing CO 2 emissions per flight The proposed TMZs do not change the usual trajectories of flights using the airspace. The only likely impact on aircraft trajectories would be a reduction in the use of avoiding action and the subsequent disruption to approach sequencing as described in paragraph 8.7. Hence an emissions assessment is not relevant and has not been undertaken. Noise, Tranquillity, Visual Intrusion, Local Air Quality 11.4 The proposed transponder mandatory zones would not change the usual trajectories of flights using the airspace. Hence analyses of noise impact, tranquillity, visual intrusion, and local air quality have not been undertaken. 12. Impact on aviation stakeholders 12.1 The change to the airspace rules being sought by this airspace development is described in Table 3 below. This information is aimed specifically at aviation stakeholders and therefore introduces technical language where necessary to describe the proposed classification and procedural arrangements for the airspace No new holds are proposed by this airspace change. Holding arrangements would remain as today NATS Swanwick London Terminal Control would be the ATSU responsible for monitoring compliance with the transponder carriage requirements in the designated airspace. Stansted TMZ Consultation Issue 1 (12 January 2009) Page 17 of 29

18 Table 3: Proposed change to the airspace rules Description of change defining the class G airspace coincident with the lateral boundaries of the Stansted CTA as a Transponder Mandatory Zone NATS justification Create a more informed and collaborative environment in the Class G airspace under the Stansted CTA. This will reduce the risk of controlled airspace infringements and losses of separation to improve safety as described in sections 7 and 8. Impact on airspace users not controlled by NATS In accordance with the procedures governing Transponder Mandatory Zones, aircraft will be required to operate an altitude reporting transponder in order to enter the airspace under the Stansted CTA. No clearance or communication with ATC will be required by aircraft complying with the equipment rules Aircraft not equipped with altitude reporting transponders will have to keep clear of the airspace unless operating under a procedure previously agreed with ATC. Stansted TMZ Consultation Issue 1 (12 January 2009) Page 18 of 29

19 13. Next steps 13.1 NATS requests that you consider this proposal and provide a written response to us. In accordance with the CAA airspace change process (Ref 1), a period of 12 weeks has been allowed for this stakeholder consultation. Where possible an early response would be appreciated so that any issues arising may be addressed as soon as possible. The closing date for replies associated with consultation issues is 06 April We request that you reply to this consultation even if you have no objection to the proposal In your response to this consultation you may wish to consider providing answers to the following questions; a) Do you operate a non-transponder equipped aircraft from an airfield within the affected airspace? b) If yes to above, will you fit a transponder if a TMZ is introduced? c) If you are not located within the affected airspace and do not fit a transponder, will the changes significantly affect your flying (e.g. reroutes)? d) What are the financial implications to you of the proposed changes? e) Are there any unintended consequences of the proposed changes that you feel that NATS should be aware of? 13.4 Responses to this consultation will be collated and a summary will be circulated to the CAA and participating stakeholders once the consultation has closed. Any matters raised during the consultation period that have not been adequately considered during the development of the proposed design may require NATS to make changes to the proposal. Any such changes may require further consultation as determined by the CAA If and when NATS is satisfied, having considered the consultation responses, that the proposal achieves the appropriate balance between all the stakeholder requirements, a formal airspace change proposal will be submitted to the CAA for consideration in line with the airspace change process (Ref 1). This will include a full record of all feedback from this consultation Responses and feedback should be sent to the address below: Stansted TMZ Consultation Co-ordinator NATS, Corporate & Technical Centre Mailbox 5a 4000 Parkway, Whiteley, Fareham, Hampshire, PO15 7FL Or via to stanstedtmz@nats.co.uk Stansted TMZ Consultation Issue 1 (12 January 2009) Page 19 of 29

20 13.7 Comments regarding NATS compliance with the consultation process as set out in the CAA s guidelines for airspace change process (Ref 1) should be directed to the CAA at: Head of Business Management Directorate of Airspace Policy CAA House Kingsway London WC2B 6TE businessmanagement@dap.caa.co.uk Stansted TMZ Consultation Issue 1 (12 January 2009) Page 20 of 29

21 14. References 1. CAP 725, CAA Guidance On The Application Of The Airspace Change Process, March 2007, CAA Directorate of Airspace Policy Glossary AIRPROX ATC ATS BAA CAA CTA CTR DAP FIR IFR ScACC Squawk SSR TMA Transponder VFR Aircraft Proximity Report (submitted by pilots and/or controllers where a loss of separation may have occurred). Air Traffic Control Air traffic control service British Airports Authority plc Civil Aviation Authority Control Area (a volume of controlled airspace extending from typically ft, to ~6000ft usually associated with a large airport) Control Area (a volume of controlled airspace extending from the surface to ~6000ft, usually associated with a large airport) Directorate of Airspace Policy (the department of the CAA responsible for airspace matters) Flight Information Region Instrument flight rules Scottish Area Control Centre Transponder code Secondary Surveillance Radar (radar giving additional information from the aircraft s transponder) Terminal manoeuvring area A device on the aircraft which transmits information (an identifying code, and usually altitude) which is displayed on the Air traffic Controller s radar screen. Visual flight rules Stansted TMZ Consultation Issue 1 (12 January 2009) Page 21 of 29

22 Appendix A: List of Stakeholders Local Airfields Andrewsfield aerodrome Audley End aerodrome Castle Camps aerodrome High Easter aerodrome Hunsdon aerodrome Matching aerodrome North Weald aerodrome Nuthamstead aerodrome Rayne aerodrome Wethersfield aerodrome NATMAC (National Air Traffic Management Advisory Committee) Airport Operators Association (AOA) AOPA UK British Airways BAe Systems British Airline Pilots Association (BALPA) British Air Transport Association (BATA) British Balloon & Airship Club (BBAC) British Business & General Aviation Association (BBGA) British Gliding Association (BGA) British Hang Gliding & Paragliding Association (BHPA) British Microlight Aircraft Association (BMAA) British Parachute Association (BPA) British Airports Authority (BAA) British Gliding Association (BGA) British Helicopter Advisory Board (BHAB) MOD ATC Flying MOD DASC European UAV Systems Centre Ltd Guild of Air Pilots & Air Navigators (GAPAN) General Aviation Safety Council (GASCo) Guild of Air Traffic Control Officers (GATCO) Helicopter Club of Great Britain (HCGB) Heavy Airlines HQ 3AF, RAF Mildenhall HQ DAAvn Light Airlines Popular Flying Association (PFA) PPL/IR Europe Royal Aero Club (RAeC) RAF HQ AIR UK Airprox Board (UKAB) UKFSC Adjacent Airfields Benington aerodrome Boones Farm Boreham Helicopter site (Essex Police Air Support Unit) Bourn aerodrome (Rural Flying Corps) Cambridge aerodrome (Cambridge Aero Club) Earls Colne aerodrome (Anglian Flight Centre) Fowlmere aerodrome (Modern Air) Gravely Microlight site Lippits Hill helicopter site Little Gransden aerodrome Panshanger aerodrome (North London Flying School) Ridgewell Glider site (Essex Gliding) Shuttleworth (Old Warden) Stapleford aerodrome Willingale aerodrome Duxford (Imperial War Museum) Stansted TMZ Consultation Issue 1 (12 January 2009) Page 22 of 29

23 Appendix B: Overview of Structure and Operation of UK Airspace The airspace over the UK is a national asset and finite resource. The safe and efficient utilisation of our airspace is vital to both the UK economy and national defence. Accordingly, it is essential that UK airspace be provided, as far as possible, for the benefit of all users. In simple terms, UK airspace, from ground level to approximately 66,000ft, is categorised as being either Controlled Airspace or Uncontrolled Airspace : Controlled airspace is established for the protection of aircraft during the various phases of flight and to facilitate a safe and expeditious flow of air traffic. Any aircraft operating within controlled airspace require an Air Traffic Control (ATC) clearance and must comply with the instructions issued. Controlled airspace is therefore, in most cases, a known environment, i.e. all traffic is known to the ATC system. Commercial, passenger-carrying aircraft operate almost exclusively inside controlled airspace. Controlled airspace can be divided into 5 main types: Control Zones, which extend from ground level and surrounding major airports Control Areas, which do not extend down to the ground but have base levels between approximately 1500 and 5000ft above the ground Airways, which are corridors of controlled airspace that form the main routes connecting major airports and are a form of Control Area Terminal Control Areas, which are larger Control Areas established around groups of airports where several airways converge Upper Airspace that comprises all UK airspace from FL245 (24,500ft) upwards. Whilst within controlled airspace standard routes are published as a template for planning purposes, Air Traffic Controllers may use the full lateral and vertical extent of this protective airspace. In fact, the ability for controllers to tactically position aircraft is essential in ensuring the most effective flow of traffic, placing the safe separation and sequencing of aircraft above all other considerations. Consequently, aircraft will not necessarily follow exactly the same flight paths. However, the closer aircraft are to the airport of arrival or departure the less flexibility exists to adapt their flight profiles. For example, an aircraft 5 miles from touchdown needs to be aligned with the runway and therefore is likely to be in exactly the same piece of sky that the aircraft ahead occupied. The further from touchdown, the more variation in positioning is likely to exist because of the requirement to achieve the safe separation in the sequencing of arriving aircraft. Only the controlled airspace established in the immediate vicinity of major airports extends down to the ground. As indicated previously, most areas of controlled airspace have base levels of several thousand feet above the surface. Detailed maps and charts depicting the UK s airspace structure can be purchased from several commercial outlets. Stansted TMZ Consultation Issue 1 (12 January 2009) Page 23 of 29

24 Uncontrolled airspace: the airspace outside controlled airspace extends from ground level to 19,500ft or to the base of controlled airspace. Although uncontrolled, pilots can request a range of Air Traffic Services (ATS) within such airspace from a variety of civil and military ATS providers. These services range from the mere provision of information to a radar service in which controllers provide sequencing and separation instructions. Uncontrolled airspace is airspace within which receipt of an ATS, whilst often available, is not an absolute requirement. Pilots can operate without talking to ATC and without a specific air traffic clearance. They therefore fly on a see and avoid basis such that they can determine their routes according to their own requirements. Such activity is subject to compliance with the basic Rules of the Air Regulations and any weather, airspace, pilot or aircraft licensing limitation. The majority of military, instructional and recreational flying takes place in uncontrolled airspace. ATC Organisation: Responsibility for the provision of ATC services in the UK lies with both civil and military service providers that will provide a service to both civil and military aircraft within their areas of responsibilities. For the most part and in very general terms, activity inside controlled airspace is managed by NATS (Enroute) plc, whose operation is regulated by the Civil Aviation Authority. Much of NATS activity is conducted from 3 control centres: NATS Swanwick (Area Control and Terminal Control): from where the flow of traffic in UK airspace south of 55 degrees North (over England and Wales) in the Upper Airspace, along the Airways system and within the high levels of Control Areas is managed; also from where the flow of traffic inbound to and outbound from the major airports in the South East of England is managed. Scottish and Oceanic Area Control Centre (ScOACC) Prestwick: from where the flow of traffic in UK airspace north of 55 degrees North (over Scotland) in the Upper Airspace, along the Airways system and within the high levels of Control Areas is managed Manchester Area Control Centre (MACC) Manchester: from where the flow of traffic bound to and outbound from the major airports in the Manchester region is managed Stansted TMZ Consultation Issue 1 (12 January 2009) Page 24 of 29

25 Appendix C: A Brief Outline of Air Traffic Control Principles Introduction The UK contains many large airports each of which generates significant volumes of air traffic. As a result the UK is recognised as having some of the most complex airspace structures and procedures in order to ensure the safe passage of aircraft flying through its airspace. Air Traffic Control (ATC) is a service provided to afford a safe, orderly and expeditious flow of air traffic. The vast majority of commercial airliners and other large aircraft plan their routes along Air Traffic Service (ATS) routes. These routes are protected by volumes of controlled airspace in which the position, height and intentions of aircraft are both known and controlled by ATC. The details of each flight s proposed route form an individual Flight Plan that is used by aircraft operators to advise ATC of the proposed route to be flown between departure and destination airports. Controlled Airspace and ATS Routes Further out from an airfield aircraft are generally at higher altitudes or levels whilst they climb to, or descend from, their cruising flight levels. This permits the controlled airspace to be arranged in steps thereby allowing other (typically noncommercial) aircraft that are not in receipt of an ATC service to operate freely in uncontrolled airspace below or laterally clear of the ATS route. ATS routes are themselves surrounded by volumes of controlled airspace which must extend a minimum of 5 nautical miles either side of the route centreline. These are established to protect aircraft during the en-route phase of flight. Large Control Areas are established in certain areas that contain many ATS routes. Aircraft wishing to operate within controlled airspace must submit a flight plan and gain a clearance to enter from an ATC unit. On entering controlled airspace aircraft must obey all ATC instructions and maintain radio contact. An aircraft flying within controlled airspace will therefore be operating within a known environment in which the Air Traffic Controller can safely separate it from all other aircraft operating within the controlled airspace. So long as an aircraft is flying within controlled airspace, it will also remain safely separated from aircraft flying freely outside of the controlled airspace environment. Uncontrolled Airspace Controlled airspace is delineated by a specified boundary and outside of this boundary the airspace is known as uncontrolled airspace. Within uncontrolled airspace aircraft operate with relative freedom without being in receipt of any Air Traffic Control Service and therefore are operating in what is sometimes referred to as an Unknown environment, i.e. the intended flight profile of aircraft is unknown. Aircraft routinely operating within uncontrolled airspace include light general aviation aircraft, military aircraft, helicopters, hot air balloons and gliders. Stansted TMZ Consultation Issue 1 (12 January 2009) Page 25 of 29

26 Wherever possible, commercial passenger aircraft operate within the confines of controlled airspace for the protection that this environment affords compared to operating within an uncontrolled and unknown environment. However, some airports, due to the small volumes of commercial air traffic operating from them, are not protected by controlled airspace. Route Centrelines and Vectoring The centreline of an ATS route is generally defined by navigational beacons or known positions called fixes. Aircraft navigate between these beacons and fixes when following ATS routes (see Figure C1 depicting an example of a simplified airspace structure). CTR (CAS around airport from ground level to protect aircraft landing/ departing) CTA (CAS from a specified lower limit to an upper limit (normally ft) Uncontrolled airspace Aerodrome Navigation Beacon or Fix Controlled airspace D C Direct Routeing 5 ATS Route Centreline 5 Hold B 5 ATS Route Centreline A 5 Figure C1 Simplified example airspace structure. Although aircraft flight-plan their routes by reference to these ATS Route centrelines, aircraft are still deemed to be on the route as long as they remain within 5 nautical miles of its centreline. The controlled airspace associated with an ATS route extends a minimum 5 nautical miles either side of the promulgated route centreline. This is to allow for any navigation inaccuracies by the aeroplane and to provide space for ATC to separate any conflicting traffic using radar (i.e. by directing aircraft onto separated tracks within the boundaries of controlled airspace). Each aircraft files a flight plan setting out the route it plans to follow (such as shown in Figure D1 from point A to B to C to D). However, in order to provide a safe and efficient service, ATC may direct aircraft to take a more direct route anywhere within controlled airspace e.g. straight from A to D. This may reduce the distance that has to be flown to reach the destination. ATC may also direct aircraft off a Stansted TMZ Consultation Issue 1 (12 January 2009) Page 26 of 29